Isolated Polyethylene Liner Exchange in a Revision Total Hip Arthroplasty

PURPOSE: To analyze the results of isolated exchange of polyethylene (PE) liners for treatment of wear and osteolysis around a well-fixed Harris-Galante (HG) cementless acetabular cup. MATERIALS AND METHODS: Thirty-three PE liner changes were performed without the removal of stably ingrown implants (33 hips of 32 patients). They were able to be followed for a mean period of 92 months. Clinically, the Harris hip score (HHS), pain evaluation, and complications were evaluated. Radiologically, the annual wear rate and the size of the osteolytic lesions were measured before the operation and the latest follow-up. The bone graft incorporation scale and the development of new osleolytic lesions were checked during the final follow-up. RESULTS: HHS improved to 89.3 at last follow-up. The size of the osteolysis was significantly reduced postoperatively. Bone graft incorporation scales were Grade I in 9 and Grade II in 14 cases. New osteolytic lesions have not developed at latest follow-up. As a complication, one case of dissociation of a liner and a periprosthetic fracture were noted. Annual wear rates during the same period were significantly reduced. There was no sign of alteration in stability of the PE liner. CONCLUSION: Exchange of a PE liner without removal of stable implants can be a good option for the treatment of wear and osteolysis around a stable cementless THA implant, even if the system has a weak locking mechanism, such as the HG cup. In these cases, under certain states with a higher risk of early failure in the locking mechanism, it would be better to select other revision procedures such as cup revision or cemented polyethylene liner fixation.

Cementless Total Hip Arthroplasty for Osteonecrosis of the Femoral Head: A Follow-up Study for 10+ Years

PURPOSE: The aim of this study was to assess the outcome of cementless total hip arthroplasty (THA) in cases of osteonecrosis of the femoral head. MATERIALS AND METHODS: We studied long-term outcomes for 54 patients (72 hips). Mean duration of follow-up was 13.5 years. Clinical outcomes were evaluated by the Harris Hip Score. Radiographic evaluation from the preoperative and follow-up periods included assessment of the fixation of the femoral and acetabular components, polyethylene wear, osteolysis, and radiolucent line. RESULTS: The mean Harris Hip Score improved from a preoperative value of 51.9 points to 89.4 at final follow-up. Regarding the femoral components, there was radiographic evidence of stable bony ingrowth in 69 hips, stable fibrous ingrowth in 2 hips and unstable fixation in 1 hip. There was a radiolucent line of less than 1 mm in 7 hips, and femoral osteolysis in 27 hips. Regarding the acetabular components, there was radiographic evidence of stable fixation in 68 hips, unstable fixation in 4 hips, and osteolysis in 39 hips. There was a significant correlation between (i) failure of components and (ii) femoral osteolysis, acetabular osteolysis, polyethylene thickness, linear wear rate per year, or total linear wear. CONCLUSION: The findings of this study show favorable long term results, both clinical and radiographic, using cementless total hip replacement arthroplasties. However, the revision rates for the Harris-Galante acetabular components were high. Wear of the load? weight? bearing surface continues to limit the long-term success rate of THA, and improved design of the acetabular components should be considered.

Morselized bone grafting in osteolysis around the stable cenmentless acetabular cup / 中国矫形外科杂志

[Objective]To evaluate the clinical and radiological results of a curettage of granulation tissue,the exchange of polyethylene liner and morselized bone grafting for the treatment of osteolysis around a stable cementless acetabular cup.[Method]From Apr.1996 to Jul.2000,26 patients underwent revision of curettage of granulation tissue,the exchange of polyethylene liner and morselized allografting,which were followed up for an average of 5.5 years.The Harris Hip Score was used to evaluate the clinical result.The size of osteolysis of periacetabular cup was measured in AP and lateral view of X-rays.The allograft union was evaluated with the bone graft incorporation scale.[Result]Clinically,the average HHS increased from 82 to 88 points postoperatively.Radiologically,the size of osteolysis of peraacetabular cup changed from average 23.8 mm?24.9 mm to 11.5 mm?8.2 mm in the AP view,and from 11.1 mm?11.6 mm to 5.3 mm?4.5 mm in the lateral view.The bone graft incorporation scales were Grade Ⅰ and Ⅱ in 12 and 14 cases,respectively.[Conclusion]The Curettage of granulation tissues,morselized bone grafting and exchange of polyethylene liner and femoral head is an effective therapy in osteolysis around a stable cementless acetabular cup and could preserve the bone stock for the further revision THA.

Wear rate of polyethylene in hybrid Total Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: Articles reporting on the wear rate of polyethylene cup in hybrid THA are rare. So, we now report the results of wear rate of polyethylene in cementless Harris-Galante acetabular components and cemented Harris precoat femoral stem. MATERIALS AND METHODS: The cementless Harris-Galante acetabular components and cemented Harris precoat femoral stem of one-hundred hips in 71 patients were followed up for 2.5 ~ 7.5 years (mean 4.7 year) . The clinical results were evaluated by Harris hip score (HHS) and wear rates were measured using Livermore technique. RESULTS: The most recent follow-up of HHS was improved from 52 to 91 in average. The mean linear wear rate in cemetless acetabular component was 0.17 0.06mm/yr (range 0.05 ~ 0.35) . Two femoral components were revised for aseptic loosening and one acetabular component revised for aseptic loosening. Wear rate in the revision group was higher than mean wear rate. In chronological change of wear rate according to final follow up period, there was decreasing tendency for mean wear rate with time. There was no correlation found between mean wear rate and body weight. There was a decreasing tendency on mean wear rate with acetabular cup shell size and increasing tendency with level of activity. CONCLUSION: We concluded that cemented femoral stem was the reason for the trend in lower wear rate of polyethylene cup than which had been previously reported in cementless THA, but further follow-up studies will be needed to confirm that.