Abstract
Background: Publications concerning recurrent disc disease quote percentage recurrence without regard to the times of recurrence and the influence of longer follow-up.
Objective: To assess the use of survival analysis to measure revision rate after lumbar microdiscectomy.
Design: A retrospective analysis of the hospital records of all patients undergoing lumbar microdiscectomy over a nine-year period was undertaken. Patients who had a repeat microdiscectomy at the same level as the index procedure were designated ‘revisions’. The overall revision rate was calculated for the average length of follow-up. A survival analysis was then carried out using the life table method, as described by Murray et al for follow-up of hip arthroplasty.
Subjects: Seven hundred and twenty-nine patients underwent primary microdiscectomy during this time period, average age 40 years.
Results: Twenty-seven patients had a revision microdiscectomy during the study period. This gave an overall revision rate of 3.7% at average follow up of five years, one month. Using survival analysis the revision rate was 5.5% at eight years of follow up, number at risk 51.
Conclusions: Survival analysis gives a more accurate estimation of the true recurrence rate for patients undergoing lumbar microdiscectomy. The method would allow better comparison between different interventions for intervertebral disc herniation.
Abstracts prepared by Mr. A. J. Stirling, FRCS, and Miss A. Weaver. Correspondence should be addressed to Miss A. Weaver at the Research and Teaching Centre, Royal Orthopaedic Hospital, Northfield, Birmingham, B31 2AP, UK
BritSpine 2002, the second combined meeting of the British Association of Spinal Surgeons, the British Cervical Spine Society, The British Scoliosis Society and the Society for Back Pain Research, took place at the International Convention Centre in Birmingham UK between 27th February and 1st March 2002. The following presentations and posters were given and displayed.
Reference:
1 D. W. Murray, A. J. Carr, C. Bulstrode. Survival Analysis of Joint Replacements. J. Bone Joint Surg, 1993; 75-B: 697–704 Google Scholar
