Femoral Morphology in Patients Undergoing Periacetabular Osteotomy for Classic or Borderline Acetabular Dysplasia: Are Cam Deformities Common?

ABSTRACT

BACKGROUND: The primary purpose of our study was to determine the prevalence of Cam deformity in patients with symptomatic acetabular dysplasia (SAD) who underwent periacetabular osteotomy (PAO). METHODS: We retrospectively reviewed 164 SAD PAO patients from 2 institutions. Preoperative anteroposterior and frog-lateral radiographs were analyzed for lateral center edge angle (LCEA), retroversion, alpha angles, and anterior femoral head-neck offset. Hips were classified as dysplastic (LCEA <20°, group A, n = 142) and borderline dysplastic (LCEA 20°-25°, group B, n = 22). There were 128 females and 36 males with an average age of 29 years (range 13-56). RESULTS: The overall prevalence of Cam deformity was 10% (17 of 164) in SAD patients. There was no difference in the prevalence of Cam deformity between the groups (P > .99). CONCLUSION: Prevalence of Cam deformities in our series of SAD patients having undergone PAO is less than prior reports. Careful radiographic measurement should be performed to avoid overtreating these hips with unnecessary osteochondroplasty procedures.