I was once told that if you don’t have any cases with complications, you either aren’t operating enough or aren’t following your patients. Although we in the orthopaedic community make every effort to minimize the occurrence of patient complications, one that remains difficult to eradicate is periprosthetic joint infection (PJI), which is a leading cause of revision total knee arthroplasty (TKA). The welfare of our patients requires successfully addressing this potentially devastating outcome, but reimbursement for these complex cases has decreased over the past decade.
In the upcoming issue of JBJS, Jella et al. offer insight on temporal trends in Medicare physician reimbursement for revision TKA. They queried the Medicare Physician Fee Schedule Look-Up Tool for pricing information corresponding to 1 and 2-stage revision TKAs and used monetary data from Medicare Administrative Contractors to calculate nationally representative means. The authors evaluated aseptic revision of 1 component, 1-stage revision (aseptic or septic), and both the first and second stages of a 2-stage septic revision.
They found that, from 2002 to 2019, there was a mild increase in the physician fee for each CPT code, with the exception of that for second-stage implantation. However, after adjusting for inflation, total Medicare reimbursements declined for both septic and aseptic revision TKAs (between 23% and 33%), with a significantly greater decline observed for septic revision.
The authors also found that Medicare spending on aseptic revision TKA nearly doubled from 2004 to 2017, while spending on septic revision TKA increased only slightly. They note that a main driver of the discrepancy between septic and aseptic revision may be the reimbursement for the second stage of the former procedure using CPT 27447 instead of a revision procedure code (27487).
We know that an increase in revision TKAs (both septic and aseptic) is expected as the number of primary TKA procedures continues to rise. If reimbursement doesn’t keep pace, it is likely to drive certain surgeons away from tackling the sometimes difficult cases, in turn, leaving our patients with fewer available resources when faced with PJI.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
In June 2019, OrthoBuzz reported on the FDA approval of a rapid, lateral-flow alpha defensin test that helps detect periprosthetic joint infections (PJIs) from synovial fluid. In the January 20, 2021 issue of The Journal of Bone & Joint Surgery, Deirmengian et al. report findings from the Level II diagnostic-accuracy study that led to this FDA approval.
The authors compared diagnostic sensitivity and specificity of the lateral-flow alpha defensin test with the “gold-standard” PJI diagnostic criteria endorsed by the Musculoskeletal Infection Society (MSIS) in 2013. They made the comparison with 2 groups: a prospective patient cohort of 305 patients with a failed hip or knee arthroplasty (57 of whom were determined by MSIS criteria to have a PJI) and among a “control” cohort of 462 synovial fluid samples (65 of which met MSIS criteria for PJI).
After excluding 17 patients from the prospective cohort who had grossly bloody aspirates, the authors found a sensitivity of 94.3% and a specificity of 94.5% for the lateral-flow test in that group. Among the control cohort, the lateral-flow test’s sensitivity was 98.5% and its specificity was 98.2%. Furthermore, after combining data from the 2 cohorts, Deirmengian et al. found no performance difference between the lateral-flow test (which yields results in 10 to 15 minutes) and the lab-based alpha defensin ELISA test (which typically yields results in 24 hours). Finally, in a nonstatistical descriptive comparison between the 2 alpha defensin tests and 4 other individual lab tests used in the MISI criteria to diagnose PJI (such as synovial fluid white blood cell count and erythrocyte sedimentation rate), the authors concluded that “alpha defensin tests led to the highest raw number of correct diagnoses (accuracy).”
The 2018 International Consensus Meeting on Orthopaedic Infections included alpha defensin as a minor criterion. That decision, along with these findings and the FDA approval of the lateral-flow test, should lead to increased adoption of the rapid test—and to more data being published on its clinical utility.
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all such OrthoBuzz specialty-update summaries.
This month, author Michael J. Taunton, MD summarizes the 5 most compelling findings from the 130 studies highlighted in the January 20, 2021 “What’s New in Adult Reconstructive Knee Surgery.”
Waiting for a Knee Replacement
–Patient wait times for joint arthroplasty, exacerbated in many places by the COVID-19 pandemic, continue to increase. As measured by the EQ-5D, the health among 12% of 2,168 patients awaiting total knee arthroplasty (TKA) in a recent cross-sectional analysis was rated as “worse than death.”1 Joint-specific function and various comorbidities were associated with these findings.
UKA vs TKA
–The multicenter randomized TOPKAT trial2 compared unicompartmental knee arthroplasty (UKA) with TKA for treating medial compartment osteoarthritis. At the 5-year follow-up, there was no between-group difference in Oxford knee scores, but UKA was more cost-effective and provided an additional 0.24 quality-adjusted life year.
Perioperative Patient Optimization
–An observational study analyzing >1,000 total joint arthroplasties3 found that implementing a “perioperative orthopaedic surgical home”—a surgeon-led screening and optimization initiative targeting 8 common modifiable comorbidities—resulted in a 1.6% 30-day readmission rate (versus 5.3% among patients not involved in the initiative).
Pain Management and Opioids
–A randomized controlled trial of >300 patients undergoing primary total knee or hip arthroplasty4 demonstrated that reducing the number of 5-mg oxycodone pills prescribed at discharge from 90 to 30 resulted in the following findings 30 days postoperatively:
- Similar between-group pain scores
- No between-group differences in patient-reported outcomes
- Significant reductions in unused opioid pills and in pain pills taken in the 30-pill group
Periprosthetic Joint Infection
–Patients undergoing primary TKA who had a history of periprosthetic joint infection (PJI) in another joint had a significantly higher risk of PJI after the primary TKA, compared with the risk among a matched cohort with no history of PJI.5
- Scott CEH, MacDonald DJ, Howie CR. ‘Worse than death’ and waiting for a joint arthroplasty. Bone Joint J.2019 Aug;101-B(8):941-50.
- Beard DJ, Davies LJ, Cook JA, MacLennan G, Price A, Kent S, Hudson J, Carr A, Leal J, Campbell H, Fitzpatrick R, Arden N, Murray D, Campbell MK; TOPKAT Study Group. The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial. 2019 Aug 31;394(10200):746-56. Epub 2019 Jul 17.
- Kim KY, Anoushiravani AA, Chen KK, Li R, Bosco JA, Slover JD, Iorio R. Perioperative orthopedic surgical home: optimizing total joint arthroplasty candidates and preventing readmission. J Arthroplasty.2019 Jul;34(7S):S91-6. Epub 2019 Jan 18.
- Hannon CP, Calkins TE, Li J, Culvern C, Darrith B, Nam D, Gerlinger TL, Buvanendran A, Della Valle CJ. The James A. Rand Young Investigator’s Award: large opioid prescriptions are unnecessary after total joint arthroplasty: a randomized controlled trial. J Arthroplasty.2019 Jul;34(7S):S4-10. Epub 2019 Feb 4.
- Chalmers BP, Weston JT, Osmon DR, Hanssen AD, Berry DJ, Abdel MP. Prior hip or knee prosthetic joint infection in another joint increases risk three-fold of prosthetic joint infection after primary total knee arthroplasty: a matched control study. Bone Joint J.2019 Jul;101-B(7_Supple_C):91-7.
It’s hard to contemplate “conservative treatment” in the case of a revised total knee arthroplasty (rTKA) with extensive instrumentation that needs a reoperation due to periprosthetic joint infection (PJI), because all the treatment options in that scenario are pretty complex. In the January 6, 2021 issue of JBJS, Barry et al. report on a retrospective review of 87 revisions of extensively instrumented rTKAs that found that irrigation and debridement (I&D) with chronic antibiotic suppression was as effective as 2-stage exchange in preventing another reoperation for infection—and more effective in terms of maintaining knee function.
The average follow-up of the cases studied was 3.2 years, and the authors carefully defined “extensive instrumentation.” Among the 56 patients who were managed with I&D and suppression and the 31 who were managed with the initiation of 2-stage exchange (average age in both groups approximately 67 years), no significant differences were found in the rates of reoperation for infection or mortality. However, 9 of the 31 patients (29%) in the 2-stage group never underwent the second-stage reimplantation. Among those 9, 3 died prior to reimplantation and 2 underwent amputation due to failure of infection control.
Moreover, at the time of the latest follow-up, a significantly higher percentage of patients in the I&D group were ambulatory (76.8% vs 54.8% in the 2-stage group) and were able to functionally bend their knee (85.7% vs 45.2% in the 2-stage group). The authors surmise that these 2 findings are related to the soft-tissue damage and bone loss that typically occur during stage-1 removal of rTKA components.
Barry et al. conclude that in similar situations “deviating from the so-called gold standard of 2-stage exchange and accepting the modest results of I&D may be in the best interest of the patient,” as long as there are no loose implants in the existing construct. But the “sobering” mortality rates in the study (39.3% in the I&D group and 38.7% in the 2-stage group) remind us that this clinical scenario is extremely challenging for patients and surgeons, no matter which option is selected.
Click here to view an “Author Insights” video about this study with co-author Jeffrey Barry, MD.
We recently celebrated Veteran’s Day with the annual tradition of rightfully honoring the men and women who have served in the Armed Forces. After their active duty ends, servicemembers are eligible for care in Veterans Health Administration (VHA) hospitals around the nation. The VHA is a “closed” medical system that affords ample opportunity for population-based research.
In the November 18, 2020 issue of The Journal, Bendich et al. utilized VHA data to compare revision rates after primary total knee arthroplasty (TKA) among veterans treated with antibiotic-laden bone cement (ALBC) or plain cement. Although results of similarly designed studies focused on this question have been equivocal, antibiotic-laden cement seems to be especially effective at preventing infection in higher-risk populations, which is what the US veteran population is considered to be.
The researchers identified 15,972 primary TKAs that were implanted using Palacos bone cement between 2007 and 2015. Approximately 70% (11,231) of those cases used cement mixed with gentamicin, while 30% (4,741) utilized plain bone cement. The authors found similar patient demographics among patients treated with ALBC and those treated with plain cement, but ALBC was used more frequently in patients with higher comorbidity scores.
Overall, utilization of ALBC increased from 50.6% of the cases in 2007 to 69.4% in 2015. At a follow-up of 5 years, ALBC TKAs had a lower all-cause revision rate (5.3%) than plain-cement TKAs (6.7%) and a lower rate of revision for infection (1.9% compared to 2.6%). Even after multivariable adjustments to account for patient, surgical, and hospital factors, these revision-rate differences remained.
Bendich et al. also found that 71 TKAs needed to be implanted with ALBC to avoid 1 revision TKA. With a cost differential of $240 per case for ALBC, I think spending $17,040 ($240 × 71) is more cost-effective than 1 revision TKA, although a formal cost analysis is warranted.
In the interest of full disclosure, as an active-duty US Air Force officer, I am inherently biased, but I feel that no cost is too great to improve the health of our veterans. The authors review arguments against using ALBC, such as a theoretical risk of poor cement mechanical properties and systemic toxicity, but the findings of this study suggest that cement with antibiotics enhances treatment outcomes among these US heroes.
Click here to view the “Author Insight” interview about this study with co-author Alfred Kuo, MD, PhD.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Every month, JBJS reviews the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz specialty-update summaries.
This month, Mengnai Li, MD, PhD, co-author of the September 16, 2020 “What’s New in Hip Replacement,” selected the five most clinically compelling findings from among the 95 noteworthy studies summarized in the article.
Medical Comorbidities and Outcomes of Joint Arthroplasty
–Among 543 malnourished joint arthroplasty patients (with albumin levels <3.4 g/L), an intervention encouraging a high-protein, anti-inflammatory diet shortened the length of hospital stay and lowered readmissions, relative to malnourished arthroplasty patients who did not receive the intervention.1
Surgical Factors and Outcomes of Total Hip Arthroplasty (THA)
–A multicenter, prospective study used propensity-score matching to compare THA performed with a direct anterior approach with THA performed with a posterolateral approach. Researchers found no patient-reported outcome differences at 1.5 months postoperatively or at ≥1 year up to 5 years.2
Periprosthetic Joint Infection (PJI)
–A Musculoskeletal Infection Society workgroup published a recommendation for a 4-tier tool for reporting outcomes after surgical treatment of PJI. Proposed outcomes include infection control with no antibiotic treatment, infection control with suppressive antibiotic therapy, need for reoperation and/or revision and/or spacer retention, and death.
–A meta-analysis found only low-quality retrospective evidence supporting the practice of routinely applying intrawound vancomycin to reduce the rates of PJI. Authors called for a prospective randomized trial before adoption of this practice.3
Postoperative Urinary Retention
–A randomized controlled trial found that preoperative and perioperative administration of tamsulosin did not reduce the incidence of postoperative urinary retention after hip and knee arthroplasty. However, the study included a general male population rather than a higher-risk group.4
- Schroer WC, LeMarr AR, Mills K, Childress AL, Morton DJ, Reedy ME. 2019 Chitranjan S. Ranawat Award: elective joint arthroplasty outcomes improve in malnourished patients with nutritional intervention: a prospective population analysis demonstrates a modifiable risk factor. Bone Joint J.2019 Jul;101-B(7_Supple_C):17-21.
- Sauder N, Vestergaard V, Siddiqui S, Galea VP, Bragdon CR, Malchau H, Elsharkawy KA, Huddleston JI 3rd, Emerson RH. The AAHKS Clinical Research Award: no evidence for superior patient-reported outcome scores after total hip arthroplasty with the direct anterior approach at 1.5 months postoperatively, and through a 5-year follow-up. J Arthroplasty.2020 Feb 12.
- Heckmann ND, Mayfield CK, Culvern CN, Oakes DA, Lieberman JR, Della Valle CJ. Systematic review and meta-analysis of intrawound vancomycin in total hip and total knee arthroplasty: a call for a prospective randomized trial. J Arthroplasty.2019 Aug;34(8):1815-22. Epub 2019 Apr 1.
- Schubert MF, Thomas JR, Gagnier JJ, McCarthy CM, Lee JJ, Urquhart AG, Pour AE. The AAHKS Clinical Research Award: prophylactic tamsulosin does not reduce the risk of urinary retention following lower extremity arthroplasty: a double-blinded randomized controlled trial. J Arthroplasty.2019 Jul;34(7S):S17-23. Epub 2019 Mar 20.
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz specialty-update summaries.
This month, Thomas K. Fehring, MD, co-author of the July 15, 2020 “What’s New in Musculoskeletal Infection,” selected the five most clinically compelling findings—all focused on periprosthetic joint infection (PJI)—from among the more than 80 noteworthy studies summarized in the article.
–A retrospective case-control study1 found that patients who received an allogeneic blood transfusion during or after knee or hip replacement had a higher risk of PJI than those who were not transfused.
–A retrospective review2 found that using inflammatory markers to diagnose PJI in immunosuppressed joint-replacement patients is not suitable and that newly described thresholds for synovial cell count and differential have better operative characteristics.
–A retrospective review3 of a 2-stage debridement protocol with component retention in 83 joint-replacement patients showed an 86.7% success rate of infection control at an average follow-up of 41 months.
–A single-center study4 of perioperative antibiotic selection for patients undergoing total joint arthroplasty found that the risk of PJI was 32% lower among those who received cefazolin compared with those who received other antimicrobial agents. The findings emphasize the importance of preoperative allergy testing in patients with stated beta-lactam allergies.
–A review of regional and state antibiograms5 showed that 75% of methicillin-sensitive S. aureus (MSSA) isolates and 60% of both methicillin-resistant S. aureus (MRSA) and coagulase-negative Staphylococcus isolates were susceptible to clindamycin, whereas 99% of all isolates were susceptible to vancomycin.
- Taneja A, El-Bakoury A, Khong H, Railton P, Sharma R, Johnston KD, Puloski S, Smith C, Powell J. Association between allogeneic blood transfusion and wound infection after total hip or knee arthroplasty: a retrospective case-control study. J Bone Jt Infect. 2019 Apr 20;4(2):99-105.
- Lazarides AL, Vovos TJ, Reddy GB, Kildow BJ, Wellman SS, Jiranek WA, Seyler TM. Traditional laboratory markers hold low diagnostic utility for immunosuppressed patients with periprosthetic joint infections. J Arthroplasty.2019 Jul;34(7):1441-5. Epub 2019 Mar 12.
- Chung AS, Niesen MC, Graber TJ, Schwartz AJ, Beauchamp CP, Clarke HD, Spangehl MJ. Two-stage debridement with prosthesis retention for acute periprosthetic joint infections. J Arthroplasty.2019 Jun;34(6):1207-13. Epub 2019 Feb 16.
- Wyles CC, Hevesi M, Osmon DR, Park MA, Habermann EB, Lewallen DG, Berry DJ, Sierra RJ. 2019 John Charnley Award: Increased risk of prosthetic joint infection following primary total knee and hip arthroplasty with the use of alternative antibiotics to cefazolin: the value of allergy testing for antibiotic prophylaxis. Bone Joint J.2019 Jun;101-B(6_Supple_B):9-15.
- Nodzo SR, Boyle KK, Frisch NB. Nationwide organism susceptibility patterns to common preoperative prophylactic antibiotics: what are we covering? J Arthroplasty.2019 Jul;34(7S):S302-6. Epub 2019 Jan 17.
Among >100,000 total hip arthroplasty (THA) patients ≥55 years of age whose data resides in a Canadian arthroplasty database, the 15-year cumulative incidence of periprosthetic joint infection (PJI) was 1.44%, according to a study by the McMaster Arthroplasty Collaborative in the March 18, 2020 issue of JBJS.
In addition to finding that the overall risk of developing PJI after THA has not changed over the last 15 years in this cohort, the authors found the following factors associated with increased risk of developing a PJI:
- Male sex (absolute increased risk of 0.48% at 10 years)
- Type 2 diabetes (absolute increased risk of 0.64% at 10 years)
- Discharge to a convalescent-care facility (absolute increased risk of 0.46% at 10 years)
The authors view the third bulleted item above as “a surrogate marker of frailty and poorer general health.”
Patient age, surgical approach, surgical setting (academic versus rural), use of cement, and patient income were not associated with an increased risk of PJI. Nearly two-thirds of PJI cases occurred within 2 years after surgery, and 98% occurred within 10 years postoperatively.
The authors conclude that these and other substantiated findings about PJI risk factors “should be reviewed with the patient during preoperative risk counseling.”
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all such OrthoBuzz summaries.
This month, co-author Nitin B. Jain, MD, MSPH selected the most clinically compelling findings from the 40 studies summarized in the November 20, 2019 “What’s New in Orthopaedic Rehabilitation.”
–A randomized controlled trial compared pain-related function, pain intensity, and adverse effects among 240 patients with chronic back, hip, or knee pain who were randomized to receive opioids or non-opioid medication.1 After 12 months, there were no between-group differences in pain-related function. Statistically, the pain intensity score was significantly lower in the non-opioid group, although the difference is probably not clinically meaningful. Adverse events were significantly more frequent in the opioid group.
–A series of nested case-control studies found that the use of the NSAID diclofenac was associated with an increase in the risk of myocardial infarction in patients with spondyloarthritis and osteoarthritis, relative to those taking the NSAID naproxen.2
–Intra-articular injections of corticosteroids or hyaluronic acid are often used for pain relief prior to an eventual total knee arthroplasty (TKA). An analysis of insurance data found that patients who had either type of injection within three months of a TKA had a higher risk of periprosthetic joint infection (PJI) after the operation than those who had injections >3 months prior to TKA.
Partial-Thickness Rotator Cuff Tears
–A randomized controlled trial of 78 patients with a partial-thickness rotator cuff compared outcomes of those who underwent immediate arthroscopic repair with outcomes among those who delayed operative repair until completing 6 months of nonoperative treatment, which included activity modification, PT, corticosteroid injections, and NSAIDs.3 At 2 and 12 months post-repair, both groups demonstrated improved function relative to initial evaluations. At the final follow-up, there were no significant between-group differences in range of motion, VAS, Constant score, or ASES score. Ten (29.4%) of the patients in the delayed group dropped out of the study due to symptom improvement.
Stem Cell Therapy
–A systematic review that assessed 46 studies investigating stem cell therapy for articular cartilage repair4 found low mean methodology scores, indicating overall poor-quality research. Only 1 of the 46 studies was classified as excellent, prompting the authors to conclude that evidence to support the use of stem cell therapy for cartilage repair is limited by a lack of high-quality studies and heterogeneity in the cell lines studied.
- Krebs EE, Gravely A, Nugent S, Jensen AC, DeRonne B, Goldsmith ES, Kroenke K, Bair MJ, Noorbaloochi S. Effect of opioid vs nonopioid medications on pain-related function in patients with chronic back pain or hip or knee osteoarthritis pain: the SPACE randomized clinical trial. JAMA. 2018 Mar 6;319(9):872-82.
- Dubreuil M, Louie-Gao Q, Peloquin CE, Choi HK, Zhang Y, Neogi T. Risk ofcmyocardial infarction with use of selected non-steroidal anti-inflammatory drugs incpatients with spondyloarthritis and osteoarthritis. Ann Rheum Dis. 2018 Aug;77(8): 1137-42. Epub 2018 Apr 19.
- Kim YS, Lee HJ, Kim JH, Noh DY. When should we repair partial-thickness rotator cuff tears? Outcome comparison between immediate surgical repair versus delayed repair after 6-month period of nonsurgical treatment. Am J Sports Med. 2018 Apr;46(5):1091-6. Epub 2018 Mar 5.
- Park YB, Ha CW, Rhim JH, Lee HJ. Stem cell therapy for articular cartilage repair: review of the entity of cell populations used and the result of the clinical application of each entity. Am J Sports Med. 2018 Aug;46(10):2540-52. Epub 2017 Oct 12.
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Thomas K. Fehring, MD, co-author of the July 17, 2019 “What’s New in Musculoskeletal Infection,” selected the five most clinically compelling findings—all focused on periprosthetic joint infection (PJI)—from among the more than 90 noteworthy studies summarized in the article.
Preventive Irrigation Solutions
–An in vitro study by Campbell et al.1 found that the chlorine-based Dakin solution forms potentially toxic precipitates when mixed with hydrogen peroxide and chlorhexidine. The authors recommend that surgeons not mix irrigation solutions in wounds during surgery.
–A clinical evaluation by Stone et al. showed that alpha-defensin levels in combination with synovial C-reactive protein had high sensitivity for PJI diagnosis, but the alpha-defensin biomarker can lead to false-positive results in the presence of metallosis and false-negative results in the presence of low-virulence organisms.
–In an investigation of next-generation molecular sequencing for diagnosis of PJI in synovial fluid and tissue, Tarabichi et al. found that in 28 revision cases considered to be infected, cultures were positive in only 61%, while next-generation sequencing was positive in 89%. However, next-generation sequencing also identified microbes in 25% of aseptic revisions that had negative cultures and in 35% of primary total joint arthroplasties. Identification of pathogens in cases considered to be aseptic is concerning and requires further research.
–A multicenter study found that irrigation and debridement with component retention to treat PJI after total knee arthroplasty had a failure rate of 57% at 4 years.2
–Findings from an 80-patient study by Ford et al.3 challenge the assumption that 2-stage exchanges are highly successful. Fourteen (17.5%) of the patients in the study never underwent reimplantation, 30% had a serious complication, and of the 66 patients with a successful reimplantation, only 73% remained infection-free. Additionally 11% of the patients required a spacer exchange for persistent infection.
- Campbell ST, Goodnough LH, Bennett CG, Giori NJ. Antiseptics commonly used in total joint arthroplasty interact and may form toxic products. J Arthroplasty.2018 Mar;33(3):844-6. Epub 2017 Nov 11.
- Urish KL, Bullock AG, Kreger AM, Shah NB, Jeong K, Rothenberger SD; Infected Implant Consortium. A multicenter study of irrigation and debridement in total knee arthroplasty periprosthetic joint infection: treatment failure is high. J Arthroplasty.2018 Apr;33(4):1154-9. Epub 2017 Nov 21.
- Ford AN, Holzmeister AM, Rees HW, Belich PD. Characterization of outcomes of 2-stage exchange arthroplasty in the treatment of prosthetic joint infections. J Arthroplasty.2018 Jul;33(7S):S224-7. Epub 2018 Feb 17.