ABSTRACT
PURPOSE: To analyze, using finite element model analysis, the causes of postoperative pain in patients who had arthroscopic treatment for femoroacetabular impingement (FAI). MATERIALS AND METHODS: Ten patients with FAI treated by arthroscopic surgery between July 2004 and July 2007 were selected. Five cases whose condition improved to a pain score of 3 postoperatively were assigned to comparative group A and 5 cases who had a second operation done due to a pain score of 1 were assigned to experimental group B. Finite element model analysis was done for the impingement test position. Femoral offset and alpha angle were measured to compare with contact pressure or von Mises stress. RESULTS: Preoperative von Mises stress and contact pressure were all higher in group B than group A. Maximal stress and pressure location was the anterolateral surface of the femoral head and neck, and this location was removed more accurately in group A. CONCLUSION: Finite element model analysis of FAI indicated that incomplete removal of a bump was the cause of pain, and that accurate location of the lesion and adequate bump removal are the definitive factors in reducing pain.
Subject(s)
Humans , Arthroscopy , Femoracetabular Impingement , Head , Hip , Neck , Pain, PostoperativeABSTRACT
PURPOSE: To determine the significance of Magnetic Resornance Arthrography (MRA) and arthroscopy for diagnosis and treatment of acetabular labral tears as a cause of chronic hip pain. MATERIALS & METHODS: Thirty-seven hips with clinical suspicion of labral lesions were examined with MRA between Mar. 1995 and Mar. 1998. Among them, twenty-two patients underwent the diagnostic and operative arthroscopy. Another fifteen patients were observed closely without management. RESULTS: The mean age was 43 years (18-68 years) and male was twenty-five (68%) . Most common causes was degenerative (10 cases, 27%) and idiopathic (10 cases, 27%) . In MRA, stage IIA (partial tear by Czerny classification) were most common findings (twenty-one portion, 47%) . Including double tears in several patients, most common labral tear was located in the anterosuperior portion ( twenty-three cases, 51%) . Comparing arthroscopic finding, the accuracy of MRA for diagnosis of labral tear was 86.4%. Arthroscopically, we modified the morphological classification of labral tear to radial fibrillated (10 portions) , radial fibrillated + peripheral longitudinal (3) , peripheral longitudinal (4) , complete detachment (5) . All patients except three (86.4%) were improved by the arthroscopic partial labrectomy. In conservative patients, only three (20%) were spontaneously improved. CONCLUSION: MRA, and subsequent arthroscopic management appears to be a promising modality for detection and treatment of labral tear in patients with chronic hip pain.