Predictors of secondary amputation in patients with grade IIIC lower limb injuries

The aim of this study was to identify risk factors for failure of limb salvage surgery in grade IIIC lower extremity injuries.A single-institution, retrospective review was performed of all patients with grade IIIC lower limb injuries presenting from January 2009 to April 2014. We gathered the data on each patient who underwent limb salvage and analyzed the final outcome for these patients (limb salvage vs secondary amputation).Grade IIIC lower limb injuries were identified in 41 patients. Primary amputation was performed in 6 patients (15%) as the initial procedure. Thirty-five patients (85%) underwent vascular reconstruction and other surgical procedures to salvage the limb. Limb salvage was successful in 23 patients (66%); 12 patients (34%) ultimately underwent secondary amputation. The median time from injury to secondary amputation was 22.5 days (range 4-380 days). The mean Mangled Extremity Severity Score (MESS) was 7.2 ± 1.5 (range 5-10). The MESS was significantly higher in the secondary amputation group compared with the limb salvage group. Additionally, statistical testing revealed that the limb ischemia time, complex fractures, rate of fasciotomy, and number of vascular reconstruction were significantly higher in the secondary amputation group. Muscle necrosis and extensive soft tissue defect were the main reasons for secondary amputation.The findings indicate that MESS of 7 or greater, complex fractures, limb ischemia time equal to or greater than 6 hours, and osteofascial compartment syndrome were associated with an increased risk of delayed amputation. The MESS is highly prognostic but not perfect; decision-making in patients with an MESS of 7 or greater should be re-evaluated for clinical use.