Comparison of Transtibial Amputations in Diabetic Patients With and Without End-Stage Renal Disease

Abstract

Background: The primary purpose of this retrospective study was to report on a consecutive series of 102 patients with diabetes mellitus (DM) who underwent transtibial amputation (TTA) for chronic infections and nonreconstructable lower extremity deformities. A secondary aim was to compare the outcomes of TTA patients with end-stage renal disease on dialysis (ESRD) to patients without ESRD, and to identify risk factors for mortality after TTA. Methods: This cohort involved a consecutive series of patients who were treated by a single surgeon. The TTA patients were divided into 2 groups for analysis. The study group included those patients with ESRD who underwent TTA, and the control group included those patients who did not have ESRD. Results: At the time of final follow-up, 64 of 102 patients were ambulatory with a prosthesis. There was a significant improvement in ambulatory status after amputation (preoperatively 45.1%, postoperatively 62.7%, P = .02). Wound healing complications (infection and/or dehiscence) occurred in 31 of 102 patients and led to a transfemoral amputation in 4 patients. After TTA patients with ESRD were significantly more likely to die (52.4% vs. 23.5%, p <0.05) and significantly less like to ambulate (42.9% vs. 67.9%, p <0.05) than patients without ESRD. Contralateral foot problems after the TTA occurred in 33 of 97 patients and resulted in 10 patients undergoing a contralateral transtibial amputation. Excluding patients with bilateral amputations (5 prior to and 10 after the index amputation), 64 of 87 patients with successful unilateral transtibial amputations were able to ambulate with a prosthesis. Thirty of 102 patients (29.4%) died during the follow-up period, and 6 of these deaths occurred during the perioperative period (within 30 days of surgery). There were no significant differences between the 2 groups with regard to the use of staged TTA, need for transfemoral amputation, or wound healing problems at the amputation site. Patients who were unable to walk postoperatively had a calculated 5-year survival rate of 30.1%, whereas those who were ambulatory had a 5-year survival rate of 68.8%. Cox proportional hazards model demonstrated a 62% reduced risk of mortality in patients who were able to ambulate after LEA compared with those patients who were not able to ambulate. Conclusion: TTA in patients with diabetes was associated with substantial morbidity and mortality. Risk factors that were significantly associated with an increased rate of mortality were the presence of ESRD, age ≥56 years, and inability to ambulate postoperatively. Level of Evidence: Level III, retrospective case controlled study.