To assist surgeons to select a total hip replacement (THR) we present comparative information on all such implants on the market in the UK. We identified 62 different primary THRs, manufactured by 19 companies; half had been introduced in the last five years, and only 30% have any results published in peer-reviewed journals. The prices range from 250 pounds to 2000 pounds, and the two cheapest implants have the longest reported follow-up. The number of THR implants available in the UK, and presumably the rest of the world, is rapidly increasing, but there is little or no scientific evidence that the newer, more expensive, implants are better than established designs. Some will undoubtedly be worse. We believe that this situation is unsatisfactory and make recommendations for improvement, in particular that preference be given to implants with good results in published peer-reviewed long-term clinical trials.

Survival analysis is a powerful tool for analysing the results of total joint replacement, but it has major drawbacks when the failure rates are very low. We have reviewed 35 recent survival analyses of joint replacements to assess the magnitude of these problems and make recommendations as to how they may be avoided.

The role of inflammatory cells in aseptic loosening and failure of cemented joint replacements is unclear. Inflammatory cells from the revision joint capsule of four failed hip arthroplasties were examined to determine their nature and resorptive capacity. The capsules contained numerous macrophages and abundant foreign-body macrophage polykaryons, distinguished from osteoclasts by their antigenic phenotype and lack of response to calcitonin. When cultured on cortical bone slices in vitro, both macrophages and macrophage polykaryons produced small resorption pits and were associated with areas of superficial resorption of the bone surface. These results indicate that foreign-body induced macrophages and macrophage polykaryons are capable of a type of low-grade bone resorption which may be of pathogenic significance in the loosening of cemented joint prosthetic components.

The results of 276 cemented revision total hip arthroplasties performed for aseptic failure between 1977 and 1986 have been reviewed. The mean time between revision and review was 75 months (range 30 to 144). Of 220 cases available for review, 159 were assessed clinically and radiographically, and 32 by postal questionnaire. Eighteen hips required further revision, 12 for loosening, two for sepsis, two for persistent pain, and one each for fracture and recurrent dislocation. A further six hips were radiologically and symptomatically loose. Pain was mild or absent in 83%. Over half were able to walk a mile or more; 70% flexed more than 70 degrees; 15% had a flexion deformity, but in only 7% was this more than 10 degrees. The mean Harris hip score was 74. Survival at five years was 95% and at 10 years, 77%.

We performed a randomised prospective trial to compare the results of 27 cemented and 26 uncemented bipolar hemiarthroplasties in active patients with displaced subcapital fractures of the femoral neck. After a mean follow-up of 17 months, significantly more of the uncemented group were experiencing pain in the hip and using more walking aids than the patients in the cemented group. The incidence of postoperative complications, the early mortality rate and the operating time and blood loss were not significantly different. Using otherwise identical prostheses the early results were much better with a cemented Thompson stem than with an uncemented Austin Moore stem.

We have reviewed 368 osteotomies carried out for osteoarthritis of the hip at the Nuffield Orthopaedic Centre. Survivorship analysis showed that 10 years after osteotomy 47% had required no further surgery, and even after 20 years 23% had still not had a hip replacement. Hips with moderate arthritic change showed significantly better results than those with more severe degeneration. Osteotomies with varus angulation as well as medial displacement showed longer survival.

Sixty unconstrained elbow replacements of a new design have been followed prospectively for three to nine years. Review showed that 50% had excellent relief of pain and return of function, 27% had had major complications requiring removal or revision of the prosthesis and 23% had minor complications which marred the result. Further research in this field seems worthwhile.