B Kendrick

Functional outcome of debridement, antibiotics and implant retention in periprosthetic joint infection involving the hip

Aims Advocates of debridement, antibiotics and implant retention (DAIR) in hip periprosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis‐bone interface is likely to lead to better survival and functional outcome compared with revision. This case‐control study aims were to compare outcome of DAIRs for infected primary total hip arthroplasty (THA) with outcomes following primary THA and two‐stage revision of infected primary THAs. Patients and Methods We retrospectively reviewed all DAIRs, performed for confirmed infected primary hip arthropasty (n = 82) at out institution, between 1997 and 2013. Data recorded included full patient information and type of surgery. Outcome measures included complications, mortality, implant survivorship and functional outcome. Outcome was compared with two control groups matched for gender and age; a cohort of primary THAs (n = 120) and a cohort of two‐stage revisions for infection (n = 66). Results Mean age at DAIR was 69 years (33 to 87) and mean follow‐up was eight years (2 to 17; standard deviation (sd) 5). A total of 52 (63%) of DAIRs were for early PJI (less than six weeks). Greater success in the eradication of infection with DAIR was identified with early PJI, comprising an interval less than a week between onset of symptoms and exchange of modular components with the DAIR procedure. Eradication of infection, complications and re‐operation rates were similar in the DAIR and two‐stage revision groups. For hips with successful eradication of infection with DAIR, the five‐year survival (98%; 95% confidence interval (CI) 94 to 100) was similar to the primary THA group (98%; 95% CI 95 to 100) (n = 43; p = 0.3). The DAIR group had inferior mean Oxford Hip Scores (OHS) (38; 12 to 48) compared with the primary THA group (42; 15 to 48) (p = 0.02) but a significantly better mean OHS compared with the two‐stage revision group (31; 0 to 48) (p = 0.008). Patients who required only one DAIR for eradication of infection had a similar mean OHS (41; 20 to 48) to the primary THA group (p = 0.2). Conclusion The DAIR procedure is associated with a similar complication rate and ability to eradicate infection as two‐stage revision. This study emphasises the need for exchange of modular components for improved chances of eradication of infection. This is the first study showing that DAIR is better than a two‐stage revision regarding functional outcome.

Outcome Following Debridement, Antibiotics, and Implant Retention in Hip Periprosthetic Joint Infection—An 18-Year Experience

BACKGROUNDnDebridement-antibiotics-and-implant-retention (DAIR) may be considered a suitable surgical option in periprosthetic joint infections (PJIs) with soundly fixed prostheses, despite chronicity. This study aims to define the long-term outcome following DAIR in hip PJI.nnnMETHODSnWe reviewed all hip DAIRs performed between 1997 and 2013 (nxa0= 122) to define long-term outcome and identify factors influencing it. Data recorded included patient demographics, medical history, type of DAIR performed (+/- exchange of modular components), and organisms identified. Outcome measures included complications and/or mortality rate, implant survivorship, and functional outcome (Oxford Hip Score).nnnRESULTSnMost DAIRs (67%) were of primary arthroplasties and 60% were performed within 6 weeks from the index arthroplasty. Infection eradication was achieved in 68% of the first DAIR procedure. Inxa032 cases, more than one DAIR was required. Infection eradication was achieved in 85% of the cases (104/122) with the (single or multiple) DAIR approach. The most common complication was PJI-persistence (15%), followed by dislocation (14%). Very good functional outcomes were obtained, especially in primary arthroplasties. All streptococcus infections were resolved with DAIR and had better outcome. Twenty-one hips have been revised (17%) to-date, 16 were for persistence of PJI. The 10-y implant survivorship was 77%. Early PJI and exchanging modular components at DAIR were independent factors for a 4-fold increased infection eradication and improved long-term implant survival.nnnCONCLUSIONnDAIR is, therefore, a valuable option in the treatment of hip PJI, especially in the early postoperative period (≤6 weeks), with good outcomes. However, DAIR is associated with increased morbidity; further surgery may be necessary and instability may occur. Where possible, exchange of modular implants should be undertaken.

Clinical Outcome of Massive Endoprostheses Used for Managing Periprosthetic Joint Infections of the Hip and Knee

BACKGROUNDnEndoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. The aim of this study is to determine the mid-term outcome of EPRs performed in the treatment of periprosthetic joint infection (PJI) and infected failed osteosyntheses around the hip and knee joint and identify factors that influence it.nnnMETHODSnWe retrospectively reviewed all hip and knee EPRs performed between 2007 and 2014 for the management of chronic infection following complex arthroplasty or fracture fixation. Data recorded included indication for EPR, number of previous surgeries, comorbidities, and organism identified. Outcome measures included PJI eradication rate, complications, implant survival, mortality, and functional outcome (Oxford Hip or Knee Score).nnnRESULTSnSixty-nine EPRs (29 knees and 40 hips) were performed with a mean age of 68 years (43-92). Polymicrobial growth was detected in 36% of cases, followed by coagulase-negative staphylococci (28%) and Staphylococcus aureus (10%). Recurrence of infection occurred in 19 patients (28%): 5 were treated with irrigation and debridement, 5 with revision, 1 with above-knee amputation, and 8 remain on long-term antibiotics. PJI eradication was achieved in 50 patients (72%); the chance of PJI eradication was greater in hips (83%) than in knees (59%) (Pxa0= .038). The 5-year implant survivorship was 81% (95% confidence interval 74-88). The mean Oxford Hip Score and Oxford Knee Score were 22 (4-39) and 21 (6-43), respectively.nnnCONCLUSIONnThis study supports the use of EPRs for eradication of PJI in complex, multiply revised cases. We describe PJI eradication rate of 72% with acceptable functional outcome.

CORR Insights®: Is Model-based Radiostereometric Analysis Suitable for Clinical Trials of a Cementless Tapered Wedge Femoral Stem?

A s populations increase in size, and as total hip arthroplasty is increasingly performed in younger patients, the burden on healthcare systems grows. Implant survivorship beyond two decades is becoming an imperative. Unfortunately, many hip implants have been introduced—often as minor modifications of a successful design—only to fail catastrophically. Joint registries pioneered by the Scandinavian countries are powerful tools with which to compare implants in the long-term, but detection of underperforming implants sooner remains difficult because registries generally have focused on the endpoint of revision, rather than on signs of failure that may be evident earlier on. By the time it is apparent that an implant does not have acceptable long-term survival, many thousands, if not tens of thousands, have been implanted. Radiostereometric Analysis (RSA) has been shown to be adept at detecting implants that are prone to early failure long before the evidence was apparent from longitudinal studies or registry data [2]. However, RSA can be time consuming and labor intensive, and it calls for modified implants. For these reasons, RSA has not become established in many centers around the world. Traditionally, most studies came from those centers (mainly in Europe) where it has long been an integral part of the research program of institutions that have focused on it. This situation has recently changed with the advent of greater computing power and software that accelerates the process, and model-based systems eradicating the need for modified components. But, as with the continuing iteration of hip components potentially leading to a failed design, the modification of RSA must not diminish its accuracy in the quest for it to be easier and quicker.