Purpose

Skeletally immature patients with coronal plane angular deformity (CPAD) may be at increased risk for anterior cruciate ligament (ACL) injury, osteochondritis dissecans (OCD), meniscus pathology, and patellofemoral instability in the short term as well as degenerative changes in the long term. Although CPAD is an important modifiable risk factor to address, there has been little published regarding surgical outcomes when addressing both the intra-articular knee pathology and concurrent placement of guided growth implants in this population. The purpose of this study is to describe the safety and efficacy of combined procedures to address both intraarticular knee pathology and concomitant coronal plane angular deformity (CPAD) using implant-mediated guided growth (IMGG) in skeletally immature patients.

Methods

A retrospective review of skeletally immature patients who underwent IMGG and concomitant surgery for ACL reconstruction, OCD repair, meniscus pathology, or patellofemoral instability at a single institution by one of 2 surgeons between 2008 and 2019 were reviewed. Demographics, surgical details, follow-up data and complications were recorded. Deformity correction was assessed in a subset of patients that had standing calibrated long leg radiographs at least 1 year postoperatively, had guided growth hardware removed or scheduled to have hardware removed at latest follow-up, or have reached skeletal maturity and chose not to have hardware removed.

Results

29 patients met the inclusion criteria and were eligible for the study. Deformity correction was assessed in a subset of 17 patients, 15 with valgus deformities, and 2 with varus deformities. At final follow-up, 16 of 17 patients had mechanical tibiofemoral (mTFA) angles of <5 degrees of varus or valgus. One patient developed “rebound” valgus >5 degrees after removal of the plate. Both varus patients developed mild “rebound” varus but had mTFAs of <5 degrees at final follow up. Preoperative mechanical lateral distal femoral angle (mLDFA) and mTFA were significantly different than those measured pre-operatively in valgus knees (p<0.0001 for both) but were not significantly different in the 2 varus knees (p= 0.656, 0.370 respectively).

Conclusions

IMGG in the setting of treating intraarticular knee pathology is safe and should be considered as an adjunctive procedure in skeletally immature patients with coronal plane angular deformity who are undergoing ACL reconstruction, OCD repair, treatment of meniscal pathology, or patellofemoral stabilization.