Abstract
Cemented stem fixation is a proven technique in total hip arthroplasty (THA), however, aseptic loosening is a noted complication. Cementless fixation is also popular in THA, however thigh pain and osteolysis are known problems with short-term and long-term follow- up, respectively. In order to improve the initial development and durability of the osseointegration of porous coated cementless implants, hydroxyapatite (HA) has been claimed to provide a biological adjuvant for femoral stem fixation in THA.
There is no prospective, randomised long-term study comparing clinical radiographic findings between proximally HA-coated and non-HA coated surfaces of an identical stem design. We investigated 177 patients (199 hips) who received either HA-coated or non-HA coated stems. Clinical information from 163 patients (181 hips), including walking ability, thigh pain, sports activity, and overall patient satisfaction was collected. Evidence of radiolucencies, stem migration, and canal fill was measured on AP and lateral radiographs. In addition, tension trabeculae on the lateral aspect of the proximal stem and stress-induced remodelling of cancellous bone against porous surface (SIRCAP) were noted as signs of bone ingrowth.
Both groups of patients performed well on the basis of HSS scores, walking ability, sports activity, and overall patient satisfaction. However the non-HA group demonstrated a significant increase (p< 0.05) in activity- related thigh pain. There were no significant radiographic differences between patient cohorts with all stems demonstrating bone ingrowth. In our prospective, randomised study, we conclude that the use of HAcoated stems results in increased clinical satisfaction to the THA patient.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
