Micheli ACL Reconstruction in Prepubescent Youths: A Retrospective Outcomes Study

OBJECTIVES: Management of anterior cruciate ligament (ACL) tears in the skeletally immature patient remains controversial. In patients with significant growth remaining, physeal injury from conventional surgical reconstruction risks creating a limb length inequality or angular deformity; however, continued instability poses significant long-term morbidity from subsequent chondral and meniscal injuries. Done with appropriate precautions, transphyseal reconstructions are reasonably safe in older adolescents; however, little evidence of safety in the prepubescent athlete exists. Micheli has described a physeal sparing technique using the iliotibial band for a combined intra-articular and extra-articular ACL reconstruction. The purpose of this study is to analyze another surgeon’s experience with this procedure. METHODS: This study was IRB approved. Between 2005 and 2011, all patients who underwent Micheli ACL reconstruction, performed by a single surgeon, were identified. Three or more years of growth remaining was a prerequisite for Micheli reconstruction. Patients were excluded if postoperative follow-up was less than one year. Patients with associated knee injuries and/or concomitant knee procedures were not excluded. Functional outcome, graft survival, radiographic outcome, growth disturbance and additional procedures were evaluated. RESULTS: Twenty-one patients (22 knees) met the inclusion criteria for this study. Mean chronological age at time of surgery of 11.8 years (range: 9.9-14.3 years). All patients were male with a minimum of three years of growth remaining. There were four concomitant meniscal repairs and five concomitant partial meniscectomies performed at the index procedure. Of the included patients, 19 patients (20 knees)(90%) completed follow-up at mean postoperative duration of 3.1 years (range: 1.0-6.9 years). Two knees (9%) underwent revision ACL reconstruction for graft failure at 2.8 and 4.0 years postoperatively. Of the remaining 18 knees, the median patient satisfaction was 10 (range: 9 to 10). Mean pedi-IKDC knee score was 96.3± 2.9 points. Mean Lysholm score was 94.7 ± 6.2 points. Mean pre-injury Tegner activity level was 8 (range: 6-10) and mean postoperative Tegner activity level was 8 (range: 6-10). All patients had a normal Lachman examination with firm endpoint and a normal pivot-shift examination. At time of follow-up, 50% of patients had closed physes. There were no radiographic angular deformities or leg length discrepancies appreciated. Four of 18 knees (22%) underwent subsequent procedures including 1 graft shrinkage, 2 partial meniscectomies and 1 meniscal repair. CONCLUSION: At mean follow-up of 3.1 years, our findings confirm excellent functional outcomes, a low revision rate and no growth disturbances associated with the Micheli ACL reconstruction. Patients are able to return to the preoperative activity level following reconstruction. This procedure offers a safe and effective alternative to trans-physeal reconstruction in prepubescent children with several years of growth ahead.