Thrombo-embolic prophylaxis in total knee replacement. Evaluation of the A-V Impulse System.

We performed a prospective randomised controlled trial of a new mechanical method of prophylaxis for venous thrombo-embolism in 60 patients undergoing knee replacement surgery. The method uses the A-V Impulse System to produce cyclical compression of the venous reservoir of the foot. The overall incidence of deep-vein thrombosis was 68.7% in patients receiving no prophylaxis and 50% in those using the device. The difference was not significant. There was, however, a reduction of the extent of thrombosis in the treated group. There were 13 major calf-vein thrombi and six proximal-vein thrombi in the control group compared with only five major calf-vein thrombi in the treated group. This difference was significant (p = 0.014). No patient developed clinical features of a pulmonary embolism.

Trochanteric growth disturbance after upper femoral osteotomy for congenital dislocation of the hip.

We reviewed 14 patients (16 hips) treated by open reduction and upper femoral derotation osteotomy for congenital dislocation of the hip. Nine patients with 11 treated hips had growth deformities of the proximal femur; in all of them the top screw of the fixation plate lay within the cartilaginous precursor of the greater trochanter. In the five control hips the top screw was more distal. In the nine patients (mean follow-up 10.8 years) there was an increase of 14 degrees in the neck-shaft angle (p = 0.01) and of 18 degrees in the angle between the capital femoral physis and the shaft (p = 0.01) compared to the control group. This indicates that growth disturbance of the greater trochanteric apophysis as a result of plate fixation leads to long-term deformity.

Tendon implantation into bone: an experimental study.

We report the results of an experimental study to investigate the mechanical properties and histological structure of the tendon-bone junction following surgical implantation of tendon into bone in the rabbit. The results following tendon transfer and tendon grafting were compared. The normal four-zone tendon junction was not reproduced histologically, in either group. After 20 weeks, the mechanical strength of the tendon transfers had reached 60% of the controls and that of the tendon grafts 20% of the controls. Microangiography demonstrated that these differences were not related to the vascularisation of the tendon bone junction. The mechanical properties of the tendon-bone junction may be dependent more on the functional state of the implanted tendon than on its structure.

Imaging study of the painful heel syndrome.

A total of 45 patients with the painful heel syndrome without evidence of an associated inflammatory arthritis, seven of whom had pain in both heels, were studied using technetium-99 isotope bone scans and lateral and 45 degrees medial oblique radiographs of both feet. Of the 52 painful heels 31 (59.6%) showed increased uptake of tracer at the calcaneum. Patients with scans showing increased uptake tended to have more severe heel pain and responded more frequently to a local hydrocortisone injection. On plain x-ray, 39 of 52 painful heels (75%) and 24 of the 38 opposite nonpainful heels (63%) showed plantar spurs, compared with five of 63 (7.9%) heels in 59 age- and sex-matched controls. No evidence of stress fractures was seen.