Clinical history in lumbar disc herniation. A prospective study in 160 patients.

In a prospective study of 160 consecutive patients who underwent primary surgery for lumbar disc herniation, we investigated the value of clinical history for diagnosing the degree of herniation-the main prognostic factor for the postoperative outcome. At surgery, the patients were classified into two groups: intact anulus (negative exploration or protruding disc) and ruptured anulus (subligamentary perforation or complete perforation). The strongest variables predicting the degree of herniation were duration of leg pain, progressive leg pain, educational level and whether or not the patient had previously undergone non-spinal surgery. In patients with ruptured anulus, the median durations of low back pain and sciatica were 16 and 10 weeks, respectively. The corresponding figures for the group with intact anulus were 79 and 50 weeks. 18% of those with ruptured anulus and 39% of those with intact anulus were undergoing medical or psychiatric treatment for other diagnoses; 32% and 55% had previously undergone non-spinal surgery. Thus the two groups differed not only in disc pathology but also in medical, behavioral and social factors that must be taken into account in the preoperative assessment and that may explain discrepancies between impairment and disability.