Assessment of eversion and plantar flexion strength after repair of Achilles tendon rupture using peroneus brevis tendon transfer.

Eight patients with Achilles tendon ruptures, one of which was a late discovery, underwent peroneus brevis tendon transfers to repair their injuries. Subsequently, both the repaired and normal extremities of all eight patients were tested for eversion and plantar flexion strength. The Cybex 340 isokinetic system (Lumex Corp, Bayshore, New York) was used at both 30 degrees per second and 120 degrees per second. Patients' affected sides were then assessed subjectively for function compared with their opposite normal sides. Results for eversion strength showed a 17.4% deficit at 30 degrees per second and a 14.9% deficit at 120 degrees per second on the repaired extremity. Only the group with the 14.9% deficit showed a statistically significant difference using the paired t test (P < 0.05). Results for plantar flexion strength showed a 1.5% difference at 30 degrees per second and a 5.8% difference at 120 degrees per second. None of these differences were statistically significant. Subjective assessment showed no functional compromise in eversion strength, plantar flexion strength, activities of daily living, or ankle stability. Conclusions are that mild objective eversion weakness and no objective plantar flexion weakness can be expected after this procedure; however, subjective assessment reveals no functional compromise.