Short-term functional assessment of gait, plantarflexor strength, and tendon properties after Achilles tendon rupture

Abstract

Background: Although early functional rehabilitation (EFR) has been suggested to yield rapid functional recovery after Achilles tendon rupture (ATR) compared to conventional rehabilitation (CR), most quantitative assessments occur long after rehabilitation has been completed. Few data exist regarding the short-term functional gains during the healing period post-ATR. It remains unclear if EFR allows for an objectively faster return to function. The aim of this study was to examine EFR's effect on gait, plantarflexor strength, and tendon properties in early post-operative follow-ups.

Methods: Fourteen patients received either EFR (n = 6) or CR (n = 8) after percutaneous ATR repair. Functional gait analysis, maximal voluntary isometric contractions (MVICs), and Achilles tendon properties were assessed at 8 and 12 weeks post-op.

Results: Comparison of EFR against CR yielded no statistically significant differences in ankle kinematics or kinetics, Achilles tendon properties or MVICs on the injured (INJ) ankle at either time point. During gait, only CR patients demonstrated significantly lower plantarflexion moments on INJ at 8 weeks (0.817 ± 0.151 N·m/kg vs. 1.172 ± 0.177 N·m/kg, p = 0.002). All patients exhibited deficits in plantarflexor moment at 8 weeks and eversion moment at 12 weeks on INJ during gait that had effect sizes of note when compared to CON.

Significance: ATR patients, regardless of rehabilitation, exhibit deficits in gait, AT properties, and single-limb strength at 8 weeks. Though AT properties and single-limb plantarflexor isometric strength remain at a deficit at 12 weeks, bipedal plantarflexion moments are comparable between INJ and CON. Though effect size calculations suggested clinically significant differences, clear benefits of EFR compared to CR were not found.

Keywords: Achilles tendon rupture; Gait; Muscle-tendon unit; Rehabilitation; Ultrasonography.