gms | German Medical Science

Objectives: Prosthetic joint infection (PJI) is a serious and challenging complication after joint arthroplasty. The cornerstone for successful outcome and restoration of the limb function is a concerted surgical procedure with an adequate antibiotic treatment. However, controversies about the optimal treatment concepts exist and an international consensus is lacking. A standardized comprehensive diagnostic and treatment algorithm was applied to a cohort of patients with hip PJI. According to the algorithm, no antibiotic discontinuation ("holidays") and no joint puncture was performed before re-implantation. The treatment outcome was determined by long-term follow-up evaluation.

Methods: All consecutive hip PJI cases treated with a two-stage exchange at our institution from 2013 to 2015 were included. Cases were identified by review of the hospital-based PJI register. Diagnosis of PJI was established when at least one of following criteria applied: macroscopic purulence, presence of sinus tract, positive cytology of joint aspirate (>2000 leukocytes/µl or >80% granulocytes), acute inflammation in periprosthetic tissue, positive culture. Treatment success was defined by absence of clinical (pain, erythema, warmth, wound discharge), laboratory (abnormal C-reactive protein) and radiological (early loosening of the prosthesis) signs of infection during follow-up visits at 3, 12 months and at last contact.

Results and Conclusion: A total of 95 patients with hip PJI were included. Median age was 72 years (range, 33-91), 52% were male. 26 cases (27%) were diagnosed with early postoperative infection (< 3 months after implantation), 54 cases (57%) with delayed postoperative infection ( >3 months after implantation) and 15 cases (16%) with a late hematogenous infection. 42 patients (44%) had a polymicrobial, 39 patients (41%) a monomicrobial PJI and in 14 cases (15%) no pathogen was identified. The leading causative agent was Staphylococcus epidermidis (40%). The mean prosthesis-free interval of the 2-stage exchange was 60 days (range, 7-158 days), of whom the interval was short (< 6 weeks) in 26 cases (27%) and long ( >6 weeks) in 69 cases (73%). The overall treatment success rate was 92% (87 patients) with a mean follow-up of 1.6 years (range, 0.5-2.6). 45 patients (47%) had previous septic surgery done, of which 7 failed (16%), while only 1 of 50 cases (2%) without previous septic revision failed (p=0.03). No correlation was found between positive cultures at the time of re-implantation (in 19 cases) and treatment failure (p=0.66). High cure rate of hip PJI (92%) was achieved by following a standardized algorithm including two-stage prosthesis exchange and optimized antibiotics. Before re-implantation, antibiotics were not discontinued and joint aspiration was not performed. Previous septic revisions were a significant risk factor for treatment failure. All efforts should be taken to perform adequate treatment at first surgery to avoid situations difficult to treat.