Failure of an uncemented non-porous metal-backed prosthesis with augmentation using impacted allograft for acetabular revision

Abstract

We have reviewed 29 patients (30 hips) who had undergone revision total hip arthroplasty using a Freeman metal-backed acetabular component and acetabular impaction allografting. The mean follow-up was for 153 years (12 to 17). Five patients (5 hips) died with the prosthesis in situ and four (4 hips) were lost to follow-up. Twelve hips had failed and in the remaining nine there were minor symptoms. The mean time to failure requiring further surgery was nine years. Excluding patients who were lost to follow-up or had died, 72% of the hips were radiologically loose at the last review. The commonest pattern in those requiring revision was failure of the reinforcement ring in adduction with remodelling of the medial wall. Of the nine patients who had not undergone revision, one with bilateral replacements had no current radiographs and only three of the remaining seven replacements had no radiological signs of loosening. The short-term results for this technique have been reported to be satisfactory, but in the long term they are not. The factors associated with failure include the design of the prosthesis, which has been implicated in disappointing long-term results when used in primary arthroplasty, but not with the frequency of failure found in this series. It seems that the reliance on peripheral screw fixation over a bed of allograft without bridging the graft does not provide sufficient stability to allow incorporation of the graft.

Modular acetabular reconstructive cup in acetabular revision total hip arthroplasty at a minimum ten year follow-up

“…The longevity of morsellised allograft with a modular cup depends on the bone deficiency of the acetabulum as the previous report [12]. There was no breakage of the iliac lag screw or ischial peg of the modular cup at a minimum ten year follow-up in the present study since the diameter of the screw was larger than another modular acetabular cup system [3,16].…”

“…First, it was a small number of hips with minimum follow-up of ten years, as in many other acetabular revision studies [3,8]. However, power analysis confirmed that number of hips fulfilled the minimum sample size, and this modular reconstructive cup showed a good longevity over ten years.…”

“…Acetabular bone deficiency due to osteolysis, infection, and/or aseptic loosening is a major problem in revision total hip arthroplasty (THA) [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Favourable long-term results of treatment for cases with Paprosky type 3A, 3B, and pelvic discontinuity is desirable [15].…”

“…the survival of 43 % at 15 years in 21 hips [3] and 64.5 % at five years in 62 hips [16]. One of the reasons for poor results is mechanical failure [17] such as screw breakage [3] and hook and side plate breakage [16] of the uncemented non-porous metal-backed prosthesis with augmentation.…”

“…the survival of 43 % at 15 years in 21 hips [3] and 64.5 % at five years in 62 hips [16]. One of the reasons for poor results is mechanical failure [17] such as screw breakage [3] and hook and side plate breakage [16] of the uncemented non-porous metal-backed prosthesis with augmentation. On the other hand, an improved modular acetabular cup system including porous metal components [18] and components composed of a flanged metal socket, an iliac lag screw, and an ischial peg [7] has been reported; the latter modular acetabular reconstructive cup with hydroxyapatite granules grafting showed the survival of 74.2 % at 11 years with aseptic loosening as the endpoint [7].…”