title: Arthroscopic management of protrusio acetabuli.
abstract: OBJECTIVE
  The purpose of this study was to evaluate 4 hips with symptomatic protrusio acetabuli treated arthroscopically for symptomatic pincer-type femoroacetabular impingement in 3 patients aged younger than 40 years.
  
  
  METHODS
  Four hips in 3 patients, all active women, aged 26 to 37 years, with hip pain and radiographic evidence of protrusio acetabuli and a center-edge angle (CEA) of 50° or more, were studied and followed up for a minimum of 2.5 years. 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.
  
  
  RESULTS
  Patient 1 had bilateral hip surgeries. The right hip was followed up for 63 months, and the CEA improved from 67° to 60°, with an mHHS score improvement by 60.4 points. The CEA for the left hip improved from 63° to 53° at 61 months' follow-up, and the mHHS improved by 43.9 points. Both hips had a final mHHS of 100 points. Patient 3, followed up for 28 months, had a final mHHS of 100 points, 32 points better than preoperatively, whereas the CEA improved from 51° to 44°. Patient 3, a 26-year-old with preoperative radiographically apparent arthritis, had a final mHHS of 87 points, 35 points better than preoperatively, and the CEA improved from 50° to 42° at 32 months' follow-up. All 3 patients were happy with their outcomes.
  
  
  CONCLUSIONS
  In this small case series, arthroscopic acetabuloplasty showed reduced symptoms and improved function in 3 patients with protrusio aged younger than 40 years at a minimum of 2.5 years' follow-up.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Orthopaedic Surgery, Stanford University, Redwood City, California, U.S.A. Electronic address: msafran@stanford.edu.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Safran
authors.forename: Noah P
authors.initials: NP
authors.lastname: Epstein
mesh_terms: D000077:Acetabulum / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D018771:Arthralgia / Q000209:etiology; D001178:Arthroplasty; D001182:Arthroscopy / Q000379:methods*; D005260:Female; D057925:Femoracetabular Impingement / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D011859:Radiography