Abstract
Purpose of Study: To prospectively study the outcome of lumbar interbody fusion with an intrasegmental device, and to determine whether smoking, previous surgery and multiple level surgery have an effect on fusion rate.
Methods Used: Between October 1998 and July 2001, 67 patients underwent lumbar interbody fusions using an intrasegmental pedicle screw system (Biomet, Spinelink). Prior to surgery Short Form 36 (UK Version 1) (SF36) scores, pain visual analogue scores (VAS) and patient demographics were recorded. Postoperative follow up was in a specialist spine clinic. Patients were followed up in this clinic until fusion was judged to have occurred both clinically and radiographically. Fusion was judged to have occurred radiographically when there was evidence of a fusion mass at all fused levels and absence of pedicle screw loosening and/or metal work breakage. Patients who were not judged to have fused were classified as either a pseudarthrosis, or indeterminate. Patients completed a questionnaire on attendance at clinic, or by post if discharged. This included an SF36, Oswestry Disability Index, employment status, analgesic use and patient satisfaction assessment.
Results: 67 patients (38 male and 29 female) were successfully followed up. The mean age was 45.2 (range 17–86). Mean follow up was 21.7 months (range 12–43 months). 36 posterolateral fusions and 31 combined posterior lumbar interbody/posterolateral fusions were performed. 22 patients were smokers and 45 non-smokers or ex-smokers at the time of surgery. 18 patients had undergone previous surgery (either discectomy, decompression or fusion). 34 patients had 2 vertebral levels fused, and 33 patients more than 2 vertebral levels.
There was radiographic evidence of fusion in 81.3% of patients. There was an improvement in mean pain VAS, and mean scores of all physical components of the SF36. Patient satisfaction was high (71%).
Subgroup analysis demonstrates that the fusion rates in non-smokers versus smokers, and primary fusions versus previous surgery, were the same. The fusion rate following multiple level fusions was lower at 72.2%.
Conclusions: The results of our study suggest that high fusion rates can still be achieved in high risk patients when an intrasegmental device is used.
The abstracts were prepared by Editorial Secretary, Dr Charles Pither. Correspondence should be addressed to SBPR at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PN
