The cause of hip pain and dysfunction in patients with protrusio acetabuli is unclear and debated. Whether it is the result of pincer type impingement, medial joint overload, or medialization of the joint center there appears to be a consensus that this condition may be best treated with open surgical dislocation or joint arthroplasty. Thus the purpose is to present the 4 year outcomes of a series of patients with protrusio acetabuli treated arthroscopically.
Four hips in 3 patients, all active women, 26 – 37 years old with hip pain and radiographic evidence of protrusio acetabuli and center edge angle of 50 degrees or more were studied and followed for an average of 4 years (32 – 63 months). Each of these patients underwent arthroscopic anterior and lateral acetabuloplasty, partial labrectomy, synovectomy and chondroplasty. Follow up included evaluation with the modified Harris Hip Score (MHHS), radiographs, and clinical history and examination.
At an average 4 year follow up, these patients were noted to have a reduction in their center edge angle of 8 degrees on average from 58 degrees (50 – 67) to 50 degrees (42 – 60) and marked improvements in their pain and function. Modified Harris Hip Score improved from an average of 54 (39.6 – 68) pre –operatively to 97 (87 – 100) at final follow up. All three patients were happy with their outcomes. The one patient with degenerative changes on pre-operative radiographs (a 26 year old), was the only one with a score of less than 100 post-operatively.
While technically difficult to perform, arthroscopic management of protrusio acetabuli may be a viable option for young patients with this diagnosis and no arthritis.