No abstract

The essentially satisfactory results from the ICLH implant as used until 1975 were marred by examples ofloosening and sinking ofthe tibia] implant, by patellar pain ofvarying severity, by wear of the tibial implant caused by fragments ofcement and by failure consistently to control the alignment ofthe leg. This report describes the methods now being used to overcome these complications and gives an account of the success so far achieved. Work on the design of an implant-which replaced only the surfaces of the affected bones and lacked, as do the natural articular surfaces, any direct mechanical link between the components-began at Imperial College in

Fifty-three failed knee replacements were revised using minimally constrained implants with smooth uncemented intramedullary stems and metal-backed tibial components. Polymethylmethacrylate was used only to replace lost bone near the surface of the implant. Excluding four knees which had serious postoperative complications, 91% had successful relief of pain, 84% had over 90 degrees of movement and 80% could walk for more than 30 minutes. Review of the radiographs showed that there were no progressive lucencies at the interface between bone and cement, and no subsidence of components or changes in alignment. At the uncemented stem-to-bone interface, thin white lines developed near the metal, and their significance is discussed. This revision technique is an effective treatment for aseptic failure of primary total knee arthroplasty.

No abstract

We report the complications of prophylactic pinning of slipped upper femoral epiphysis with Crawford Adams pins in 95 cases. Complications of pin placement were seen in 13.7%. Although seven hips had penetration of the joint, there were no cases of chondrolysis or avascular necrosis. Excavation of the lateral femoral cortex was required at pin removal in 12.5% of cases. Analysis of the growth around pins allowed recommendations to be made regarding pin protrusion. The use of improved fixation devices may reduce the need for multiple pins.

1. The femoral head has been examined in specimens taken from cadavers, patients suffering subcapital fracture of the femoral neck and patients undergoing total replacement arthroplasty for osteoarthrosis and rheumatoid arthritis. 2. Lesions have been seen, some of which appear to be uniting fatigue fractures of individual trabeculae. 3. It is suggested that excessive cyclical loading, sometimes leading to fatigue fractures, may represent a fundamental pathological process of general importance in the evolution of certain skeletal and articular diseases.

1. Senile subcapital fractures in osteoporotic patients are due to fatigue, not to the impact of a fall, since they are preceded by the local accumulation of isolated trabecular fatigue fractures. 2. One pathological significance of the isolated trabecular fractures described by Todd, Freeman and Pirie (1972) has been demonstrated.

No abstract