Abstract
Aim
The purpose of this study was to report on outcomes after stabilization of large skeletal defects following radical debridement of hip or knee infections and staged reimplantation using segmental antibiotic mega-spacers.
Method
From 1998–2018, 39 patients (18 male, 21 female) were treated for musculoskeletal infections at the hip (14) or knee (25). Patients were treated for infection after a procedure related to oncology (20), arthroplasty (16), or trauma (3). Following debridement, defects were stabilized with antibiotic impregnated PMMA and intramedullary nails. All patients underwent a standardized protocol: 6 weeks of intravenous antibiotics followed by 6 weeks of oral antibiotics guided by intraoperative cultures. After a 6-week holiday of antibiotics, repeat intraoperative cultures and inflammatory markers were analysed for infection resolution. Success was defined by reimplantation without additional infection-related complications or requirement of suppressive antibiotics at latest follow-up.
Results
Mean age was 50.5±19.4 years. Mean defect size was 20.4cm. Mean time from surgery until infection was 34.5 months, with 74% of patients presenting with infection greater than one year after their most recent surgery. Mean follow-up was 110±68 months. Most common organisms of infection were Staphylococcus Epidermidis (11) and Staphylococcus Aureus (10). Mean defect size was significantly different among oncology (28±8 cm), trauma (19±5 cm) and arthroplasty (12±6 cm) patients (p<0.0001), though outcomes were comparable. Two patients with antibiotic spacers have not underwent attempted reimplantation – one patient with clinical and laboratory signs of resolved infection; one patient with recent spacer placement. One patient died of oncologic disease shortly after spacer placement. These three patients were excluded from outcomes analysis. Twenty-nine (81%) patients were successfully re-implanted with a segmental endoprosthesis. Eight patients required an additional procedure prior to infection resolution, including additional antibiotic spacer and debridement due to sustained inflammatory markers and clinical signs of infection (5), antibiotic spacer exchange due to mechanical failure (2), and polyethylene exchange 9 months after reimplantation (1). Two patients have remained on chronic suppressive antibiotics, but have retained their limb, prosthesis, and pain-free function. Four (11%) patients ultimately required an amputation for infection control (3 above knee amputations; 1 hip disarticulation).
Conclusions
Following radical debridement for infection, staged management of large segmental defects at the hip and knee with antibiotic cement and temporary intramedullary stabilization results in an 81% success-rate of limb salvage with infection control.
