Implant Failure in Slipped Capital Femoral Epiphysis: A Report of Two Cases.

Abstract

Slipped capital femoral epiphysis (SCFE) is a common hip disorder in adolescents. The current standard treatment in North America is percutaneous fixation with either a fully threaded or partially threaded cannulated screw1-3. Although several historical references have described implant complications4,5, failure of modern implants is rare. We present two cases of implant failure in SCFE in two adolescents. We found no other recent reports in the literature of broken partially threaded cannulated screws used for fixation of SCFE as occurred in our patients. Both patients and their parents were informed that data concerning their cases would be submitted for publication, and they all provided consent. Case 1. After three weeks of experiencing slowly progressive anterior hip pain, a fourteen-year-old boy had in situ fixation of an unstable right SCFE with a single 6.5-mm partially threaded cannulated screw (Figs. 1-A and 1-B). The initial postoperative course was uneventful. Against the advice of the surgeons, he began participating in contact sports six months after surgery. One month after resuming sports activity, the hip pain returned. Radiographs revealed that the screw was broken in the smooth shaft portion, distal to the physis and distal to the screw-shaft junction (Figs. 1-C and 1-D). No evidence of physiodesis was present. The broken portion of the screw was removed, and a 7.0-mm fully threaded screw was inserted for revision fixation. Six months later, radiographs demonstrated physeal fusion, and the patient was asymptomatic with no hip pain (Figs. 1-E and 1-F). Fig. 1-A Fig. 1-B Figs. 1-A through 1-F Radiographs of Case 1. Figs. 1-A and 1-B Fixation of SCFE with partially threaded cannulated screw. Fig. 1-C Fig. 1-D Figs. 1-C and 1-D One month after return to sports, the broken screw was seen. No …