Does surgical technique influence clinical outcome after lumbar spinal stenosis decompression? A comparative effectiveness study from the Norwegian Registry for Spine Surgery.
The aim of this study was to compare the clinical outcome of spinal process osteotomy with two other midline-retaining methods, bilateral laminotomy and unilateral laminotomy with crossover, among patients undergoing surgery for lumbar spinal stenosis.



This cohort study was based on data from the Norwegian Registry for Spine Surgery (NORspine). Patients were operated on between 2009 and 2013 at 31 Norwegian hospitals. The patients completed questionnaires at admission for surgery, and after 3 and 12 months. The Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were duration of surgery and hospital stay, Numeric Rating Scale (NRS) for back pain and leg pain, and EQ-5D and EQ-VAS. The patients were classified into one of three treatment groups according to the surgery they had received, and a propensity score was utilized to minimize bias. The three treatment groups were divided into subgroups based on Propensity Scores, and the statistical analyses were performed with and within the Propensity Score stratified subgroups.



103 patients had spinal process osteotomy, 966 patients had bilateral laminotomy, and 462 patients had unilateral laminotomy with crossover. Baseline clinical scores were similar in the three groups. There were no differences in improvement after 3 and 12 months between treatment groups. At 12 months, mean ODI improvement was 15.2 (SD 16.7) after spinous process osteotomy, 16.9 (SD 17.0) after bilateral laminotomy, and 16.7 (SD 16.9) after unilateral laminotomy with crossover. There were no differences in the secondary clinical outcomes or complication rates. Mean duration of surgery was greatest for spinal process osteotomy (p < 0.05). Length of stay was 2.1 days (SD 2.1) in the bilateral laminotomy group, 3.5 (SD 2.4) days for unilateral laminotomy, and 6.9 days (SD 4.1) for spinous process osteotomy group (p < 0.05).



In a propensity scored matched cohort, there were no differences in the clinical outcome 12 months after surgery for lumbar spinal stenosis performed using the three different posterior decompression techniques. Bilateral laminotomy had shortest duration of surgery and shortest length of hospital stay. Surgical technique does not seem to affect clinical outcome after three different midline-retaining posterior decompression techniques.
Department of Orthopedic Surgery, Ålesund Hospital, Møre and Romsdal Hospital Trust, Ålesund, Norway. Erland.hermansen@helse-bergen.no.|Kysthospitalet in Hagevik, Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway. Erland.hermansen@helse-bergen.no.|Department of Clinical Medicine, University of Bergen, Bergen, Norway. Erland.hermansen@helse-bergen.no.
Erland
E
Hermansen
Department of Research, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway.
Ulla Kristina
UK
Romild
Kysthospitalet in Hagevik, Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Ivar Magne
IM
Austevoll
Department of Neurosurgery, University Hospital of North Norway, Tromsø, Norway.|Norwegian National Registry for Spine Surgery, University Hospital of North Norway, Tromsø, Norway.
Tore
T
Solberg
Communication and Research Unit for Musculoskeletal Disorders (FORMI), Oslo University Hospital, University of Oslo, Oslo, Norway.
Kjersti
K
Storheim
Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway.
Jens Ivar
JI
Brox
Department of Orthopedics, Oslo University Hospital, Oslo, Norway.
Christian
C
Hellum
Kysthospitalet in Hagevik, Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Kari
K
Indrekvam
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D057186:Comparative Effectiveness Research; D019299:Decompression, Surgical / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007796:Laminectomy; D007902:Length of Stay; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009664:Norway; D061646:Operative Time; D010027:Osteotomy; D010147:Pain Measurement; D012042:Registries; D013130:Spinal Stenosis / Q000601:surgery*
Laminotomy; Lumbar spinal stenosis; Posterior decompression; Spinal process osteotomy