No Difference in Functional Outcomes When Lateral Extra-Articular Tenodesis Is Added to Anterior Cruciate Ligament Reconstruction in Young Active Patients: The Stability Study

Purpose: To assess the functional outcomes of patients included in the Stability Study randomized controlled trial comparing anterior cruciate ligament reconstruction (ACLR) alone with ACLR with lateral extra-articular tenodesis (LET) at 6, 12, and 24 months postoperatively.

Methods: Six hundred eighteen patients undergoing ACLR, all under the age of 25 years 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, calculated using a series of 4-hop tests at 6, 12, and 24 months postoperatively. 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 = .76), and 24 months (21 vs 23; P = .87). Of those who completed hop testing, there were no statistically significant differences between groups in Limb Symmetry Index at 6, 12, or 24 months. Self-reported function (Lower Extremity Functional Score) significantly favored the ACLR alone group at 3 (P = .01) and 6 months (P = .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 = .03) and average power (P = .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 postoperative (P = .11 and P = .32, respectively).

Conclusions: 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 postoperatively. However, these differences do not have any impact on objective function as measured by hop test limb symmetry index.

Level of evidence: I, Randomized Controlled Trial.