Is it real adjacent segment pathology by stress concentration after limited fusion in degenerative lumbar scoliosis?
METHODS
A retrospective comparative study.


OBJECTIVE
To investigate adjacent segment pathology (ASP) after limited lumbar fusion in the treatment of degenerative lumbar scoliosis (DLS).


BACKGROUND
The assessment of appropriate surgical techniques for DLS remains one of the most controversial topics in spinal surgery. So far, there has been no study specifically addressing why ASP shows different patterns with respect to different fusion levels after instrumented lumbar fusion for DLS.


METHODS
Fifty-nine patients were enrolled and divided into 2 groups with respect to the proximal fusion level: group I consisted of 29 patients who underwent fusion below the proximal neutral vertebrae, and group II consisted of 30 patients who underwent fusion to the proximal neutral vertebrae. Clinical and radiological assessments were performed with an average of 59.4 months of follow-up. The number of radiological findings for ASP was determined on the basis of a 7-point scale that gave 1 point for each radiological finding. The 2 groups were analyzed according to radiological ASP (RASP). The Oswestry Disability Index and visual analogue scale scores were recorded prospectively.


RESULTS
Overall, RASP developed in 16 (27.1%) patients. In group I, 12 (41.4%) of 29 patients, and in group II, 4 (13.3%) of 30 patients showed RASP. Group I yielded an average of 4.5 points, and group II, 1.8 points. RASP scores were much higher in group I than in group II, with statistical significance (P = 0.000). In group I, 4 patients underwent revision surgery, but in group II, only 1 patient did so.


CONCLUSIONS
RASP displayed variance according to different fusion levels. RASP in group I showed similar patterns to the natural progression of DLS. It is suggested that fusion be included at least at the proximal neutral vertebrae to reduce RASP although RASP with different patterns is unavoidable.


METHODS
4.
From the Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Kee-Yong
KY
Ha
Young-Hoon
YH
Kim
Joo-Hyun
JH
Ahn
D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects / Q000379:methods; D017116:Low Back Pain / Q000503:physiopathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012600:Scoliosis / Q000503:physiopathology* / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D013314:Stress, Mechanical; D016896:Treatment Outcome