Do Transtibial Amputations Outperform Amputations of the Hind- and Midfoot Following Severe Limb Trauma?: A Secondary Analysis of the OUTLET Study.

BACKGROUND: The purpose of this study was to compare 18-month clinical and patient-reported outcomes between patients with severe lower-limb injuries treated with a transtibial amputation or a hind- or midfoot amputation. Despite the theoretical benefits of hind- and midfoot-level amputation, we hypothesized that patients with transtibial amputations would report better function and have fewer complications.

METHODS: The study included patients 18 to 60 years of age who were treated with a transtibial amputation (n = 77) or a distal amputation (n = 17) and who were enrolled in the prospective, multicenter Outcomes Following Severe Distal Tibial, Ankle, and/or Foot Trauma (OUTLET) study. The primary outcome was the difference in Short Musculoskeletal Function Assessment (SMFA) scores, and secondary outcomes included pain, complications, amputation revision, and amputation healing.

RESULTS: There were no significant differences between patients with distal versus transtibial amputation in any of the domains of the SMFA: dysfunction index [distal versus transtibial], 31.2 versus 22.3 (p = 0.13); daily activities, 37.3 versus 26.0 (p = 0.17); emotional status, 41.4 versus 29.3 (p = 0.07); mobility, 36.5 versus 27.8 (p = 0.20); and bother index, 34.4 versus 23.6 (p = 0.14). Rates of complications requiring revision were higher for distal amputations but not significantly so (23.5% versus 13.3%; p = 0.28). One distal and no transtibial amputees required revision to a higher level (p = 0.18). A higher proportion of patients with distal compared with transtibial amputation required local surgical revision (17.7% versus 13.3%; p = 0.69). There was no significant difference between the distal and transtibial groups in scores on the Brief Pain Index at 18 months post-injury.

CONCLUSIONS: Surgical complication rates did not differ significantly between patients who underwent transtibial versus hind- or midfoot amputation for severe lower-extremity injury. The average SMFA scores were higher (worse), although not significantly different, for patients undergoing distal compared with transtibial amputation, and more patients with distal amputation had a complication requiring surgical revision. Of note, more patients with distal amputation required closure with an atypical flap, which likely contributed to less favorable outcomes.

LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.