We aimed to develop a better understanding and method of rating the success or failure of low back surgery by studying 185 patients prospectively. Identical pre-operative and postoperative assessment by an independent observer included pain, disability, physical impairment, psychological distress and illness behaviour. Outcome was assessed by the patient, by the observer and by return to work. There was 96% follow-up at two years. Correlation co-efficients varied considerably between the various measures of outcome, both patient and observer appearing to base their assessment mainly on postoperative status rather than on any change produced by surgery. The observer was influenced most by postoperative pain, disability and physical impairment. Patients were influenced most by residual physical impairment, type of surgery and proportional change in disability. Return to work was moderately influenced by postoperative disability and to a larger extent by social and work-related factors. We developed a simple formula to judge overall success or failure which accurately reproduced the combined assessment of patient and observer. If surgical audit is to be meaningful it must be based on an improved understanding of how the outcome of surgery should be assessed.

We have reviewed 61 children treated for septic arthritis from 1972 to 1981. The diagnosis in all cases was confirmed by bacteriology or by radiographic changes. Routine arthrotomy was not performed, but most patients had a joint aspiration. The management and outcome are described. We suggest that arthrotomy should be selective rather than mandatory. Septic arthritis of the hip in infants requires arthrotomy, but in the older child an infected hip can be treated by aspiration if the duration of symptoms is less than four days; arthrotomy may be needed if there has been more delay. Infected joints other than the hip can be satisfactorily managed by aspiration.