Correlation factors analysis for spontaneous correction of proximal compensated curve after posterior lumbosacral hemivertebra resection and short-segment fusion in children

English Keywords:Congenital scoliosis  Lumbosacral hemivertebra  Compensated curve  Hemivertebra resection  Spontaneous correction

English Abstract:

  【Abstract】 Objectives: To evaluate the surgical outcomes and correlation factors for spontaneous correction of proximal compensated curve (PCC) after posterior lumbosacral hemivertebra resection with short-segment fusion in children. Methods: The clinical data of 25 congenital scoliosis children with lumbosacral hemivertebra treated from Jan 2012 to Dec 2018 were reviewed retrospectively. There were 14 boys and 11 girls with an average age of 6.74±2.81 (3.3-13.00) years. The hemivertebra conditions included: 10 cases located at L4-S1 level, 13 cases located at L5-S1, and 2 cases located at L6-S1. All the patients underwent one-stage posterior-only hemivertebra resection with short-segment internal fixation and fusion, with at least a 24-month follow-up. Standing anteroposterior and lateral radiographs of full spine pre-operatively, post-operatively, and at the last follow-up were acquired and compared. Radiographic evaluation included measured changes in deformity segmental scoliosis and lordosis, sacral slanting angle(SSA), proximal fused vertebral obliquity(PVO), thoracic kyphosis, lumbar lordosis, trunk shift(TS), sagittal trunk shift(STS) and pelvic incidence(PI), pelvic tilt (PT), and sacral slope(SS). The correlations between the PCC at the final follow-up and multiple factors including age, deformity segmental scoliosis, congenital segmental scoliosis correction rate, PCC at pre-operation, and SSA and PVO at the latest follow-up were analyzed. Based on the PVO (≥5° or <5°), patients were divided into oblique group and horizontal group. The spinal parameters were compared between groups. Results: The mean follow-up period was 37.72±14.90(24-70) months. The mean fusion level was 2.58±0.77(2-4) segments. The mean operation time was 167.60±42.45(120-300) minutes with the average blood loss of 362.00±215.50ml(100-1000ml). 2 cases had a lower limb transient pain after operation which alleviated within two weeks. The mean segmental scoliosis was 28.8°±5.8° preoperatively, 5.8°±3.5° postoperatively (correction rate 79.7%, P<0.01), and 7.8°±3.2° at the latest follow-up(correction rate 72.9%, P<0.01). The PCC was spontaneously corrected from 25.8°±10.9° preoperatively to 13.1°±8.0° at the latest follow-up(correction rate 49.2%, P<0.01). TS was significantly improved on both coronal (13.5±11.7mm vs 5.5±4.5mm, P<0.01) and STS(16.1±9.6mm vs 7.0±5.0mm, P<0.01) planes at the latest follow-up. There was no difference of the values of PI, PT, and SS between that preoperatively and at the last follow-up, respectivley. PCC at the latest follow-up was correlated with preoperative PCC and PVO(P<0.01, P<0.05). There was no difference between the oblique group(14 cases) and the horizontal group(11 cases) in terms of age, congenital segmental scoliosis, PCC, sacral slanting, preoperatively and fused segments. But the horizontal group had a better PCC spontaneous correction over the oblique group(9.8° vs 17.4°, P<0.05). Conclusions: One-stage posterior lumbosacral hemivertebra resection with short-segment fusion in children can offer excellent scoliosis correction and trunk shift improvement. Take preoperative PCC as a predict factor and horizontalize the proximal fused vertebral during-operation could be helpful for PCC spontaneous correction.