The driving reactions of 25 patients were assessed before and after operation for hip replacement. Driving reactions were tested by monitoring the delay and force of brake application after an emergency signal, using a simulated driving control system. Fifteen normal subjects were also tested. Statistical analysis demonstrated significant differences between patients with either left or right hip replacement and between pre- and postoperative testing. Most patients improved by the eighth week, but some had deteriorated and did not recover until re-tested eight months after operation. It is concluded that for most patients eight weeks' delay for return to driving is appropriate, but for a minority of patients with right hip replacement recovery of reaction speed requires longer rehabilitation.

Sixty-eight patients suffering deep infection from a consecutive series of 1746 total hip replacement operations are reviewed. The infection rate has been reduced considerably by improved technique and multiple antibiotic prophylaxis without the use of a special operation enclosure. Factors affecting deep infection are analysed and discussed.