Percutaneous hemiepiphysiodesis using transphyseal screws for adolescent tibia vara.

Abstract

Hemiepiphysiodesis around the knee is becoming the mainstay procedure in adolescents for a wide range of aetiological deformities, when considering adolescent tibia vara (ATV), the published series have variable results. The purpose of this study was to review our experience with the percutaneous transphyseal screw (PETS) in these patients followed until bone maturity. We analysed the charts from 13 patients (20 knees) that underwent lateral tibial hemiepiphysiodesis using PETS. The radiographs were accessed before surgery, at implant removal, when occurred, and at the final follow-up. The clinical evaluation noted if there were complaints regarding pain or range of motion, and the radiographic assessment included: the femorotibial angle, the mechanical axis zone, the anatomic lateral distal femoral angle, and medial mechanical proximal tibial angle. There was one overcorrection, and after the screw removal (14 knees), rebound was observed in two knees modifying the result from excellent to good in all three knees. No bone bars and no implant breakage were observed. At the last appointment, all patients had normal knee range of motion, and two patients had unilateral alignment complaints, one of whom referred to occasional pain. Overall, the surgery was excellent in 12 knees (60%), good in six knees (30%), and poor in two knees (10%). This technique is indicated to be well tolerated and effective for treating ATV. When a complete correction cannot be obtained, in our opinion, it is advantageous to at least stabilise the deformity and postpone osteotomies until after skeletal maturity. Level of Evidence: Level IV - Case Series, Therapeutic Study.