Relation between pain location and disc pathology: a study of pain drawings and CT/discography.

OBJECTIVE The purpose of this study was to determine whether pain location indicated in pain drawings was related to the specific lumbar disc level(s) that was abnormal in appearance and painful upon discographic injection. DESIGN Data were collected prospectively. SETTING This study was conducted in a spine specialty clinic. PATIENTS The study group consisted of 187 patients (118 men, 69 women; mean age = 37.2 years, range = 18-62 years) with low back pain with or without leg pain. All patients were undergoing computed tomography (CT)/discography at the three lowest lumbar levels for diagnostic purposes. INTERVENTIONS Pain drawings were completed the day of but prior to undergoing discography. Discographic pain responses were recorded with respect to the similarity to the patient's clinical symptoms. Pain drawings were classified based on the presence or absence of pain in five areas: low back and/or buttocks, posterior thigh, posterior leg, anterior thigh, and anterior leg. The drawings were scored with the system described by Ransford et al. (1976, Spine 1: 127-34), and those likely to be indicative of psychological problems were analyzed separately (n = 43). OUTCOME MEASURES Results were determined by analyzing the relation between the location of pain in the drawings and the specific lumbar disc level(s) found to be painful and disrupted by discography. RESULTS There was a significant relation between pain location indicated in the drawing and the lumbar disc level(s) identified as clinically painful and disrupted by CT/discography (p < 0.05, chi-square). Pain limited to the low back and buttocks was frequently associated with the absence of disc pathology (58.3%). When pain in the posterior thigh or leg was present but there was no pain in the anterior drawing, patients frequently had a positive L5-S 1 disc (> or =75%). In patients with anterior thigh pain, with or without posterior thigh or leg pain, the L4-5 disc was frequently symptomatic (>63%). The pattern of no posterior thigh or leg pain but with pain radiating into the leg anteriorly was most commonly associated with the L3-4 disc (71.4%). CONCLUSIONS The results of this study indicate that pain drawings may be helpful in identifying which specific discs are associated with pain complaints. As with any evaluation, the drawings should be considered in combination with findings from other assessments.