Repeat two-stage exchange arthroplasty for recurrent periprosthetic hip or knee infection: what are the chances for success?

INTRODUCTION: Two-stage revision is a frequently chosen approach to treat chronic periprosthetic joint infection (PJI). However, management of recurrent infection after a two-stage exchange remains debated and the outcome of a repeat two-stage procedure is unclear. This study investigates the success rates of repeat two-stage exchange arthroplasty and analyzes possible risk factors for failure. MATERIALS AND METHODS: We retrospectively identified 55 patients (23 hips, 32 knees) who were treated with repeat resection arthroplasty and planned delayed reimplantation for recurrent periprosthetic joint infection between 2010 and 2019 after a prior two-stage revision at the same institution. The minimum follow-up was 12 months with a median follow-up time of 34 months (IQR 22-51). The infection-free survival, associated revision surgeries, and potential risk factors for further revision were analyzed using Kaplan-Meier survival curves and comparative non-parametric testing. RESULTS: 78% (43/55) underwent reimplantation after a repeat implant removal. Of those who completed the second-stage surgery, 37% (16/43) underwent additional revision for infection and 14% (6/55) underwent amputation. The reinfection-free implant survivorship amounted to 77% (95% CI 64-89%) after 1 year and 38% (95% CI 18-57%) after 5 years. Patients with a higher comorbidity score were less likely to undergo second-stage reimplantation (median 5 vs. 3, p = 0.034). Furthermore, obese patients (p = 0.026, Fisher's exact test) and diabetics (p < 0.001, log-rank test) had a higher risk for further infection. Most commonly cultures yielded polymicrobial growth at the repeat two-stage exchange (27%, 15/55) and at re-reinfection (32%, 9/28). Pathogen persistence was observed in 21% (6/28) of re-reinfected patients. CONCLUSION: The success rates after repeat two-stage exchange arthroplasty are low. Patients must be counseled accordingly and different modes of treatment should be considered.

Good to excellent long-term survival of a single-design condylar constrained knee arthroplasty for primary and revision surgery.

PURPOSE: The purpose of the study was to determine the long-term survivorship, functional outcomes of a single-design condylar constrained (CCK) TKA in primary and revision cases as well as to assess specific risk factors for failure. It was hypothesized that primary CCK TKA had a better survival than revision knees. METHODS: One hundred and forty three patients who underwent revision TKA (n = 119) or complex primary TKA (n = 24) using a single-design condylar constrained knee system (Genesis CCK, Smith & Nephew) performed at a single institution between 1999 and 2008 were retrospectively included. The median follow-up amounted to 11.8 years (IQR 10.3-14.4). Implant survivorship was analyzed using Kaplan-Meier survival estimates and multivariate Cox regression analysis to identify risk factors for failure. Function was determined using the Oxford Knee Score (OKS). RESULTS: The implant survival was 86.4% after five, 85.5% after ten and 79.8% at 15 years. A reduced implant survivorship was found in males (HR 5.16, p = 0.001), smokers (HR 6.53, p = 0.004) and in obese patients (HR 2.26, p = 0.095). Patients who underwent primary TKA had a higher revision-free implant survivorship compared to revision TKA at 15 years (100% vs. 76%, p = 0.036). The main cause for re-revision was infection in 10% of all revision TKA performed with the CCK design included, while no case was revised for instability. The median OKS was 39 (IQR 35-44) in 102 patients available for long-term functional outcome. CONCLUSION: CCK implants are associated with excellent long-term survival when used in primary TKA; however, survival was worse when used during revision TKA. Males, smokers, obese patients and are at higher risk for revision. While instability and aseptic loosening were rare, infection remains a major concern. LEVEL OF EVIDENCE: Level IV, retrospective observational study.

Do Positive Cultures at Second Stage Re-Implantation Increase the Risk for Reinfection in Two-Stage Exchange for Periprosthetic Joint Infection?

BACKGROUND: Intraoperative cultures are important in the diagnosis and targeted treatment of periprosthetic joint infection (PJI). Positive cultures at reimplantation during a two-stage exchange are discussed as a risk factor for reinfection. The aim of this study is the investigation of the incidence and risk factors for positive cultures during reimplantation. METHODS: We retrospectively identified 204 patients (111 knees, 93 hips) who were treated between 2012 and 2016 for PJI using a two-stage exchange protocol at a median follow-up of 42 months. PJI was diagnosed using the criteria of the musculoskeletal infection society (MSIS) of 2011. All cultural findings from first and second stage surgery were recorded. The primary endpoint was revision for infection. Risk factors for positive cultures and reinfection were analyzed. RESULTS: During reimplantation 25% (51/204) of patients had at least one positive culture, in 19.1% (39/204) only a single culture. Patients with culture-negative infections had a higher risk for positive cultures at reimplantation (HR 2.946 (95% CI 1.247-6.961), P = .014) and patients with infected total hip arthroplasty (THA) (HR 3.547 (95% CI 1.7-7.4), P = .001). Patients with positive cultures during reimplantation had a higher risk for reinfection (HR 2.27 (95% CI 1.181-4.363), P = .014) as well as patients with a single positive culture (HR 2.421 (95% CI 1.139-5.143), P = .021). CONCLUSION: As positive cultures are common and increase reinfection risk irrespective of their numbers, longer antibiotic therapy following reimplantation can be an option. Single positive cultures in reimplantation surgery should not be considered contamination.

Acceptable mid- to long-term survival rates and functional outcomes following a single design rotating hinge total knee arthroplasty.

PURPOSE: This study first analyzes implant survival of this single design modular rotating hinge knee and identifies potential risk factors for failure and evaluates joint function using the postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score, active flexion and extension deficit. METHODS: 131 prostheses implanted for failure of prior total knee arthroplasty (n = 120) or complex primary procedures (n = 11) using a single modular implant (MUTARS-modular universal tumor and revision system GenuX, Implantcast, Buxtehude, Germany) between 2006 and 2014 including 73 patients treated for periprosthetic joint infection with a two-stage revision protocol were retrospectively identified. Implant survival was assessed using the Kaplan-Meier method; potential risk factors were identified using the log-rank test, as well as non-parametric analysis. Postoperative function was assessed using the WOMAC and measurement of range of motion. RESULTS: After a median follow-up of 62 months, 37 implants required implant revision (28%). Five-year survival was 69.7% [95% CI (confidence interval) 60.9-78.5] with periprosthetic (re-) infection being the main cause for failure (15%), followed by aseptic loosening (9%). In cases of periprosthetic infection, infection-free survival was 83% at 5 years (95% CI 74-92) with twelve patients suffering reinfection (16%).While body mass index (p = 0.75), age (p = 0.16) or indication for rotating hinge knee arthroplasty (p = 0.25) had no influence on survival, Charlson comorbidity score (CCI) (p = 0.07) and number of previous revision surgeries (p = 0.05) correlated with implant failure. There was trend (p = 0.1) for improved survival in fully cemented implants. Mean postoperative WOMAC was 127(range 55-191), 11 patients (15%) had limited knee extension. CONCLUSIONS: Rotating hinge total knee arthroplasty using a single modular implant shows acceptable survival rates and function compared to previous studies with (re-)infection being the most relevant mode of failure. Patients with a high CCI and multiple previous surgeries are at increased risk for failure. LEVEL OF EVIDENCE: Retrospective cohort study, III.

Fungal prosthetic joint infection in total hip or knee arthroplasty: a retrospective single-centre study of 26 cases.

AIMS: Fungal prosthetic joint infections (PJIs) are rare and account for about 1% of total PJIs. Our aim was to present clinical and microbiological results in treating these patients with a two-stage approach and antifungal spacers. PATIENTS AND METHODS: We retrospectively reviewed our institutional database and identified 26 patients with positive fungal cultures and positive Musculoskeletal Infection Society (MSIS) criteria for PJI who were treated between 2009 and 2017. We identified 18 patients with total hip arthroplasty (THA) and eight patients with total knee arthroplasty (TKA). The surgical and antifungal treatment, clinical and demographic patient data, complications, relapses, and survival were recorded and analyzed. RESULTS: The median follow-up was 33 months. The success rate was 38.5% (10/26). Fluconazole resistance was found in 15%. Bacterial co-infection was common in 44% of patients for THA and 66% of patients with TKA. Mortality, reoperations, and treatment failure were common complications. CONCLUSION: Treatment with a two-stage exchange is a possible option for treatment, although fungal infections have a high failure rate. Therapeutic factors for treatment success remain unclear. Cite this article: Bone Joint J 2019;101-B:589-595.