AbstractPurposeThere has been a resurgence in the use of a lateral extra‐articular procedure (LEAP) in association with anterior cruciate ligament (ACL) reconstruction to reduce the risk of graft failure. The aim of this study was to examine whether the use of a LEAP in the setting of a primary ACL reconstruction was associated with an increased rate of reoperation for loss of range of motion or a symptomatic cyclops lesion.MethodsA consecutive cohort of patients aged less than 30 years who received a primary hamstring or quadriceps tendon autograft ACL reconstruction between January 2016 and December 2021 was retrospectively analysed. The usage of a modified Ellison LEAP in this cohort increased from 0% in 2016 to 51% in 2021. Reoperation rates for loss of motion or a symptomatic cyclops lesion during the first year after surgery, as well as knee extension deficits at 12 months, were compared between LEAP and no‐LEAP patients. Contingency analyses with risk ratio (RR) were calculated.ResultsA total of 1076 patients were included in this study [59.6% male, mean age 21.6 (SD 4.4) years, 84.9% hamstring tendon autografts]. In 17.3% (186/1076) of the patients the ACL reconstruction was augmented with a modified Ellison procedure. Of this group [67.2% male, mean age 18.8 (SD 3.7) years, 79.6% hamstring tendon autografts], 8.1% (confidence interval (CI) 4.2%–12%) required further surgery for restricted motion or a cyclops lesion in the first year after surgery, compared to 3.8% (CI 2.6%–5.1%) in the no‐LEAP group (risk ratio (RR) 2.1, p = 0.012). The difference in reoperation rates between those with and those without LEAP was more marked for patients who received a quadriceps tendon autograft (13.2% vs. 3.2%, RR 4.1, p = 0.019), compared to patients treated with a hamstring tendon autograft (6.8% vs. 3.9%, RR 1.8, p = 0.122). There was no significant difference in extension deficit at 12 months between patients with and those without a LEAP (mean 1.02 ± SD 2.6 degrees vs. mean 0.97 ± SD 2.4 degrees, p = 0.85).ConclusionSurgical intervention for a loss of range of motion or symptomatic cyclops lesion in the first postoperative year after primary ACL reconstruction was more common in patients who had an additional LEAP than in those who did not. The higher intervention rate was more apparent in patients who had a quadriceps tendon autograft ACL reconstruction.Level of EvidenceLevel III, retrospective comparative study.