Abstract:

BACKGROUND: Most of the patients suffered from degenerative lumbar instability are treated by exposure both sides and bilateral pedicle screw fixation, which bring highly operative risk, large blood loss and great medical expenditure to patients.
OBJECTIVE: To explore the clinical efficacy of single cage plus unilateral pedicle screw placement for treating lumbar degenerative instability.
METHODS: Totally 51 cases with lumbar degenerative instability underwent single cage plus unilateral pedicle screw placement were selected, including 32 males and 19 females, aged ranging from 41 to 72 years. 47 cases had single segment involved and 4 cases had two segments involved. All cases experienced unilateral laminectomy and transforamenal lumbar interbody fusion. The therapeutic effect was assessed by Japanese Orthopaedic Association (JOA) score system.
RESULTS AND CONCLUSION: The blood loss was 90-430 mL. The surgical time was 100 minutes (85-120 minutes) for single segment and 150 minutes (120-170 minutes) for double segments. The patients were allowed to early ambulation at 2-3 days after operation. Two cases did not get improvement on back-leg pain, but there was no abnormality from CT and MRI recheck, one case felt pain relieved after anti-symptom treatment for 3 months while the other did not relieve. The average JOA scores at pre-operation and 1 year follow-up was 11 (7-13 scores) and 25 (18-27 scores), respectively. The total improvement rate of JOA was larger than 50%. 44 cases were evaluated as fusion and 7 cases as possible fusion. The average fusion time was 5.4 months (4.3-7.1 months). Postoperative X-ray showed no evidence of pedicle screw loosening, broken, or cage displacement. Single cage plus unilateral pedicle screw placement is characterized by simple operation, small blood loss, short operation and few interference to spine, which is a better method for treating lumbar degenerative instability.