Osteoarthritis (OA), a painful, debilitating joint disease, often caused by excessive joint stress, is a leading cause of disability (World Health Organisation, 2003) and increases with age and obesity. A 5° varus malalignment increases loading in the medial knee compartment from 70% to 90% (Tetsworth and Paley, 1994). Internal unloading implants, placed subcutaneously upon the medial aspect of the knee joint, are designed to offload the medial compartment of the knee without violating natural joint tissues. The To simulate surgical treatment of medial knee OA, a three-dimensional computer-aided design of an Atlas™ knee system was virtually fixed to the medial aspect of a validated finite element knee model (Mootanah, 2014), using CATIA v5 software (Dassault Systèmes, Velizy Villacoublay, France). The construct was meshed and assigned material properties and boundary conditions, using Abaqus finite element software (Dassault Systèmes, Velizy Villacoublay, France). A cartilage defect was simulated by removing elements corresponding to 4.7 mm2. The international cartilage repair society (ICRS) Grade II and III damage were simulated by normalized defect depth of 33% and 67%, respectively. The femur was mechanically grounded and the tibia was subjected to loading conditions corresponding to the stance phase of walking of a healthy 50-year-old 68-Kg male with anthropometrics that matched those of the cadaver. Finite element analyses were run for peak shear and von Mises stress in the medial and lateral tibiofemoral compartments.Introduction
Methods
There has not been a comparison of patients and outcomes between two separate countries for any knee prosthesis. This study compares total knee replacement outcomes between an Indonesian and American cohort. We aim to compare the clinical results between two different hospitals in two different countries using post-operative range of motion as the primary clinical result. 177 Indonesian RPF TKR patients were compared to 84 American patients. Demographics, patient recorded outcomes scores (KSS, PAQ, WOMAC), flexion, and component size were compared between the groups. Standard t-test was used to compare the variables between the two countries and regression analysis adjusting for age, BMI, length of follow-up, sex, preoperative WOMAC and PAQ score, preoperative KSS knee score, preoperative KSS function score, and preoperative UCLA was used to compare outcomes.Introduction
Materials and Methods
The advent of ambulatory total joint replacements has called for measures to reduce postoperative length of stay, while improving patient function and postoperative satisfaction. This prospective, randomized trial evaluated the efficacy of one-on-one preoperative physical therapy (PT) education with a supplemental web-based PT web-portal on discharge disposition, postoperative function and patient satisfaction after total joint replacement. Between February and June 2015, 126 patients underwent unilateral total knee (n=63) or total hip arthroplasty (n=63). All patients attended a group preoperative education (preopEd) class [standard of care] and were subsequently randomized into two groups. One group received no further education as per the standard of care [control; TKA= 31; THA=32] and the other received an in-person one-on-one preoperative PT education session (preopPTEd) as well as access to a web-portal during the postoperative period [experimental; TKA=32; THA=31]. Discharge disposition was attained from hospital records. Patient satisfaction and WOMAC scores were evaluated by a series of patient administered questionnaires.Introduction
Materials & Methods
Several studies have shown that functional outcomes are similar regardless of being discharged directly to home or to a rehabilitation center after total knee arthroplasty (TKA). Therefore, we sought to determine if there is a difference in patient care or patient satisfaction for patients discharged to in-patient rehabilitation or home-based rehabilitation. Between February and May of 2015, one hundred and seventy one consecutive patients were prospective identified after undergoing TKA by one of three surgeons. At an average of six-weeks post TKA, all patients were asked a patient administered questionnaire to determine if diagnostic testing (ultrasounds, or x-rays) or blood transfusions were performed during the first-six weeks at either home (n=86) or a rehab (n=85) facility.Introduction
Materials and Methods
Total hip arthroplasty (THA) is a common operation. Different operative approaches have specific benefits and compromises. Soft tissue injury occurs in total hip arthroplasty. This prospective study objectively measured muscle volume changes after direct anterior and posterior approach surgeries. Patients undergoing Direct Anterior Approach (DAA) and Posterior Approach (PA) THA were prospectively evaluated. 3 orthopaedic surgeons performed all surgeries. Muscle volumes of all major muscles around the hip were objectively measured using preoperative and 2 different postoperative follow-up MRIs. 2 independent measurers performed all radiographic volume measurements. Repeated-measures ANOVA was used to compare mean muscle volume changes over time. Student's t-test was used to compare muscle volumes between groups at specific time intervals.Introduction
Methods
Femoroacetabular impingement (FAI) is a common cause of hip pain in the young adult. Uncertainty regarding surgical indications, outcome assessment, management preferences and perceptions of the literature exist. We conducted a large international survey assessing the perceptions and demographics of orthopaedic surgeons regarding FAI. A survey was developed using previous literature, focus groups and a sample-to-redundancy strategy. The survey contained forty-six questions and was emailed to national orthopaedic associations and orthopaedic sports medicine societies for member responses. Members were contacted on multiple occasions to increase response rates. Nine hundred orthopaedic surgeons from twenty national and international organisations completed the survey. Surgeons responded across 6 continents, 58.2 % from developed nations with 35.4 % having sports fellowship training. North American and European surgeons reported significantly greater exposure to hip arthroscopy during residency and fellowships in comparison to international respondents (48.0% vs. 44.5% vs. 25.6% respectively; p<0.001). Surgeons performing a higher volume of FAI surgery (over 100 cases per year) were significantly more likely to have practiced for more than 20 years (OR 1.91; 95% CI 1.01 to 3.63), be practicing at an academic hospital (OR 2.25; 95% CI 1.22 to 4.15), and have formal arthroscopy training (OR 46.17; 95% CI 20.28 to 105.15). High volume surgeons were over two-fold more likely to practice in North America and Europe (OR 2.26; 95% CI: 1.08 to 4.72). The exponential rise in the diagnosis and surgical management for FAI appears to be driven largely by experienced surgeons in developed nations. Our analysis suggests that although FAI management is early in the innovation cycle we are at a tipping point towards wider uptake and utilisation. The results of this survey will help guide further research and study.
The outcomes of hip arthroscopy in the treatment of dysplasia are variable. Historically, arthroscopic treatment of severe dysplasia (lateral center-edge angle [LCEA] < 18°) resulted in poor outcomes and iatrogenic instability. However, in milder forms of dysplasia, favorable outcomes have been reported. The purpose of this study was to compare outcomes following hip arthroscopy for femorocetabular impingement (FAI) in borderline dysplastic (BD) patients compared with a control group of non-dysplastic patients. Between March 2009 and July 2012, a BD group (LCEA 18°–25°) of 46 patients (55 hips) was identified. An age and sex-matched control group of 131 patients (152 hips) was also identified (LCEA 25°–40°). Patient-reported outcome scores, including the Modified Harris Hip Score (mHHS), the Hip Outcome Score-Activity of Daily Living (HOS-ADL), the Sport-specific Subscale (HOS-SSS), and the International Hip Outcome Tool (iHOT-33), were collected pre-operatively, at 1, and 2 years. The mean LCEA was 22.4 ± 2.0° (range, 18.4°–24.9°) in the BD group and 31.0 ± 3.1° (range, 25.4°–38.7°) in the control group (p<0.001). The mean preoperative alpha angle was 66.3 ± 9.9° in the BD group and 61.7 ± 13.0° in the control group (p=0.151). Cam decompression was performed in 98.2% and 99.3% of cases in the BD and control groups. Labral repair was performed in 69.1% and 75.3% of the BD and control groups respectively, with 100% of patients having a complete capsular closure performed in both groups. At a mean follow-up of 31.3 ± 7.6 months (range, 23.1–67.3) in unrevised patients and 21.6 ± 13.3 months (range 4.7–40.6) in revised patients, there was significant improvement (p<0.001) in all patient reported outcome scores in both groups. Multiple regression analysis did not identify any significant differences between groups. Importantly, female sex did not appear to be a predictor for inferior outcomes. Two patients (4.3%) in the BD group and six patients (4.6%) in the control group required revision arthroscopy during the study period. Favorable outcomes can be expected following the treatment of impingement in borderline dysplastics when labral refixation and capsular closure are performed, with comparable outcomes to non-dysplastic patients. Further follow-up in larger cohorts is necessary to prove the durability and safety of hip arthroscopy in this challenging group and to further explore potential gender-related differences in outcome.
Acetabular fixation is one of the major factors affecting long-term longevity and durability of total hip arthroplasty (THA). Limited data exist regarding mid-term performance of modern non-cemented rim-fit cups with HA coating. The aim of this study was to assess the minimum 5 year clinical and radiographic performance of PSL cups. Therefore we retrospectively analyzed results of this component in patients that had adequate followup from a prospective institutional database. A retrospective analysis of a prospective database was performed to identify patients that underwent non-cemented THA between 2003 and 2007. 223 primary THA (210 patients) were performed by single surgeon via posterolaeral approach using a grit-blasted, HA coated rim-fit design and highly cross-linked polyethylene and were followed with minimum 5 years. The mean age was 62.5 years ± 10.8. The majority of the stems were non-cemented (87%) and the majority of the femoral heads were metal (75%), 22- or 28-mm diameter. 72% of the cups were solid and 28% were multi-hole. Clinical assessment included the Hospital for Special Surgery (HSS) hip score [18] at final follow-up, and Kaplan-Meier survivorship. All patients received pre- and post-operative anteroposterior (AP) weight bearing pelvis radiograph as well as a false profile view of the hip. Cup positioning was analyzed using the EBRA software (Einzel-Bild-Roentgen-Analysis; University of Innsbruck, Innsbruck, Austria) for functional abduction angle, anteversion, and cup migration. Osseointegration was assessed on the DeLee and Charnley's zones on both AP and false profile views. Osseointegration was defined based on the following characteristics: presence of Stress Induced Reactive Cancellous Bone (SIRCaB), where new bone condensation (not apparent on preoperative radiographs) was present at the load bearing area of the cup (Figure 1) presence of radial trabeculae that project in continuum from the shell into the pelvis, suggesting integration of the trabecular bone onto the metal surface at the load bearing area, (Figure 2) absence of radiolucency. Radiolucency was determined by radiolucent lines that were at least 1–2 mm wide and were seen in sequential radiographs, not apparent on the initial postoperative radiograph. Linear and rotational migration was defined as > 3 mm or > 5°change in the cup position, respectively, as measured on serial radiographs. Any changes in cup position or presence of circumferential radiolucencies were considered as loosening.Introduction
Materials and Methods
Wear and osteolysis are major contributors, which limit the durability of total hip Arthroplasty (THA) and ultimately cause it to fail. Efforts were made to decrease wear by highly cross-linked polyethylene (HXLPE) and using ceramic bearings. The purpose of this study is to analyze and compare the five year performance of large sized (32mm and 36mm) ceramic and metal heads on X3 HXLPE (Stryker, Mahwah, NJ, USA).Background
Questions/Purposes
Highly cross-linked polyethylene (HCLPE) was introduced to reduce wear and osteolysis in total hip arthroplasty (THA). There is no reported data regarding wear rates and clinical performance of Crossfire HCLPE (Stryker, Mahwah, New Jersey) in young and active patients. The purpose of this prospective study is to assess minimum 10-year wear rates and survivorship of Crossfire in young and active patients. Between January 2001 to December 2003, 52 consecutive THAs (43 patients; 26 males and 17 females), 55 years and younger, with an average University of California Los Angeles activity (UCLA) score of 7.3 ± 1.5 (5 – 10) at the time of surgery were prospectively followed. The mean age of patients was 47.4 ± 7.8 years old (range 24 to 55 years). Indication for surgery included osteoarthritis in all cases. All operations were performed by the senior surgeon via a posterolateral approach. All components were non-cemented SecurFit femoral stem, 28 mm Cobalt-Chromium (Co-Cr) femoral head, and Trident PSL cup with Crossfire HCLPE acetabular liner (Stryker, Mahwah, New Jersey). At minimum 10-years follow-up (mean 11.5 ± 0.94 years), wear rates were assessed using the Roman software. Hospital for Special Surgery (HSS) scores and survivorship data were analyzed.Background
Material and Methods
Accurate and reproducible cup positioning is one the most important technical factors that affects outcomes of total hip arthroplasty (THA). Although Lewinnek's safe zone is the most accepted range for anteversion and abduction angles socket orientation, the effect of fixed lumbosacral spine on pelvic tilt and obliquity is not yet established.
What is the change in anteversion and abduction angle from standing to sitting in a consecutive cohort of patients undergoing THA? What is the effect of fixed and flexible spinal deformities on acetabular cup orientation after THA? Between July 2011 and October 2011, 68 consecutive unilateral THAs were implanted in 68 patients with a mean age of 71 ± 6 years old. Radiographic evaluation included standing anteroposterior (AP) and lateral pelvic radiographs, and sitting lateral pelvic radiograph, measuring lumbosacral angle (LSA), sacral angle (SA), and sagittal pelvic tilt angle (SPTA). Computer generated 3D pelvis models were used to analyze the correlation between different pelvic tilts and acetabular cup orientation in abduction and anteversion.Introduction
Material and Methods
Junior level orthopaedic surgery residents who train with a virtual surgical simulator can lead to improved arthroscopy performance. Study participants were first and second year orthopaedic surgery residents at a single institution who were randomized to either train on the virtual reality surgical simulator (Introduction
Methods
Anterior knee pain (AKP) is a recognized cause of patient's dissatisfaction after total knee arthroplasty. Potential implant/technique related contributors to AKP are patellofemoral maltracking, trochlear geometry, femoral malrotation, patellar tilt and overstuffing. The primary aim of this prospective, matched pair study was to assess the safety, efficacy and performance of an anatomic patella and its effect on AKP in in a matched pair analysis. Between July 2012 and May 2013, 55 consecutive posterior stabilized cemented Attune TKAs (Depuy) were matched to the PFC Sigma group based on age, gender, and body mass index (BMI). All surgeries were performed via medial parapatellar approach with patellar resurfacing. Clinical and radiographic analysis was performed prospectively with minimum 6 month follow-up. Radiographic measurements included overall limb alignment, anterior offset, posterior offset, joint line, patellar thickness, patellar tilt and patellar displacement by two independent observers.Introduction
Material and Methods
Patient-specific or “custom” total knee replacements have been designed to fit the arthritic knee in primary total knee arthroplasty (TKA) better than “off-the-shelf” implants. Using computer technology, patient-specific cutting-blocks and custom-made implants are created to more accurately fit the contour of the knee and reproduce the anatomic J-curve with the hope of providing a better functional outcome. This retrospective, matched-pair study evaluates manipulation under anesthesia (MUA) rates in cemented patient-specific cruciate-retaining (PSCR) TKA compared to that in both cemented posterior-stabilized (PS) and non-cemented cruciate-retaining rotating-platform (NC CR RP) TKA.Objective:
Purpose:
Non-cemented, porous-coated metaphyseal sleeves have been designed to improve biologic fixation and stability in revision total knee arthroplasty (TKA) with major bone defects. The aim of this study was to evaluate the clinical results and osteointegration of these sleeves in major bone loss. Between 2008 and 2011, 24 revision TKAs with major bone loss were reconstructed with non-cemented, porous-coated proximal sleeve (DePuy, Warsaw, IN). All patients were prospectively followed for a minimum of 2 years. Indications for use of sleeves were major metaphyseal tibial and femoral bone loss, younger age, and higher activity level. Osteointegration around the sleeves were classified as:
Grade 1: Complete osteointegration in all views without any demarcation. Grade 2: Sleeves that are not completely osteointegrated but they are stable. Grade 2A: Demarcation less than 2 mm on any view Grade 2B: Demarcation more than 2 mm on any view
Grade 3: Sleeves that are not osteointegrated and unstable with evidence of subsidence. Grade 3A: Subsidence less than 2 mm on any view Grade 3B: Subsidence more than 2 mm on any viewIntroduction:
Materials and Methods:
The earliest evidence of particle-induced response is found in the synovium, leading to osteolytic defect. The degree of synovitis can be quantified by magnetic resonance imaging (MRI). This is the first long-term, prospective, matched-pair study using MRI to analyze wear-induced synovitis and osteolysis between rotating-platform posterior-stabilized (RP-PS), fixed-bearing metal-back (FB-MB), and all-polyethylene tibial (APT) designs in active patients with identical femoral components and polyethylene. From September 1999 to October 2001, a matched-pair analysis of 24 TKAs (18 patients, 3 groups: 8 RP-PS, 8 FB-MB, and 8 APT) was performed. TKAs were matched for age, sex, body mass index (BMI), and University of California Los Angeles (UCLA) activity scores. All patients underwent MRI using MAVRIC (multi-acquisition variable-resonance image combination) knee protocol designed to reduce metal susceptibility artifact. Images were evaluated for volumetric measure of synovitis and/or osteolysis and presence of fibrous membrane formation at the cement-bone interface.Introduction:
Methods:
Severe bone loss creates a challenge for fixation in femoral revision. The goal of the study was to assess reproducibility of fixation and clinical outcomes of femoral revision with bone loss using a modular, fluted, tapered distally fixing stem. 92 consecutive patients (96 hips) underwent hip revision surgery using the same design of a modular, fluted, tapered titanium stem between 1998 and 2005. Fourteen patients with 16 hips died before a 2-year follow-up. Eighty hips were followed for an average of 11.3 years (range of 8 to 13.5 years). Bone loss was classified as per Paprosky's classification, osseointegration assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Serial radiographs were reviewed by an independent observer to assess subsidence, osseointegration and bony reconstitution.Introduction:
Methods:
Unicompartmental knee arthroplasty (UKA) is a well established method for treatment of single compartment arthritis. However, a subset of patients still present with continued pain after their procedure in the setting of a normal radiographic examination. We propose the use of magnetic resonance imaging (MRI) as a useful modality in determining the etiology of symptoms in symptomatic unicompartmental knee arthroplasties. An IRB-approved retrospective analysis of 300 consecutive unicompartmental knee arthroplasties between 2008–2010 found 28 cases symptomatic for continued pain. Magnetic resonance imaging was performed with a 1.5 T Surface Coil unit after clinical and radiographic assessment. MRI evaluation included assessment for osteoarthritis, synovitis, osteolysis, and loosening. Validated questionnaires including PAQ, WOMAC and UCLA Activity Score were used for clinical assessmentIntroduction:
Materials & Methods:
The aim was to study the evolution of radiographic patterns of osteointegration of tapered wedge stems and determine if there is correlation with bony morphology and initial stem fit. We reviewed primary total hip replacements performed by two surgeons using a single cementless tapered wedge design and that had a complete series of radiographs (defined as preoperative, 6 weeks, 1 year and 5 or more years). Signs of bony remodeling were recorded at each Gruen zone. Calcar remodeling, changes in cortical thickness, evidence of subsidence and pedestal formation were recorded (Figure 1). 57 hips (50 patients) were available for analysis with a mean follow up of 5.03 years. Mean changes in cortical thickness were positive in zones 2(7.51) and 6(5.36) and negative in zones 1(−7.53) and 7(−13.51). Radiolucent lines were found in gruen zones 3,4(39%), and 5. Femoral neck cancellization was seen in zone 7 in 8 patients (14%) in year 1 and 36 (63%) by year 5. Correlations were seen with proximal canal fill and radiolucent lines at zones 3 (0.278; p0.36) and 5 (0.258; p 0.05) and with distal canal fill and hypertrophy of the cortex in zone 3 (0.429; p0.001) and 5. Cortical hypertrophy around the midstem, lack of radiolucent lines around the proximal stem and cancellization of the calcar are all radiographic patterns which occur routinely. A positive correlation with distal canal fill and hypertrophy of zones 3 and 5 was noted. There was no significant correlation with preoperative boney morphology or initial stem fit proximally.
Proper component orientation and soft tissue balancing are essential for longevity of total knee arthroplasty (TKA), especially in young and active patients. The aim of this study was to evaluate long-term results and quality of TKA in young and active patients with extension first gap balancing technique, in 2 Posterior-Stabilized (PS) total knee designs with identical femoral component. 43 consecutive Rotating-Platform (RP-PS, 33 patients) and 38 Fixed-Bearing (FB-PS, 29 patients) with University of California Los Angeles (UCLA) activity score of 5 or above and mean age was 53 ± 1.5 years were followed prospectively for a minimum of 10 years. 18 random TKAs were analyzed for component rotation using MRI.Introduction:
Material and Methods:
Hard-on-hard bearings and surface replacement (SR) have been used in young and active patients due to the reduced wear and lower rates of osteolysis. However, neither of these options resulted in survivorship higher than 90%–95% in this group of patients. The purpose of this prospective study was to compare minimum 10-year survivorship of non-cemented total hip arthroplasty (THA) using 28 mm metal head against highly-cross linked polyethylene (HXLPE) in our cohort as compared to published reports of other bearings, including surface replacements, in young-active patients. From 1999 to 2003, 91 consecutive patients (112 hips; 57 males and 34 females) with average UCLA score of 8 and mean age 53 years (range 24–65 years), who received metal on HXLP (Crossfire), were included. At minimum 10-years follow-up, patients' clinical data was assessed. All level I, II studies, registry data, and prospective cohorts published in the literature with minimum 10 years of surface replacement (SR) and ceramic on ceramic (CoC) in young patients were included.Introduction:
Matierial and Methods:
Total hip arthroplasty (THR) is one of the most successful procedures performed today. Uncemented acetabular components have by and large replaced cemented cups. As such, optimal fixation, bony ingrowth with longevity, and safety is highly demanded. In this study, we look at the safety and efficacy of the Stryker® Trident PSL™ acetabular component based on radiographic and clinical analysis. We looked at 860 consecutive patients between 2003 and 2007. Of these, 231 consecutive patients had a minimum 5 year follow up. All cases were for degenerative joint disease (DJD), except 2 for dysplasia, 1 for avascular necrosis (AVN), 1 femoral neck nonunion. Average Hospital for Special Surgery (HSS) hip scores at final follow up were recorded. Radiographic analysis included classification based on Delee and Charnley's zones 1–3. Osseointegration was assessed based on presence of Introduction
Materials and Methods
Jumbo cups (58 mm or larger diameter in females and 62 mm or larger diameter in males), theoretically have lowered the percentage of bleeding bone that is required for osseointegration in severe acetabular defects. The purpose of this study was to analyze the safety and efficacy of Tritanium jumbo cups in patients with major acetabular defects (Paprosky type IIIa and IIIb) and assess the extent of osseointegration. From February 2007 and August 2010, 28 consecutive hips (26 patients, mean age of 69 years) underwent acetabular revision arthroplasty for treatment of Paprosky type IIIa and IIIb defects using Tritanium jumbo cups (Stryker, Mahwah, New Jersey).Introduction:
Material and Methods:
Numerous studies have reported the importance of acetabular component positioning in decreasing dislocation rates, the risk of liner fractures, and bearing surface wear in total hip arthroplasty (THA). The goal of improving acetabular component positioning has led to the development of computer-assisted surgical (CAS) techniques, and several studies have demonstrated improved results when compared to conventional, freehand methods. Recently, a computed tomography (CT)-based robotic surgery system has been developed (MAKO™ Robotic Arm Interactive Orthopaedic System, MAKO Surgical Corp., Fort Lauderdale, FLA, USA), with promising improvements in component alignment and surgical precision. The purpose of this study was to compare the accuracy in predicting the postoperative acetabular component position between the MAKO™ robotic navigation system and an imageless, CAS system (AchieveCAS, Smith and Nephew Inc., Memphis, TN, USA). 30 THAs performed using the robotic navigation system (robotic cohort) were available for review, and compared to the most recent 30 THAs performed using the imageless, CAS system (CAS cohort). The final, intraoperative reading for acetabular abduction and anteversion provided by each navigation system was recorded following each THA. Einsel-Bild-Roentgen analysis was used to measure the acetabular component abduction and anteversion based on anteroposterior pelvis radiographs obtained at each patient's first, postoperative visit (Figure 1). Two observers, blinded to the treatment arms, independently measured all the acetabular components, and the results were assessed for inter-observer reliability. Comparing the difference between the final, intraoperative reading for both acetabular abduction and anteversion, and the radiographic alignment calculated using EBRA analysis, allowed assessment of the intraoperative predictive capability of each system, and accuracy in determining the postoperative acetabular component position. In addition, the number of acetabular components outside of the “safe zone” (40° + 10° of abduction, 15° + 10° of anteversion), as described by Lewinnek et al., was assessed. Lastly, the operative time for each surgery was recorded.Background:
Materials and Methods:
Patellar mobilisation methods used during total knee arthroplasty (TKA) have been debated in the literature, with some proponents of minimally invasive TKA suggesting that laterally retracting, rather than everting the patella may be beneficial. It was our hypothesis that by using randomised, prospective, blinded study methods, there would be no significant difference in clinical outcome measures based solely on eversion of the patella during total knee arthroplasty. After an Introduction
Methods
The goal of revision total hip arthroplasty (THA) for acetabular defects is to achieve the best stability and fixation with available host bone. Tritanium is a highly porous metal construct with a titanium matrix coating. We are reporting our experience of utilizing this material in patients with major acetabular defects. Between February 2007 and August 2010, 24 consecutive hips (23 patients) underwent acetabular reconstruction using the Tritanium cups. The acetabular defects were assessed using the Paprosky classification. Anteroposterior and lateral radiographs were analyzed at follow-up based for the presence of radiolucent lines more than 2 mm in any of the 3 zones.Introduction
Methods
Ceramic femoral heads have superior scratch resistant with better wettability and improved wear characteristics compared to metal heads in the laboratory setting. The objective of this study was to compare long-term in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation with cementless stems in young, active patients. Thirty-one matched pair of alumina and metal (Cr-Co) femoral heads against conventional polyethylene in young patients (between 45 and 65 years old) were analyzed for wear and failures for mechanical reasons. The match was based on gender and age at the time of surgery. All procedures were performed between June 1989 and May 1992 by a single surgeon via posterolateral approach, using cementless RB (Ranawat-Bernstein) stems, HG II (Harris-Galante) cups, 4150 conventional polyethylene and 28 mm femoral heads. Hospital for Special Surgery (HSS) hip score was used for clinical analysis. Wear measurements were performed between the initial anteroposterior standing pelvis radiographs, at a minimum of one year after the index procedure to eliminate the effect of bedding-in period, and the latest follow-up. Two independent observers analyzed polyethylene wear rates using the computer-assisted Roman 1.70 software. In revision cases, the wear rates were calculated from radiographs prior to revision surgery. A pair student t test was performed to analyze the statistical difference. Two-tailed ρ values less than 0.05 were considered statistically significant.Introduction
Materials and Methods
Cadaveric studies have reported damage to the direct head of rectus femoris and tensor fascia lata muscles with direct anterior approach(DAA) and to the abductors, external rotators with posterior approach(PA). The aim of this prospective study was to evaluate differences in hip muscle strength recovery between DAA and posterior approach (PA) THA. Patients with unilateral hip osteoarthritis undergoing THA at a single institution from January 2011 to October 2011 were enrolled. All DAA THA's were performed by one surgeon, and all PA THA's were performed by another surgeon with similar design of components, pain management and rehabilitation protocols. Hip muscle strength was measured with a handheld dynamometer in all planes by a single observer preoperatively, at 6 weeks, 3 months and 6 months. Functional recovery was assessed with the motor component of Functional Independence Measure, UCLA activity score, Harris hip score, SF-12 score.INTRODUCTION
METHODS
Osteoarthritis (OA) of the hip and the knee has been found to affect sexual activity. Few retrospective studies have investigated the role of total hip replacement on sexual function. We designed a prospective study to evaluate the influence of total hip arthroplasty (THA) and total knee arthroplasty (TKA) on the physical and psychological aspects of sexuality of patients. Between April 2009 and April 2011, patients under 70 years of age scheduled for primary THA or TKA for OA were invited to anonymously participate in this study. All patients were recruited from the practices of 2 arthroplasty surgeons (at the same institution) by mailing the 2 questionnaires, 2 pre-paid self-addressed envelopes and a cover letter. Patients were instructed to mail back the pre-operative questionnaire prior to surgery and the post- operative questionnaire 6 months after surgery. Enrolled patients were also contacted after 1 year of surgery to fill a similar questionnaire. Responses were identified only by a unique code number on the questionnaire.INTRODUCTION
METHODS
Unicompartmental knee replacement (UKR) has good outcomes for the treatment of compartmental osteoarthritis of the knee. Mechanical alignment overcorrection is associated with early failure of the femoral and tibial components. Preoperative mechanical alignment is the most important predictor of postoperative alignment. However, most studies do not take into consideration the magnitude of preoperative deformity when reporting on mechanical alignment outcomes after UKR. We aimed to determine the magnitude of postoperative mechanical alignment achieved based on the magnitude of preoperative alignment; and to compare the number of cases of overcorrection into valgus to historical data. This was a radiographic review of patients who underwent robotic medial UKR by a single surgeon between 2007 and 2011. Two examiners measured pre- and postoperative mechanical alignment for all patients on long-leg radiographs. Patients were classified into three groups of preoperative mechanical alignment: mild varus (0–5®); moderate varus (5–10®); and severe varus (>10®). Patients with valgus alignment (<0®) were excluded. Linear regression was used to estimate the magnitude of postoperative alignment for each group, adjusting for age, BMI, gender, side, implant type, and polyethylene thickness. 89 patients were included. Mean preoperative alignment was 7.3® varus (95% CI = 6.6®–8®; range, 0.1–15® varus). Mean postoperative alignment was 2.8® varus (95% CI = 1.9®–3.8®; range, 1.4® valgus–9.7® varus). There was a significant difference in postoperative mechanical alignment between the three groups (Table 1) (P<0.05). Four overcorrections (4.5%) were detected, all under 1.5® valgus. This percentage of overcorrection was significantly better than previous conventional UKR reports (mean = 12.6%; P = 0.04). The magnitude of postoperative alignment in medial UKR depends on the severity of the preoperative deformity. Reports on radiographic outcomes of UKR should be stratified by the magnitude of preoperative alignment. The risk of overcorrection is reduced when using robotic assistance compared to using the conventional manual technique.
Ceramic femoral heads have proven to be more scratch resistant with better wettability and improved wear characteristics compared to metal heads in the laboratory setting. The objective of this study was to compare long-term survivorship and in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation in young patients. Thirty-one matched pair of alumina and metal femoral heads against conventional polyethylene in young patients (≤ 65 years) were analyzed for wear and failures for mechanical reasons. The match was based on gender and age at the time of surgery. All procedures were performed between June 1989 and May 1992 by a single surgeon via posterolateral approach, using non-cemented RB (Ranawat-Bernstein) stems, HG II (Harris-Galante) cups, 4150 conventional polyethylene and 28mm femoral heads. Hospital for Special Surgery (HSS) hip score was used for clinical analysis. Wear measurements were performed between the initial anteroposterior standing pelvis radiographs, at a minimum of one year after the index procedure to eliminate the effect of bedding-in period, and the latest follow-up. Two independent observers analyzed polyethylene wear rates using the computer-assisted Roman 1.70 software. In revision cases, the wear rates were calculated from radiographs prior to revision surgery. A pair student t test was performed to analyze the statistical difference. Two-tailed ρ values less than 0.05 were considered statistically significant.Introduction
Materials and Methods
Symptomatic hip disorders associated with cam deformities are routinely treated with surgery, during which the deformity is resected in an effort to restore joint range of motion, reduce pain, and protect the joint from further degeneration. This is a technically demanding procedure and the amount of correction is potentially critical to the success of the procedure: under-resection could lead to continued progression of the OA disease process in the joint, while over-resection puts the joint at risk for fracture. This study compares the accuracy of a new robotically assisted technique to a standard open technique. Sixteen identical Sawbones models with a cam type impingement deformity were resected by a single surgeon simulating an open procedure. An ideal final resected shape was the surgical goal in all cases. 8 procedures were performed manually using a free-hand technique and 8 were performed using robotic assistance that created a 3-dimensional haptic volume defined by the desired post-operative morphology. All of 16 sawbones, including uncut one as well, were scanned by Roland LPX-600 Laser scanner with 1mm plane scanning pitch and 0.9 degree of rotary scanning. Post-resection measurements included arc of resection, volume of bone removed and resection depth and were compared to the pre-operative plan.INTRODUCTION
METHODS
Fixation remains a challenge in Revision TKR. Irregular and cavitary bone loss may precludeproper metaphyseal cementation and pressurization. Metaphyseal sleeves have been proposed to improve theinherent rotational stability of the implant bone interface. The goal of this study was to assess the effect of the use of metaphyseal sleeves on the quality of the cement fixation achieved. Fifty consecutive revision TKRs for AORI type 2 and 3 bone loss between January 2005 through January 2008 with average 2 years follow up were assessed retrospectively. Twelve patients were excluded for inadequate follow up. Nineteen patients with 26 cemented metaphyseal sleeves (15 tibiae and 11 femora) formed group 1 and 19 patients with 36 revision components (without metaphyseal sleeves) served as control (group 2). Patients were assessed clinically with knee society scores (KSS) and radiographically by quality of metaphyseal cement mantle and radiolucent lines(RLL). Groups were matched for pre-op bone loss and length of follow-up.Introduction
Methods
Mechanical integrity of patella can be weakened by the technique of removing the articulating surface. The senior author developed the technique of maintaining subchondral bone of the lateral patellar facet in early 1980s. Though laboratory studies have demonstrated deleterious effect of excessive resection of patella on the strains in the remaining bone under load; clinical studies have not shown the importance of strong subchondral bone of lateral facet to have an effect on patellar fracture prevalence. We present the results of our patellar resection technique preserving the subchondral bone of lateral facet. 393 TKRs were performed between 1989 and 1996 using cruciate substituting modular knee with recessed femoral trochlear groove and congruent patello-femoral articulation. 45 patients with 48 knees died and 37 patients with 41 knees were lost to follow-up. Three hundred and four knees were followed for an average 10 years (range 5 -16 years). Patellar surface was resected with an oscillating saw without the use of cutting guide. The medial facet and most of the articular cartilage of the lateral facet was resected, while preserving the subchondral bone of lateral facet. An all-polyethylene implant with single peg was used in most cases.Introduction
Methods
It is not uncommon to encounter patients with atypical hip or lower extremity pain, ill-defined clinico-radiological features and concomitant hip and lumbar spine arthritis. It has been hypothesized that an anaesthetic hip arthrogram can help identify the source of pain in these cases. The purpose of this study is to analyze our experience with this technique in order to verify its accuracy. We undertook a retrospective analysis of 204 patients who underwent a hip anesthetic-steroid arthrogram for diagnostic purposes matching our inclusion criteria. Patient charts were scrutinized carefully for outcomes of arthrogram and treatment. Harris Hip Score was used to quantify outcome.Introduction
Methods
The current fellowship hiring process is decentralized, poorly functioning, unraveled and generally unfair. It creates anxiety for residents, residency directors, and fellowship directors alike. Residents are facing exploding offers, limited exposure to fellowship programs and, ultimately, an unraveling hiring market. Residents are in favor of changing the current decentralized process into either a more centralized clearing-house system or subspecialty-based match approach. In either system, accountability for both residents and fellowship directors is critical. Both the AOA and AAOS should devote resources to improve the fellowship hiring process.
The ability of optimised MRI to detect periarticular bony and soft tissue pathology in the post-arthroplasty hip is well documented; specifically it is able to detect early stages of particle disease well before osteolysis is apparent on radiographs. This is a prospective study designed to utilise MRI for the detection of early particle disease in asymptomatic patients after total hip arthroplasty. Patients who underwent routine non-cemented THA were recruited from three different groups: metal-on-polyethylene, ceramic-on-ceramic, and ceramic-on-polyethylene bearing surfaces. All patients enrolled underwent optimised MRI one to three years (mean 1.7) after the index procedure. Images were analyzed for the presence of synovial proliferation, fibrous membrane formation or osteolysis. Particle disease was correlated with type of bearing surface, pain, activity level, patient satisfaction, and clinical outcome scales. Thirty-two hips have been enrolled in the study to date. Early particle disease was seen in two of seven metal-on-polyethylene hips (29%), four of twelve ceramic-on-ceramic hips (33%), and six of thirteen ceramic-on-polyethylene hips (46%). Focal osteolysis was seen in one patient with a ceramic-on-polyethylene hip. These values were not statistically significant among the groups. The presence of early particle disease did not correlate with pain, activity level, patient satisfaction, or other clinical outcome scales. This study allows patients with a well functioning total hip arthroplasty to be prospectively followed with MRI. It is the first to document the natural history of particle disease in vivo and considerably enhances our knowledge of periarticular pathology in the post-operative hip. These results demonstrate early particle disease is relatively common yet asymptomatic; they do not demonstrate advantages of any bearing couple over another for protection against particle disease at short-term follow-up.
We previously reported no clinical differences in short-term results in 26 patients that underwent fixed-bearing (FB) total knee arthroplasty in one knee followed by a rotating-platform (RP) version of the same implant in the contralateral knee at a later date. This study presents intermediate-term results in this unique cohort and uses optimised MRI for detection of particle disease in both knees. Patients from the original series were asked to complete questionnaires regarding both knees. In addition, both knees were evaluated with optimised MRI, which has been shown to be useful in evaluating early particle disease and osteolysis before its appearance on radiographs. Nine patients have been enrolled to date. At an average follow-up of 8.3 years for the FB side and 6.5 years for the RP side, no significant differences were found with respect to knee preference, pain, or overall satisfaction. Seven patients underwent MRI studies of both knees. Two FB knees demonstrated a massive intracapsular burden of particle disease (average 3066 mm3) with reactive synovitis, compared to no obvious particle disease in any RP knees. Osteolysis was seen around the femur in one FB knee and around the patella in two FB knees, compared to only around a single patella in the RP side. RP knees continue to demonstrate excellent patient satisfaction that is comparable to clinical results of the FB design; however, FB knees demonstrate higher rates of particle disease and early osteolysis on MRI. This is the first study to demonstrate in vivo advantages of RP over FB designs. It is unclear whether this is due to the slightly longer follow-up period for the FB knees or a decreased wear rate in the RP design; these differences may become apparent with longitudinal follow-up.
