Abstract
Aim
Data of optimal management of infections after internal fixation (IIF) is scarce and long-term follow-up results often lack. We analyzed characteristics of infections after intramedullary (IIIF) and extramedullary long bone fixation (IEIF) and evaluated their infection and functional outcome.
Method
Consecutive patients with IIF diagnosed at our institution from 01/2010-10/2017 were retrospectively included. Infection was defined as visible purulence, sinus tract, microbial growth in ≥2 independent samples or positive histopathology. The outcome was compared before and after implementation of a comprehensive surgical and antimicrobial treatment algorithm in 04/2013.
Results
Of 127 patients, infection involved lower extremity in 111 patients (87%). Median age was 53 years (range, 19–89 years), 70% were men. Fixation was performed with intramedullary nail in 47 (37%) and with extramedullary osteosynthesis (plates, screws, pins) in 80 patients (63%). At infection diagnosis, the implant was in situ in 96 patients (76%), whereas 31 patients (24%) had residual osteomyelitis after implant removal. The time from bone fixation to infection was longer in IIIF than IEIF (25 vs. 7 months, p=0.027). Pain was reported in 55 patients (43%) and local infection signs in 96 patients (75%), including sinus tract in 46 patients, more commonly reported after IIIF than IEIF (49% vs. 29%, p=0.035). Infections were monomicrobial in 85 (67%), polymicrobial in 18 (14%) and culture-negative in 23 patients (18%). Most common pathogens were S. aureus (43%), coagulase-negative staphylococci (28%) and gram-negative rods (22%). Débridement (with device retention, if present) was performed in 40, device removal in 43, one-stage exchange in 16 and two-stage exchange in 20 patients. One patient had no surgery and 7 patients underwent limb amputation. 43 patients (34%) were treated before implementation of the interdisciplinary treatment concept and 84 patients (66%) afterwards. Among 111 patients with available follow-up (median, 5.2 months; range, 0.2–86 months), in 78 cases (70%) infection eradication was achieved (similar in IIIF and IEIF). However, overall infection and functional outcome was only 48% (53 patients). After implementation of the treatment algorithm, the infection outcome improved from 56% to 79% (p=0.03) and the overall success from 33% to 56% (p=0.016).
Conclusions
Approximately half of infections after IIF failed in terms of infection eradication or restoration of function. After implementation of standardized surgical and antibiotic treatment concept, infection and functional outcome improved significantly. No significant differences between IIIF and IEIF was observed in terms of infection and functional success.
