Revision Total Hip Arthroplasty Using Acetabular Reinforcement Ring: Midterm Follow-up Result

PURPOSE: To evaluate the clinical and radiographic outcomes of the revision total hip arthroplasty using the acetabular reinforcement ring. MATERIALS AND METHODS: Thirty-six acetabular revisions were performed in 36 patients with use of the reinforcement ring and structural or morselized allograft, between 1997 and 2005, in thirty-six patients. According to the AAOS classification, thirty-four cases of acetabular defects were Ttype III, and two were Ttype IV. Mean follow-up period after surgery was 7.2 years. RESULTS: The mean Harris hip score was 92.3, which was significantly increased compared with the preoperative score. (p<0.001). There were five failures: a case of aseptic loosening of Muller ring, two cases of infection (5.4%) and two cases of hip dislocation (5.4%). Graft incorporation and bone remodeling occurred successfully in all hips, but in the case of aseptic loosening in which the ring fixation had been inadequate at the time of surgery. The success rate was 91.7% with a mean follow-up of 7.2 years, if the cases of revision or loosening of the component were classified into failure cases. CONCLUSION: Patients treated with acetabular revision with three kinds of reinforcement ring had reconstitution of periacetabular bone stock as well as good clinical and radiographic results. For the good results, the secure implant fixation during the surgery should be confirmed and we should completely understand the characters of the each kinds of reinforcement rings.

Acetabular reinforcement ring: surgical principles and technique / 中国矫形外科杂志

To investigate the surgical principle of various degrees of acetabular bone defect in acetabular arthroplasty. Indications and clinical effect of different allografts are also discussed. Acetabular reinforcement ring (ARR) is emphasized on its types, se-lection principle, surgical technique and common technical errors.

Acetabular Rebision Using Acetabular Reinforcement Ring and Allograft Impaction

Purpose: We wanted to evaluate the clinical and radiologic results of acetabular revision using the acetabular reinforcement ring and also the allograft impaction in the acetabulum having deficient bone stock. Material and Methods: Nineteen hips revision arthroplasty were performed in 18 patients (9 males and 9 females) with using an acetabular reinforcement ring and allograft between July 1993 and December 2003. The patients were followed for an average of 64 months (range: 24-153). The mean age at the time of arthroplasty was 59 years old (range: 34-76). The causes of revision were aseptic loosening of the acetabular component in 16 cases, severe progressive osteolysis around the acetabular component in 2 cases and Girdlestone state after infected total hip arthroplasty in one case. The acetabular deficiency was type II in 5 hips, type III in 13 hips, and type IV in one hip according to the AAOS classification. The clinical results were evaluated using the modified Harris hip score, and the radiologic results were evaluated by assessing the preoperative and serial follow-up radiographs. Results: The mean preoperative Harris hip score of 47 was improved to 86 points at the latest follow-up. Periacetabular osteolysis was found in 2 cases, which did not progress at follow-up. The anatomic hip center was restored after revision arthroplasty (p<0.05). Complications were dislocation in 2 cases, breakage of the hook of the Ganz ring in one case, heterotopic ossification in one case and femoral artery injury in one case. All cases showed stable fixation of the acetabular component and good remodelling of the impacted allograft. There was neither recurrence of dislocation nor progression of the acetabular component loosening on the radiographs. Conclusion: Acetabular revision with acetabular reinforcement ring and allograft impaction showed satisfactory clinical and radiologic results with restoration of the hip center and consolidation of the allograft.

Revision hip arthroplasty with use of the acetabular reinforcement ring:8 cases follow-up study / 中国矫形外科杂志

[Objective]To evaluate the midterm clinical and radiographic results of revision hip arthroplasty by acetabular reinforcement ring (ARR) with impaction bone grafting. [Methods]Revision hip arthroplasty by ARR with impaction bone grafting of 8 hips was performed from May 2001 to December 2006. There were 5 males and 3 females with an average age of 53 years (range, 36~70 years).The mean BMI was 20 (range, 15~28). The mean interval between the primary arthroplasty and revision was 5 to 20 years (mean 6.7 years). The causes for revision were infective loosing in 2 and aseptic loosening in 6. In the 8 hips, 6 hips underwent a revision total hip arthroplasty, 2 hips received replacement of the acetabular component. Consecutive radiographs were compared to evaluate component conditions and the influence of bone deficiency to fix the prothesis was analyzed. Harris hip scores (HHSs) were determined before surgery and at the most recent follow-up examination. The Kaplan-Meier survivorship analysis was used to estimate the probability of survival of the prothesis.[Results]Seven hips were available for complete clinical and radiographic analysis. One patient died for myocardial infarction. The mean follow-up period was 4.5 years (range, 1.5~7.1 years).The mean preoperative Harris hip score of 30(range, 20~64) points improved to 88 (range, 74~94) points at the time of final follow-up, the pain and function socre improved from 13.8 and 11.5 to 40.3 and 39.9 respectively. All patients had severe limp before revision. At the time of final follow-up, 5 patients still had slight limp and 1 patients had moderate limp.Five hips had an excellent result. Infective osteolysis and migration were seen in 2 hips, which need re-revision. Heterotopic ossification developed in 2 hips . Kaplan-Meier survivorship at 4.5 years was 63% with repeat revision or radiographic loosening.[Conclusion]ARR with impaction bone grafting is an effective approach to treat massive acetabular bone defect in revision hip arthroplasty, the midterm result is acceptable, but any possible reason for infection must be monitored.

Clinical and Radiological Results of Revision Acetabular Arthroplasty using an Acetabular Roof Reinforcement Ring / 대한정형외과학회잡지

PURPOSE: We evaluated the clinical and radiological results of acetabular reconstructions using an acetabular roof reinforcement ring (ARR). MATERIALS AND METHODS: From May 1993 to November 1999, 18 hips revised with ARR were evaluated. The mean age at operation was 53 years. The average follow-up period was 51 months (24-94 months). Acetabular defects were classified based on the AAOS classification system. There was one case of type IIA defect, six cases of type IIB defect, ten cases of type III defect and one case of type IV defect. All were treated with morselized allografts and autografts, and three were reconstructed with additional structural autografts. RESULTS: The average Harris hip score improved from 54 preoperatively to 76 postoperatively, but five patients complained of intermittent hip pain. On the last follow-up radiographs, the bone grafts were united and remodeled in all cases, but only partial resorption was observed in two hips. We found evidence of osteolysis in four hips and observed cup migration in three hips. Three hips, in which Muller rings were used, were re-revised during the follow-up period. CONCLUSION: Acetabular reconstruction using ARR led to good clinical and radiological results, but a relative high rate of rerevision was shown in the cases fitted with the Muller ring. Appropriate ARR should be used depending on the extent of the acetabular defect.

Early Failure of Acetabular Component after Total Hip Arthroplasty in Irradiated Hip / 대한정형외과학회잡지

PURPOSE: The treatment of the osteonecrosis in the acetabulum and femoral head after irradiation has not been well estabilished. The early failure of acetabular component after total hip arthroplasty (THA) is the main concern in osteonecrosis after irradiation. MATERIALS AND METHODS: Our study included 18 patients with post-radiation osteonecrosis of 26 hips who had a THA, mean age 54.2 years. Average irradiation dosage was 4611 cGy and interval between irradiation and primary total hip replacement was 64.3 months. The cementless acetabular components were used in 16 hips (group one) and acetabular reinforcement rings were used in 10 hips (group two: Muller cup 6 cases, Ganz cup 4 cases). RESULTS: Acetabular loosenings were occurred at 8 of 16 hips (Group 1: 50%) during the mean follow-up 46 months. The cases of Muller cup (Group 2: 33%) was failed in 2 of 6 hips at postoperative 12 months and 22 months. CONCLUSION: Although follow up duration is short and cases are small, the use of cemented cup with acetabular reinforcement ring was better than non-cemented cup for THA in irradiated hip in terms of preventive of early failure of acetabular component.

Acetabular Reconstruction using Acetabular Roof Reinforcement Ring / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical and radiographic results of acetabular reconstruction in severe acetabular bony defect using acetabular roof reinforcement ring with hook. MATERIALS AND METHODS: Thirty-five acetabular reconstructions using acetabular roof reinforcement ring with hook were performed between 1993 and 1997 and were followed up for more than two years. Bony defect was classified according to AAOS classification system. The clinical function was evaluated by Harris hip score and radiographical evaluation was focused on the osseous union of the grafted bone, reconstruction of center of rotation and any signs of socket loosening. RESULTS: The mean Harris hip score improved from 49 points preoperatively to 85 points at the final follow up. The bone graft was incorporated in 33 cases as shown by radiographic remodelling and had a homogenous trabecular appearance. In all cases, the center of rotation was repositioned within three milimeters from the anatomical position. One case was rerevised due to hook failure and postoperative deep infection. Another hook failure without infection was found in one case, but this patient had no radiographic or clinical instability because of bony consolidation after the grafted bone initially settled down at final follow up. Postoperative complications were hip dislocation in 3 hips, nonunion of the greater trochanter in one hip and discomfort at autograft donor site in 3 hips. CONCLUSION: Acetabular reconstruction using acetabular roof reinforcement ring with hook combined with morcellised bone graft was considered to be an useful methods especially in severe acetabular bone deficiency.