Editorial Commentary: Full Extension or 30° Flexion in Graft Fixation for Anatomic Anterior Cruciate Ligament Reconstruction. Is This Surgeons' Preference?

Recovery of Full Hyperextension After Anterior Cruciate Ligament Reconstruction Is Associated With Better Functional Outcomes but Greater Anterior Cruciate Ligament-Related Laxity After a Minimum 24-Month Follow-Up

PURPOSE

To evaluate patients who had anterior cruciate ligament (ACL) reconstruction with preoperative hyperextension and compare physical examination (KT-1000 and pivot shift) and patient-reported outcome measures of patients who recovered the entire hyperextension with patients who did not.

METHODS

Patients aged 18 to 60 years with more than 5° of knee hyperextension who had anatomic ACL reconstruction with any graft from June 2013 to June 2021 and at least a 24-month follow-up were evaluated retrospectively. Hamstrings and patellar tendon grafts were fixed around 20° to 30° of flexion and in full extension, respectively. Patients who could recover hyperextension were compared with patients who did not. Preoperative, intraoperative, and postoperative data, including physical examination and patient-reported outcome measures, were evaluated.

RESULTS

Of the 225 patients evaluated, 48 (21.3%) did not recover hyperextension, and 177 recovered full range of motion. Patients who did not recover hyperextension had a larger graft diameter (8.7 ± 0.7 mm [confidence interval, 8.502-8.898 mm] vs 8.3 ± 0.7 mm [confidence interval, 8.197-8.403 mm]; P = .018). Regarding the postoperative subjective variables, patients who recovered hyperextension showed improvement on all scales (International Knee Documentation Committee, Lysholm, Forgotten Joint Score, and Global Perceived Effect) evaluated compared with patients who did not recover the range of motion. Patients who recovered hyperextension also showed more laxity on physical examination, measured by the KT-1000 (1.8 ± 0.8 vs 1.1 ± 1.0; P = .0006) and the pivot shift (62.1% [grade 0] and 37.9% [grade 1] vs 79.2% [grade 0] and 20.8% [grade 1]; P = .027).

CONCLUSIONS

Patients with knee hyperextension who regained range of motion after ACL reconstruction have worse knee laxity than patients who regained full extension but not hyperextension. However, patients who recover full range of motion showed higher scores on subjective function scales, including a greater number of patients who achieved patient acceptable symptom state for the International Knee Documentation Committee score.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Editorial Commentary: Major Technical Advances in Knee Anterior Cruciate Ligament Reconstruction Address Anatomy, Biomechanics, and Healing

The surgical techniques in knee anterior cruciate ligament (ACL) reconstruction continue to evolve significantly. Improved understanding of the anatomy, biomechanics, and healing of the ACL has offered the foundation for several advances. The goal of these innovations is to successfully restore the native anatomy and biomechanical function of the native ligament, provide a stable and pain-free knee joint, allow return to prior level of activity, prevent rerupture, and prevent osteoarthritis. Taken in sum, these are lofty goals. The shift toward anatomic ACL reconstruction, development of diverse graft options and configurations, and the addition of reinforcement techniques, such as the anterolateral ligament reconstruction and lateral tenodesis techniques, are major advancements in ACL reconstruction.

Anterior Cruciate Ligament Patellar Tendon Autograft Fixation at 0° Versus 30° Results in Improved Activity Scores and a Greater Proportion of Patients Achieving the Minimal Clinical Important Difference For Knee Injury and Osteoarthritis Outcome Score Pain: A Randomized Controlled Trial

PURPOSE

The aim of the current study was to determine the effect of the knee flexion angle (KFA) during tibial anterior cruciate ligament (ACL) graft fixation on patient-reported outcomes, graft stability, extension loss, and reoperation after anatomic single-bundle ACL reconstruction.

METHODS

All 169 included patients (mean age 28.5 years, 65% male) were treated with anatomic single-bundle ACL reconstruction using patellar tendon autograft and were randomized to tibial fixation of the ACL graft at either 0° (n = 85) or 30° (n = 84). The primary outcome was the Knee Injury and Osteoarthritis Outcome Score (KOOS) 2 years after surgery. Secondary outcomes were the Marx Activity Scale (MAS), the rate of reoperation, and physical examination findings at 1 year, including KT-1000 and side-to-side differences in knee extension.

RESULTS

The follow-up rate was 82% (n = 139) for the primary outcome. Graft failure rate at 2 years was 1% (n = 2, 1 per group). ACL tibial graft fixation at 0° or 30° did not have a significant effect on KOOS scores at 2 years after ACLR. Patients whose graft was fixed at a knee flexion angle of 0° had greater scores on the MAS (mean 9.6 95% confidence interval [CI] 8.5 to 10.6, versus 8.0, 95% CI 6.9 to 9.1; P = .04), and a greater proportion achieved the minimal clinical important difference (MCID) for the KOOS pain subdomain (94% versus 81%; P = .04). There was no significant difference in knee extension loss, KT-1000 measurements, or reoperation between the 2 groups.

CONCLUSION

In the setting of anatomic single-bundle ACLR using patellar tendon autograft and anteromedial portal femoral drilling, there was no difference in KOOS scores between patients fixed at 0° and 30°. Patient fixed in full extension did demonstrate higher activity scores at 2 years after surgery and a greater likelihood of achieving the MCID for KOOS pain.

LEVEL OF EVIDENCE

II, prospective randomized trial.