Factors Associated with Failed Hardware Salvage in High Risk Patients Following Microsurgical Lower Extremity Reconstruction

Purpose:  Lower extremity hardware salvage remains a difficult challenge in patients with multiple, complex co-morbidities.  Surgeons must weigh the benefit of lower extremity stabilization against the costs of compromised wound healing and potential limb loss.  Presently, guidelines are lacking with regard to suitable/unsuitable conditions for attempted hardware salvage.  The purpose of this study was to identify factors associated with failed hardware salvage following microsurgical lower extremity reconstruction

Methods:  The authors performed a retrospective, IRB-approved review of patients who underwent lower extremity hardware salvage via free tissue transfer by the senior author (I.D.) from 2004-2010.  Patient demographics, wound characteristics, microbiology, and pathology were reviewed.  Outcomes were binarized into successful versus failed hardware salvage, with failure defined as the absence of hardware at latest follow-up.  Univariate analysis was used for comparison of associations, with a p value < 0.05 considered significant. 

Results:  34 patients underwent lower extremity hardware salvage via free tissue transfer, with an average follow-up of 2.6 years (range 0.3 – 7.0 years).  Fifteen patients had successful hardware salvage; 19 patients eventually required hardware removal, representing a 55.9% failure rate.  Comparison of patient demographics revealed similar surgical age, BMI, and co-morbidities between successful versus failed hardware salvage groups.  Analysis of wound characteristics revealed a significantly longer time to hardware coverage and longer duration of IV antibiotic coverage in failed versus successful hardware salvage patients (38.9 versus 9.3 weeks, p = 0.02; and 6.5 versus 4.1 weeks, p = 0.03, respectively). Initial wound cultures demonstrated a significantly higher frequency of positive growth in patients with failed versus successful hardware salvage (100.0% versus 57.1%, p = 0.003); the distribution of microbial flora on initial and final cultures was similar for the two groups.  Initial pathology revealed a borderline-significantly higher frequency of chronic osteomyelitis in failed versus successful hardware salvage patients (66.7% versus 33.3%, p = 0.08); absence of osteomyelitis and presence of acute osteomyelitis were similar for the two groups.

Conclusions:   Based on this retrospective review of microsurgical lower extremity reconstruction, factors associated with failed hardware salvage included: longer time to hardware coverage; increased duration of IV antibiotics; positive initial wound cultures; and presence of chronic osteomyelitis on initial pathology.  These findings underscore the need for early and timely hardware coverage to maximize the likelihood of salvage.