Sagittal alignment of the cervical spine in adolescent idiopathic scoliosis treated by posteromedial translation
Brice Ilharreborde, Christophe Vidal, Wafa Skalli, Keyvan Mazda
January 2013, Volume 22, Issue 2, pp 330 - 337 Original Article Read Full Article 10.1007/s00586-012-2493-7
First Online: 11 September 2012
Purpose
To analyze postoperative changes in the cervical sagittal alignment (CSA) of patients with AIS treated by posteromedial translation.
Methods
49 patients with thoracic AIS underwent posterior arthrodesis with hybrid constructs, combining lumbar pedicle screws and thoracic universal clamps. Posteromedial translation was the main correction technique used. 3D radiological parameters were measured from low-dose biplanar radiographs. CSA was assessed using the C2C6 angle, and the central hip vertical axis (CHVA) was used as a reference axis to evaluate patients’ balance.
Results
Preoperatively, 58 % of patients had thoracic hypokyphosis, and 79 % had a kyphotic CSA. Significant correlation was found (r = 0.45, P = 0.01) between thoracic hypokyphosis and cervical kyphosis. Increase in T4–T12 thoracic kyphosis (average 14.5° ± 10°) was associated with significant decrease in cervical kyphosis in the early postoperative period. The CSA further improved spontaneously during follow-up by 7.6° (P
Conclusions
Thoracic hypokyphosis and cervical hypolordosis, observed in AIS, can be improved postoperatively, when the posteromedial translation technique is used for correction. The cervical spine remains adaptable in most patients, but the proportion of patients with physiological cervical lordosis at final follow-up remained low (24.5 %).
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