Ankle Power and Endurance Outcomes Following Isolated Gastrocnemius Recession for Achilles Tendinopathy

Background: Studies have demonstrated improved ankle dorsiflexion and pain reduction following a gastrocnemius recession (GR) procedure. However, changes in muscle performance during functional activities are not known. The purpose of this study was to determine the effect of an isolated GR on ankle power and endurance in patients with Achilles tendinopathy. Methods: Fourteen patients with chronic unilateral Achilles tendinopathy and 10 healthy controls participated in this study. Patient group data were collected 18 months following GR. Pain was compared to preoperative values using a 10-cm visual analog scale (VAS). Patient-reported outcomes for activities of daily living (ADL) and sports were assessed using the Foot and Ankle Ability Measure (FAAM). Kinematic and kinetic data were collected during gait, stair ascent (standard and high step), and repetitive single-limb heel raises. Between-group and side-to-side differences in ankle plantarflexor muscle power and endurance were evaluated with appropriate t tests. Results: Compared with preoperative data, VAS pain scores were reduced (pre 6.8, post 1.6, P < .05). Significant differences were observed between GR and Control groups for FAAM scores for both ADL (GR 90.0, Control 98.3, P = .01) and Sports subscales (GR 70.6, Control 94.6, P = .01). When compared to controls, ankle power was reduced in the involved limb of the GR group for all activities (all P < .05). Between-group and side-to-side deficits (GR group only) were also found for ankle endurance. Conclusion: The gastrocnemius recession procedure provided significant pain reduction that was maintained at the 18-month follow-up for patients with chronic Achilles tendinopathy who failed nonoperative interventions. There were good patient-reported outcomes for activities of daily living. However, compared to controls, ankle plantarflexion power and endurance deficits in the GR group were noted. The functional implications of the muscle performance deficits are unclear, but may be reflective of patients' self-reported difficulty during more challenging activities. Level of Evidence: Level III, comparative study.