Modified Star Excursion Balance Testing at 12 Months After Anterior Cruciate Ligament Reconstruction: Is There a Difference Between Quadriceps or Hamstring Tendon Autografts?

Background: Quadriceps tendon (QT) autograft has emerged as an increasingly popular graft for anterior cruciate ligament reconstruction (ACLR). The modified Star Excursion Balance Test (MSEBT) measures dynamic balance and is frequently used in evaluating preparedness to return to sport as part of return-to-sport test batteries. There is limited information available about the MSEBT performance of patients who have undergone ACLR with QT autograft. Hypothesis/Purpose: The purpose was to compare the MSEBT performance at 12 months after primary ACLR of patients with QT autografts with the performance of patients with hamstring tendon (HS) autografts. It was hypothesized that there would be a difference in the 2 groups due to harvest from either an extensor or a flexor of the knee joint. Study Design: Cohort study; Level of evidence, 3. Methods: The cohort consisted of 132 patients (44 patients with QT, 88 patients with HS) who had undergone primary ACLR with either a QT or HS autograft, were <30 years of age at the time of surgery, and had participated in sports regularly before injury. Patients with contralateral anterior cruciate ligament injury or an additional lateral extra-articular tenodesis were excluded. The mean age of the patients was 22.1 years, and 18% were female. The anterior reach, posterolateral reach, and posteromedial reach on the MSEBT were recorded at 12 months postoperatively and normalized to leg length. The limb symmetry index (LSI) and the composite score (CS) were calculated for each measurement. Patient-reported outcome measures were also collected. Results: There were no significant differences between the mean LSI and the CS of the QT and HS groups for any reach direction of the MSEBT (LSI: QT = 99.9 and HS = 98.9 for anterior reach, QT = 100.9 and HS = 100.2 for posterolateral reach; QT = 101.1 and HS = 100.8 for posteromedial reach, CS: QT = 96.6 and HS = 96.9). Patient-reported outcome measures also showed no significant difference. Conclusion: There were no differences in symmetry between QT and HS grafts in MSEBT performance at 12 months, with both patient groups having >98% limb symmetry in each reach direction.