Selection of the upper vertebra to be instrumented in the treatment of thoracolumbar and lumbar adolescent idiopathic scoliosis by anterior correction and fusion surgery using dual-rod instrumentation: a minimum 12-year follow-up study.
BACKGROUND
Consensus regarding the optimal upper vertebra to be instrumented during surgical treatment of Lenke 5C thoracolumbar and lumbar adolescent idiopathic scoliosis (AIS) remains limited.


OBJECTIVE
This study aimed to assess whether a short fusion strategy is appropriate for correction of a Lenke 5C AIS curve by anterior correction and fusion surgery using dual-rod instrumentation.


METHODS
This study design used retrospective comparative analysis of a prospectively collected, consecutive, non-randomized series of patients at a single institution.


METHODS
Thirty consecutive patients with Lenke 5C AIS treated with anterior correction and fusion surgery using dual-rod instrumentation were included.


METHODS
Patient demographics, radiographic measurements, and Scoliosis Research Society-22 questionnaire (SRS-22) scores were the outcome measures for this study.


METHODS
Thirty patients were treated surgically for AIS with a Lenke 5C curve (mean age, 14.4 years [11-19 years)]) and followed up for a mean period of 17.2 years (12-23 years). Radiographical parameters and clinical outcomes were compared between patients treatment with the end vertebra (EV) instrumented (n=14) and those treated by short fusion (S group) with instrumentation starting at the vertebra one level caudal to the EV (n=16 patients). There were no study-specific biases related to conflicts of interest.


RESULTS
In the EV group, a mean preoperative Cobb angle of 56° was corrected to 5° after surgery and to 8° at the final follow-up. In the S group, a mean preoperative Cobb angle of 55° was corrected to 10° after surgery and 14° at the final follow-up. The mean correction rate at the final follow-up was significantly lower in the S group (74%) than in the EV group (86%; p=.020). The coronal and sagittal balance, thoracic kyphosis, lumbar lordosis, and clinical outcomes evaluated using SRS-22 did not differ between the two groups.


CONCLUSIONS
The short fusion strategy, which involves instrumentation of the vertebra one level caudal to the upper EV, can be considered as an alternative to the conventional strategy, which includes instrumentation of the upper EV, for treating Lenke 5C curves via anterior spinal fusion.
Department of Orthopaedic Surgery, Hokkaido University Hospital, North-15, West-7, Sapporo, Hokkaido 060-8638, Japan. Electronic address: hidekisudo@yahoo.co.jp.
Hideki
H
Sudo
Department of Orthopaedic Surgery, Orthopaedic Hokushin Hospital, Kikusuimotomachi 3-3, Sapporo, Hokkaido 003-0823, Japan.
Kiyoshi
K
Kaneda
Department of Orthopaedic Surgery, Japan Community Health Care Organization Hokkaido Hospital, Nakanoshima 1-8 Sapporo, Hokkaido 062-8618, Japan.
Yasuhiro
Y
Shono
Department of Orthopaedic Surgery, Hokkaido University Hospital, North-15, West-7, Sapporo, Hokkaido 060-8638, Japan.
Norimasa
N
Iwasaki
D000293:Adolescent; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D011795:Surveys and Questionnaires; D013904:Thoracic Vertebrae / Q000601:surgery*
Adolescent idiopathic scoliosis; Anterior spinal fusion; Comparison study; Lenke 5C scoliosis; Short fusion; Upper instrumented vertebra