Do patients with bone bridge amputations have improved gait compared with patients with traditional amputations?

BACKGROUND: Two surgical techniques for performing a transtibial amputation include a traditional approach and a bone bridge approach. To date, there is no conclusive evidence of superiority of either technique in terms of temporal-spatial, kinetic, and mechanical work parameters.

QUESTIONS/PURPOSES: We sought to compare instrumented three-dimensional gait parameters and mechanical work measurements of patients who had undergone a traditional or bone bridge amputation at the transtibial level. Residual limb length and its effect on those functional outcomes was a secondary interest irrespective of amputation type.

METHODS: This retrospective comparative study included 14 active-duty military men with a mean age of 25 years (range, 20-28 years). Comparisons were made between seven patients with traditional and seven patients with bone bridge amputations at the transtibial level. The patients walked at self-selected and fast paces while three-dimensional gait analysis data were collected and comparisons were made between patients with the two amputation types as well as by length of the residual limb.

RESULTS: With the numbers available, we observed no differences between the two surgical groups at either speed for the temporal-spatial parameters or mechanical work metrics. However, the bone bridge group did demonstrate greater rolloff vertical ground reaction force during the fast walking condition with a median 1.02% of body weight compared with 0.94% (p = 0.046), which suggests a more stable platform in terminal stance. When the two groups were combined into one to test the effect of residual limb length, the linear regression resulted in an R(2) value of 0.419 (p = 0.012), in which patients with longer residual limbs had improved F3 force values during self-selected walking.

CONCLUSIONS: Overall, limited functional differences were found between the two groups in this small pilot study, so a superior surgical technique could not be determined; whereas our limited sample size prevents a firm conclusion of no difference, our data can be considered hypothesis-generating for future, larger studies. Although some evidence indicated that patients with a bone bridge have improved loading at higher speeds, a regression of all patients walking at self-selected speed indicates that as residual limb length increases, loading increases regardless of amputation type. Thus, our data suggest it is important to preserve residual limb length to allow for improved loading in terminal stance.