The results of three different types of meniscectomy have been compared in 219 knees, 71 treated by arthroscopic partial meniscectomy, 45 treated by open partial meniscectomy, and 103 treated by open total meniscectomy, with a mean follow-up of 4.3 years. Knees which had undergone previous operations or had other simultaneous operative procedures or ligamentous damage were excluded. Knees with chondromalacia were included provided that this did not amount to frank osteoarthritis. Simple indicators were used for the rate of early recovery from the operation, and the Tapper and Hoover scale was used to record the symptomatic results in the longer term. It was found that knees treated by arthroscopic partial meniscectomy did considerably better than the others by all the criteria used. In most parts of the study there was a clear

A 3D finite element (FE) model of an implanted pelvis was developed as part of a project investigating an all-polymer hip resurfacing design. The model was used to compare this novel design with a metal-on-metal design in current use and a metal-on-polymer design typical of early resurfacing implants. The model included forces representing the actions of 22 muscles as well as variable cancellous bone stiffness and variable cortical shell thickness. The hip joint reaction force was applied via contact modelled between the femoral and acetabular components of the resurfacing prosthesis. Five load cases representing time points through the gait cycle were analysed. The effect of varying fixation conditions was also investigated. The highest cancellous bone strain levels were found at mid-stance, not heel-strike. Remote from the acetabulum there was little effect of prosthesis material and fixation upon the von Mises stresses and maximum principal strains. Implant material appeared to have little effect upon cancellous bone strain failure with both bended and unbonded bone-implant interfaces. The unbonded implants increased stresses in the subchondral bone at the centre of the acetabulum and increased cancellous bone loading, resembling behaviour obtained previously for the intact acetabulum.

The place of the myo-electric prosthesis in below-elbow amputees has been reviewed. Forty-three patients were seen and all possessed both a myo-electric prosthesis and a standard artificial limb. Nearly half the patients used the newer device almost all the time at work and many of these wore it for the majority of their waking hours. Its use at work was mainly related to the patient's type of job and here in turn there was concern about damaging the device. It is suggested that acceptance would be further increased if greater attention were paid to the durability of the arm and its glove. Criteria for prescription and future developments are discussed.

We report a clinical and radiological survival analysis of 148 consecutive revisions of hip arthroplasties. All patients referred were offered revision if it was indicated and they were medically fit. About one-third (32%) had had at least one previous revision, and about one-third had an established deep infection. The revisions were performed in ultra-clean air with body-exhaust suits. The usual method of fixation was by contained and pressurised cement of standard viscosity, to which appropriate antibiotics had been added in infected cases. Some patients had cementless revision. Clinical failure meant that one or both of the implants had been removed; radiological failure was assessed from serial radiographs. The clinical survival at ten years was 95%. The Merle D'Aubigne and Postel rating for pain improved from a mean of 2.9 to 5.2; and in Charnley group A and B cases, walking ability improved from 2.3 to 4.3. In contrast to some reports we also found good radiological survival; this was 90.5% for cemented femoral stems. Isoelastic revision stems inserted without cement gave poor results.

In 65 mature Wistar rats a Kirschner wire was introduced into the medullary cavity of each femur. A closed transverse mid-shaft fracture of one femur was produced by a three-point bending technique. Subsequently the mechanical characteristics of the healing fracture, including the torque and angle of twist required to take the callus to its yield point and to ultimate failure, were compared with those for the opposite femur of each rat. Controls were killed in groups at two, three, four, five and seven weeks. Test animals were given bovine growth hormone in a daily dose of five milligrams before being killed in groups at two, three and four weeks. A significant increase in torque index was found in the two-week group of test animals but not in subsequent groups. No evidence was found that growth hormone given alone could produce an overall shortening of the healing time in fresh fractures.