Preoperative Gait Analysis of Peroneal Tendon Tears

Background: Little is known regarding the impact of peroneal tendon tears on function. This study quantifies gait changes associated with operatively-confirmed peroneal tendon tears. Methods: Sixty-five patients with unilateral peroneal tendon tears were prospectively evaluated using preoperative 3D multisegment gait analysis of both limbs. Data were analyzed according to pattern/severity of tears, as confirmed surgically: peroneus brevis tears, reparable (PBR); peroneus brevis tears, irreparable (PBI); peroneus longus tears, irreparable (PLI); and concomitant irreparable tears of both tendons (PBI+PLI). The following parameters were analyzed: ankle sagittal motion, coronal motion, axial rotation, foot progression angle, sagittal power, sagittal moment. Results: Twelve patients (18.5%) had the PBR pattern, 37 (56.9%) PBI, 10 (15.4%) PLI, and 6 (9.2%) PBI+PLI. Compared with the contralateral, nonpathologic extremities, limbs with peroneal tears had diminished ankle sagittal motion (mean 23.14 vs 24.30 degrees, P =.012), ankle/hindfoot axial rotation (6.26 vs 7.23 degrees, P =.001), sagittal moment (1.16 vs 1.29 Nm/kg, P <.001), and sagittal power (1.24 vs 1.47 W/kg, P <.001). The most severe tear patterns had the greatest derangements in multiple parameters of gait (PBI+PLI > PBI or PLI > PBR). For example, all groups except PBR had loss of ankle sagittal moment and/or power in the affected limb, and the greatest losses in moment and power were in the PBI+PLI group (1.22 vs 0.91 Nm/kg, P =.003 for moment; 0.73 vs 1.31 W/kg, P <.001 for power). The PBI+PLI group had a >10-degree varus shift in coronal motion on the affected side (P =.002). Conclusion: This is the first study to demonstrate diminished biomechanical function in patients with peroneal tendon tears. In vivo 3-dimensional gait analysis found significant changes in hindfoot motion, ankle motion, and ankle power. Impairments were related to the pattern and severity of the tears, and demonstrated a strong association of peroneal tendon tears with diminished ankle plantarflexion strength. Level of Evidence: Level III, retrospective cohort study.