Single-level lumbar fusion in chronic discogenic low-back pain: psychological and emotional status as a predictor of outcome measured using the 36-item Short Form.

OBJECT: The authors examined the effect of psychological and emotional status on the outcome in patients with suspected chronic discogenic low-back pain (LBP) who have undergone lumbar fusion.
METHODS: The authors retrospectively analyzed the medical records, including the results of the 36-item Short Form (SF-36), of 57 consecutive patients (mean age 42.7 years) who underwent single-level lumbar reconstructive surgery between 1994 and 2000. The SF-36 physical component summary (PCS) and mental component summary (MCS) domains were evaluated. Data were sorted into the following categories: excellent, good, fair, same, and worse. Scores greater than 40 for MCS and PCS were defined as "normal" according to US general population data provided by the Medical Outcomes Trust. Of 57 patients, 47 completed postoperative SF-36 surveys at 1 year and 36 completed the 2-year follow-up surveys. Analysis showed that preoperative MCS scores exhibited a significant, direct correlation with PCS score improvements at 1 (r = 0.584, p = 0.000) and 2 (r = 0.623, p = 0.000) years after surgery. In patients in whom preoperative MCS scores reflected normal status, outcomes were excellent or good in 60% at 1-year (18 of 30 cases) and 2-year (15 of 25 cases) follow-up intervals. Patients in whom MCS scores represented abnormal status had less satisfactory outcomes, with excellent or good outcome in only two (18.2%) of all patients at the 2-year follow-up study.
CONCLUSIONS: Analysis of the data suggests that psychological and emotional distress may negatively affect postoperative outcome in patients with chronic discogenic LBP. The SF-36 may be easily and effectively used to measure both preoperative psychosocial distress and postoperative outcome.