Posterior-only hemivertebra resection and short segmental fusion in pediatric lumbosacral hemivertebra

English Keywords:Congenital scoliosis  Lumbosacral  Hemivertebra  Short segmental fusion  Coronal balance  Correction outcomes

English Abstract:

  【Abstract】 Objectives: To investigate the radiographic outcomes and complications after one-stage posterior hemivertebra resection and short segmental fusion for congenital scoliosis(CS) secondary to lumbosacral hemi-vertebra(HV). Methods: The young CS patients with lumbosacral hemivertebra who underwent hemivertebra resection and short segmental fusion form March 2003 to February 2013 and experienced more than 5 years follow-up were reviewed retrospectively. A total of 21 patients with an average age of 8.4 years at surgery was recruited. Among whom, there were 13 males and 8 females. HV was located at L4-L5 in 11 cases and L5-S1 in 10 cases. Radiological parameters including segmental curve, compensatory curve, upper instrumented vertebra(UIV) tilt, gravity trunk shift and segmental kyphosis, thoracic kyphosis, lumbar lordosis and SVA were measured on the X-rays before operation, immediately after operation, 2 years after operation and at the final follow-up. Patients were classified according to preoperative C7 translation. Complications were also recorded. Results: The follow-up time was 5.0-13.0 years(6.5±2.4 years). The fusion segments were 2-4 levels(2.9±0.6 levels). The segmental curve was corrected from 29.8°±10.1° before operation to 6.5°±5.1° immediately after operation(P<0.001), and 7.4°±5.4° and 7.8°±6.1° at 2 years after operation and the final follow-up respectively. With regard to preoperative coronal balance, 5 patients were identified with type A, 6 with type B and 10 with type C. The coronal imbalance was significantly corrected after operations in the three groups. The gravity trunk shift improved from 24.5±14.2mm to 14.6±11.9mm immediately after surgery (P<0.01), to 12.0±8.9mm and 9.8±8.0mm at 2 years after operation and the final follow-up respectively. The compensatory curve was spontaneously corrected from 22.9°±11.1° preoperatively to 8.5°±5.2° immediately after operation(P<0.001), 10.1°±6.0° and 11.9°±6.5° at 2 years after operation and the final follow-up, respectively. The UIV tilt improved from 14.4°±7.1° preoperatively to 2.6°±3.8° immediately after operation(P<0.05), 3.1°±4.0° and 3.8°±4.2° at 2 years after operation and the final follow-up. No significant statistical difference of sagittal parameters was observed(P>0.05). One patient experienced pedicle fracture during the operation. One patient had transient neurologic deficit after operation and recovered 3 months later. Two patients encountered compensatory curve progression and one patient received revision surgery. Conclusions: One-stage posterior hemivertebra resection and short segmental fusion is an effective procedure for congenital scoliosis secondary to lumbosacral hemivertebra, and the correction can be well maintained during the longitudinal follow-up.