Reported incidence of blood transfusion following primary and revision total hip arthroplasty (pTHA, rTHA) has decreased considerably compared to historical rates. However, it is not known if further adoption of techniques to limit transfusions has resulted in further reduction on a large scale. The purpose of this study was to assess recent trends in blood transfusions and contemporary risk factors for transfusions using a large, national database.

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing pTHA and rTHA between 2011 to 2019. pTHA for fracture, infection, tumor, and bilateral procedures were excluded. Only aseptic rTHA were included. Annual incidence of transfusions and proportion of patients with optimized preoperative hematocrit (HCT) (defined as ≥33%) were assessed. Risk factors for transfusion were evaluated with 2018 and 2019 data using multivariate analyses.

234,352 pTHA and 16,322 rTHA were included. Transfusion following pTHA decreased from 21.4% in 2011 to 2.5% in 2019 and from 33.5% in 2011 to 12.0% in 2019 for rTHA (p<0.0001). Patients with optimized HCT increased for pTHA (96.7% in 2011 vs 98.1% in 2019, p<0.0001) and did not change for rTHA (91.5% in 2011 vs 91.6% in 2019, p=0.27). Decreased HCT was most strongly associated with transfusions, with each three-point change corresponding to odds ratio of 1.90 and 1.78 for pTHA and rTHA, respectively. Increased age, female sex, history of bleeding disorders or preoperative transfusion, ASA score ≥3, non-spinal anesthesia, and longer operative times were also associated with increased odds for transfusion.

Incidence of blood transfusion has continued to decrease following pTHA and rTHA. Despite care improvements, transfusions still occur in certain high-risk patients. While transfusion in pTHA may have reached the lower asymptote, further reduction in rTHA may be possible through further improvements in preoperative optimization and surgical technique.

Aims

The aim of this study was to develop a single-layer hybrid organic-inorganic sol-gel coating that is capable of a controlled antibiotic release for cementless hydroxyapatite (HA)-coated titanium orthopaedic prostheses.

Introduction

Current methodologies for designing and validating existing THA systems can be expensive and time-consuming. A validated mathematical model provides an alternative solution with immediate predictions of contact mechanics and an understanding of potential adverse effects. The objective of this study is to demonstrate the value of a validated forward solution mathematical model of the hip that can offer kinematic results similar to fluoroscopy and forces similar to telemetric implants.

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.

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.

We identified 64,648 patients who underwent THA and 97,137 patients who underwent TKA. Obese THA patients had significantly higher rates of wound complications (1.53% vs 0.96%), deep infection (0.31% vs 0.17%), reoperation rate (2.11% vs 1.02%), and total complications (5.22% vs. 4.63%) compared to TKA patients. Morbidly obese patients undergoing THA were also found to have significantly higher rates of wound complications (3.25% vs 1.52%), deep infection (0.84% vs 0.23%), reoperation rate (3.65% vs 1.60%), and total complications (7.36% vs. 5.57%). Multivariate regression analysis identified increasingly higher odds of each outcome measure as BMI increased.

This study demonstrates the impact of obesity on postoperative complications is more profound for THA than TKA. This emphasizes the importance of considering patient comorbidities in the context of the specific procedure (hips and knees should be analyzed independently) when assessing risks of surgery.

Contemporary crosslinked polymers didn't just happen. The material was, has, and continues to be studied more than any other bearing surface material used in the total hip and total knee replacement construct. Historical failures and successes provided the information needed to make it the success that it is today as we approach the end of the second decade of extensive use.

Recognition that wear particles, not cement, was the major cause of osteolysis was important. Next, understanding that oxidation from free radical formation was deleterious to wear resistant polyethylene was understood and finally, that crosslinking was responsible for magnitude increases in wear resistance.

Although manufacturers have developed multiple processes to develop their crosslinked polymers (gamma and e beam radiation, melting and annealing, and most recently the addition of antioxidants) there are excellent 10-year results demonstrating head penetration rates (indicative of wear and creep) in the 0.02 to 0.04 mm/year range for many materials with minimal if any detection of osteolysis on radiographs and close to 0% revised for wear at 10+ years.

Are there any cautions? Recently, at 10- to 15-year follow up, some clinically insignificant osteolysis has been noted in one study and in that same study, 36 mm heads had twice the volumetric wear as 32 mm heads, but it was still a relatively low volume compared to the previous generation polyethylenes. We need further follow up, but at two decades of use, crosslinked polymers have dramatically reduced the osteolysis problem.

Successful nonarthroplasty solutions for the treatment of osteonecrosis of the femoral head continued to be sought. However, no definitive nonarthroplasty solutions have to date been found. Hence, even in the best of hands a large number of patients with osteonecrosis end up with debilitating end-stage osteoarthritis.

In the inception of total hip arthroplasty (THA), the results of treatment of femoral head osteonecrosis by THA were inferior to total hip replacement performed for osteoarthritis. Reasons for this included the young age of many osteonecrosis patients, the high numbers of comorbidities in this population (SLE, sickle cell anemia, alcoholism), and the poor bone quality at the time of surgery. Arthroplasty considerations included bipolar replacement, hemiresurfacing, resurfacing (non metal-on-metal and later metal-on-metal), cemented total hip arthroplasty and cementless total hip arthroplasty. Previous to the use of cementless arthroplasty, all of these procedures had a relatively high 5 to 10 year failure rate of 10–50%. Even our own 10-year results using contemporary cementing techniques demonstrated 10% failure compared to 1–2% failure in our nonosteonecrosis patients. For this reason, it made sense to continue exploring nonarthroplasty solutions for osteonecrosis of the hip.

The introduction of cementless fixation for total hip arthroplasty changed the entire thinking about hip osteonecrosis treatment for many of us. Although initially we were concerned about whether bone would grow into the prosthesis in the environment of relatively poor bone, the early results demonstrated that it can and does. Most recently, with the use of crosslinked polyethylene, the cementless construct gives many of us hope that with cementless fixation, the treatment of many patients including the young (especially if followed closely to exchange bearing surfaces if necessary) will last a lifetime with THA being the only and definitive procedure. Our most recent 10-year results demonstrated a femoral stem revision rate of 1.5% will all other stems (other than the stem revised) bone ingrown. Acetabular fixation was also 100% and although 6% required liner exchange, our own and others' results with crosslinked polyethylene would suggest that this problem should be markedly reduced.

Introduction

Fracture around the knee can lead to posttraumatic osteoarthritis (PTOA) of the knee. Malunion, malalignment, intra-articular osseous defects, retained internal fixation devices, and compromised soft tissues may affect the outcome of total knee replacement (TKR). On average, the posttraumatic patient subsets were 10.4 years younger than those for primary knee OA. Recently, there were several studies reporting the outcome of THA for posttraumatic OA hip. However, no current literature defines the comparative functional outcome between PTOA and primary OA knee.

The purpose of our study was to compare the midterm outcomes of patients undergoing TKR following periarticular knee fractures/ligamentous injuries versus primary osteoarthritis (PO) of the knee.

Background

Readmission following any total joint arthroplasty has become a closely watched metric for many hospitals in the United States because financial penalties imposed by CMS for excessive readmissions occurring within thirty days of discharge has occurred since 2015. The purpose of this study was to identify both preoperative comorbidities associated with and postoperative reasons for readmission within thirty days following primary total joint arthroplasty in the lower extremity.

Background

We have reported an injectable L-pNIPAM-co-DMAc hydrogel with hydroxyaptite nanoparticles (HAPna) which promotes mesenchymal stem cell (MSC) differentiation to bone cells without the need for growth factors. This hydrogel could potentially be used as an osteogenic and osteoconductive bone filler of spinal cages to improve vertebral body fusion. Here we investigated the biocompatibility and efficacy of the hydrogel in vivo using a proof of concept femur defect model.

Use of large databases for orthopaedic research has increased exponentially. Each database represents unique patient populations and vary in methodology of data acquisition. The purpose of this study was to evaluate differences in reported demographics, comorbidities and complications following total hip arthroplasty (THA) amongst four commonly used databases.

Patients who underwent primary THA during 2010–2012 were identified within National Surgical Quality Improvement Programs (NSQIP), Nationwide Inpatient Sample (NIS), Medicare Standard Analytic Files (MED) and Humana Claims Database (HAC). NSQIP definitions for comorbidities and surgical complications were queried in NIS, MED, and HAC using coding algorithms. Age, sex, comorbidities, inpatient and 30-day postoperative complications were compared (NIS has inpatient data only).

Primary THAs from each database were 22,644 (HAC), 371,715 (MED), 188,779 (NIS) and 27,818 (NSQIP). Age and gender distribution were similar between databases. There was variability in the prevalence of comorbidities and complications depending upon the database and duration of post-operative follow-up. HAC and MED had twice the prevalence of COPD, coagulopathy and diabetes than NSQIP. NSQIP had more than twice the obesity than NIS. HAC had more than twice the rates of 30-day complications at all endpoints compared to NSQIP and more than twice the DVTs, strokes and deep infection as MED at 30-days post-op. Comparison of inpatient and 30-day complications rates demonstrated more than twice the amount of infections and DVTs are captured when analysis is extended from inpatient stay to 30-days post-op.

Amongst databases commonly used in orthopaedic research, there is considerable variation in complication rates following THA depending upon the database. It will be important to consider these differences when critically evaluating database research. Additionally, with the advent of bundled payments, these differences must be considered in risk adjustment models.

There are several clinical scenarios to consider cementing an acetabular liner into a secure cementless shell including cases of: 1) inadequate capturing mechanism, 2) damaged locking mechanisms, 3) unavailability of the mating polyethylene liner, 4) instability following debridement for wear, 5) instability at the time of femoral side revision, and 6) recurrent dislocation. The last two situations are common scenarios for cementing a constrained liner into a secure shell.

Technique includes: 1) scoring the shell in cases with no screw holes or polished inner shells, 2) scoring the acetabular liner in a “spider web” pattern, 3) pressurizing cement into the shell, and 4) inserting a liner that allows 2mm of cement mantle.

Results of Cementing Constrained Liner Into Secure Cementless Shell: Callaghan et al. JBJS 2004. Thirty-one hips at 2–10 year follow-up. Two of 31 failed. Technical considerations: do not cement proud and do not cement into a malpositioned shell; Haft et al. J Arthroplasty 2002. Seventeen hips with minimum 1 year follow-up. One of 17 failed. Technical considerations: do not cement proud.

Results of Cementing Non-Constrained Liners Into Secure Cementless Shell: Beaule et al. JBJS 2004. Thirty-two hips at mean 5.1 year avg f/u. Four components revised for loosening; Callaghan et al. CORR 2012. Thirty-one hips at mean 5.3 year f/u. No revisions.

Liner exchange and bone grafting are commonly used in cases of wear and osteolysis around well- fixed acetabular components in revision total hip arthroplasty. However, in total knee revision, liner exchange is a more rare option.

In a multicenter study, we evaluated 22 TKAs that were revised with liner exchange and bone grafting for wear and osteolysis. All knees were well-fixed and well-aligned, and all components were modular tibial components. Osteolytic areas averaged 21.1cm2 and 7.6cm2 on AP projections of the femur and tibia, respectively, and averaged 21.6cm2 and 5.7cm2 on lateral projections of the femur and tibia, respectively, with the largest area being 54cm2 on a single projection. Follow up was minimum 2 years and average 40 months. No knees were revised and radiographically, all osteolytic lesions showed evidence of complete or partial graft incorporation. In addition, there was no radiographic evidence of loosening at final follow up.

The Mayo Clinic evaluated 56 isolated tibial insert exchange revisions at their institution. Cases of loosening, infection, knee stiffness, or extensor mechanism problems were excluded. At minimum 2-year follow up (average 4.6 years), 14 knees (25%) required re-revision.

Baker et al. evaluated 45 total knees undergoing isolated tibial insert exchange. At minimum 2 years, 4 knees (9%) required revision. Significant improvement was seen in clinical outcomes questionnaires, but only 58% had clinical successful global WOMAC scores.

In summary, isolated liner exchange in the revision total knee setting has variable results. It can be successful but it is indeed a rare option and should be limited to cases were the total knee arthroplasty is both well-fixed and well-aligned.

In primary total hip replacements there are numerous options available for providing hip stability in difficult situations (i.e. Down's syndrome, Parkinson's disease). We have considered constrained liners in some of these cases.

However, in the revision situation in general and in revision for recurrent dislocation situation specifically it is important to have all options available including tripolar constrained liners in order to optimise the potential for hip stability as well as function of the arthroplasty. Even with the newer options available dislocation rates of higher than 10–15% have been reported following revision surgery at institutions where high volumes of revision surgery are performed. Because of the deficient abductors, other soft tissue laxity and the requirement for large diameter cups revision cases will always have more potential for dislocation. In these situations in the lower demand patient, constraint has provided excellent success in terms of preventing dislocation and maintaining implant construct fixation to bone at intermediate- term follow-up. Hence in these situations tripolar constrained liners remains the option we utilise. We are also confident in using this device in cases with instability or laxity where there is a secure well- positioned acetabular shell. We cement a dual mobility constrained liner in these situations using the technique described below.

Present indication for tripolar constrained liners: low demand patient, large outer diameter cups, instability with well-fixed shells that are adequately positioned, abductor muscle deficiency or soft tissue laxity, multiple operations for instability

Technique of cementing liner into shell: score acetabular shell if no holes, score liner in spider web configuration, all one or two millimeters of cement mantle

Significant hip osteoarthritis has been reported in 8–28% of patients with Down Syndrome. The prolonged life expectancy of these patients has allowed many of them to become disabled by their hip arthritis with the need for hip replacement.

We have been able to perform a multi-center study evaluating total hip replacement in patients with Down Syndrome. Twenty patients (25 hips) with Down Syndrome underwent primary THA at a mean age of 35 years old with a mean 105-month follow-up. Cementless acetabular fixation with screws were used in all cases and all but one femoral component was cementless. Constrained liners were used in 8 cases to enhance stability. Five hips required revision surgery: two femoral components (one for periprosthetic fracture and one for aseptic loosening), two acetabular components (one for recurrent dislocation and one for wear with metallosis), and one hip required a two-stage revision for infection. Other than the hip revised for loosening, no other hip had radiographic evidence of loosening. The mean Harris Hip score improved from 42 points pre-operatively to 83 points at final follow-up.

THA is a reliable surgical intervention in patients with Down Syndrome and symptomatic coxarthrosis. These patients and their families have been tremendously satisfied with this procedure. Strategies to prevent dislocation post THA are appropriate and need continued evaluation.

Total knee arthroplasty has been demonstrated to provide durable results with excellent pain relief and improvement in function. Our institution has studied and published the longest follow-up of mobile bearing TKR, fixed bearing modular TKR, and unicompartmental replacement. Indeed these studies support the durability of the operation and the improvement in function and relief of pain. They, however, are not perfect. In tricompartmental replacement, up to 5 or 6% are revised for loosening and or wear and in unicompartmental replacement, up to 25% are revised for loosening. There are also one or two percent of cases revised for periprosthetic fracture and one or two percent for hematogenous infection. One must remember these cases were performed in patients of average age 71.

When one looks at our results in more active patients with osteoarthritis who are less than 55, the results are less spectacular with 15% revised at 10 to 15 years for loosening. We all hope that better polyethylene and better tibial tray locking mechanisms (in fixed bearing modular designs) will improve these results, but to predict there will be no failures is a “leap of faith”. Long-term follow-up of cemented TKA in patients under 55 where monolithic tibial trays were utilised have demonstrated better results at 20 years (92.3%) survivorship versus those where modular tibial trays (68%) were utilised. Long-term studies of cementless total knee replacement, especially in younger patients are needed to see if this approach provides better results.

The United States is in the midst of an opioid epidemic, with the World Health Organization reporting that American's consume 99% of the world's supply of hydrocodone and 83% of the world's oxycodone. Additionally, pre-operative opioid use has been associated with worse clinical outcomes and higher rates of complications following TKA. This is especially important in the TKA population given that approximately 15% of patients are either dissatisfied or very dissatisfied at least one year after their TKA procedure. Given the concerning rise is opioid use the American Academy of Orthopaedic Surgeons (AAOS) has recently released an information statement with practice recommendations for combating this excessive and inappropriate opiate use. However, little is known regarding peri-operative opioid use for TKA patients. Therefore, the purpose of this study was to: 1) identify rates of opioid use prior to primary TKA, 2) evaluate post-operative trends in opioid use throughout the year following TKA and 3) identify risk factors for prolonged opioid use following TKA.

Overall, 31% of TKA patients are prescribed opioids within 3-months prior to TKA; this percentage has increased over 9% during the years included in this study. Pre-operative opioid use was most predictive of increased refills of opioids following TKA, however, other intrinsic patient characteristics were also predictive of prolonged opioid use. These characteristics remained predictive after controlling for opioid user status. The increasing rates of opioid prescribing prior to TKA are concerning, especially given literature concluding opioids have minimal effect on pain or function in patients with osteoarthritis and pre-operative opioid use is associated with poor outcomes and more complications following TKA. This data provides an important baseline for opioid use trends following TKA that can be used for future comparison and identifies risk factors for prolonged use that will be helpful to prescribers as the AAOS works to decreased opioid use, misuse and abuse within the United States. Our data on THA and unicompartmental arthroplasty is similar with an increase in pre-THA use of 9% with 38% receiving narcotics within 3 months of surgery and continued use in opioid users (9 times non-opioid users at 12 months).

Background

Readmission following any total joint arthroplasty has become a closely watched metric for many hospitals in the United States because financial penalties imposed by CMS for excessive readmissions occurring within thirty days of discharge will be forthcoming in 2015. The purpose of this study was to identify both preoperative comorbidities associated with and postoperative reasons for readmission within thirty days following primary total joint arthroplasty in the lower extremity.

Three basic design concepts of cementless femoral fixation have emerged. They include: anatomic designs, straight stem designs, and tapered designs. In addition, there have been modular designs. The most successful have been designs that have a metaphyseal sleeve with a tapered stem. A more recent newer concept has been the double taper neck designs which have not performed well in general.

Anatomic Stem Designs: The rationale for an anatomic stem design was to design a component that matched the sagittal plane bow of the femur. The APR (Centerpulse, Austin, Texas) and the PCA (Howmedica, Rutherford, New Jersey) were the initial designs. Although these designs provided excellent micromotion stability, they are not used in their present length today because they could not fit in to all femurs.

Straight Stem Designs: The concept of a straight stem design was to machine the femur to accept the prosthesis. This was done with diaphyseal reaming, proximal broaching, and preparing a proximal triangle to accommodate the proximal metaphyseal portion of the stem. These had previously, and still do, come in proximally coated and distally coated designs. They have proven to be durable long term. The AML fully coated stem (DePuy, Warsaw, Indiana) was and still is the prototype device.

Tapered Stem Designs: The most popular designs today are the tapered stems. They are inserted either by a broach only, or ream and broach technique. Some only taper in the ML plane and are flat in the AP plane. These are called ML taper or blade devices (Taperloc and Trilock). These are usually inserted broach only. Some have a double taper with proximal fill and include the Zweymuller stem (Zimmer, Warsaw, Indiana), the Omnifit stem (Stryker, Mahwah, New Jersey), the Summit stem, and the Corail stem (both DePuy, Warsaw, Indiana). Some are hydroxyapatite coated (Omnifit and Corail), some are porous coated (Summit), and some are only grit blasted (Zweymuller). Some are broach only including the Zweymuller and Corail, and some are broach and ream including the Omnifit and Summit. Some are tapered throughout, one of which is a Wagner type design, Trilogy (Zimmer, Warsaw, Indiana). These Wagner type devices are useful in abnormal anatomy (CDH and Perthes).

Modular Stem and Dual Modular Neck Designs: Metaphyseal sleeve modular stem designs are extremely versatile and can be inserted press fit into just about any femoral anatomy. They are most commonly utilised in cases of hip dysplasia with marked femoral anteversion. The S-ROM device is the prototype design. The long term concern with these as well as the double neck tapered devices is fretting and corrosion at the extra modular junctions.

Short Stem Designs: Short stem designs were developed to provide metaphyseal only fixation and to enable easy insertion through small incision techniques, especially those performed through anterior and antero-lateral approaches.

In the revision situation in general and for recurrent dislocation specifically, it is important to have all options available including tripolar constrained liners in order to optimise the potential for hip stability as well as function. Even with the newer options available, dislocation rates of higher than 5% have been reported in the first two years following revision surgery at institutions where high volumes of revision surgery are performed (Wera et al). Because of the deficient abductors, other soft tissue laxity and the requirement for large diameter cups, revision cases will always have more potential for dislocation. In these situations, in the lower demand patient, tripolar constrained liners provided excellent success in terms of preventing dislocation and maintaining implant construct fixation to bone at intermediate term follow-up. Hence in these situations, tripolar with constraint remains the option we utilise in many cases. We are also confident in using this device in cases with instability or laxity where there is a secure well positioned acetabular shell. We cement a tripolar constrained liner in these situations using the technique described below.

Present indication for tripolar constrained liners: low demand patient, abductor muscle deficiency or soft tissue laxity, large outer diameter cups, multiple operations for instability, instability with well-fixed shells that are adequately positioned

Technique of cementing liner into shell: score acetabular shell if no holes, score liner in spider web configuration, all one or two millimeters of cement mantle

Results: Constrained Tripolar Liner - For Dislocation: 56 Hips; 10 year average f/u; 7% failure of device, 5% femoral loosening, 4% acetabular loosening

Constrained Tripolar Liner - For Difficult Revisions: 101 hips; 10 year average f/u; 6% failure of device, 4% femoral loosening, 4% acetabular loosening

Cementing Liner into Shell: 31 hips; 3.6 year average f/u (2–10 years); 2 of 31 failures

We, like others, are trying to define cases where dual mobility will be as successful or more successful than tripolar constrained liners.

Liner exchange and bone grafting are commonly used in cases of wear and osteolysis around well fixed acetabular components in revision total hip arthroplasty. However, in total knee revision, liner exchange is a more rare option.

In a multicenter study, we evaluated 22 TKAs that were revised with liner exchange and bone grafting for wear and osteolysis. All knees were well fixed and well aligned, and all components were modular tibial components. Osteolytic areas averaged 21.1 cm2 and 7.6 cm2 on AP projections of the femur and tibia, respectively, and averaged 21.6 cm2 and 5.7 cm2 on lateral projections of the femur and tibia, respectively, with the largest area being 54 cm2 on a single projection. Follow up was minimum 2 years and average 40 months. No knees were revised and radiographically, all osteolytic lesions showed evidence of complete or partial graft incorporation. In addition, there was no radiographic evidence of loosening at final follow up.

The Mayo Clinic evaluated 56 isolated tibial insert exchange revisions at their institution. Cases of loosening, infection, knee stiffness, or extensor mechanism problems were excluded. At minimum 2 year follow up (average 4.6 years), 14 knees (25%) required re-revision.

Baker et al evaluated 45 total knees undergoing isolated tibial insert exchange. At minimum 2 years, 4 knees (9%) required revision. Significant improvement was seen in clinical outcomes questionnaires, but only 58% had clinical successful global WOMAC scores.

In summary, isolated liner exchange in the revision total knee setting has variable results. It can be successful but it is indeed a rare option and should be limited to cases where the total knee arthroplasty is both well fixed and well aligned.

Introduction: I always aim for neutral mechanical axis alignment. My principles of a successful TKA are proper alignment in all 3 planes, soft tissue balance in extension first, flexion gap balancing by parallel to tibial cut technique, maintenance of joint line, correct sizing of femoral component, and proper cement fixation.

Long-term Survivorship: There is long-term data that supports the efficacy and durability of the neutral position of proximal tibial cut. Over a 20-year follow-up there was a 92.6% success rate in my study. Other authors have found similarly successful survivorship for mechanical failure.

Balance Technique in TKR: My technique to balance the knee is a balance extension gap first, which requires medial soft tissue balancing. Next, I balance the flexion gap parallel to the tibial cut.

Our Results: In one study, I examined the clinical and radiographic data of 68 varus knees. Average post-operative mechanical alignment was 0 ± 3 degrees. There were no outliers which displays the reproducibility of the technique. This is the method of choice in the hands of most surgeons.

In primary total hip replacements there are numerous options available for providing hip stability in difficult situations (i.e. Down's syndrome, Parkinson's disease).

However, in the revision situation in general and in revision for recurrent dislocation specifically, it is important to have all options available including dual mobility constrained liners in order to optimise the potential for hip stability as well as function of the arthroplasty. Even with the newer options, available dislocation rates of higher than 5% have been reported in the first two years following revision surgery at institutions where high volumes of revision surgery are performed. Because of the deficient abductors, other soft tissue laxity and the requirement for large diameter cups, revision cases will always have more potential for dislocation. In these situations in the lower demand patient and where, a complex acetabular reconstruction that requires time for ingrowth before optimal implant bone stability to occur isn't present, dual mobility with constraint has provided excellent success in terms of preventing dislocation and maintaining implant construct fixation to bone at intermediate term follow-up. Hence in these situations dual mobility with constraint remains the option we utilise. We are also confident in using this device in cases with instability or laxity where there is a secure well-positioned acetabular shell. We cement a dual mobility constrained liner in these situations using the technique described below.

Present indication for dual mobility constrained liners: low demand patient, large outer diameter cups, instability with well-fixed shells that are adequately positioned, abductor muscle deficiency or soft tissue laxity, multiple operations for instability

Technique of cementing liner into shell: score acetabular shell if no holes, score liner in spider web configuration, all one or two millimeters of cement mantle

Results: Constrained Dual Mobility Liner – For Dislocation: 56 Hips, 10 year average follow-up, 7% failure of device, 5% femoral loosening, 4% acetabular loosening. For Difficult Revisions: 101 hips, 10 year average follow-up, 6% failure of device, 4% femoral loosening, 4% acetabular loosening. Cementing Liner into Shell: 31 hips, 3.6 year average follow-up (2–10 years), 2 of 31 failures.

The United States is in the midst of an opioid epidemic, with the World Health Organization reporting that American's consume 99% of the world's supply of hydrocodone and 83% of the world's oxycodone. Additionally, pre-operative opioid use has been associated with worse clinical outcomes and higher rates of complications following total knee arthroplasty (TKA). This is especially important in the TKA population given that approximately 15% of patients are either dissatisfied or very dissatisfied at least one year after their TKA procedure. Given the concerning rise in opioid use the American Academy of Orthopaedic Surgeons (AAOS) has recently released an information statement with practice recommendations for combating this excessive and inappropriate opiate use. However, little is known regarding peri-operative opioid use for TKA patients. Therefore, the purpose of this study was to: 1) identify rates of opioid use prior to primary TKA, 2) evaluate post-operative trends in opioid use throughout the year following TKA and 3) identify risk factors for prolonged opioid use following TKA.

Overall, 31% of TKA patients are prescribed opioids within 3-months prior to TKA; this percentage has increased over 9% during the years included in this study. Pre-operative opioid use was most predictive of increased refills of opioids following TKA, however, other intrinsic patient characteristics were also predictive of prolonged opioid use. These characteristics remained predictive after controlling for opioid user status. The increasing rates of opioid prescribing prior to TKA are concerning, especially given literature concluding opioids have minimal effect on pain or function in patients with osteoarthritis and pre-operative opioid use is associated with poor outcomes and more complications following TKA. This data provides an important baseline for opioid use trends following TKA that can be used for future comparison and identifies risk factors for prolonged use that will be helpful to prescribers as the AAOS works to decreased opioid use, misuse and abuse within the United States.

Moderately to highly crosslinked UHMWPEs have functioned for at least a decade with dramatic reduction in wear volumes in THA. This wear reduction has been associated with a markedly reduced incidence of radiographic osteolysis. However, CT studies have demonstrated that osteolysis is not completely eliminated.

There, however, are still questions which include: Is cost for further improvements warranted?; Is 10 years long enough to assure that no clinically relevant osteolysis occurs, especially in younger patients?; Do we have any data demonstrating improvement in revision scenarios?; With high levels of crosslinking (requiring more radiation) some fractures have been demonstrated at the region of the locking mechanism of the liner to shell. Will this prevalence increase? These materials are softer and can cause quicker crack propagation than conventional polyethylene.; Do better locking mechanisms need to be developed to prevent fracture problems that have been demonstrated in the present generation cementless designs?; Do we need more information as to the optimal counterface choice (cobalt chrome, ceramic, oxinium)?; Can hip results be extrapolated to the knee where fatigue failure is a major problem both on the bearing surface and with the locking mechanism?; Is the oxidation we are beginning to see on the surface of retrieved liners (thought to be related to lipids from the synovium and cyclical loading) the tip of the iceberg?

I too am encouraged by the mid-term results of crosslinked polyethylene. Our own data supports it. However, we must keep in mind the questions outlined.

In primary total hip replacements there are numerous options available for providing hip stability in difficult situations i.e. Down's syndrome, Parkinson's disease. However, in the revision situation, in general, and in revision for recurrent dislocation situations specifically, it is important to have all options available including dual mobility constrained liners in order to optimise the potential for hip stability as well as function of the arthroplasty. Even with the newer options available dislocation rates of higher than 5% have been reported in the first two years following revision surgery at institutions where high volumes of revision surgery are performed [Della Valle, Sporer, Paprosky unpublished data]. Because of the deficient abductors, other soft tissue laxity and the requirement for large diameter cups, revision cases will always have more potential for dislocation. In these situations in the lower demand patient and where, a complex acetabular reconstruction that requires time for ingrowth before optimal implant bone stability to occur isn't present, dual mobility with constraint has provided excellent success in terms of preventing dislocation and maintaining implant construct fixation to bone at intermediate term follow-up. Hence in these situations dual mobility with constraint remains the option we utilise. We are also confident in using this device in cases with instability or laxity where there is a secure well-positioned acetabular shell. We cement a dual mobility constrained liner in these situations using the technique described below.

Present indication for dual mobility constrained liners: low demand patient, abductor muscle deficiency or soft tissue laxity, large outer diameter cups, multiple operations for instability, and instability with well-fixed shells that are adequately positioned.

Technique of cementing liner into shell: score acetabular shell if no holes; score liner in spider web configuration; all one or two millimeters of cement mantle.

Reoperation on the acetabular side of the total hip arthroplasty construct because of acetabular liner wear with or without extensive osteolysis is the most common reoperation performed in revision hip surgery today. The options of revision of the component or component retention, liner exchange (cemented or direct reinsertion) and bone grafting represent a classic surgeon dilemma of choices and compromises.

CT scanning is helpful in determining the size and location of osteolytic lesions. My preference is to retain the existing shell when possible especially when there are large osteolytic lesions but where structural support is maintained.

The advantages of complete revision are easy access to lytic lesions, ability to change component position and the ability to use contemporary designs with optimal bearing surfaces (for wear and dislocation prevention).

The disadvantage is bone disruption including pelvic discontinuity with component removal (less so with Explant Systems) and difficult reconstructions due to excessive bone loss from the osteolytic defects (sometimes requiring cup cages).

The advantage of component retention is that structural integrity of the pelvis is maintained and in general, a higher quality polyethylene is utilised. For large lesions I use windows to debride and bone graft the lesions. If the locking mechanism is inadequate, cementing a liner, including a constrained liner in some cases, that has been scored in a spider web configuration provides durable results at 5-year follow-up. The downside to liner exchange is potential instability. We immobilise all liner exchange patients postoperatively.

Arthrodesis

Today, knee arthrodesis is most commonly performed for cases of chronic sepsis after total knee arthroplasty in patients who are not candidates for reimplantation. This is typically a host in whom the risk of recurrent infection is high, especially when extensor mechanism problems such as patellar tendon rupture is present. Local and systemic host factors place the patient at this high risk for failure of reimplantation. Local factors include chronic lymphedema, major vessel disease, venous stasis, extensive scarring and radiation fibrosis. Systemic problems include malnutrition, malignancy, extremes of age, hepatic or renal failure, diabetes mellitus and alcohol abuse. Also, at least in one study, patients who fail one two-stage reimplantation have at least a 50% change for recurrence the second time.

Methods of knee arthrodesis include external fixation, single or double plate fixation and intramedullary nailing either monolithic or modular. External fixation can be performed as a single procedure. With external ring fixators leg lengthening has been described. Plate and nailing procedures are commonly performed after the infection is eradicated. If infection recurs but fusion has occurred, removal of a modular nail may be difficult although techniques have been described. Fusion rates of 85% to 100% have been reported with the newer techniques and fusion rates are usually correlated with the amount of bone loss after removal of the prosthesis. Optimal position of fusion is slight anatomic valgus and slight flexion. Placing a bowed intramedullary nail with the bow anteromedially can facilitate this alignment. One study comparing arthrodesis after failed knee arthroplasty with primary total knee replacement found nearly identical Short-Form 36 scores. Physical mobility was better with knee arthroplasty but pain control was better with arthrodesis.

Resection Arthroplasty

Indication: Low demand patient with comorbidities

Results: Falahee et al.; 28 knees;15 patients walked independently; Most severely disabled more satisfied. Less disabled least satisfied.

Amputation - Above the Knee Amputations after TKA (Sierra et al)

Prevalence: 0.36% (all causes – most common was peripheral vascular disease), 0.14% (for causes related to TKA: infection, periprosthetic fracture, pain, bone loss, vascular complication)

Results: 25 amputations for causes related to TKA; Avg 8.6 years after TKA

Complications: deep infection 5, superficial infection 1, skin necrosis 1, perioperative death 1. 9 of 25 fitted with above knee prosthesis; Only 5 were walking even to limited degree with prosthesis

Whether to preserve the posterior cruciate ligament in total knee arthroplasty remains a topic of debate. Long term studies out to 20 or more years have shown both posterior-stabilised (PS) as well as cruciate-retaining (CR) total knees to perform well. Studies supporting both sides are abundant, and there are even studies supporting one being superior to the other, and vice versa.

In closer examination of this issue through a recent meta-analysis, the following conclusions can be drawn:

Flexion: mean difference of 2.24, favoring PS designs (p = 0.009)

Patellar crepitance with PS designs can be minimised with design alternations and techniques for patella preparation

Any issues with post impingement can be minimised using PS rotating platform designs

The debate of PS vs CR total knees remains unresolved. There is not a 100% clear advantage. Surgeons should make their choice based on their own clinical outcomes, objectively monitored over the long term. For me personally, the choice is PS.

There are several clinical scenarios to consider cementing an acetabular liner into a secure cementless shell including cases of: 1) inadequate capturing mechanism, 2) damaged locking mechanisms, 3) unavailability of the mating polyethylene liner, 4) instability following debridement for wear, 5) instability at the time of femoral side revision, and 6) recurrent dislocation. The last two situations are common scenarios for cementing a constrained liner into a secure shell.

Technique includes: 1) scoring the shell in cases with no screw holes or polished inner shells, 2) scoring the acetabular liner in a “spider web” pattern, 3) pressurising cement into the shell, and 4) inserting a liner that allows 2mm of cement mantle.

Results of Cementing Constrained Liner Into Secure Cementless Shell: Callaghan et al. JBJS 2004 (31 hips, 2–10 year follow up, 2 of 31 failed, Technical considerations - Do not cement proud, Do not cement into a malpositioned shell); Haft et al. J Arthroplasty 2002 (17 hips, Minimum 1 year follow up, 1 of 17 failed, Technical considerations - Do not cement proud)

Results of Cementing Non-Constrained Liners Into Secure Cementless Shell: Beaule et al. JBJS 2004 (32 hips, Mean 5.1 year avg follow up, 4 components revised for loosening); Callaghan et al. CORR 2012 (31 hips, Mean 5.3 year follow up, No revisions)

Allograft materials have been the mainstay in addressing bone deficiencies in knee and hip replacement and revision surgery for decades because of the associated donor site morbidity of autografts. Bone graft substitutes have been developed to address allograft issues including potential contamination, disease transmission, and availability. Although non-autogenous products have no osteogenic potential, they do have a variable degree of osteoinductive and osteoconductive properties.

Unfortunately, there are limited reports regarding use of bone graft substitutes for use in total hip and knee arthroplasty. Bone graft substitutes have most frequently been used as an “extender”, in combination with morsellised allograft, to fill cavitary defects. Incorporation of this bone graft substitute and morsellised allograft combination appears to occur incompletely. Stable implant fixation appears to be a prerequisite for incorporation of bone graft substitutes, as these cannot be relied upon for structural support. Although bone graft substitutes appear to perform satisfactorily as “fillers” for contained cavitary bone defects, ultraporous metal augments have become the preferred method of providing structural support for some defects. In view of their substantial cost, high quality clinical, radiographic and retrieval data regarding performance of bone graft substitutes is needed.

Significant hip osteoarthritis has been reported in 8–28% of patients with Down Syndrome. The prolonged life expectancy of these patients has allowed many of them to become disabled by their hip arthritis with the need for hip replacement.

We have been able to perform a multi-center study evaluating total hip replacement in patients with Down Syndrome. Twenty patients (25 hips) with Down Syndrome underwent primary THA at a mean age of 35 years old with a mean 105 month follow-up. Cementless acetabular fixation with screws were used in all cases and all but one femoral component was cementless. Constrained liners were used in 8 cases to enhance stability. Five hips required revision surgery: two femoral components (one for periprosthetic fracture and one for aseptic loosening), two acetabular components (one for recurrent dislocation and one for wear with metallosis), and one hip required a two-stage revision for infection. Other than the hip revised for loosening, no other hip had radiographic evidence of loosening. The mean Harris Hip score improved from 42 points preoperatively to 83 points at final follow-up.

THA is a reliable surgical intervention in patients with Down Syndrome and symptomatic coxarthrosis. These patients and their families have been tremendously satisfied with this procedure.

The designs available today have greatly improved our ability as surgeons to perform successful total knee revision surgery. However, as more and more knee replacements are in service for longer periods of time, the numbers of revisions have increased and have required us as surgeons to address challenging problems including infection, instability and bone loss from wear, osteolysis and loosening.

Understanding the problems needed to be addressed is paramount. Careful preoperative planning is key. Knowing the cause of failure and the aspects of reconstruction that need to be addressed including skin, soft tissues, extensor mechanisms, bone and ligament loss is critical.

Intraoperatively, understanding and applying principles related to establishing joint lines, balancing flexion extension gaps, addressing bone loss and ligament instability and constructing stable knee replacements with the use of stabilising implant articulations, bone deficiency reconstruction with augments and grafts as well as cones and sleeves, and stems for implant stability is also essential.

Postoperatively, rehabilitation and follow-up must be tailored to the individual patient because of the marked nuances of construct in the various revision scenarios.

There are several clinical scenarios to consider cementing an acetabular liner into a secure cementless shell including cases of: 1) inadequate capturing mechanism, 2) damaged locking mechanisms, 3) unavailability of the mating polyethylene liner, 4) instability following debridement for wear, 5) instability at the time of femoral side revision, and 6) recurrent dislocation. The last two situations are common scenarios for cementing a constrained liner into a secure shell.

Technique includes: 1) scoring the shell in cases with no screw holes or polished inner shells, 2) scoring the acetabular liner in a “spider web” pattern, 3) pressurising cement into the shell, and 4) inserting a liner that allows 2 millimeters of cement mantle.

Results of Cementing Constrained Liner Into Secure Cementless Shell A.

Callaghan et al. JBJS 2004

Results of Cementing Non-Constrained Liners Into Secure Cementless Shell A.

Beaule et al. JBJS 2004

In the revision situation, there are times where larger heads are just not enough to obtain and maintain stability. The two most relevant times that this is the case is in patients with very lax tissues, or in patients with insufficient or absent soft tissues, especially abductor mechanisms. In addition, in cases where a revision is being performed for dislocation and components looked well-positioned, constrained liners have been extremely beneficial in our hands.

Constrained acetabular liners have been available for close to two decades. Two basic types of liners are available. The type first developed by Joint Medical Products was the SROM constrained liner which captured the femoral head with a locking ring in the polyethylene. These liners may have better results with larger head sizes because the hip can be taken through a larger range of motion (with larger head sizes) before the locking ring is stressed. The second type of constraining liner was developed by Osteonics (Stryker). It consisted of a tripolar replacement which is constrained by a locking ring in the outer polyethylene of the device. Indications for constrained liners include patients undergoing primary arthroplasty who are low demand and have dementia or hip muscle weakness or spasticity. Indications for constrained liners in the revision situation include cases with previously failed operations for instability, elderly low demand patients with instability, cases with poor or absent hip musculature, and cases with well positioned acetabular and femoral components and with hip instability. In this last scenario we cement the liners into fixed shells.

Our results at average 10-year follow-up in 101 hips, demonstrate a 6% failure of the device. Four hips were revised for acetabular loosening and four hips for femoral loosening. One additional hip was revised for acetabular osteolysis. Considering the difficulty of the cases we consider these results to be quite encouraging. At average 3.9 year follow-up of 31 cases where the liner was cemented into the secure shell only one case failed by dislodgement of the liner and one case by fracture of the locking mechanism.

Our experience has led to the following technical recommendation: (1) if cementing the component score the liner and make sure it is contained within the shell (2) avoid inserting the liner into a grossly malpositioned shell (3) avoid positioning the elevated rim of the liner into a position where impingement might occur and (4) avoid placing the shell and constrained liner in cases with massive acetabular allografts unless additional fixation, i.e. cages, are utilized. Especially in the elderly, these liners are our components of choice for many pre-operative and intra-operative cases of instability.

The first 101 posterior cruciate retaining modular tibial components of a single design performed by a single surgeon in 75 patients were evaluated at a minimum 20-year follow-up. All components were fixed with cement. These patients had been prospectively followed at five-year intervals and evaluated clinically using Knee Society ratings and documenting any need for reoperation. Serial radiographs were evaluated for radiolucencies, osteolysis or component migration until the time of patient death or at minimum 20-year follow-up.

At minimum 20-year follow-up, five knees (5%) had required a revision operation. All revisions occurred greater than 10 years following the index procedures. Benefits of modularity (i.e. retention of the tibial tray) were utilized in three of five cases in this closely followed cohort. Survivorship from any revision was 90.8% at 20 years. For the 16 living patients with 22 knees, the average Knee Society Clinical and Functional scores were 91 and 59, respectively, and the average range of motion was 115 degrees.

When considering gamma irradiated in air polyethylene and a first generation locking mechanism were utilized, these results encourage the authors to continue to use modular tibial trays.

Purpose: Femoroacetabular impingement (FAI) is a precursor to osteoarthritis (OA) of the hip. To investigate the fate of impingement abnormalities we analyzed the contralateral hip in patients undergoing THA for advanced FAI. Our purpose was to determine the bilaterality of FAI abnormalities, and to describe the prognosis of these deformities.

Method: We reviewed 508 patients ≤50 years of age treated with THA. Radiographic review identified 70 hips that had OA secondary to FAI (71% cam, 5% pincer, 24% combined). Bilaterality was determined radiographically, and the fate of the contralateral hip was analyzed by determining radiographic presence and progression of OA, and the need for subsequent THA.

Results: 71% of the patients were male and the average age was 43.2 years. The contralateral hip was analyzed on radiographs over an average 9 year period (range, 4–30 years). 100% of the contralateral hips had radiographic features of FAI. 49 (70%) of the contralateral hips demonstrated degenerative disease. 14 had advanced OA at presentation, 41 had progressive joint space narrowing, 25 had progression of Tonnis OA grade and 26 underwent subsequent THA. Statistical analysis showed that alpha angle, LCEA, joint space width, and head-neck ratio have strong predictive value for subsequent THA (p< 0.05).

Conclusion: This study demonstrates that FAI abnormalities are commonly bilateral and are associated with OA progression in the majority of hips. Patients diagnosed with FAI should have both hips monitored, and joint preservation surgery or THA considered when appropriate.

Patient postoperative outcome can be accurately predicted by the patient’s preoperative HHS or WOMAC score. Prospective, cohort studies of one hundred and seventy-five THAs. SF-36, WOMAC and Harris Hip Score (HHS)questionnaires were used to determine pre-operative and two year final outcome. Student’s t-test, 95% confidence intervals, receiver operator characteristic curves, simple regression analysis and probability were measured. Patients with a HHS = sixty-five pre-operatively had a 100% probability of having an excellent result postoperatively. A preoperative HHS value of thirty-four, and preoperative WOMAC (physical function) value of fifty were the best cutoff points to attain a significantly better postoperative functional outcome.

Total hip arthroplasty (THA) has been well documented to enhance patient function, but patient outcome is dependant on preoperative statuts. The exact timing of surgery to optimize patient outcome after THA remains unknown. This study determines the ideal timing for surgery to obtain the best possible functional outcome.

Prospective, multicenter, cohort studies of one hundred and seventy-five identical, cemented THAs. General health (SF-36) and disease specific (WOMAC and Harris Hip Score(HHS)) questionnaires were used to determine preoperative and two year final outcome. Student’s t-test, 95% confidence intervals, receiver operator characteristic curves, simple regression analysis and probabilty were measured.

All functional scores were improved significantly postoperatively (p< 0.001). Patients with a HHS = sixtyfive preoperatively had a 100% probability of having an excellent result postoperatively. A preoperative HHS value of thirty-four, and preoperative WOMAC (physical function) value of fifty were the best cutoff points to attain a significantly better postoperative functional outcome.

Patient postoperative outcome can be accurately predicted by the patient’s preoperative HHS or WOMAC score. Optimization of surgical timing, by prioritizing wait lists or deciding to treat the arthritis operatively, based on these preoperative score guidelines will help ensure an excellent outcome post THA.

Historically we know that all femoral, cemented stems have not performed the same. The Muller stem with its sharp comers did not perform as well as the Charnley femoral component. Titanium femoral components have not performed as well in the cemented situation as have stiffer chrome cobalt components.

Today we have come to recognise that the durability of a cemented femoral component is dependent on a number of variables to include stem geometry and surface finish as well as the cement technique.

Since several designs including the Trapezoidal-28, the Exeter, and the Iowa have incorporated various surface finishes over time, the issue of surface finish is one that some investigators think is relatively important. Components with rougher surface finishes adhere better to cement, decrease cement strains, and when they become loose are more likely to abrade cement. Components with smooth surface finishes do not adhere to cement, place cement under compression and when they become loose they are less likely to abrade cement. When these three stems were evaluated with both smooth and matte finishes the smooth surface finish stems have always demonstrated better results with less loosening and less osteolysis. However some matte finish designs have performed well including the CAD and the HD-2. Whatever prosthesis is utilised all investigators agree that it is optimal to have the prosthesis surrounded by cement, hence the use of centralisers.

Hence today all would agree that the surgeon should use a torsionally sound stem and place an adequate cement mantle around that stem at the time of surgery .If that can be achieved all stems may be equal, however if cement mantle defects are inevitable a smooth surface finish probably has better durability.

With dislocation, prevention is more optimal than treatment. Causes of dislocation include patient compliance, soft tissue tensioning, and component malpositioning problems. Dislocation can occur from bone impingement, component impingement, and spontaneously.

Most work on dislocation has evaluated the differences in the propensity for dislocation based on head size. The larger the head to neck ratio the more motion that can be obtained before cup neck impingement occurs. Skirted modular femoral heads decrease the head to neck ratio and in addition the modular necks must be wider because of strength issues. Because of modularity propensity for dislocation has been on the rise.

As wear has been associated with larger head sizes and thinner polyethylene when conventional polyethylene is used, use of larger head sizes was not considered an option for dislocation prevention and treatment. Constrained liners and bipolar components were used instead. If the newer hyper crosslinked polyethylene components do markedly reduce wear it will be possible to use larger head sizes to prevent dislocation. However, there may be problems with bony impingement associated with larger head sizes.

One hundred hips in patients who had had primary uncemented replacements were followed up for one or two years, and assessed by five different methods. All produced different results. The Hospital for Special Surgery rating produced the most optimistic assessment and the Merle d'Aubigne rating the most pessimistic. The functional class of the patients, as defined by Charnley in 1979, significantly affected the ratings, and these should clearly be included in all rating systems. Moreover, if systems are to be compared, they should all use descriptive words, such as limp or pain, in precisely the same way.