Incidence of Radiographic Cam-Type Impingement in Young Patients (<50) After Femoral Neck Fracture Treated with Reduction and Internal Fixation |
| |
Authors: | Matthew C Wendt Joseph R Cass Robert R Trousdale |
| |
Institution: | Mayo Clinic, 200 First Street SW, Rochester, MN 55905 USA |
| |
Abstract: | Background:Cam-type femoral impingement is caused by structural abnormalities of the hip and is recognized as a cause of degenerative hip arthritis. Identifiable etiologies of this structural abnormality include congenital malformation, pediatric hip disease, and malunion of femoral neck fractures after internal fixation.Purpose:The purpose of this study was to determine the prevalence of radiographic impingement in healed Orthopaedic Trauma Association (OTA) type 31B fractures treated with reduction and internal fixation.Methods:Seventy OTA 31B hip fractures treated with internal fixation were identified from our institutional trauma database and radiographs were retrospectively reviewed for signs of impingement. Mean follow-up was 53 months after fracture. Alpha angle, Mose templates, and femoral head retroversion were the measurements used to determine impingement.Results:The overall prevalence of any sign of radiographic impingement was 75%. Alpha angle was elevated in 32 hips (46%), asphericity was present in 46 femoral heads (65%), and femoral head retroversion was present in 26 hips (37%). The rates were highest in displaced subcapital fractures (OTA 31B-3) with a 63% (13/19) prevalence of elevated alpha angle, 68% (14/19) prevalence of asphericity, and 47% (10/19) prevalence of retroversion.Conclusions:Prevalence of radiographic signs of impingement in this population is higher than expected based on population-based controls. Surgeons must be vigilant about reduction and fixation of femoral neck fractures. Malunion should be recognized as early intervention may be beneficial in improving long-term outcomes. |
| |
Keywords: | femoroacetabular impingement femoral neck fracture alpha angle cam lesion |
|
|