Hamstring muscle recovery following arthroscopic anatomic lateral ankle ligament reconstruction.

PURPOSE Arthroscopic anatomic lateral ankle ligament reconstruction using gracilis autograft has become common practice in the treatment of chronic lateral ankle instability. While morbidity of hamstring harvesting has been extensively studied in anterior cruciate ligament reconstruction, no study has assessed the impact of this autograft on muscle recovery in ankle ligament reconstruction. The purpose of this study was to evaluate short-term hamstring recovery using isokinetic tests.

METHODS All patients operated on for chronic lateral ankle instability by arthroscopic anatomic ligament reconstruction, who underwent isokinetic testing of hamstring function at the time of return to sports, were included. Isokinetic tests were performed in a standardized manner. Primary outcome was concentric hamstring strength at 60°/s, compared to the contralateral limb with the Limb Symmetry Index (LSI). Secondary outcomes included concentric quadriceps strength at 60°/s, muscle balance measured by hamstring-to-quadriceps ratio and a functional assessment of the operated ankle by jump tests. A subgroup analysis was performed on isokinetic testing according to sport level.

RESULTS Twenty-nine patients were included (34% engaged in competitive sports). At 9 months, satisfactory hamstring recovery was observed in 52% of patients (mean LSI of 92%). Regarding the quadriceps, 83% of patients had a satisfactory recovery (mean LSI of 99.6%). The mean hamstring-to-quadriceps muscle balance was 55% on the operated side and 59% on the healthy side. Competitive athletes showed significantly lower hamstring strength loss (p = 0.005) and more balanced hamstring-to-quadriceps ratios compared to recreational athletes (p = 0.05). Functional ankle tests showed an impact at short term in single-leg jump, but few patients presented apprehension when jumping (29%) or residual pain (33%).

CONCLUSION The isolated harvesting of gracilis tendon is safe with only a modest hamstring strength loss at 9 months. Level of sports appears to influence muscle recovery, even when well-conducted and tailored rehabilitation is followed by all patients.

LEVEL OF EVIDENCE Level II.