Specificity of the Oxford knee status questionnaire - The effect of disease of the hip or lumbar spine on patients' perception of knee disability

There is a need for the accurate measurement of the outcome after knee surg ery. The Oxford Knee Score is being increasingly used since it is reported to be short, simple, inexpensive and validated. We sent the questionnaire to 346 patients awaiting surgery to the hip or lu mbar spine. Only 11% of 141 patients with proximal pathology who denied kne e problems gave a maximum score, Their mean score was substantially lower t han expected at 28.7 (maximum 48), and was significantly lower than the sco re of 36.5 obtained from patients after total knee replacement. We therefore suggest that the frequent coexistence of hip or spinal patholo gy will significantly alter both the absolute score and any improvement to be expected after knee surgery. Although sensitive to disability originatin g from the knee the Oxford Knee Score is not sufficiently specific since it is heavily influenced by more proximal pathology.