Uncemented total hip arthroplasty. Prospective analysis of the tri-lock femoral component.

Fifty consecutive hip disease patients (56 hips) with total hip arthroplasties (THA) utilized the uncemented Tri-Lock femoral component. Forty-five patients (51 hips) were followed for an average of 46 months (range, 24-66). Forty-two patients (47 hips) were followed with clinical examination and roentgenographs, three (four hips) by telephone interview, four (four hips) were deceased, and one (one hip) was lost to follow-up evaluation. The diagnoses included osteoarthritis (30 hips), avascular necrosis (11 hips), juvenile rheumatoid arthritis (two hips), and degenerative joint disease secondary to childhood hip disorder (four hips). Of 47 hips, 34 were graded excellent, seven good, three fair, and three poor using the Harris hip score. The incidence of thigh pain was 19% at one year, but only 6% at final follow-up evaluation. Limp persisted in 19% of the patients. Of the three patients with four hips contacted by telephone, two had slight pain and two had no pain. The roentgenographic results found an alarming 38% incidence of varus shift of the components, relative to their preoperative position. The presence of a varus shift did not adversely affect the clinical results. Early experience with the Tri-Lock femoral component shows results comparable to those reported in the literature. The high incidence of femoral component shift, presumably because of geometry of the stem is of concern. Longer follow-up evaluation will be necessary to determine the fate of these uncemented THA operations.