We describe three cases of fracture of the titanium JRI-Furlong hydroxyapatite-ceramic (HAC)-coated femoral component. We have examined previous case reports of failure of this stem and conclude that fracture may occur in two places, namely at the neck-shoulder junction and at the conical-distal cylindrical junction. These breakages are the result of fatigue in a metallurgically-proven normal femoral component. All the cases of failure of the femoral component have occurred in patients with a body mass index of more than 25 in whom a small component, either size 9 or 10, had been used.

In patients with a body mass index above normal size 9 components should be avoided and the femoral canal should be reamed sufficiently to accept a large femoral component to ensure that there is adequate metaphyseal fixation.

We have studied the case records of 16 patients with dislocations of the cervical spine who deteriorated neurologically during or after reduction. The dislocations were reduced by skull traction in four patients, by manipulation in four and by operation in seven. This complication was not related to age, sex, mechanism of injury, or the level and the type of dislocation. Fourteen patients made substantial recoveries, one made a partial recovery and one patient remained totally paralysed and died three months later. The causes and prevention of spinal-cord damage at this stage of management are discussed, and the early use of MRI or CT myelography is recommended.

The effect of calcaneal traction on the compartmental pressure in the legs of five individuals with tibial fractures was studied. Mean resting pressures without traction were found to be 31.9 mmHg for the deep posterior compartment and 27.0 mmHg for the anterior compartment. For each kilogram weight of traction applied the deep posterior pressure rose by 5.7 per cent of the resting value and the anterior pressure by 1.6 per cent. It is suggested that the weight of traction should be only sufficient to render the patient comfortable and maintain alignment of the limb. Excessive traction is likely to increase the risk of compartmental ischaemia. The application of six kilograms of traction would raise the mean resting pressure by 34 per cent from 31.9 to 42.7 mmHg.