A ligamentum flavum-preserving approach to the lumbar spinal canal

Study Design. This is a retrospective study of a consecutive series of patients undergoing spinal decompression or disc enucleation with preservation of the ligamentum flavum. MacNab criteria and Prolo scoring was used to assess them pre- and after surgery. Objectives. The aim of the study was to assess the incidence of perioperative complications and long-term clinical outcome of the procedure. Summary of the Background Data. One previous study has shown this technique to be effective in reducing the rate of perioperative complications and recurrences in patients undergoing microscopic disc enucleation. However, this study does not comment on the long-term clinical results or the use of the technique in a wider range of spinal procedures. Methods. Between 1991 and 1999, we operated on 214 patients for peripheral lumbar radiculopathy. MacNab criteria and Prolo scoring was used for their pre- and postoperative assessment. Postoperative assessment was with the help of a postal questionnaire. In addition, clinical notes were studied to look for any further procedures or operative complications. Results. All 214 patients returned the postoperative questionnaires. There were 104 males and 110 females. The mean follow-up was 5.97 years. Thirty-eight patients had an associated fusion or Graf ligament stabilization. Two hundred ninety-six levels were operated in all. There were four instances of dural tear and one of nerve root injury. Five patients underwent revision. There was a statistically significant improvement in the MacNab criteria ( P < 0.001) and Prolo score ( P < 0.001) after surgery. Conclusions. We recommend a ligamentum flavum preserving approach because it decreases the rate of perioperative complications while giving comparable long-term results.