Management of Symptomatic Isolated Congenital Anterior Cruciate Ligament Deficiency with Gradual Correction of Biplanar Proximal Tibial Deformity: A Case Report

Abstract

Introduction: Isolated congenital ACLD is a rare condition with limited literature on the optimal management approach. At present, patients with instability symptoms have been managed with ACL reconstruction in case reports. We present a case report of symptomatic isolated congenital anterior cruciate ligament deficiency (ACLD) managed effectively with gradual correction of biplanar proximal tibial deformity alone. Case Presentation: This was a case of bilateral isolated congenital ACLD in a 15-year-old girl with chronic bilateral knee instability, bilateral mild genu valgum, and positive Lachman’s tests. Biplanar tibial deformity was evident with a 50 proximal tibia valgus and a posterior tibial slope angle of 260 on the more symptomatic right knee. This was treated with a proximal tibial osteotomy and gradual correction with a hexapod frame using the CORA method. The right knee alignment was restored to normal. At 2-year post-surgery, her symptoms of instability had resolved, and there was a soft end point on the Lachman’s test. Conclusion: We recommend that symptomatic isolated congenital ACLD be treated by correction of any existing bony deformities first, keeping in view of ACL reconstruction if instability persists thereafter. To date, there are no reports on correction of proximal tibial deformities as the first-line treatment in isolated congenital ACLD before consideration of ACL reconstruction. To the best of our knowledge, this is the first report of symptomatic isolated congenital ACLD managed with correction of the biplanar deformity of the proximal tibia alone. Our management strategy proved to be effective in the treatment of this patient’s instability, with good post-operative outcomes. Keywords: Congenital anterior cruciate ligament deficiency, hexapod frame, deformity correction, knee instability, case report.