Mid term results of total hip arthroplasty using polyethylene-ceramic composite (Sandwich) liner

Abstract

Background: Ceramic-on-ceramic (COC) couplings are an attractive alternative bearing surfaces that have been reported to eliminate or reduce problems related to polyethylene wear debris. However, the material in total hip arthroplasty (THA) remains one of the major concern regarding the risk of fracture. The present study aims at reporting the fracture rate of bearings in a series of COC THAs with the use of a sandwich liner and attempt to detect the relative risk factors, the possible cause and assess the clinical results.

Materials and methods: We retrospectively evaluated 153 patients (163 hips) using the sandwich liner COC THA between 2001 and 2009. Patient assessment was based on demographic factors, including age, weight, gender and body-mass index (BMI). All patients were evaluated clinically and radiographically or using computed tomography viz-a-viz dislocation, osteolysis, periprosthetic fracture, infection, loosening and implant fracture.

Results: Three ceramic sandwich liners fracture (1.84%) were observed at an average of 7.3 years' followup. The factors which were found to be non-significant to the ceramic liner fracture, included age (P = 0.205), weight (P = 0.241), gender (P = 0.553), BMI (P = 0.736), inclination (P = 0.199) and anteversion (P = 0.223). The overall survival was 91.4% at 12-year with revision as the endpoint. Other complications included osteolysis in 4 (2.45%), dislocation in one and periprosthetic fracture in one. In no hip aseptic loosening of the implants was seen.

Conclusions: Our experience with the ceramic-polyethylene sandwich liner acetabular component has been disappointing because of the high rate of fracture and osteolyis. We have discontinued the use of this device and recommend the same.

Keywords: Arthroplasty; Fracture; hip; hip prosthesis; osteolysis; replacement; sandwich liner; total hip arthroplasty.

Figure 1

Photographs showing (a) Acetabular component with three different layers: The outer metal shell, polyethylene liner and inner alumina ceramic liner (b) The contact acetabular component section with three different layers. Femoral component (Lima-Lto) including: (c) C2 stem (d) F2L stem (e) Self-locking stem

Figure 2

(a) Anteroposterior view. (b) Lateral view radiographs of (Rt) hip joint showing fracture of the right ceramic sandwich liner (red arrow). (c) Radiograph of same hip after revision of a ceramic sandwich fracture and a fourth generation alumina ceramic bearing was implanted

Figure 3

Computed tomographic scan of the right hip 12-year after surgery, revealing local osteolysis around the acetabular component

Figure 4

Survival curves with revision due to ceramic liner fracture as endpoint

Figure 5

(a) Photograph of the retrieved alumina insert, polyethylene shell, and alumina head. The polyethylene show deformed indentations and scrape and the alumina insert shows extensive rim fracture and a black stain on the surface of the unbroken rim. A narrow edge of damage, called stripe wear, on the surface of the femoral head. (b) Note the notching of the femoral stem (red arrow) and the ceramic liner rim (red arrow) indicating sites of impingement between the femoral stem neck and the ceramic liner rim