Primary anterior cruciate ligament repair: Current concepts

Anterior Cruciate Ligament Repair Results in Similar Patient-Reported Outcome Measures as Anterior Cruciate Ligament Reconstruction: A Systematic Review of Prospective Comparative Studies

PURPOSE

To investigate the patient-reported outcomes (PROs), knee stability, and complications in prospective comparative studies of patients undergoing augmented anterior cruciate ligament (ACL) repair compared with anterior cruciate ligament reconstruction (ACLR).

METHODS

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Human clinical studies of Level I-II evidence comparing PROs, knee stability, and complications after ACL repair and reconstruction were included, and a qualitative analysis was performed. Excluded studies included those lacking reporting outcomes, studies that performed open ACLR or repair, studies published before the year 2000, and studies with evidence Levels III-IV. Study quality was assessed using the Cochrane Collaboration's risk of bias tool.

RESULTS

Seven Level I-II studies were retained, comprising 190 ACLR and 221 repairs (75 bridge-enhanced ACL repair [BEAR], 49 suture augmentation [SA], and 97 dynamic intraligamentary stabilization [DIS]). At final follow-up, re-rupture rates varied between 0 and 14% (BEAR) versus 0 and 6% (ACLR) and mean side-to-side differences measured using KT-1000 testing ranged from 1.6 to 1.9 mm (BEAR) versus 1.7 to 3.14 mm (ACLR). For DIS versus ACLR, mean anterior tibial translation values at final follow-up were 1.7 mm (DIS) versus 1.4 mm (ACLR), and re-rupture rates ranged from 20.8% to 29% (DIS) versus 17% to 27.2% (ACLR). For SA versus ACLR, the mean side-to-side difference ranged from 0.2 to 0.39 mm (SA) versus 0.33 to 0.4 mm (ALCR), whereas the re-rupture rates were 10% (SA) versus 0% (ACLR). International Knee Documentation Committee, Tegner, Lysholm, and Knee Injury and Osteoarthritis Outcome scores across both cohorts exhibited statistically significant, and comparable improvement, from baseline to final follow-up ranging from 1 to 5 years.

CONCLUSIONS

Augmented ACL repair results in similar patient-reported outcome measures in comparison with ACLR. However, augmented ACL repair may be associated with greater rates of failure, given re-rupture rates of up to 14%, 29%, and 10% for BEAR, DIS, and SA, respectively.

LEVEL OF EVIDENCE

Level II, systematic review of Level I-II studies.

Reproducibility of the native ACL mid-substance cross-sectional area in anatomical single bundle ACL reconstruction

Purpose

The purpose of this study was to evaluate the reproducibility of the native anterior cruciate ligament (ACL) mid-substance cross sectional area in anatomic single-bundle ACL reconstruction.

Methods

Fifty-eight subjects who were performed anatomic single-bundle ACL reconstruction were included. Cross section size of the ACL graft was calculated from the graft diameter during surgery. Computed tomography (CT) of the knee was performed pre-operatively. Following Iriuchishima's report, native ACL size was estimated from the axial CT image of intercondylar notch area of femur at the most distal level of Blumensaat's line (In the report, native ACL size was equal to 14% of the intercondylar notch area of femur). The measured ACL graft cross-sectional size and estimated native ACL size were compared and correlation was evaluated.

Results

Measured ACL graft cross-sectional size was 49 ± 14 mm2. Measured intercondylar notch area of femur at the most distal level of Blumensaat's line was 372 ± 91.6 mm2, and estimated native ACL size was 53 ± 12.5 mm2. Measured ACL graft cross-section and estimated native ACL showed no significant size difference. Measured ACL graft cross-section and estimated native ACL had no significant size correlation.

Conclusion

Native ACL cross-sectional size was reproduced in anatomic single-bundle ACL reconstruction. However, as measured ACL graft and estimated native ACL showed no size correlation, it is possible that size of native ACL might not be reproduced. Such cases would be susceptible to the risk of graft impingement or knee instability.

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.