Background

Hip dysplasia has traditionally been classified based on the lateral center edge angle (LCEA). A recent meta-analysis demonstrated no definite consensus and a significant heterogeneity in LCEA values used in various studies to define hip dysplasia and borderline dysplasia. To overcome the shortcomings of classifying hip dysplasia based on just LCEA, a comprehensive classification for adult acetabular dysplasia (CCAD) was proposed to classify symptomatic hips into three discrete prototypical patterns of hip instability; lateral/global, anterior, or posterior. The purpose of this study was to assess the reliability of this recently published CCAD.

Methods

One hundred thirty-four consecutive hips that underwent a PAO were categorized using a validated software (Hip2Norm) into four categories of normal, lateral/global, anterior or posterior. Based on the prevalence of individual dysplasia and using KappaSize R package version 1.1, seventy-four cases were necessary for reliability analysis: 44 dysplastic and 30 normal hips were randomly selected. Five surgeons (3 fellowship trained in hip preservation) did a first reading (Time 1) to classify the hips, followed by four raters for a second reading (Time 2) minimum two weeks apart. Thereafter, a consensus meeting was held where a simplified flow diagram was devised before a third reading by four raters using a separate set of 74 radiographs took place.

Introduction

The role for hip arthroscopy (HS) in combination with periacetabular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia has not been clearly defined. In this study, we assessed midterm outcomes of concurrent hip arthroscopy and PAO (HS/PAO) for the treatment of symptomatic acetabular dysplasia with associated intra-articular pathology.

Methods

We performed a retrospective review of concurrent HS/PAO cases in a prospectively collected institutional hip preservation database. From November 2005 to December 2012, 85 hips in 80 patients underwent combined HS/PAO. Two hips had a diagnosis other than acetabular dysplasia and 12 hips were lost to follow up, leaving 71 hips for analysis at mean 6.6-year follow-up (range 4–11 years). Hips were evaluated using the University of California, Los Angeles (UCLA) Activity Score, modified Harris Hip Score (mHHS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscore. Hips were stratified into preserved or failed groups, with failure defined as conversion to THA or a symptomatic hip (mHHS <70 or WOMAC pain subscore > 10). Complications were recorded and graded by the Clavien-Dindo classification. Regression analyses were performed to identify the interaction between patient factors, radiographic measures, and surgical details with outcome.

Introduction

The aim of this study was to compare patient reported outcomes, radiographic measurements, and survival free from total hip arthroplasty (THA) in patients who underwent periacetabular osteotomy (PAO) for mild, moderate, or severe developmental dysplasia of the hip (DDH).

Methods

We performed a retrospective cohort study on all patients (n=223, n=274 hips) who underwent a PAO procedure between May 1996 and May 2016, by a single surgeon at one academic center. Cases with a history of retroversion (n=64), Perthes (n=5), and those with <2 years of follow-up (n=63) were excluded. Patients were evaluated based on severity of dysplasia using the preoperative lateral center edge angle (LCEA): 18° – 25° was considered mild dysplasia (n=19), 10° – 17° moderate (n=62), and <10° severe (n=61). There was no difference in patient characteristics (age, sex, body mass index, or ASA score) between then cohorts (all, p>0.05). NIH PROMIS outcome measures included the physical function computerized adaptive test (PF CAT) and the Global 10 health assessment. Generalized estimating equations were used for all comparisons and missing data was imputed using the multivariate imputation by chained equations method. A Kaplan-Meier analysis was used to assess survival. Failure was defined as conversion to THA and follow-up was ended at time of failure or at the time of last follow-up. Mean follow-up was five years (1 – 19).

Introduction

Ascertaining the etiology of hip pain in young patients can be challenging. Osteoid osteoma about the hip has only been described in case reports and small case series in this sub-population. This study assessed the clinical course, radiologic findings, and treatment approaches in a large series of pediatric osteoid osteoma cases about the hip. Potential diagnostic and treatment pitfalls were identified.

Methods

A single-center tertiary care departmental database was queried for all cases of osteoid osteoma seen between Jan 1, 2003 and December 31, 2015. Medical records were reviewed to identify those with lesions identified within or around the hip joint. Clinical, demographic, and radiologic data were analyzed.

Introduction

Numerous musculoskeletal and systemic conditions may affect the hips of paediatric patients. While the large majority of patients go on to achieve positive outcomes, a small number will progress to end stage arthropathy with significant functional impairment. Management options have been significantly limited for this population. An adolescent hip arthroplasty program was developed with the aim to improve symptoms and quality of life for patients with pain and disability refractory to joint preserving management strategies.

Methods

All patients were assessed jointly by a paediatric hip surgeon and an adult hip arthroplasty surgeon pre-operatively, with all procedures conducted at a dedicated tertiary care paediatric centre under general anesthesia. All procedures were completed through a direct lateral (trans-gluteal) approach, using uncemented components (Zimmer Biomet®, Warsaw, IN) and a ceramic on highly cross-linked polyethylene bearing. Data was collected prospectively after approval from the Institutional Review Board. All patients completed clinical examination and functional scores pre-operatively and at six months post-operatively.

Introduction

As new innovations are developed to improve the longevity of joint replacement components, preclinical testing is necessary in the early stages of research into areas such as osseointegration, metal-cartilage wear and periprosthetic joint infection (PJI). Large-animal studies that test load-bearing components are expensive, however, requiring that animals be housed in special facilities that are not available at all institutions. Comparably, small animal models, such as the rat, offer several advantages including lower cost. Load-bearing implants remain difficult to manufacture via traditional methods in the sizes required for small-animal testing. Recent advances in additive manufacturing (3D metal-printing) have allowed for the creation of miniature joint replacement components in a variety of medical-grade metal alloys. The objective of this work is to create and optimize an image-based 3D-printed rat hip implant system that will allow in vivo testing of functional implant properties in a rat model.

Methods

A database of n=25 previously-acquired, 154μm micro-CT volumes (eXplore Locus Ultra, GE Medical) of male Sprague-Dawley rats (390–610g) were analyzed to obtain spatial and angular relationships between several anatomical features of the proximal rat femora. Mean measurements were used to guide the creation of a femoral implant template in computer-aided design software (Solidworks, Dassault Systemes). Several different variations were created, including collarless and collared designs, in a range of sizes to accommodate rats of various weights. Initial prototypes were 3D-printed 316L stainless steel with subsequent iterations printed in Ti6Al4V titanium and F75 cobalt-chrome. Implants were post-processed via sandblasting, hand-polishing, ultrasonic bath, and sterilization in an autoclave. Innate surface texturing was left on manufactured stems to promote osseointegration. Surgical implantation was performed in three live Sprague-Dawley rats (900g, 500g, 750g) with preservation of muscle attachments to the greater trochanter. Micro-CT imaging and X-ray fluoroscopy were performed post-operatively on each animal at 1 day, and 1, 3, 9 and 12 weeks to evaluate gait and component positioning.

Introduction

Porous surfaces developed over the past decades have been shown to promote tissue ingrowth. Hydroxyapatite (HA) coatings have been added to these porous coatings in an attempt to further augment bone ingrowth. The development of additive manufacturing techniques has allowed for precision in building these complex porous structures. The effect of supplemental HA coatings on these new surfaces is unclear. The purpose of this study is to evaluate the biological fixation of a novel 3D printed porous implant in a canine model. In addition, we evaluated the effect of different HA coatings on this 3D printed implant.

Methods

A canine transcortical model was used to evaluate the performance of three different laser rapid manufacturing (LRM) Ti6Al4V cylindrical implants (5.2 mm diameter, 10mm length): LRM with precipitated hydroxyapatite (P-HA), LRM with plasma sprayed hydroxyapatite (PS-HA), and a hydroxyapatite-free control (No-HA). The implants were 50–60% porous with a mean pore size of 450 μm and have a random interconnected architecture with irregular pore sizes and shapes that are designed based on the structure of cancellous bone. A lateral approach to the femoral diaphysis was used to prepare 5 mm unicortical, perpendicular drill holes in 12 canines. One of each implant type was press-fit into each femur. The femora were harvested at both 4 and 12 weeks post implantation, radiographed and prepared for either mechanical push-out testing to assess the shear strength of the bone-implant interface (left femora, N=6) or for histological processing (right femora, N=6). An un-paired Student's t-test was used to compare statistical significance between the 4 and 12-week results, as well as differences due to implant type; p<0.05 was considered significant.

Background

Structural bone allografts are an established treatment method for long-bone structural defects arising from such conditions as trauma, sarcoma, and osteolysis following total joint replacement. However, the quality of structural bone allografts is difficult to non-destructively assess prior to use. The functional lifetime of structural allografts depend on their ability to resist cyclic loading, which can lead to fracture even at stress levels well below the yield strength. Because allograft bone has limited capacity for remodeling, optimizing allograft selection for bone quality could decrease long-term fracture risk. Raman spectroscopy biomarkers can non-destructively assess the three primary components of bone (collagen, mineral, and water), and may predict the resistance of donor bone allografts to fracture from cyclic loads.

The purpose of this study was to prospectively assess the ability of Raman biomarkers to predict number of cycles to fracture (“cyclic fatigue life”) of human allograft cortical bone.

Methods

Twenty-one cortical bone specimens were from the mid-diaphysis of human donor bone tissue (bilateral femurs from 4 donors: 63M, 61M, 51F, 48F) obtained from the Musculoskeletal Transplant Foundation. Six Raman biomarkers were analyzed: collagen disorganization, type B carbonate substitution (a surrogate for mineral maturation), matrix mineralization, and 3 water compartments. Specimens underwent cyclic fatigue testing under fully reversed conditions at 35 and 45MPa (physiologically relevant stress levels for structural allografts). Specimens were tested to fracture or to 30 million cycles (“run-out”), simulating 15 years of moderate activity (i.e., 6000 steps per day). Multivariate regression analysis was performed using a tobit model (censored linear regression) for prediction of cyclic fatigue life. Specimens were right-censored at 30 million cycles.

Introduction

Cephalomedullary nails (CMN) are commonly used for the treatment of intertrochanteric (IT) hip fractures. Total hip arthroplasty (THA) is commonly used as a salvage procedure for failed IT hip fractures that progress to post-traumatic arthritis. This study analyzed the complications of THA following treatment of failed IT hip fractures with cephalomedullary nails.

Methods

Patients who had a primary THA were identified from the 5% subset of Medicare Parts A/B from 2002–2015. A subgroup with previous CMN for IT hip fracture within the previous 5 years was identified and compared to the remaining THA patients without prior CMN. Length of stay (LOS) was compared using both univariate and multivariate analysis. Infection, dislocation, revision, and readmission were compared between those with and without prior CMN, using multivariate analysis (adjusted for demographic, hospital, and clinical factors).

Introduction

Early functional recovery following total hip arthroplasty (THA) has the potential to increase patient satisfaction and reduce resource utilization. The direct anterior approach (DA) has been shown to provide earlier recovery compared to the direct lateral (DL) approach based on functional tests and outcome scores. There are limited studies that objectively evaluate functional recovery comparing the two approaches in the early post-operative period. Activity trackers have emerged as a valid tool to objectively quantify physical activity levels and potentially better assess functional status compared to commonly reported functional questionnaires. The purpose of this study is to measure physical activity levels in patients undergoing THA with the DA approach and compare these to THA with the direct lateral approach in the immediate postoperative period.

Methods

In a tertiary academic center we prospectively enrolled patients with primary OA that were eligible for a primary THA undergoing either the DA or the DL approach using the same prosthesis. Patients with comorbidities precluding them from ambulation, diagnoses of AVN or RA or undergoing bilateral THA were excluded. The number of steps walked per day were measured using wristband activity tracking technology for one week preoperatively, the first 2 weeks postoperatively and for 1 week leading up to their 6-week follow-up appointment. The University of California, Los Angeles (UCLA) activity score was also collected at the same two time points. Demographics were analyzed with descriptive statistics. A non-parametric Mann Whitney U test was used to determine whether a difference in physical activity levels exist between the DA and DL approach groups in the first 2 weeks and 6 weeks postoperatively.

Introduction

Despite well-fixed implants, persistent pain following total hip arthroplasty (THA) remains a concern. Various surgical approaches have been advocated, yet whether patient-reported pain differs amongst techniques has not been investigated. This study's purposes were to determine differences in patient-reported pain based on surgical approach (direct anterior –DA versus posterolateral-PL) or PL approach incision length. Our hypothesis was that no differences in patient-reported pain would be present.

Methods

A retrospective, IRB-approved investigation from 2 centers was performed. 7 fellowship trained arthroplasty surgeons (3 DA, 3 PL, 1 both) enrolled patients undergoing primary THA for non-inflammatory arthritis. PL approach patients were categorized based on incision length (6–8cm, 8–12cm, 12–15cm). Exclusion criteria were a prior hip surgery, revision procedure, or limited postoperative mobility. All THAs were performed using a cementless titanium, proximally coated, tapered femoral stem and hemispherical acetabular component. All patients had a minimum of 1-year clinical follow-up with radiographically well-fixed components.

A pain-drawing questionnaire was administered in which patients identify the location and intensity of pain on an anatomic diagram. Independent Student's t-tests and Chi-square analyses were performed (p<0.05 = significant). Power analysis indicated 800 patients in each cohort would provide adequate power to detect a 4% difference in patient-reported pain (alpha = 0.05, beta = 0.80).

Introduction

Perioperative hospital adverse events are an issue that every surgeon endeavors to avoid and minimize as much as possible. Even “minor events” such as fever or tachycardia may lead to significant costs due to workup tests, inter-consultations, and/or increased hospital stay. The objective of this study was compare perioperative outcomes (hospital length of stay [LOS], discharge disposition), rates of in-hospital adverse events and transfusion, and postoperative readmission and reoperation rates for simultaneous and staged bilateral direct anterior total hip arthroplasty (DA-THA) patients.

Methods

A retrospective chart review was conducted on a consecutive series of 411 primary bilateral DA-THAs performed between 2010 and 2016 at a single institution by two fellowship trained surgeons. These were categorized as: (1) simultaneous (same anesthesia, n=122) and (2) staged (different hospitalizations, n=289). The mean time between staged surgeries was 468 days (± 414 days). Baseline patient demographics as well as hospital LOS, discharge disposition (home vs. other), hospital adverse events (i.e., nausea, vomiting, tachycardia, fever, confusion, pulmonary embolism, etc.), blood transfusions, and unplanned hospital readmissions and reoperations within 90 days were collected. Groups were compared using independent –tests, Fisher's exact test, and Pearson Chi-Square.

Background

Despite growing interest in direct anterior approach total hip arthroplasty, perioperative femoral fracture and early aseptic loosening are increasingly recognized complications. Previous research has documented the role of surgeon experience in association with these femoral complications. The purpose of this study was to explore the relationship between femoral component design and early periprosthetic femoral complications.

Methods

This was an extension of previous work with an updated patient cohort of 5090 consecutive direct anterior primary total hip arthroplasties at a single institution with a single-taper, wedge femoral stem with 4 variants involving length and geometry: Group 1) full length, standard profile; Group 2) full length, reduced distal profile; Group 3) short length, standard profile; and Group 4) short length, reduced distal profile. Records were reviewed retrospectively for the incidence of early periprosthetic fracture or aseptic loosening and analyzed with regard to patient demographics and femoral stem type.

Introduction

Several surgical approaches are available for elective total hip arthroplasty (THA) for osteoarthritis. While posterior surgical approaches are the most common, interest in a direct anterior (Hueter) approach is increasing because of alleged advantages in convalescence. However, no studies have examined differences in patient-reported global and condition-specific measures of health across multiple institutions. The ongoing Pulmonary Embolism Prevention after Hip and Knee Replacement (PEPPER) study is a PCORI-funded multicenter pragmatic clinical trial randomizing patients to three different antithrombotic regimens. We analyzed operative data from PEPPER to compare pre-post changes in validated patient-reported outcome measures after THA based on surgical approach.

Methods

Participants (age 21 or older) were recruited from 27 academic medical centers for the PEPPER trial. Eligibility screening, baseline measures, and operative detail were entered into a central database with standardized blinded post-operative data collection protocol. We included participants undergoing elective primary total hip arthroplasty, excluding those undergoing revision, resurfacing, bilateral procedures, on chronic preoperative anticoagulation, with a recent history of gastrointestinal, cerebral, or other hemorrhage, defective hemostasis, or uncontrolled hypertension. Participating centers reported the operative approach as “Posterior”, “Transgluteal”, or “Anterior”. The brief version of the Hip Dysfunction and Osteoarthritis Outcome Score (HOOS Jr.) and the Patient Reported Outcome Measurement Information System Global Survey (PROMIS10) were ascertained pre-operatively, and at 1, 3 and 6 months post-operatively. Mixed-effects linear regression was used to compare difference in patient-reported outcomes over time based on surgical approach, adjusting for baseline measures of health outcome, patient age, sex, race, ethnicity, BMI, comorbidity, education, work status, alcohol use, and smoking status.

Introduction

The influence of surgical approach for total hip arthroplasty (THA) on scar healing and scar perception is unknown. The purpose of this study was to evaluate patients’ perception of their scar following direct anterior (DA) or posterior approach (PA) for THA utilizing validated scar assessment scales.

Methods

Fifty DA and 58 PA THA patients underwent scar assessment using the Patient Observer Scar Assessment Scale (POSAS) and Stony Brook Scar Evaluation Scales (SBSES). Patients were included if they had at least 1-year follow-up, and had no previous surgery or intervention (i.e. radiation) around the assessed hip. The mean age was different between the cohorts (DA 67 vs PA 62 years, p=0.03). Other variables including gender, BMI, Charlson Comorbidity Index, steroid use, diabetes, and smoking were similar (p>0.05 for all comparisons). All patients had subcuticular running closure, secured with skin adhesive glue. Mean time from THA to scar assessment was 3.1 and 3.6 years for the DA and PA groups, respectively (p=0.18).

Introduction

Periprosthetic osteolysis (PPO) gradually became the single dominant late failure mechanism of total hip replacements. It afflicted 1 million patients worldwide, leading to countless, difficult revision operations. The widespread adoption of highly cross-linked polyethylene (XLPE) drastically reduced that disease. But going beyond that remarkable reversal, two further substantial consequences have resulted: A) a major reduction in revision operations and B) a major reduction in aggregate costs of total replacement surgery. This paper assembles data on the decrease in revision rates and uses them to estimate the massive reduction in total hip surgery costs.

Methods

Review the literature produced registry data and controlled studies data establishing that XLPE reduced the “all cause” revision rate over the first 15 years of follow-up of total hip replacements at least in half, and often more.

A conservative estimate of the number of revisions annually in the United States is 50,000. A conservative estimate of the average, integrated cost for a THR revision in the United States is $50,000, meaning that the costs of these revisions annually is at least $2.5 billion.

Using a very conservative figure of just 40% for the percent reduction in revision surgery resulting from the use of XLPE reduces this burden by at least $1 billion annually.

Introduction

Patients under the age of 50 who undergo a total hip arthroplasty (THA) are at high risk for wear-related complications due to their higher activity level. Previous studies have shown that highly crosslinked polyethylene (HXLPE) is more durable with no evidence of loosening compared to conventional polyethylene due to its improved wear characteristics. Unfortunately, there are few studies with long term follow-up of HXLPE in this patient population. The purpose of this study was to evaluate two questions related to this population of patients undergoing THA. First, what were the clinical outcomes for HXLPE in patients 50 years or younger at an average follow-up of 15 years? Second, was osteolysis observed in any of these hips?

Methods

Between November 1999 and April 2005, 105 THAs were performed for 90 patients 50 years of age or younger (mean, 42 years; range, 20–50 years). The mean body mass index (BMI) was 30 kg/m2 (range, 17–51 kg/m2). The mean follow-up was 15.25 years (range, 12–19 years). Eight patients (two bilateral) were lost to follow-up, which left 82 patients with 95 hips for analysis. HXLPE was the acetabular bearing for all hips. Harris Hip Scores were collected from all patients. Radiographs were obtained on all patients to evaluate for wear and osteolysis.

Introduction

Modular dual-mobility constructs reduce the risk of dislocation after total hip arthroplasty (THA). However, questions about metal ions from the cobalt-chrome (CoCr) liner persist, and are particularly germane to patients being revised for adverse local tissue reactions (ALTR) to metal. We determined the mid-term serum Co and Cr levels after modular dual-mobilities used in revision and complex primary THAs, and specifically included patients revised for ALTR.

Methods

Serum Co and Cr levels were measured prospectively in 22 patients with a modular dual-mobility construct and a ceramic femoral head. Patients with CoCr heads or contralateral THAs with CoCr heads were excluded. Mean age 64 years with 50% female. The mean follow-up was 4 years. Indications for modular dual-mobility were: periprosthetic joint infection treated with 2-stage exchange and subsequent reimplantation (n=8), ALTR revision (n=7), complex primary THA (n=6), and periprosthetic femoral fracture (n=1). Mean preoperative Co and Cr in patients revised for an ALTR were 29.7 µg/L and 21.5 µg/L, respectively.

Introduction

In 2010, a widely used metal-on-metal hip implant was voluntarily recalled from the market by the manufacturer. Our lab performed detailed retrieval analysis of 548 of the explanted devices and 165 periprosthetic tissue specimens. We reported a high degree of variability in the multiple measurements that we performed on the components, including volumetric wear.

Other studies using semi-quantitative tissue grading methods to describe the histology of the periprosthetic tissues from metal-on-metal hips have looked for relationships between component wear and histological features. Grammatopoulos et al found higher ALVAL scores in 45 hip resurfacing patients with pseudotumors compared to 11 without pseudotumors and a moderately positive correlation between wear and the histological rankings for tissue necrosis and lymphocytic response.

We examined correlations between the component wear measurements from retrieval analysis and the tissue features in this large group of one metal-on-metal hip design.

Materials and Methods

Tissues were processed routinely into paraffin sections, stained with H&E and characterized with light microscopic semi-quantitative scores for ALVAL features and for the number of macrophages and lymphocytes, extent of metal debris and the estimated percentage of necrosis per slide. Spearman correlation analysis was conducted to evaluate any correlations between retrieval wear measurements and histological findings.

Introduction

Failure of metal on metal (MOM) total hip arthroplasty (THA) and resurfacing arthroplasty (HRA) due to development of adverse local tissue reaction (ALTRs) is a significant problem. The prevalence of ALTRs in asymptomatic MOM arthroplasty patients is highly variable. The purpose of this prospective, longitudinal study was to: 1) determine MRI ALTR prevalence in patients with HRA; 2) determine if patients with HRA have a greater rate of MRI ALTRs compared to control patients with ceramic on poly (COP) THA; and 3) evaluate changes in patient reported outcomes between these implant designs.

Methods

Following IRB approval with informed consent, self-reported asymptomatic primary COP and HRA patients greater than one year post arthroplasty were evaluated with 4 annual (TP1–4) MRIs using a standardized protocol and serum ion level testing. Morphologic and susceptibility reduced images were acquired for each hip and evaluated for synovial thickness, volume, capsule dehiscence and the presence of ALTR. Patient reported outcomes were evaluated by Hip Disability and Osteoarthritis Outcome Scores (HOOS). Analyses were performed to detect differences of synovial thickness and volume, and HOOS subgroups between and within bearing surfaces at each time point and over time, and to compare the time to and the risk of developing MRI ALTR. Analyses were adjusted for age, gender, and length of implantation.

Introduction

Because of concerns regarding excessive wear and short-term failures attributed to the metal-on-metal bearings, the use of metal-on-metal hip resurfacing arthroplasty (MOMHRA) has been greatly reduced since 2008, despite great mid-term results for well-designed implants and in certain patient populations. The true cause of excessive wear was then unknown. Therefore, identification of true risk factors for the procedure became paramount to refine indications and improve survivorship outcomes.

Methods

Over the last 10 years, a systematic search of the US national library of Medicine and National institutes of health with the key words “metal-on-metal” and hip resurfacing” was conducted and returned 2186 items. Of these items, 862 were deemed relevant to our research purposes and entered in our center's reference database from which this review was performed.

Introduction

Bundle payment models have clinical and economic impacts on providers. Despite efforts made to improve care, experience has shown that a few episodes with costs well above a target (bundle busters) can reduce or negate positive performances. The purpose of this study was to identify both the primary episode drivers of cost and patient factors that led to episodes above target.

Methods

A retrospective study of 10,000 joint replacement episodes from a large healthcare system in CJR and a private orthopedic practice in BPCI was conducted. Episodes with costs greater than target price (TP) were designated as bundle busters and sub-divided into 4 groups:

1)

< 1 standard deviation (SD) above TP (n=1700)

Bundle busters were compared to the control that were at/below the TP (n= 7500). For the CJR/BPCI cohorts, one SD was defined as $10,700/$13,000, respectively.

Two linear regressions assessed the likelihood of factors predicting a bundle buster and the total episode cost. These variables included demographics, acuity classifications, comorbidities, length of stay, readmissions, discharge disposition, post-acute utilization, and episode costs.

Introduction

The Comprehensive Care for Joint Replacement (CJR) model for total hip arthroplasty (THA) involves a target reimbursement set by the Center for Medicare and Medicaid Services (CMS). Many patients exceed these targets, but predicting risk for incurring these excess costs remains challenging, and we hypothesized that select patient characteristics would adequately predict CJR cost overruns.

Methods

Demographic factors and comorbidities were retrospectively reviewed in 863 primary unilateral CJR THAs performed between 2013 and 2017 at a single institution. A predictive model was built from 31 validated comorbidities and a base set of 5 patient factors (age, gender, BMI, ASA, marital status). A multivariable logistic regression model was refined to include only parameters predictive of exceeding the target reimbursement level. These were then assigned weights relative to the weakest parameter in the model.

Background

The Bundled Payments for Care Improvement (BPCI) initiative was introduced to reduce healthcare costs while maintaining quality. We examined data from a healthcare system comprised of five hospitals that elected to participate in the BPCI Major Joint Replacement of the Lower Extremity Model 2 initiative beginning July 1, 2015. We compared one hospital that did 439 BPCI hip cases to the four other hospitals that did 459 cases. Stratifying the data by hospital volume, we sought to determine if costs decreased during the BPCI period, how the savings were achieved, and if savings resulted in financial rewards for participation.

Methods

The Medicare data included the target cost for each episode (based on historical data from 2009–2012 for each hospital that was adjusted quarterly) and actual Part A and Part B spending for 90 days. Using 1,574 primary hip replacements, we analyzed the costs associated with the anchor hospitalization, inpatient rehabilitation, skilled nursing facilities, home health, outpatient physical therapy and readmission to compare the 898 hips done during the 16-month BPCI initiative period with the 676 hips done during the 1-year period preceding BPCI participation. Owing to the nonparametric distribution of the cost data, a Mann-Whitney U test was used to compare the higher volume hospital with the four lower volume hospitals.

Introduction

Patient demand for hip and knee arthroplasty continues to rise. Information sources providing data on the volume and cost of Medicare total joint arthroplasty by hospital are of use to patients and healthcare professionals. Data have demonstrated that higher volume surgeons are associated with lower cost, morbidity, and mortality. The current study assesses if the same is true for hospitals.

Methods

The Limited Data Set (LDS) from the Centers for Medicare and Medicaid (CMS) were used for this study. All elective, DRG 470 Total Hip Arthroplasties (THA) reported by CMS from the first quarter of 2013 through the second quarter of 2016 were included. Volume and part A Medicare payments over a 90-day period for the 20 highest volume hospitals in the US were analyzed. Cost associated with initial hospital stay and post discharge skilled nursing, home health, long term acute care, inpatient rehabilitation facilities, and readmission was aggregated and analyzed. For each episode, demographic information (age, sex, and race), geographic location, and Elixhauser comorbidities were calculated to control for major confounding factors in the regression.

Introduction

The purpose of this study is to estimate the cost-effectiveness of performing total hip arthroplasty (THA) versus nonoperative management (NM) in non-obese (BMI 18.5–24.9), overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–49.9), and super-obese (50+) patients.

Methods

We constructed a state-transition Markov model to compare the cost-utility of THA and NM in the six above-mentioned BMI groups over a 15-year time period. Model parameters for transition probability (i.e. risk of revision, re-revision, death), utility, and costs (inflation adjusted to 2017 US dollars) were estimated from the literature. Direct medical costs of managing hip arthritis were accounted in the model. Indirect societal costs were not included. A 3% annual discount rate was used for costs and utilities. The primary outcome was the incremental cost-effectiveness ratio (ICER) of THA versus NM. One-way and Monte Carlo probabilistic sensitivity analysis of the model parameters were performed to determine the robustness of the model.

Purpose

Obesity has previously been demonstrated to be an independent risk factor for increased complications following total hip (THA) and total knee arthroplasty (TKA). The purpose of this study was to compare the effects of obesity and BMI to determine whether the magnitude of the effect was similar for both procedures.

Materials & Methods

We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database to identify patients who underwent primary THA or TKA between 2010 and 2014. Patients were stratified by procedure and classified as non-obese, obese, or morbidly obese according to BMI. Thirty-day rates of wound complications, deep infection, total complications, and reoperation were compared using univariate and multivariate logistic regression analyses.

Introduction

Previous studies have indicated that prolonged surgical time may lead to higher rates of infection following total hip arthroplasty (THA). The purpose of this study was to evaluate the influence of surgical time on 30-day complications following THA and to determine if there was a time interval associated with worse outcomes.

Methods

Patients ≥18 years who underwent THA between 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complications were ascertained. Multivariable regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for relevant covariables, and to identify independent predictors of operation length. Covariables of interest included age, sex, American Society of Anaesthesiologists (ASA) class, smoking status, functional status, comorbidities, anesthesia type, and Body Mass Index (BMI).

Background

Routine closed suction drainage and postoperative laboratory studies have long been tenets of most TJA protocols. However, recent literature has called into question whether either is necessary with modern outpatient TJA clinical pathways.

Methods

Demographic, cost, and readmission data for 2,605 primary unilateral TJA cases was collected retrospectively and analyzed prior to and after a protocol change where routine closed suction drains and postoperative laboratory tests were eliminated. This protocol change was designed to treat all primary TJA like outpatients regardless of their admission status. Drain usage changed from routine to selective based on hemostasis. Lab studies changed from routine to selective for patients on warfarin for VTE prophylaxis (INR), with ASA 4 or 5 status (BMP), and with a hematocrit < 27% in the recovery room after THA (CBC).

Purpose

Patients may present with concurrent symptomatic hip and spine problems, with surgical treatment indicated for both. Controversy exists over which procedure, total hip arthroplasty (THA) or lumbar spine procedure, should be performed first, and does the surgeon's area of expertise influence the choice.

Materials & Methods

Clinical scenarios were devised for 5 fictional patients with both symptomatic hip and lumbar spine disorders for which surgical treatment was indicated. An email with survey link was sent to 110 clinical members of the Hip Society and 101 experienced spine surgeons in the USA requesting responses to: which procedure should be performed first, and the rationale for the decision with comments. The clinical scenarios were painful hip osteoarthritis and (1) lumbar spinal stenosis with neurologic claudication; (2) lumbar degenerative spondylolisthesis with leg pain; (3) lumbar disc herniation with leg weakness; (4) lumbar scoliosis with back pain; and (5) thoracolumbar disc herniation with myelopathy. Surgeon choices were compared among scenarios and between surgical specialties using chi-square analysis and comments analyzed using text mining.

Background

Much effort has been aimed at strategies for patient optimization, perioperative standards of care, and postoperative risk stratification to reduce the incidence of SSI. Examples include, newer dressing modalities, antibiotic-impregnated bone cement, intra-wound powdered antibiotics, as well as novel suture types and techniques, all of which have shown great potential. However, the question remains as to whether these changes in practice have led to lower overall infections over the past few years. Therefore, the purpose of this study was to track the annual rates and trends of: 1) overall; 2) deep; and 3) superficial SSI following total hip arthroplasty (THA) using the most recent data (2012 to 2016) from a large nationwide database.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs (CPT code 27130) between 2012 and 2016, yielding 122,451 cases. Cases with reported superficial and/or deep SSIs were combined for an overall rate, and then independently analyzed as deep and superficial SSIs. The infection incidence for each year was calculated. After an overall 5-year correlation and trends, univariate analysis was also performed to compare the most recent year, 2016, with each of the preceding 4 years. Furthermore, a comparison of overall and deep SSI incidences from this study were compared to meta-analysis of pooled data from 2001 to 2011. Pearson correlation coefficients and chi-squared tests were used to determine correlation and statistical significance which was maintained at a p-value less than 0.05.

Introduction

There has been a renewed interest in the surgical approach used for total hip arthroplasty (THA). Risk factors for periprosthetic joint infection (PJI) have been well studied over the past decade, yet PJI remains one of the most devastating complications following THA. We studied the impact of direct anterior (DA) versus non-direct anterior (NA) surgical approaches on PJI, and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution.

Methods

6086 continuous patients undergoing primary THA at a single institution from 2013–2016 were retrospectively evaluated. Data obtained from electronic patient medical records included age, sex, body mass index (BMI), medical comorbidities, surgical approach, and presence of deep PJI. Deep PJI was defined according to National Healthcare Safety Network's (NHSN) criteria for joint space infection following prosthetic hip replacement. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios for risk of development of PJI with DA compared to NA approaches. In order to determine the effect of adopting a set of infection prevention protocols and patient optimization on PJI, we calculated odds ratios for PJI comparing patients undergoing THA for two distinct time periods: 2013–2014 and 2015–2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols.

Introduction

Patients with rheumatoid arthritis (RA) have a higher risk of surgical site infection (PJI) than patients with osteoarthritis (OA). Disease modifying therapy is in widespread use in RA patients, and biologic medications may increase Staphylococcus aureus colonization rates. Because S. aureus colonization likely increases risk of surgical infection, perioperative assessments and therapies to decrease the risk of invasive S.aureus infections may be warranted. The objective of this study was to determine if there was a difference in S. aureus carriage among patients with RA, OA, and RA on biologics (RA+B).

Methods

An a priori power analysis determined 123 participants per group were needed to detect a relative difference of 20% among groups with 80% power. After IRB approval, patients were screened; included patients met American College of Rheumatology classification criteria. Patients were approached between April 2017 and May 2018 and asked to perform a nasal swab while on site using the Center for Disease Control's swabbing protocol; questionnaires pertaining to their current health status were collected. Swabs were inoculated onto ChromAgar/ChromID MRSA plates for detection of S. aureus. Mann-Whitney U and Chi-square tests were used to evaluate baseline differences between groups. Logistic regression evaluated the associations between groups and S. aureus carriage. All statistical analyses were performed using SAS Software version 9.3 (SAS Institute, Cary, NC); statistical significance was defined as p<0.05.

Introduction

The infection rate after total joint arthroplasty (TJA) has been shown to be 1–2% in multiple series and registry data. Irrigation, debridement, and polyethylene exchange (IDPE) is a common first line treatment in many cases of acute prosthetic joint infection (PJI). The reinfection rate in open IDPE procedures is variable with studies showing reinfection rates of 10–70% depending on various patient and microbial factors. Our pilot study aimed to determine if the bacterial load in infected total joints was sufficiently reduced by IDPE to allow for the use of post-debridement cultures as an independent marker of procedural success.

Methods

46 prosthetic joint infections underwent irrigation and debridement using 6L of normal saline and 3L of a normal saline and bacitracin mixture prior to the insertion of a new polyethylene liner. This protocol utilized a single equipment setup with all surgical members donning new gloves prior to polyethylene exchange. Between 3 and 5 intraoperative cultures were obtained both prior to and after debridement as per the surgeon's standard protocol. A two-tailed student's t-test was used to evaluate for any differences in the rate of positive culture between these two groups.

Introduction

Studies are being done comparing 1-stage vs. 2-stage protocols for PJI. 1-stage protocols take an extended period of time requiring 2 separate preps and sets of instruments in order to ensure optimal sterility. While intraoperative service time is one part of the reimbursement algorithm, reimbursement has lagged behind for single stage treatment. If 1-stage results are acceptable, but not reimbursed appropriately, surgeons may be discouraged from managing PJI in a 1-stage fashion. We ask, “What is the reimbursement and intraoperative service time for 1-stage procedures compared to primary surgery?”

Methods

Relative Value Unit's (RVU's), reimbursement and operative time for 50 PJI procedures were reviewed and compared to 250 primary (1°) THA and 250 primary (1°) TKA by four surgeons. Coding was done per AAOS guidelines.

Introduction

Single-stage resection and reimplantation for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) is of recent interest, yet outcomes may be skewed by selected populations with healthier patients and less virulent organisms. This study quantified the effectiveness of a contemporary, evidence-based and standardized two-stage treatment protocol in patients with THA PJI including chronically infected, poor hosts.

Methods

Sixty-one consecutive two-stage resection and reimplantation THAs for PJI between 2011 and 2017 were retrospectively reviewed in a prospectively collected registry database. Patients were categorized with McPherson's Staging System and infection was defined by MSIS criteria. Contemporary standardized protocols were adhered to including implant resection and meticulous surgical debridement, six-week intravenous antibiotics with a high-dose antibiotic spacer, a two-week drug holiday, and laboratory assessment of infection eradication prior to reimplantation. Extended antibiotics after reimplantation were not routinely used. Successful treatment was defined as reimplantation with component retention at minimum two-year follow-up.

Introduction

Two-stage revision surgery remains the gold standard as treatment for periprosthetic hip infections. The purpose of this study was to determine the rate of infection eradication after two-stage revision hip arthroplasty in patients treated with intraoperatively surgeon-molded articulating spacers as well as to foreshadow the future economical impact of these articulating antibiotic spacers to those commercially available.

Methods

Thirty-five patients who underwent two-stage revision hip arthroplasty due to chronic periprosthetic infection between 2003–2014 were followed clinically and radiographically an average of 4.9 years postoperatively [2.2–9.2]. 17 male and 18 female patients with a mean age of 62 [34–82] had articulating spacers, made in the operating room, inserted at the first stage. [The overall expense of the custom-made antibiotic spacers and the commercially available spacers was calculated and compared using a student t test.]

Introduction

Iliopsoas tendonitis after total hip arthroplasty (THA) can be a considerable cause of pain and patient dissatisfaction. The optimal cup position to avoid iliopsoas tendonitis has not been clearly established. Implant designs have also been developed with an anterior recess to avoid iliopsoas impingement. The purpose of this cadaveric study was to determine the effect of cup position and implant design on iliopsoas impingement.

Materials

Bilateral THA was performed on three fresh frozen cadavers using oversized (jumbo) offset head center revision acetabular cups with an anterior recess (60, 62 and 66 mm diameter) and tapered wedge primary stems through a posterior approach. The relatively large shell sizes were chosen to simulate THA revision cases. At least one fixation screw was used with each shell. A 2mm diameter flexible stainless steel cable was inserted into the psoas tendon sheath between the muscle and the surrounding membrane to identify the location of the psoas muscle radiographically. Following the procedure, CT scans were performed on each cadaver. The CT images were imported in an imaging software for further analysis. The acetabular shells, cables as well as pelvis were segmented to create separate solid models of each. To compare the offset head center shell to a conventional hemispherical shell in the same orientation, the offset head center shell was virtually replaced with an equivalent diameter hemispherical shell by overlaying the outer shell surfaces of both designs and keeping the faces of shells parallel. enabled us to assess the relationship between the conventional shells and the cable. The shortest distance between each shell and cable was measured. To determine the influence of cup inclination and anteversion on psoas impingement, we virtually varied the inclination (30°/40°/50°) and anteversion (10°/20°/30°) angles for both shell designs.

Introduction

Accurate acetabular position is an important goal during THA. It is also well known that accurate acetabular positioning is very frequently not achieved, even by experienced, high volume surgeons. Problems associated with cup malposition are: dislocation, accelerated poly wear, impingement, ceramic squeaking, metalosis. Murray et al described 3 methods of measurement and assessment of acetabular inclination and anteversion (I&A): anatomic, radiographic and operative. It is the hypothesis of the authors, that the differences and details of these 3 methods are poorly understood by many surgeons and this is contributory to inconsistent cup positioning. Additionally, the radiographic method, which is most commonly used for post op assessment and academic studies, contributes to misunderstanding and error. Modern computer guidance and software assessment of radiographs allows us to easily measure anatomic I&A which should be thought of as “true” I&A.

Methods

The mathematical criteria for radiographic measurement of anatomic I&A are defined as well as the mathematical relationships and discrepancies between anatomic and radiographic I&A for any given cup.

$$\begin{array}{c}A=Angle\hspace{0.17em}of\hspace{0.17em}anteversion\hspace{0.17em}of\hspace{0.17em}cup\\ I=Angle\hspace{0.17em}of\hspace{0.17em}inclination\hspace{0.17em}of\hspace{0.17em}cup\end{array}$$

E = Angle of ellipse major diameter to horizontal

E = Radiographic inclination

$$\begin{array}{l}\text{Sin}\hspace{0.17em}A=\frac{Horizontal\hspace{0.17em}width\hspace{0.17em}of\hspace{0.17em}ellipse}{Length\hspace{0.17em}of\hspace{0.17em}ellipse\hspace{0.17em}major\hspace{0.17em}diameter}\hfill \\ \text{Sin}\hspace{0.17em}I=\frac{Vertical\hspace{0.17em}height\hspace{0.17em}of\hspace{0.17em}ellipse}{Length\hspace{0.17em}of\hspace{0.17em}ellipse\hspace{0.17em}major\hspace{0.17em}diameter}\hfill \end{array}$$

Tan I = Tan E / Cos A

Tan E = (Tan I) x (Cos A)

Introduction

Malposition of the acetabular component in total hip arthroplasty (THA) is linked to multiple adverse outcomes. Changes in the sagittal plane position of the pelvis, owing both to patient positioning in the operating room and to altered spinopelvic alignment following surgery, potentially contribute to variation in component position. The dynamics of sagittal plane pelvic position before, during, and after THA have not been defined. We measured the differences in pelvic ratio, a measure of sagittal plane pelvic position, between preoperative, intraoperative, and postoperative anteroposterior (AP) radiographs of patients undergoing THA in the lateral decubitus position.

Methods

We retrospectively compared the radiographic pelvic ratio among 90 patients undergoing THA. AP radiographs were obtained in the standing position preoperatively and at 6 weeks after surgery; in the lateral decubitus position after trial reduction intraoperatively; and in the supine position in the post anesthesia care unit (PACU). Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Radlink software was used to determine the pelvic ratio on each radiograph. Changes in apparent cup position based on changes in pelvic ratio were calculated using data from the literature, and a change of at least 10 degrees in acetabular component position was defined as clinically meaningful. Analyses were performed using paired t-tests, with p<0.05 defined as significant.

Introduction

Complete or nearly complete disruption of the gluteus attachment is seen in 10–20% of cases at the time of total hip arthroplasty (THA). Special attention is needed to identify the lesion at the time of surgery because the avulsion often is visible only after a thickened hypertrophic trochanteric bursa is removed. The purpose of this study was to evaluate a technique designed to restore abductor function by transferring the gluteus maximus to compensate for the deficient medius and minimus muscles.

Methods

From Jan 1 2009 to Dec 31 2013, 525 primary THAs were performed by the author. After the components were implanted, the greater trochanteric bursa was removed, and the gluteus medius and minimus attachments to the greater trochanter were visualized and palpated. Ninety-five hips (95 patients) were found to have damaged muscle attachments to bone. Fifty-four hips had mild damage consisting of splits in the tendon, but no frank avulsion of abductor tendon from the bone attachment. None had severe atrophy of the abductor muscles, but all had partial fatty infiltration. All hips with this mild lesion had repair of the tendons with #5 Ticron sutures to repair the tendon bundles together, anchored to the greater trochanter. Forty-one hips had severe damage with complete or nearly complete avulsion of the gluteus medius and minimus muscles from their attachments to the greater trochanter. Thirty-five of these hips had partial fatty infiltration of the abductor muscles, but all responded to electrical stimulation. The surface of the greater trochanter was denuded of soft tissue with a rongeur, the muscles were repaired with five-seven #5 Ticron mattress sutures passed through drill holes in the greater trochanter, and a gluteus maximus flap was transferred to the posterior third of the greater trochanter and sutured under the vastus lateralis. Six hips had complete detachment of the gluteus medius and minimus muscles, severe atrophy of the muscles, and poor response of the muscles to electrical stimulation. The gluteus medius and minimus muscles were sutured to the greater trochanter, and the gluteus maximus flap was transferred. Postoperatively, patients were instructed to protect the hip for 8 weeks, then abductor exercises were started.

Introduction

Hip abductor tendon tears have been referred to as “rotator cuff tears of the hip,” and are a recognized etiology for persistent, often progressive, lateral hip pain, weakness, and limp. Multiple repair techniques and salvage procedures for abductor tendon tears have been reported in the literature; however, re-tear remains a frequent complication following surgical repair. This study compares the short-term outcomes of open abductor tendon repairs with decortication and suture fixation (DSF) compared to a modified technique repair into a bone trough (BT), to determine best surgical results for large abductor tendon avulsions. Additionally, surgical treatment of small tears versus large tears was examined.

Methods

The outcomes of 37 consecutive hip abductor tendon repairs treated between January 2009 and December 2017 were retrospectively reviewed. Large tears were defined as detachment of 33–100% of the gluteus medius insertion. There were 15 DSF and 10 BT cases. Postoperative pain, ability to perform single leg stance, hip abduction, and Trendelenburg lurch, were examined. Small tears (12 cases) were defined as having no gluteus medius avulsion from the trochanteric insertion and were comprised of longitudinal tears (repaired side-by-side) and isolated gluteus minimus tears (repaired by tenodesis to the overlying gluteus medius). Standard statistical analyses were utilized. Type I error for all analyses was set at α=0.05.

Background

Instability is one of the most common complications after total hip arthroplasty (THA), particularly when using the posterior approach. Repair of the posterior capsule has proven to significantly decrease the incidence of posterior hip dislocation. The purpose of the present study is to evaluate if braided polyblend suture provides a stronger repair of the posterior soft tissues when compared to a non-absorbable suture repair after a posterior approach to the hip.

Methods

Ten cadaveric hips from donors who were a mean (and standard deviation) of 80 ± 9 years old at the time of death were evaluated after posterior soft tissue repair utilizing two different techniques. Five specimens were repaired using no. 2 non-absorbable sutures while five specimens had a repair utilizing braided polyblend suture with a rucking hitch knot technique. Cadaveric specimens were matched based upon age, sex, and laterality. Biomechanical tensile testing using the Instron E10000 Mechanical Testing System and the mechanism of failure were assessed.

Introduction

The goal of the current study was to determine if SES affects PROMs in patients treated with THA. Specifically, we sought to determine any potential differences between low and high SES patients in pre-surgical PROMs, post-surgical PROMs, and PROM improvement after surgery while controlling for any potential confounding demographic factors.

Methods

Patients were selected from a clinical registry at an urban tertiary academic medical center. All patients undergoing primary THA between January 1, 2000 and April 1, 2016 were eligible for this study. During this period, patients were asked to complete the Harris Hip Score (HHS), Euro-QoL 5 Dimension (EQ-5D), 0–10 Numerical Rating Scale (NRS) Pain, 0–10 NRS Satisfaction (only given postoperatively), the Charnley Classifier, and the University of California Los Angeles (UCLA) Activity Score.

To determine SES, patients were matched by zip code to corresponding median household income as reported by the United States Census Bureau. Patients were then dichotomized into low and high SES groups using 2016 median household income of $57,617 USD as a cutoff point.

Statistical differences between low and high SES patients were determined for demographic factors, preoperative PROMs, postoperative PROMs, and PROM change. Non-parametric variables were tested with the Mann Whitney U test and categorical variables were tested with the Chi squared test.

Multivariate models were created to determine if SES group was independently predictive of achieving a minimal clinically important improvement (MCII) in PROMs (18.0 for HHS, −2.0 for NRS Pain, and 0.92 for UCLA). As potential confounders, we tested body mass index (BMI), preoperative health state from EQ-5D visual analog scale (EQ VAS), age at surgery, preoperative Charnley class, sex, and time between PROMs.

Introduction

As orthopaedics shifts towards value-based models of care, methods of evaluating the value of procedures such as a total hip arthroplasty (THA) will become crucial. Patient reported outcome measures (PROMs) can offer a meaningful way for patient-centered input to factor into the determination of value.

Despite their benefits, PROMs can be difficult to interpret as statistically significant, but not clinically relevant, differences between groups can be found. One method of correcting this issue is by using a minimal clinically important improvement (MCII), defined as the smallest improvement in a PROM determined to be important to patients.

This study aims to find demographic and surgical factors that are independently predictive of failing to achieve a MCII in pain and physical function at 1-year following THA.

Methods

A total of 976 patients were enrolled into a prospective international, multicenter study evaluating the long-term clinical performance of two acetabular shells and two polyethylene liners from a single manufacturer. All patients consented to be followed with plain radiographs and a set of PROMs preoperatively and at 1-year after surgery.

The outcomes considered in this study were achieving literature-defined MCIIs in pain and physical function at one year after THA. The MCII in pain was defined as achieving a 2-point decrease on the Numerical Rating Scale (NRS)-Pain or reporting a 1-year NRS-Pain value of 0, indicating no pain. The MCII in physical function was defined as achieving an 8.29-point increase on the SF-36 Physical Function subscore.

Univariate analyses were conducted to determine if there were statistically significant differences between patients who did achieve and did not achieve a MCII. Variables tested included: demographic and surgical factors, general and mental health state, and preoperative radiographic findings such as deformity and joint space width (JSW). Significant variables were entered into a multivariable binary logistic regression.

Receiver-operating characteristic (ROC) analysis was used to generate cutoff values for significant continuous variables. Youden's index was used to identify cutoff points that maximized both specificity and sensitivity.

Introduction

Within the field of arthroplasty, the use of patient-reported outcome measures (PROMs) is becoming increasingly ubiquitous in an effort to employ more patient-centered methods of evaluating success. PROMs may be used to assess general health, joint-specific pain or function, or mental health. General and joint-specific questionnaires are most often used in arthroplasty research, but the relationship between arthroplasty and mental health is less well understood. Furthermore, longitudinal reports of PROM changes after arthroplasty are lacking in the literature.

Our primary aim was to quantify the improvement in general, joint-specific, and mental health PROMs following total hip arthroplasty (THA) as well as the extent of any deterioration through the 7 years follow-up. Our secondary aim was to identify predictors of clinically significant PROM decline.

Methods

A total of 864 patients from 17 centers across 8 countries were enrolled into a prospective study. Patients were treated with components from a single manufacturer, which have been shown to be well-functioning in other studies.

Patients completed a battery of PROMs preoperatively, and at one, three, five, and seven years post-THA. Changes in PROMs between study visits were assessed via paired tests.

Postoperative trends for each PROM were determined for each subject by the slope of the best-fit line of the four postoperative data points. Significant PROM deterioration was defined as one literature-defined minimum clinically important difference over 5-years. Binary logistic regressions were used to identify independent predictors of significant decline in the EuroQol (EQ-5D) visual analogue scale (VAS) for Health State, 36-Item Short Form Survey (SF-36) physical composite summary (PCS), and SF-36 mental composite summary (MCS).

Introduction

There are several potential biological mechanisms that may influence aseptic implant failure including excessive innate and adaptive immune responses to implant debris. We investigated the hypothesis that patients with painful total joint replacements will exhibit elevated levels of metal reactivity and inflammatory markers compared to patients with well-performing TJA. We evaluated this hypothesis by testing for metal hypersensitivity using in vitro LTT assay and analyzing serum levels of selected inflammatory markers.

Methods

Subject Groups: Blinded de-identified data from patients with TJR referred for metal hypersensitivity testing using a lymphocyte transformation test (LTT) and serum markers of inflammation using Luminex Multi-Analyte Assay was approved by Rush University IRB and retrospectively reviewed. None of the patients had radiographically identifiable osteolysis. Two groups of TJA patients were tested: Group 1: Well-functioning implant (<3 yrs. post-op), with no self-reported pain, i.e. <1 on 0–10 VAS scale (n=8) and Group 2: Painful TJR (<3 yrs. post-op), with self-determined pain of >8 on a 0–10 VAS scale at the time of blood draw (n=25). Metal-LTT: Peripheral blood mononuclear cells (PBMCs) were collected from 30mL of peripheral blood by Ficoll gradient separation. PBMCs were cultured with NiCl2. 3H Thymidine was added at day 5 of culture and 3H thymidine incorporation was analyzed using a beta scintillation counter at day 6. A stimulation index (SI) of reactivity was calculated by dividing scintillation counts per minute (cpms) of Ni challenged cells by those of untreated controls. A SI of <2 was considered nonreactive, 2 to <4 was mildly reactive and 4 to <8 was reactive. Luminex Assay: Serum samples were collected from whole blood and were analyzed according to manufacturer's protocols. Statistical analysis: Statistical differences were determined using unpaired t-test with Welch's correction with statistical significance at p≤0.1 (90% confidence interval).

Introduction

The American Joint Replacement Registry (AJRR) was created to capture total hip (THA) and total knee arthroplasty (TKA) procedural data in order to conduct implant-specific survivorship analyses, produce risk-adjusted patient outcome data, and provide hospitals and surgeons with quality benchmarks. The purpose of this study is to compare early reports from the AJRR to other national registries to identify similarities and differences in surgeon practice and potential topics for future analysis.

Methods

Hip arthroplasty data were extracted from the annual reports from the AJRR and other national registries including: the Australian registry; the New Zealand registry; the United Kingdom, Wales, and Isle of Man registry; the Norwegian registry; and the Swedish registry from 2014 to 2016. Data regarding femoral and acetabular fixation, bearing surface type, femoral head size, the use of dual mobility articulation bearings, hip resurfacing utilization, and THA revision burden were evaluated. Revision burden is defined as the ratio of implant revisions to the total number of arthroplasties performed in a given time period. Registry characteristics and patient demographic data were recorded across all registries. The results were compared between the various registries and reported using descriptive statistics.

Background

Delay in access to primary total hip (THA) arthroplasty continues to pose a substantial burden to patients and society in publicly funded healthcare systems. The majority of strategies to decrease wait times have focused on the time from surgical consult to surgery, however a large proportion of total wait time for these patients is the time from primary care referral to surgical consultation. Prioritization scoring tools and patient reported outcome measures are being used in an attempt to ration limited resources in the face of increasing demand. However, to our knowledge, no study has investigated whether a referral Oxford Hip Score (OHS) could be used to triage non-surgical referrals appropriately, in an effort to increase timely access to specialists for patients that are candidates for total joint replacement (TJR).

Purpose

1) To determine if a referral OHS has the predictive ability to discriminate when a hip patient will be deemed surgical versus conservative by the surgeon during their first consultation 2) To identify an OHS cut-off point that can be used to accurately predict when a primary THA referral will be deemed conservative by the consultant surgeon during the first consultation.

Introduction

The vast majority of intertrochanteric fractures treated with cephalomedullary nails (CMN) will heal. Occasionally even though bony union occurs excessive lag screw sliding can cause persistent pain and soft tissue irritation and return to surgery for hardware removal. The purpose of this study was to evaluate if fracture stability, lag screw tip-apex distance (TAD), and quality of reduction have any impact excessive lag screw sliding and potential cutout.

Methods

As part of our level one trauma center's institutional hip fracture registry, a retrospective analysis identified 199 intertrochanteric fractures fixed with CMN between 2009 and 2015 with follow up to union or a minimum of three months. The mean follow-up was 22 months (3 to 94 months). Mean patient age was 75 years (50 to 97 years) and 72% were women. Postoperative radiographs were used to measure the TAD, quality of reduction, neck-shaft angle (NSA), and lateral lag screw prominence. Follow-up radiographs were reviewed to assess fracture union, translation, and progression of lateral lag screw prominence. Complications and reoperations were recorded.

Introduction

Total hip arthroplasty (THA) is gaining popularity as a treatment for displaced femoral neck fractures (FNF), especially in physiologically younger patients. While elective THA for primary osteoarthritis (OA) has demonstrated low rates of complications and readmissions, the outcomes of THA for FNF are less predictable. Additionally, these THA procedures are equally included in various alternative payment bundles. Therefore, the aim of this study is to assess postoperative complication rates after THA for primary OA compared with FNF.

Methods

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2008 to 2016 was queried. Patients were identified using the Current Procedural Terminology (CPT) code for THA (27130) and divided into groups by diagnosis; OA in one group and FNF in another. Univariate statistics were performed. T-test compared continuous variables between groups, and Chi-square test compared categorical variables. Multivariate and propensity matched logistic regression analyses were performed to control for risk factors of interest. The primary outcomes for this study were death or serious morbidity (surgical site infection (SSI), infection, respiratory complication, cardiac complication, sepsis, or blood loss anemia requiring postoperative transfusion). Additional secondary outcomes included the incidence of specific complications, total operative time (time from incision to closure), length of hospital stay and proportion of patients that were discharged home.

Introduction

Hip fractures are a common pathology treated by Orthopaedic surgeons. The Comprehensive Care for Joint Replacement (CJR) model utilizes risk stratification to set target prices for these patients undergoing hemiarthroplasty or total hip arthroplasty (THA). We hypothesized that sub-specialty arthroplasty surgeons would be able to treat patients at a lower cost compared to surgeons of other specialties during cases performed while on call.

Methods

Patients with hemiarthroplasty or THA for hip fractures were retrospectively collected from June, 2013, to May, 2017, from a single tertiary referral center. Demographic information and outcomes based on length of stay (LOS), net payment, and target payment were collected. Patients were then stratified by surgeon subspecialty (arthroplasty trained vs. other specialty). Univariable and multivariable analysis for payment based on treating surgeon was then performed.

Introduction

Manual chart review is labor-intensive and requires specialized knowledge possessed by highly-trained medical professionals. The cost and infrastructure challenges required to implement this is prohibitive for most hospitals. Natural language processing (NLP) tools are distinctive in their ability to extract critical information from raw text in the electronic health records (EHR). As a simple proof-of-concept, for the potential application of this technology, we examined its ability to discriminate between a binary classification (periprosthetic fracture [PPFFx] vs. no PPFFx) followed by a more complex classification of the same problem (Vancouver).

Methods

PPFFx were identified among all THAs performed at a single academic institution between 1977 and 2015. A training cohort (n = 90 PPFFx) selected randomly by an electronic program was utilized to develop a prototype NLP algorithm and an additional randomly-selected 86 PPFFx were used to further validate the algorithm. Keywords to identify, and subsequently classify, Vancouver type PPFFx about THA were defined. The algorithm was applied to consult and operative notes to evaluate language used by surgeons as a means to predict the correct pathology in the absence of a listed, precise diagnosis (e.g. Vancouver B2). Validation statistics were calculated using manual chart review as the gold standard.

Background

Prior research has shown that depression negatively impacts outcomes after total hip arthroplasty (THA); however, arthroplasty patients may also have depressive symptoms without an established diagnosis. The purpose of this study was to determine whether the Patient Health Questionnaire-2 (PHQ-2), a two-question depression screener, correlates with joint-specific symptom improvement after primary THA.

Methods

This was a prospective cohort study. Patients completed the PHQ-2 and the Hip Disability and Osteoarthritis Outcome Score - Joint Replacement (HOOS-JR) prior to THA, with follow-up at 6 weeks and 6 months. An a priori power analysis determined a sample size of 31 would detect an effect size of 0.5 with a power of 0.80. We used previously established minimum clinically important difference (MCID) values for HOOS-JR. Continuous variables were analyzed with t-tests or Mann-Whitney tests while categorical variables were analyzed with Chi square or Fisher exact tests.

Introduction

Despite evidence-based recommendations opioids and benzodiazepines are commonly prescribed to treat osteoarthritis. This study aims to quantify the prevalence of opioid and benzodiazepine prescriptions given for the primary diagnosis of osteoarthritis across a large healthcare system. Additionally, we aim to characterize risk factors for drug misuse, abuse, and diversion.

Methods

We conducted a descriptive analysis of adult patient encounters with a primary diagnosis of osteoarthritis during a one-year time period from Jan –Dec 2016 at a large, healthcare system. Demographic data, prescription data, patient-specific prescription drug use risk criteria were collected. Descriptive analysis was conducted to characterize the population of arthritis patients who received prescription opioids. The rate of controlled substance prescribing was calculated for the population as a whole and among subgroups (age, facility type, and patient risk profile).

Summary

Narcotic administration within the inpatient setting is highly variable any may benefit from the implementation of standardized multi-modal pain management protocols.

Introduction

Total joint arthroplasty (TJA) candidates have historically received high doses of opioids within the perioperative period for the management of surgical pain. Healthcare systems have responded by improving opioid prescribing documentation and implementing narcotic-sparing pain protocols into TJA integrate care pathways (ICP). Despite these efforts, there are few technological platforms designed to curtail excessive inpatient narcotic administration. Here we present an early iteration of an inpatient narcotic administration reporting tool which normalizes patient narcotic consumption as an average daily morphine milligram equivalence (MME) per surgical encounter (MME/day/encounter) among total hip arthroplasty (THA) recipients. This information may help orthopaedic surgeons visualize their individual granular inpatient narcotic prescribing habits individually and compared to other surgeons, while taking into consideration patient and procedure specific variables.

Introduction

Deaths due to overdose involving opioids have nearly quadrupled in USA in the last 20 years. Several published studies have shown that preoperative opioid use independently predicts perioperative complications in total joint arthroplasty. Our objectives were to (1) assess preoperative opioid consumption in patients undergoing total hip arthroplasty (THA) and (2) to determine how preoperative opioid use affects patient oriented outcomes (POO's) and hip scores before and after THA.

Methods

54 primary THA by a single surgeon were reviewed. A new patient questionnaire was administered to document preoperative opioid consumption (type, dosage and length of use); preoperatively and postoperatively POO's measurements [visual analog scale (VAS), QWB-7, SF-36, and WOMAC] and hip scores were recorded. Patients were stratified into two groups: (1) Opioid Users and (2) Non-Opioid Users. Oral morphine equivalents (OME) were calculated for opioid using patients using standard methodology.

Background

Orthopedic surgeons have relied heavily on opiates after total hip replacement (THR) despite no clear evidence of benefit and a rapidly growing abuse epidemic. Multimodal analgesia may reduce or even obviate the need for opiates after elective surgery.

Methods

In a cluster-randomized, crossover trial, 235 patients undergoing THR were assigned to receive multimodal analgesia with minimal opiates (Group A-10 tablets), multimodal analgesia with a full opiate supply (Group B-60 tablets), or a traditional opiate regimen without multimodal analgesia (Group C-60 tablets). The multimodal regimen comprised scheduled-dose acetaminophen, meloxicam, and gabapentin. Primary outcomes were daily pain and opiate utilization for the first 30-days. Secondary outcomes included assessments of satisfaction, sleep-quality, opiate-related symptoms, hip function, and adverse events.

Introduction

Opioids are an important component of multimodal analgesia, but improper utilization places patients at risk for overdose and addiction. The purpose of this randomized controlled trial is to determine whether the quantity of opioid pills prescribed at discharge is associated with the total amount of opioids consumed or unused by patients after total hip (THA) and knee (TKA) arthroplasty.

Methods

304 Opioid naïve patients undergoing THA or TKA were randomized to receive a prescription for either 30 or 90 5mg oxycodone immediate release (OxyIR) tablets at discharge. All patients received acetaminophen, meloxicam, tramadol and gabapentin perioperatively. Daily opioid consumption, reported in morphine equivalent dose (MED), number of unused OxyIR, and pain scores were calculated for 30 days postoperatively with a patient-completed medication diary. The number of OxyIR refills and total MED received were recorded for 90 days postoperatively. Power analysis determined that 141 patients per group were necessary to detect a 25% reduction in means in opiate consumption between groups. Statistical analysis involved t-test, rank sum, and chi-squared tests with alpha=0.05.

Introduction

Increasingly, patients with bilateral hip arthritis wish to undergo staged total hip arthroplasty. With the rise in demand for arthroplasty perioperative risk assessment and counseling is critical for shared decision making; however, it is unknown if complications that occur after a unilateral hip arthroplasty predict complications following surgery of the contralateral hip.

Methods

We used nation-wide linked discharge data from the Hospital Cost and Utilization Project from 2005–2014 to analyze the incidence and recurrence of complications following the first and second stage operations in staged bilateral total hip arthroplasty (BTHAs). Complications included perioperative risks within 30–60 days, and infection and mechanical complications within one year. Conditional probabilities and odds ratios were calculated to determine whether experiencing a complication after the first stage of surgery increased the risk of developing the same complication after the second stage.

Introduction

Interferon (IFN) based treatments for chronic hepatitis C (HCV) have been the standard of care until 2014 when direct antiviral agents (DAA) were introduced. Patients with HCV have had extremely high complication rates after total hip arthroplasty (THA). It is unknown whether HCV is a modifiable risk factor for these complications prior to THA. The purpose of this study was 1) to compare perioperative complication rates between untreated and treated HCV in THA and 2) to compare these rates between patients treated with two different therapies (IFN vs. DAA).

Methods

A multicenter retrospective database query was used to identify patients diagnosed with chronic hepatitis C virus who underwent total hip arthroplasty from 2006–2016. All patients (n=105) identified were included and were divided into two groups: untreated HCV (n=63) and treated (n=42); the treated group were further subdivided into those receiving IFN based therapies (n=16) or DAA therapies (n=26). Comparisons between the treated and untreated groups were made with respect to demographic data, comorbidities, preoperative viral load, MELD score, and all surgical (≤1 yr) and medical (≤90d) complications; a sub-group analysis of the treated patients was also performed. Separate independent t-tests were conducted for dependent variables that were normally distributed, and Mann-Whitney U tests were conducted for variables which were not normally distributed. Categorical variables were compared through the chi-square test of independence. The level of statistical significance was set at p<0.05.

Introduction

Many pharmacologic agents have been used for venous thromboembolism (VTE) prophylaxis after elective total hip arthroplasty (THA). Rivaroxaban was the first novel oral anticoagulant approved for THA patients, but its actual efficacy and safety in clinical practice, beyond randomized trials, is unknown.

Materials and Methods

This is a retrospective study, using the Truven Health MarketScan database, of anticoagulation medication prescriptions after elective THA, in both commercially insured (CI) and Medicare supplement insured (MS) patients, from 2010 to 2015. After exclusions, there were 83,179 CI and 50,534 MS patients available for analysis. There were 12,876 new users of warfarin (W) and 10,892 new users of rivaroxaban (R) in CI patients, and 7,416 new users of W and 4,739 new users of R in MS patients. We asked the following questions: (1) What were the trends and predictive factors for anticoagulant use after elective THA? (2) What was the actual clinical efficacy: frequency of deep vein thrombosis (DVT) and pulmonary embolism (PE), and frequency of adverse events within 90 days with the two most commonly used oral agents, rivaroxaban and warfarin, from June 2011 to September 2015? Data was analyzed for each anticoagulant by odds ratios using logistic regression models with stabilized inverse probability treatment weighting.

Introduction

Historically, US arthroplasty revision rates are based on CMS data that cannot verify initial surgery date in patients under 65 years or laterality of revision. We calculated US one-year revision rates for primary total hip replacement (THR) using a representative cohort. Reasons for revision were documented.

Methods

A multi-center cohort from US surgeons in 28 states collected sociodemographic data; medical, emotional, musculoskeletal comorbidities; BMI; and patient-reported pain and function (SF36, HOOS) for elective THR patients. Cases in 2011–2013 were matched with CMS data to ascertain 1 year revision through 2014. Predictors of revision were identified. Chart reviews to verify reasons for revision were performed.

Introduction

Complications can be defined as preventable, potentially preventable, or non-preventable. While often discussed, there are virtually no data whether or not the most common causes of revision total hip arthroplasty (THA) are preventable or not. The goal of this study was to identify and report preventable causes of revision THA within 5 years of the index THA.

Methods

We conducted a retrospective review of 128 consecutive revision THAs between August 2015 and August 2017, with 62% being referred from another institution. Mean time to revision THA from the index arthroplasty was 10 months. Mean age at revision THA was 61 years, with 67% being female. Three fellowship-trained adult reconstruction surgeons reviewed the radiographs and operative notes and classified the revision THAs into two categories: preventable vs. non-preventable. Reviewers were instructed to be extremely lenient with the benefit of the doubt given to the operative surgeon. Inter-observer reliability was assessed by Cohen's kappa analysis.

Introduction

Historically, the most common indications for re-revision of a total hip arthroplasty (THA) have been aseptic loosening, instability, infection, and peri-prosthetic fracture. As revision implants and techniques have evolved and improved, understanding why contemporary revision THAs fail is important to direct further improvement and innovation. As such, the goals of this study were to determine the implant survivorship of contemporary revision THAs, as well as the most common indications for re-revision.

Methods

We retrospectively reviewed 2568 aseptic revision THAs completed at our academic institution between 2005 and 2015 through our total joint registry. There were 34% isolated acetabular revisions, 18% isolated femoral revisions, 28% both component revisions, and 20% modular component exchanges. The mean age at index revision THA was 66 years, and 46% were males. The most common indications for the index revision THA were aseptic loosening (21% acetabular, 15% femoral, 5% both components), polyethylene wear and osteolysis (18%), instability (13%), fracture (11%), and other (17%). Mean follow-up was 6 years.

Introduction

Ceramic heads are used in hip revision surgery to mitigate corrosion concerns. Manufacturers recommend using a pristine titanium sleeve in conjunction with a well-fixed metal stem to prevent early failure of the ceramic head. However, the influence of impact force, head size, and sleeve offset on pull-off strength and seating displacement of a revision head assembly is not fully understood. Therefore, the purpose of this study was to investigate the pull-off strength and displacement of commercially available revision ceramic heads and titanium taper sleeve offsets (BIOLOX OPTION, CeramTec GmbH, Plochingen, Germany) while covering a range of clinically relevant impaction forces.

Methods

Two head sizes (28 mm, n = 12 and 36 mm, n = 12) and two taper adapter sleeve offsets (small, n = 12 and extra-large, n = 12) were tested in this study. A dynamic impaction rig was constructed to seat the head, sleeve, and stem assembly (Fig. 1). Consistent impaction forces were achieved by dropping a hammer fixed to a lever arm from a pre-determined height onto a standard impactor instrumented with a piezoelectric force sensor (PCB Piezotronics Inc.). Axially applied forces of 2 kN and 6 kN were used to cover a range of typical impaction forces. Three non-contact differential variable reluctance transducers (LORD Sensing Systems) were used to track the displacement of the head relative to the stem. Subsequently, samples were transferred to a servo hydraulic testing machine, and a pull-off test was carried out per ISO 7206–10 to measure the disassembly force.

Introduction

During revision total hip arthroplasty, successful treatment of acetabular bone loss with an associated chronic pelvic discontinuity is dependent upon the remaining bone stock, stability of the construct, potential for biologic fixation, and healing of the discontinuity. Several techniques have been described for the treatment of this clinical entity; the authors recommend the use of acetabular distraction technique in conjunction with a jumbo cup with or without augments.

The authors recently evaluated the minimum two-year follow-up of acetabular distraction technique for the treatment of chronic pelvic discontinuity. In the process, a chronic pelvic discontinuity classification was created based on the type of reconstruction required. The purpose of this study is to introduce the initial observations of this novel classification system.

Methods

Patients from two academic institutions undergoing acetabular distraction for chronic pelvic discontinuity were identified between January 2002 and December 2013 with minimum 2-year follow-up. Radiographs at latest follow-up were compared to serial radiographs from the index surgery. Data was collected by chart review in accordance with institutional IRB protocol from both institutions.

Introduction

Custom flanged acetabular components (CFAC) have been shown to be effective in treating complex acetabular reconstructions in revision total hip arthroplasty (THA). However, the specific patient factors and CFAC design characteristics that affect the overall survivorship remain unclear. Once the surgeon opts to follow this treatment pathway, numerous decisions need to be made during the pre-operative design phase and during implantation, which may influence the ultimate success of CFAC. The goal of this study was to retrospectively review the entire cohort of CFAC cases performed at a large volume institution and to identify any patient, surgeon, or design factors that may be related to the long-term survival of these prostheses.

Methods

We reviewed 96 CFAC cases performed in 91 patients between 2004 and 2017, from which 36 variables were collected spanning patient demographics, pre-operative clinical and radiographic features, intraoperative information, and implant design characteristics. Patient demographics and relevant clinical features were collected from individual medical records. Radiographic review included analysis of pre-operative radiographs, computer tomographic (CT) scans, and serial post-operative radiographs. Radiographic failure was defined as loosening or gross migration as determined by a board-certified orthopedic surgeon. CFAC implant design characteristics and intra-operative features were collected from the design record, surgical record and post-operative radiograph for each case respectively.

Two sets of statistical analyses were performed with this dataset. First, univariate analyses were performed for each variable, comprising of a Pearson chi-square test for categorical variables and an independent t-test for continuous variables. Second, a random forest supervised machine learning method was applied to identify the most influential variables within the dataset, which were then used to perform a bivariable logistic regression to generate odds ratios. Statistical significance for this study was set at p < 0.05.

Background

Fully constrained liners are used to treat recurrent dislocations or patients at high risk after total hip replacements. However, they can cause significant morbidities including recurrent dislocations, infections, aseptic loosening and fractures. We examine long term results of 111 patients with tripolar constrained components to assess their redislocation and failure rate.

Questions/purposes

The purpose of this study was to assess survivorship, complications and functional outcomes at a minimum 10 years after the constrained tripolar liners used in our institute.

Background

High complication rates and poor outcomes have been widely reported in patients undergoing revision of large head metal-on-metal arthroplasty. A previous study from our center showed high rates of dislocation, nerve injury, early cup loosening and pseudotumor recurrence. After noting these issues, we implemented the following changes in surgical protocol in all large head MOM revisions: 1. Use of highly porous shells in all cases 2. Use of largest femoral head possible 3. Low threshold for use of dual mobility and constrained liners when abductors affected or absent posterior capsule 4. Use of ceramic head with titanium sleeve in all cases 5. Partial resection of pseudotumor adjacent to sciatic and femoral nerves.

Questions/purposes

The purpose of the present study is to compare the new surgical protocol above to our previously reported early complications in this group of patients

We specifically looked at (1) complications including reoperations; (2) radiologic outcomes; and (3) functional outcomes. Complication rates after (Group 1), and before (Group 2) modified surgical protocol were compared using Chi-square test, assuming statistical significance p<0.05.

Introduction

Tranexamic acid (TXA) has been shown to significantly reduce transfusion rates in primary total hip arthroplasties (THAs), but data is limited in the revision setting. The purpose of the current study was to compare the rate of blood transfusions and symptomatic venous thromboembolic events (VTEs) in a large cohort of revision THAs treated with or without IV TXA.

Methods

We performed a retrospective review of 3,264 revision THAs (2,645 patients) between 2005–2014, of which 1,142 patients received IV TXA (1g at incision and 1g at closure). The mean age was 65 years with 49% males in the revision group with TXA, and 67 years with 45% males in the revision group treated without TXA. Outcomes analyzed included rates of transfusion and VTE (within 90 days) between cases treated with TXA and cases not treated with TXA. These comparisons were performed for the overall cohort, as well as within the subset of aseptic cases and septic cases. In order to minimize potential bias between these two subgroups, the analyses were weighted with inverse probability of treatment weights based on a propensity score which included age at revision THA, sex, BMI, ASA score, preoperative anticoagulation, and year of surgery. Mean follow-up was 2 years.

Introduction

Modularity in femoral stem designs allow surgeons to independently control leg length, offset, and femoral version in revision or complex primary THA cases. Initial enthusiasm in these modular stems has been tempered by recognition of modular junction failures. This study evaluates mean 5-year clinical results and survival rates of a 3-part titanium alloy modular femoral implant with unique taper geometries and a metaphyseal plasma spray surface. The current results are presented after pre-market independent fatigue testing performed by Orthopaedic Laboratory (Greenwald) and previously published early clinical results in 2006. Low plasticity burnishing (LPB) was added in 2005 to further strengthen the neck metaphyseal modular junction. The modular stem component is a polished cylindrical splined clothespin design. Our hypothesis is that these unique modular junctions succeed in offering the advantages of modularity without failure at this midterm follow-up period.

Methods

Between May 2010 and July 2016, 32 total hip arthroplasties were performed using a 3-part femoral stem with neck-metaphyseal-stem modular junctions. Surgeries were either the final stage of a two-stage revision for infection, revision THR for loosening, or a revision of a previous non-prosthetic replacement procedure. Patients were entered into an IRB-approved registry and followed with x-rays, HHS, Oxford scores, and patient satisfaction scores. Patients who failed to return for routine follow-up were contacted by phone or email. Two patients had died with their implants intact. Six patients could not be reached for an updated follow-up. One stem was revised for loosening at 33 months due to failed osseointegration in a patient with chronic renal failure. This removed stem was submitted for taper exam and sectioning.