First results of a uniform regional treatment protocol and registration for acute prosthetic join infection in the South-East of the Netherlands

Image-guided synovial biopsy with a focus on infection

Image-guided biopsy of the synovium is a relatively uncommon but safe procedure with a high-diagnostic yield in the correct clinical scenario. Whilst surgical and arthroscopic techniques are still commonly performed and remain the gold standard, they are more invasive, expensive and not widely available. Ultrasound and X-ray-guided synovial biopsy are being increasingly performed by radiologists to diagnose both native and periprosthetic joint infection (PJI) to guide surgical and microbiological management. The purpose of this review article is to present the historical background to synovial biopsy particularly related to potential joint infection, including common and uncommon pathogens encountered, sampling techniques and pitfalls, focusing mainly on its role in PJI and its role in patient pathways and decision-making within a joint infection multi-disciplinary framework.

Higher 1-year risk of implant removal for culture-positive than for culture-negative DAIR patients following 359 primary hip or knee arthroplasties

Background and purpose: To date, the value of culture results after debridement, antibiotics, and implant retention (DAIR) for early (suspected) prosthetic joint infection (PJI) as risk indicators in terms of prosthesis retention is not clear. At the 1-year follow-up, the relative risk of prosthesis removal was determined for culture-positive and culture-negative DAIR patients after primary total hip or knee arthroplasty. The secondary aim of this work was to explore differences in patient characteristics, infection characteristics, and outcomes between these two groups. Methods: A retrospective regional registry study was performed in a group of 359 patients (positive cultures: n=299; negative cultures: n=60) undergoing DAIR for high suspicion of early PJI in the period from 2014 to 2019. Differences in patient characteristics, the number of deceased patients, and the number of subsequent DAIR treatments between the culture-positive and culture-negative DAIR groups were analysed using independent t tests, Mann–Whitney U tests, Pearson's chi-square tests, and Fisher's exact tests. Results: The overall implant survival rate following DAIR was 89 %. The relative risk of prosthesis removal was 7.4 times higher (95 % confidence interval (CI) 1.0–53.1) in the culture-positive DAIR group (37 of 299, 12.4 %) compared with the culture-negative DAIR group (1 of 60, 1.7 %). The culture-positive group had a higher body mass index (p=0.034), a rate of wound leakage of >10 d (p=0.016), and more subsequent DAIR treatments (p=0.006). Interpretation: As implant survival results after DAIR are favourable, the threshold to perform a DAIR procedure for early (suspected) PJI should be low in order to retain the prosthesis. A DAIR procedure in the case of negative cultures does not seem to have unfavourable results in terms of prosthesis retention.

Methods and probability of success after early revision of prosthetic joint infections with debridement, antibiotics and implant retention

Prosthetic joint infection (PJI) is a rare-and dreaded-complication of arthroplasty requiring multidisciplinary care. Given the dual goal of treating the infection and maintaining satisfactory function, it is preferable to determine how and when the implanted components can be retained. Bacteria and fungi organize themselves into biofilms that shield them from antibiotics and the immune system. This biofilm is in place after 15 days of active infection. Some antibiotics have a better activity on biofilms. The following factors have a negative impact on the probability of a successful debridement, antibiotics and implant retention (DAIR) intervention: fracture or revision, use of cement, bacteremia, kidney and/or liver failure, immunosuppression and elevated CRP. Hematogenous infections have a worse prognosis than early postoperative infections. Using a decision algorithm increases the chances of DAIR being successful. The KLIC score applies to early postoperative infections (<4 weeks postoperative and<3 weeks from the first signs) while the CRIME-80 score applies to hematogenous infections (<3 weeks from the first signs). Arthroscopic treatments have no role here, whereas DAIR through an arthrotomy is well standardized. Wide spectrum antibiotic therapy, secondarily adapted to the causative microorganism, is indicated for a total of 3 months. The results against the infection are mixed, although following a decision algorithm resolves the infection in about 75% of cases. The functional outcomes and quality of life are close to those of patients who have undergone primary joint replacement. It is not recommended to carry out a second DAIR if the first one fails. It is logical to apply the principles set out for the hip and knee to other joint replacements, and to use the same algorithm. For the upper limb, and especially for reverse shoulder arthroplasty, one must be careful about Cutibacterium acnes infections as they are hard to diagnose. Surgeons should not hesitate to contact a referral center for any PJI, although it is preferable that early infections be treated at the facility that performed the implantation.

Exchange of Modular Components Improves Success of Debridement, Antibiotics, and Implant Retention: An Observational Study of 575 Patients with Infection After Primary Total Hip Arthroplasty

Debridement, antibiotics, and implant retention (DAIR) is a surgical treatment for periprosthetic joint infection (PJI). DAIR is a desirable treatment option from an economic and patient perspective, if successful. The aim of this observational study was to compare the rates of success, defined as no additional reoperations due to PJI, between DAIR with exchange of modular components and DAIR without exchange in patients who had first-time PJI after primary total hip arthroplasty (THA).

METHODS

Patients with PJI at the site of a primary THA who were treated with DAIR in Sweden between January 1, 2009, and December 31, 2016, were identified in the Swedish Hip Arthroplasty Register. Supplementary questionnaires were sent to orthopaedic departments for additional variables of interest related to PJI. The primary end point was another reoperation due to PJI within 2 years after the first-time DAIR. DAIR with exchange was compared with DAIR without exchange using Kaplan-Meier survival analysis and Cox regression analysis.

RESULTS

A total of 575 patients treated with DAIR for a first-time PJI at the site of a primary THA were analyzed; 364 underwent component exchange and 211 did not. The exchange of components was associated with a lower rate of reoperations due to PJI after DAIR (28.0%) compared with non-exchange (44.1%). The Kaplan-Meier implant survival estimate for exchange was 71.4% (95% confidence interval [CI] = 66.9% to 76.3%) compared with 55.5% (95% CI = 49.1% to 62.7%) for non-exchange. With the analysis adjusted for confounders, DAIR with exchange was associated with a significantly decreased risk of another reoperation due to PJI compared with non-exchange (hazard ratio [HR] = 0.51 [95% CI = 0.38 to 0.68]).

CONCLUSIONS

In patients with a first-time PJI at the site of a primary THA, DAIR with exchange of modular components was superior to non-exchange DAIR. Surgeons should strive to exchange components when they perform DAIR, but there is a need to further identify how DAIR best should be practiced and which patients benefit from it.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.