Residual-limb quality and functional mobility 1 year after transtibial amputation caused by vascular insufficiency.

INTRODUCTION Transtibial (TT) amputation is a surgical procedure that has been performed for centuries. Originally, it was a lifesaving procedure on the battlefield. Later it became the end point of surgical treatment for a vascular patient or, from another perspective, the starting point of a rehabilitation treatment aimed at restoring mobility with a prosthesis [1-2]. Despite this long history, the systematic evaluation of the amputation technique has only become a point of interest in the last decade [3-5]. We hypothesized that residual-limb quality may be important for the effectiveness of rehabilitation. No consensus in the literature exists with respect to tibial length; a range of measures have been given, including "one hand's breadth" [6], no advice at all [7], 20 cm [8], 9-11 cm distal from the knee joint line as ideal for the ischemic patient [9], 8 cm distal to the tibial tuberosity [10], and 4-7 in. [11]. We also noted a lack of consensus for other residual-limb factors, such as the length of the fibula. The question still remains: What are the characteristics of an adequate residual limb? The International Society for Prosthetics and Orthotics (ISPO) has devised a clinical standard for measurement and classification of the residual limb [12]. Based on this standard, Chakrabarty developed a scoring system with a useful format for the clinical setting. This scoring system covers several aspects of residual-limb quality, including wound healing and soft tissue condition. This study investigated whether residual-limb quality was related to functional mobility 1 year after amputation. In addition to the soft tissue conditions, we specifically focused on evaluating the bony aspects of the residual limb because these can be adequately assessed 1 year after amputation. A better insight into these aspects of residual-limb quality may inform optimal surgical procedures. MATERIALS AND METHODS Patients In this study, we focused on patients with a unilateral TT amputation caused by vascular insufficiency. Patients were evaluated 1 year after a TT amputation. Patients were recruited from five hospitals in the southwest region of the Netherlands by means of operating room records. We evaluated a retrospective cohort of 117 patients that underwent a TT amputation. Inclusion criteria were (1) [greater than or equal to] 18 years, (2) unilateral TT amputation caused by vascular insufficiency, and (3) ability to visit the outpatient clinic. In total, 71 patients met the inclusion criteria. A relevant number of patients (n = 28) died, as could be expected [13-15]. Four patients could not be traced because of incorrect addresses. Of the 39 patients contacted, 28 were willing to participate in the study, a 72 percent response rate. Of the 28 subjects who participated in the study, 5 were unable to use their prosthesis at the time of data collection because of an ulcer, pain, or other problems. We were unable to collect certain data on these subjects, and therefore, they were not included in the statistical analysis. All participants gave written informed consent. The research protocol was approved by the Medical Ethics Committee of Leiden University Medical Center. Determinants We assessed general residual-limb quality with the scoring system developed by Chakrabarty [5] (Appendix, available online only at http://www.rehab.research.va.gov/). The Chakrabarty score is a graded summed score that includes soft tissue condition, wound healing, and joint mobility. The maximum possible score is 100 points. Chakrabarty indicated a score of =60 points as a high-quality residual limb (grade A) and a score of