Management Of Acetabular Deficiency In Total Hip Arthroplasty: A Series Of 15 Cases

OBJECTIVE: Deficiency of the acetabular bone stock is one of the major problems in revision total hip arthroplasty and certain primary total hip arthroplasty. This study was done to find a new method of fixation of such fractures. METHODS: 15 Patients in whom an aseptic acetabular deficiency has been surgically reconstructed during THR between 2003-2008 were included. There were ten primary arthroplasties and five revision cases. Mean duration of follow-up is 3.2yrs (range 6months5yrs). All patients underwent surgery in the lateral position, and all were treated through a posterolateral approach. RESULTS: The postoperative radiographs were used as a reference to determine the initial position of the implant with the use of the criteria of Johnston et al. The clinical evaluations were made on the basis of Merle d' Aubigne score. Of the patients evaluated at the most recent follow-up evaluation, six (75%) were free of pain and Two (13.3%) had occasional mild pain with normal activity. CONCLUSION: We conclude that stable fixation by uncemented primary replacement with bone graft augmentation and screw fixation of bone graft was more commonly obtained in Type II and Type III defects in which the medial wall of the acetabulum was not disrupted. These cases have shown good clinical and radiological results. Cases with acetabular medial wall defect Type III and Type IV in fixation with reinforcement ring had been achieved with bone grafting at the time of the surgery have shown significantly good clinical and radiological results. Deficiency of the acetabular bone stock is one of the major problems in revision total hip arthroplasty and certain primary total hip arthroplasty. It may result from numerous factors, including the following: (1) osteolysis caused by wear, loosening, or infection; (2) excessive bone resection at the time of previous surgery, especially if the patient has had a resurfacing procedure or previous acetabular revision; (3) preexisting bone deficit from acetabular fracture or dysplasia that was not corrected at the time of previous surgery; and (4) inadvertent destruction of bone during removal of a previous component or cement. The goals of acetabular reconstruction are to establish: the center of rotation of the hip to its anatomical location for normal joint mechanics; and to reestablish the structural integrity of the acetabulum by rigid fixation of bone graft, adequate containment of the new prosthesis. MATERIAL AND METHODS 15 Patients in whom an aseptic acetabular deficiency has been surgically reconstructed during THR between 2003-2008 were included. The criteria used to select the study population included: Aseptic loosening acetabular component with a stable or unstable femoral component. A bone defect requiring the use of allograft bone or augmentation with a reinforcement ring or cage both in primary and revision arthroplasty. Primary Arthroplasty requiring Reverse Hybrid. There were ten primary arthroplasties and five revision cases. The indication for primary surgery were protrusio in Five patients, secondary arthritis post-trauma or post inflammatory with medial wall defect in three hips, dysplasia in two hips. The indication for revision was acetabular aseptic loosening in four hips and discontinuity of medial wall in one hip. Mean duration of follow-up is 3.2yrs (range 6months5yrs). Nine patients were females and six were men with mean age of fifty nine years (range, 47-72 years). As per AAOS 1 classification six patients were of type II, eight patients were type III and one patient with pelvic discontinuity i.e. type IV. Management Of Acetabular Deficiency In Total Hip Arthroplasty: A Series Of 15 Cases