Recovery of Muscle Strength after Microdiscectomy for Lumbar Disk Herniation: A Prospective Cohort Study with 1-Year Follow-Up

• Published in: Global Spine Journal
• Main Authors: Lønne, G., Solberg, T. K., Sjaavik, K., Nygaard, ø. P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2012
• Subjects: Norway; North Norway
• Online Access: http://dx.doi.org/10.1055/s-0032-1319850; http://journals.sagepub.com/doi/pdf/10.1055/s-0032-1319850

Introduction It has not been shown that surgery is better than nonsurgical management for treating limb paresis caused by lumbar disk herniation. 1–3 However in clinical practice, limb paresis is a frequent additional symptom to pain 4–6 , and for the patients, a major concern remains: “What are the chances that my muscle strength will recover after surgery?”. The aim of this study is to give an answer to this question. We also wanted to investigate if persisting paresis is associated with worse outcome measured by changes in physical function, health related quality of life (HRQL), pain, and working capability. Materials and Methods In this prospective cohort study, we evaluated 403 consecutive patients operated with microdiscectomy for lumbar disk herniation. Of these patients, 91 (23%) had limb paresis and were included. All patients were operated at the Department of Neurosurgery, University Hospital of North Norway. Data were collected in a comprehensive clinical spine surgery registry for quality control and research between 1st of January 2004 and 30th of September 2006. Follow-up time from date of operation (baseline) was 1 year. The primary outcome measure was muscle strength of the affected limb. We used Daniels and Worthingham's techniques of manual muscle testing, 7 which was graded to range from 0 to 5. Based on this scale we categorized the patients into three groups: severe paresis (grade 0–3), mild paresis (grade 4), and normal muscle strength (grade 5). Changes in motor function were classified as recovery (normal muscle strength) or nonrecovery (incompletely improved, unchanged or worse). Secondary outcome measures were HRQL (EQ-5D), Oswestry disability index (ODI), visual analogue scale (VAS) for leg pain and back pain, EQ-5D for general health state, and employment status. Results At 12 months 68 patients (75%) were fully recovered. Out of 23 patients (25%) who were not fully recovered, 9 (10%) were improved and 14 (15%) were unchanged. None got worse. Out of 29, 16 (55%) patients with severe ...