Summary

All-epiphyseal and Micheli-Kocher anterior cruciate ligament reconstruction yield promising rates of return to sports, substantially limit anteroposterior laxity, surpass IKDC thresholds for substantial clinical benefit, and regain fully functional range of motion to comparable levels in the skeletally immature population.

Abstract

Background

Early physeal-sparing anterior cruciate ligament reconstruction (ACLR) is considered the optimal treatment method in the skeletally immature population to preserve the integrity of the knee joint while reducing the risk of growth disturbances and angular deformities. Contemporary treatment algorithms recommend the use of Micheli-Kocher (MK) or all-epiphyseal (AE) ACLR techniques in patients with considerable growth remaining. Nevertheless, no research exists comparing the two techniques. Therefore, the purpose of this review is to comprehensively compare postoperative outcomes and complication profiles following all-epiphyseal (AE) and Micheli-Kocher (MK) anterior
cruciate ligament reconstruction (ACLR) in skeletally immature patients.

Hypothesis

There will be no clinically significant differences in clinical or functional outcomes across AE and MK ACLR, with similar complication profiles and rates between the two operative techniques.

Methods

A systematic search of Embase, Medline, and PubMed was conducted from inception to April 30, 2024. All studies reporting outcomes and/or complications following AE or MK ACLR were included. Study demographics, patient demographics, reported outcomes, and complications were abstracted. Screening and data abstraction were designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) guidelines. Descriptive statistics were presented when applicable, with data for heterogeneous outcomes presented in narrative summary fashion.

Results

Twenty-nine studies with 1,177 patients were included. One study had high quality of evidence, 23 had moderate quality of evidence, and five had low quality of evidence. AE ACLR and MK ACLR yielded similar results for rates of return to preinjury level of activity (91.8% and 93.4%, respectively), negative pivot-shift (93.9% and 95.2%) and Lachman test grades (93.9% and 90.8%), IKDC subjective scores (94.0 and 93.6), ROM flexion (144.1° and 136.3°) and hyperextension (2.5° and 3.1°). There were a total of 130 major complications reported across 18 studies (689 knees; 18.9%) following AE ACLR, including 73 graft failures (10.6%), 29 contralateral ACL tears (4.2%), eight growth disturbances (1.5%), and seven angular deformities (1.3%). Whereas, there were a total of 35 major complications reported across 5 studies (211 knees; 16.6%) following MK ACLR, including 14 graft failures (6.6%), 14 contralateral ACL tears (6.6%), and notably no growth disturbances or angular deformities. AE ACLR yielded a greater risk of growth disturbances, angular deformities, and graft failures (1.5%, 1.3%, 10.6%, respectively), but a lower risk of contralateral ACL tears (4.2%) relative to MK ACLR (0.0%, 0.0%, 6.6%, and 6.6%, respectively).

Conclusion

Both AE and MK ACLR yield promising rates of RTS, substantially limit anteroposterior laxity, surpass IKDC thresholds for acceptable knee health, and regain fully functional ROM to comparable levels, though yield marginally different complication profiles. However, the majority of the included studies were moderate or low quality evidence with high statistical heterogeneity. Therefore, no statistical conclusions regarding the differences in complication profiles can be drawn. Future randomized controlled trials or large prospective cohort studies should compare the efficacy and complication profile of quadriceps tendon autograft AE ACLR relative to MK ACLR.

Level of Evidence: Level V.