No Difference in Functional Outcomes When Lateral Extra-articular Tenodesis is Added to Anterior Cruciate Ligament Reconstruction in young active patients: The Stability Study

Abstract Purpose The purpose of this study was to assess the functional outcomes of patients included in the Stability Study randomized controlled trial comparing anterior cruciate ligament reconstruction (ACLR) alone to ACLR with lateral extra-articular tenodesis (LET) at 6, 12 and 24 months post-operative. Methods Six hundred and eighteen patients undergoing ACLR, all under the age of 25 either returning to contact pivoting sport or displaying signs of high grade rotatory laxity or generalized ligamentous laxity, were randomly assigned to receive ACLR alone or ACLR plus LET. A total of 356 of these patients were randomized at centers participating in the functional assessments. Our primary outcome was Limb Symmetry Index (LSI) calculated using a series of four hop tests at six, twelve, and twenty-four months postoperative. Secondary outcome measures included pain, patient-reported function and isokinetic strength testing. Results We found no statistically significant difference in the proportion of patients either unwilling or unfit to complete the hop testing in the ACLR alone or ACLR with LET group at 6 months, (40 vs. 40 respectively; p=1.00), 12 months (25 vs. 27; p=0.76) and 24 months (21 vs. 23; p=0.87). Of those who completed hop testing, there were no statistically significant differences between groups in LSI at 6, 12 or 24 months. Self-reported function (Lower Extremity Functional Score) significantly favored the ACLR alone group at 3 (p=0.01) and 6 months (p=0.02) postoperative but was similar by 12 months postoperative. Pain scores (P4) also showed a statistically significant difference in favor of the ACL alone group but this also resolved by 6 months. Quadriceps peak torque (p=0.03) and average power (p=0.01) were also significantly different in favor of the ACLR alone group at 6 months postoperative; however, these were similar between groups by 12 months post-operative (p=0.11and p=0.32 respectively). Conclusion The addition of a LET to ACLR results in slightly increased pain, a mild reduction in quadriceps strength and reduced subjective functional recovery up to 6 months post-operative. However, these differences do not have any impact on objective function as measured by hop test limb symmetry index.