Multiple Acetabular Revisions in THA - Poor Outcome Despite Maximum Effort

Abstract

A consecutive series of 52 acetabular revisions was evaluated retrospectively. Inclusion criteria for all patients were at least one former exchange of the acetabular component. Reconstruction was performed with reliable techniques and implants other than extensively porous coated device (e.g. tantalum). The mean follow up was 5.63 (0.01-14.05) years. Cumulative survival at 14.05 years with removal of the acetabular component due to aseptic loosening or the worst case criterion (removal of the acetabular component for any cause and/or lost to follow-up) as the end point was 66.38 (95 % C.-I.: 47.80-84.96) % and 58.42 (95 % C.-I.: 41.01-75.83) %, respectively. The cumulative survival rate with mechanical failure of the acetabular reconstruction as the endpoint was significantly lower in patients with two or more previous revisions in comparison to those with only one former procedure (log rank test: p=0,0112 respectively). The mean Merle d'Aubignée-score improved from 7.3 (0-14) preoperatively to 10.6 (0-17) points at latest follow up examination.Survival of acetabular reconstructions with common techniques and implants is decreasing with the number of previous revisions. This may cause major concerns with regard to the rising number of patients needing repeated revisions. Maximizing durability of primary THA, precise preoperative planning as well as improved techniques and implants for revision may decrease this problem in the long term.

Keywords: Hip arthroplasty; acetabular reconstruction.; porous metal device; revision; tantalum.

Fig. (1)

Survivorship analysis: worst case criterion.

Fig. (2)

Survivorship analysis: aseptic loosening and infection.

Fig. (3)

Survivorship analysis (aseptic loosening): 2^nd vs. at least 3^rd revision at index operation.

Fig. (4)

Compared to standard views (Fig. 2) additional information with respect to the bony defect situation can be obtained with further radiological diagnostics. In this case, simple oblique iliac radiograph shows a highly deficient posterior wall, massive sclerosis of the host bone and defects at the bottom due to loosening and dislocation of screws.

Fig. (5)

This ap radiograph of the pelvis is showing a dislocation of an acetabular reconstruction by reinforcement ring with hook and allogenous, morselized bone graft 6 months after the 4^th revision procedure elsewhere. This female patient was 49 years old at index operation. Primary THA was performed at the age of 42 years due to developmental dysplasia of the hip.

Fig. (6)

14 days postoperatively after a standard reconstruction by allogenous, morselized bone graft and reconstruction ring (antiprotrusio cage).

Fig. (7)

A (primary,) stable situation was present for over one year. 15 months postoperatively, breakage of screws and slight migration of the construct was revealed for the first time after regular follow-up indicating non integration of bone transplant and/or implant due to massive sclerosis.

Fig. (8)

Sudden dislocation occurred less than six years after the index operation leading to the 6^th revision procedure due to immobility and pain.