[Medium-term therapeutic evaluation of an uncemented femoral component]

To study the clinical and radiographic results of tatal hip arthroplasty (THA) with an uncemented femoral component after 6 to 10 years follow-up, and to investigate factors effecting their efficacy.

From January 2000 to December 2003, 58 patients were treated with primary total hip arthroplasty. Among the patients, 27 patients were male and 31 patients were female, ranging in age from 25 to 73 years, with an average of 56 years. The 58 patients were clinically and radiographically followed up including before operation, postoperative 1.5, 3, 6 and 12 months, and then once a year. Therapeutic evaluation was measured by using Harris scoring system. The incidence of osteolysis around the components in different Gruen zones was radiologically determined. The data were analyzed by SPSS 16.0 software.

All the patients were followed up, and the duration ranged from 6 to 10 years, with a mean of 8.2 years. The Harris hip score of the patients improved from preoperative mean of (54.0 +/- 7.8) to (88.3 +/- 6.1) at the latest follow-up. There were 32 patients with an excellent result, 22 good, 3 fair and 1 poor. Radiological analysis showed that 48 patients had stable bone in growth, 10 patients got stable fibrous in growth and nobody showed unstable fixation with aseptic loosening. Subsidence (1 to 3 mm) was observed in 4 patients. Osteolysis of the femoral cortex was seen in 4 patients without progressive development, and the latest follow-up radiographs showed a significantly greater incidence of osteolysis in Gruen zone I, VI, VII compared with others (P = 0.031). All the patients with low Harris score had received prostheses which were undersized in the intramedullary canal, and these differences were statistically significant.

The uncemented femoral component has good medium-term clinical follow-up results because of high stability and no aseptic loosening.