Paul M. Lichstein

Why Are Total Knee Arthroplasties Failing Today—Has Anything Changed After 10 Years?

The purpose of this study was to determine the frequency and cause of failure after total knee arthroplasty and compare the results with those reported by our similar investigation conducted 10 years ago. A total of 781 revision TKAs performed at our institution over the past 10 years were identified. The most common failure mechanisms were: loosening (39.9%), infection (27.4%), instability (7.5%), periprosthetic fracture (4.7%), and arthrofibrosis (4.5%). Infection was the most common failure mechanism for early revision (<2 years from primary) and aseptic loosening was the most common reason for late revision. Polyethylene (PE) wear was no longer the major cause of failure. Compared to our previous report, the percentage of revisions performed for polyethylene wear, instability, arthrofibrosis, malalignment and extensor mechanism deficiency has decreased.

Revision knee arthroplasty for bone loss: choosing the right degree of constraint.

Revision total knee arthroplasty (TKA) in the setting of bone deficiency requires varied levels of constraint to restore knee stability. However, the outcomes between different levels remain controversial. Clinical outcomes for 183 AORI Type I knees, 168 Type II knees and 124 Type III knees utilizing posterior stabilized (PS), unlinked constrained (UC) or hinged prostheses were evaluated with standardized clinical assessment tools and radiographic results over an average of 7.4 years. PS yielded superior knee scores in AORI Type I patients (P<0.05), UC in Type II and III aseptic patients (P<0.05), and a hinge was preferred in septic Type II or III knees (P<0.05). Revision TKA conducted with increased constraint appears effective in the setting of increased bone deficiency.

Diagnosis of Periprosthetic Joint Infection in Medicare Patients: Multicriteria Decision Analysis

BackgroundIn the setting of finite healthcare resources, developing cost-efficient strategies for periprosthetic joint infection (PJI) diagnosis is paramount. The current levels of knowledge allow for PJI diagnostic recommendations based on scientific evidence but do not consider the benefits, opportunities, costs, and risks of the different diagnostic alternatives.Questions/purposesWe determined the best diagnostic strategy for knee and hip PJI in the ambulatory setting for Medicare patients, utilizing benefits, opportunities, costs, and risks evaluation through multicriteria decision analysis (MCDA).MethodsThe PJI diagnostic definition supported by the Musculoskeletal Infection Society was employed for the MCDA. Using a preclinical model, we evaluated three diagnostic strategies that can be conducted in a Medicare patient seen in the outpatient clinical setting complaining of a painful TKA or THA. Strategies were (1) screening with serum markers (erythrocyte sedimentation rate [ESR]/C-reactive protein [CRP]) followed by arthrocentesis in positive cases, (2) immediate arthrocentesis, and (3) serum markers requested simultaneously with arthrocentesis. MCDA was conducted through the analytic hierarchy process, comparing the diagnostic strategies in terms of benefits, opportunities, costs, and risks.ResultsStrategy 1 was the best alternative to diagnose knee PJI among Medicare patients (normalized value: 0.490), followed by Strategy 3 (normalized value: 0.403) and then Strategy 2 (normalized value: 0.106). The same ranking of alternatives was observed for the hip PJI model (normalized value: 0.487, 0.405, and 0.107, respectively). The sensitivity analysis found this sequence to be robust with respect to benefits, opportunities, and risks. However, if during the decision-making process, cost savings was given a priority of higher than 54%, the ranking for the preferred diagnostic strategy changed.ConclusionsAfter considering the benefits, opportunities, costs, and risks of the different available alternatives, our preclinical model supports the American Academy of Orthopaedic Surgeons recommendations regarding the use of serum markers (ESR/CRP) before arthrocentesis as the best diagnostic strategy for PJI among Medicare patients.Level of EvidenceLevel II, economic and decision analysis. See Instructions to Authors for a complete description of levels of evidence.

One-stage versus two-stage exchange.

Liaison: Paul Lichstein MD, MSLeaders: Thorsten Gehrke MD (International), Adolph Lombardi MD, FACS (US), Carlo RomanoMD (International), Ian Stockley MB, ChB, MD, FRCS (International)Delegates: George Babis MD, Jerzy Bialecki MD, La´szlo´ Bucsi MD, Xu Cai MD, Li Cao MD, Briande Beaubien MD, Johannes Erhardt MD, Stuart Goodman MD, PhD, FRCSC, FACS, FBSE,William Jiranek MD, Peter Keogh, David Lewallen MD, MS, Paul Manner MD, WojciechMarczynski MD, J. Bohannon Mason MD, Kevin Mulhall MB, MCh, FRCSI, Wayne PaproskyMD, Preetesh Patel MD, Francisco Piccaluga MD, Gregory Polkowski MD, Luis Pulido MD, IanStockley MBBS, ChB, FRCS, Juan Suarez MD, Fritz Thorey MD, Rashid Tikhilov MD, JobDiego Velazquez MD, Heinz Winkler MD

Extensor Mechanism Reconstruction with Achilles Tendon Allograft in TKA: Results of an Abbreviate Rehabilitation Protocol

Various treatment alternatives address extensor mechanism failure after total knee arthroplasty. We present the results of a protocol utilizing Achilles tendon allograft followed by an abbreviated immobilization program to treat extensor mechanism disruptions after TKA in 29 knees (27 patients). Failed reconstruction was defined as mechanical allograft failure requiring re-intervention, extension lag >30°, recurrent falls, regression to a lower ambulatory status, and revision due to infection. With mean follow-up of 3.5 years, seventeen cases (58.6%) had satisfactory results, eleven cases (37.9%) were considered failures, and one case was lost to follow-up. Among failures, eight (27.5%) underwent reoperation with four (13.8%) due to late infections. Our observational data suggest that 1) a shortened immobilization protocol yields less favorable results than expected, and 2) continuous monitoring of patients who had allograft reconstruction for possible development of late infection is recommended.

One-stage vs two-stage exchange.

Liaison: Paul Lichstein MD, MSLeaders: Thorsten Gehrke MD (International), Adolph Lombardi MD, FACS (US),Carlo Romano MD (International), Ian Stockley MB, ChB, MD, FRCS (International)Delegates: GeorgeBabisMD,JerzyBialeckiMD,LaszloBucsiMD,XuCaiMD,LiCaoMD,BriandeBeaubienMD,Johannes Erhardt MD, Stuart Goodman MD, PhD, FRCSC, FACS, FBSE, William Jiranek MD,PeterKeoghFRCSI,DavidLewallenMD,MS,PaulMannerMD,WojciechMarczynskiMD,J.BohannonMasonMD,Kevin Mulhall MB, MCh, FRCSI, Wayne Paprosky MD, Preetesh Patel MD, Francisco Piccaluga MD,Gregory Polkowski MD, Luis Pulido MD, Ian Stockley MBBS, ChB, FRCS, Juan Suarez MD, Fritz Thorey MD,Rashid Tikhilov MD, Job Diego Velazquez MD, Heinz Winkler MD

Diagnosis of Periprosthetic Joint Infection: The Role of Nuclear Medicine May Be Overestimated.

Although the International Consensus Meeting on Periprosthetic Joint Infections definition of periprosthetic joint infection (PJI) does not include nuclear imaging as part of the diagnostic criteria, many contemporary nuclear imaging studies are reporting exceptional results in PJI diagnosis. We conducted a systematic review of studies published from 2004 to 2012 reporting the accuracy of nuclear imaging for diagnosis of PJI, utilizing a specially designed tool (QUADAS-2) for critical appraisal and investigation of bias. Our results revealed high risk of bias as well as high levels of concern regarding the clinical applicability of these tests in a majority of the studies. On the basis of our findings, we recommend that the use of nuclear imaging for diagnosis of PJI be limited to a few select cases.

Medicare Fails to Compensate Additional Surgical Time and Effort Associated with Revision Arthroplasty

In comparison to primary total knee arthroplasty, surgical time was 1.8 times greater for all knee revisions and 2.4 times greater for complex knee revisions. Knee revisions had an 8.5% higher rate of 90-day repeat procedures. In comparison to primary total hip arthroplasty, surgical time was 1.8 greater for all hip revisions and 2.6 fold greater for complex hip revisions. Hip revisions had a 3.4% higher rate of 90-day repeat procedures. Practices based on revisions or complex revisions alone would see a 32% and 50% decrease in reimbursement respectively compared to the ones based on primary arthroplasty. The projected future increase in primary arthroplasties and the relative incentive to perform primary arthroplasty may soon put patient access to physicians willing to perform revision arthroplasty at risk.

Treatment of Periprosthetic Knee Infection With a Two-stage Protocol Using Static Spacers.

BackgroundTwo-stage exchange arthroplasty is a standard approach for treating total knee arthroplasty periprosthetic joint infection in the United States, but whether this should be performed with a static antibiotic spacer or an articulating one that allows range of motion before reimplantation remains controversial. It is unclear if the advantages of articulating spacers (easier surgical exposure during reimplantation and improved postoperative flexion) outweigh the disadvantages of increased cost and complexity in the setting of similar rates of infection eradication.Questions/purposesThe purposes of this study were (1) to determine the ultimate range of motion; and (2) to determine the proportion of patients who remained free of infection at a minimum 2 years after treatment with static antibiotic spacers as part of a two-stage revision TKA for the treatment of periprosthetic joint infection.MethodsBetween 1999 and 2011, we treated 121 patients with chronically infected TKAs, of whom three had medical comorbidities precluding a two-stage exchange, four had died before 2-year followup for reasons other than the surgical intervention, and seven were lost to followup. The remaining 107 patients (109 knees; 53 men and 54 women) were treated using a two-stage approach with static spacers and are evaluated here at a mean of 3.7 years (range, 2.0–9.8 years); no patients were treated with articulating spacers during this study period. Twenty-five percent (27 of 109) of the organisms isolated the first-stage procedure were resistant to methicillin and/or vancomycin. Median age at the time of reimplantation was 67 years (range, 42–89 years). Range of motion was measured by an independent physical therapist with a standard goniometer. Knee Society knee and function scores were calculated before the first stage and at the 2-year mark. Because many of these patients were treated before consensus definitions of infection were established, we made the diagnosis of infection (and established that a patient was believed to be free of infection) using the approaches prevalent at that time, which generally included presence of a sinus tract communicating directly with the implant, two positive tissue cultures, or a combination of cultures, fluid analysis, and serology.ResultsPostoperatively, 67 knees had full extension and no patients had a flexion contracture > 10°. Median flexion was 100° (range, 60°–139°). Thirty-nine knees had postoperative flexion > 120°. Ninety-four percent of patients were clinically free of infection at last followup.ConclusionsOur two-stage exchange protocol with static spacers yielded comparable flexion and infection eradication when compared with other recent studies that have used articulating spacers. The large proportion of resistant organisms is alarming. Future multicenter studies should compare static with articulating spacers and should evaluate both cost and efficacy, because our study suggests that adequate range of motion can be achieved without the added cost of the articulating spacer.Level of EvidenceLevel IV, therapeutic study.

Femoral Alignment and Femoral Rotation

Although there have been many advancements that facilitate performing a successful total knee arthroplasty (TKA), failures that require revision surgery continue to arise. The numbers of such failures are predicted to increase dramatically in the future. It is important to appreciate that accurately establishing femoral coronal and axial component alignment is important for achieving a successful revision of TKA. Our chapter seeks to review techniques facilitating femoral resections that provide beneficial soft tissue tensions and bony relationships throughout the gait cycle. We will review the anatomy and axes pertinent to the distal femur, biomechanics and forces through the knee, and strategies commonly used to align the femur in the axial and coronal plane during revision surgery. Additionally, we have updated our chapter with a review of more contemporary techniques.