両側膝蓋骨形成不全に伴う恒久性膝蓋骨脱臼に対し両側内側膝蓋大腿靱帯（MPFL）再建術を施行した1例

Medial Patellofemoral Ligament Reconstruction for Bilateral Permanent Patellar Dislocation in a Patient with Patellar Aplasia and Hypoplasia. Case Report

　両側膝蓋骨形成不全に伴う恒久性膝蓋骨脱臼に対し両側内側膝蓋大腿靱帯（以下MPFL）再建術を施行した．症例は22歳の女性で，主訴は両膝関節痛・脱臼感であった．左大腿骨開放骨折を来し手術加療した際の単純X線写真で，右膝蓋骨完全欠損，左高度膝蓋骨低形成を認め，MRIで，両側に脱臼した膝蓋骨様組織を認めた．骨折治療後，症状が増強し改善なく，両側のMPFL再建術を施行した．人工靱帯でMPFLを再建したところ，術後経過は良好である．膝蓋骨形成不全に伴う膝蓋骨脱臼に対してもMPFL再建術は有効であった．

　We report a good outcome of medial patellofemoral ligament (MPFL) reconstruction performed to treat bilateral permanent patellar dislocation in a 22-year-old female with patellr aplasia and hypoplasia. The patient sustained a fracture of the left femoral shaft, and it was treated by internal fixation. Radiological examination revealed patellar aplasia on the right side and severe patellar hypoplasia on the left side. Bilateral axial MR images showed dislocated patella-like fibrous tissue after union of the femoral fracture, the patient. complained of a severe feeling of instability in both knees. When her symptoms persisted almost unchanged, we performed bilateral MPFL reconstruction with artificial ligament and wide lateral release. At surgery, we confirmed the presence of patella-like fibrous tissue between the patellar ligament and the quadriceps tendon on both sides. As of 18 months postoperatively the patient is satisfied with the results.

　MPFL reconstruction was an effective method of treating bilateral permanent patellar dislocation in a patient with patellar aplasia and hypoplasia.