[Efficacy analysis of hemivertebra bone-disc-bone osteotomy for congenital scoliosis in children younger than 5 years old].

Objective: To analyze the clinical efficacy of posterior-only bone-disc-bone osteotomy (BDBO) for the treatment of congenital scoliosis (CS) caused by a single hemivertebra in children younger than 5 years old. Methods: This is a retrospective case series study. A retrospective analysis was conducted on the clinical data of 32 children under 5 years of age with CS caused by a single hemivertebra, who underwent single-stage posterior hemivertebra BDBO at the Department of Orthopedics, the Third Affiliated Hospital of Zhengzhou University, between January 2000 and January 2023. There were 16 males and 16 females, with a surgical age of (29.0±16.2) months (range: 1 to 57 months). Hemivertebra BDBO is a partial resection of the hemivertebra around the intervertebral disc. Type Ⅰ BDBO involves an osteotomy performed near the pedicle of the hemivertebra while preserving the pedicle of the hemivertebra extending into the cancellous bone of the adjacent vertebra. Type Ⅱ BDBO involves resection of the pedicle of the hemivertebra and extends into the cancellous bone of the adjacent vertebra. Type Ⅲ BDBO involves resection of the pedicle of the hemivertebra and extends into the cancellous bone of the adjacent vertebra until close to the pedicle. Radiographic parameters measured on full-spine anteroposterior and lateral X-ray scans preoperatively, postoperatively, and at the latest follow-up included: segmental scoliosis angle, main curve Cobb angle, compensatory cranial curve, compensatory caudal curve, coronal balance, segmental kyphosis angle, thoracic kyphosis, lumbar lordosis, and sagittal balance. Comparisons of radiographic outcomes were performed using one-way analysis of variance or Kruskal-Wallis H test. Results: The surgical procedures were successfully completed in all pediatric patients. There were 9 cases of type Ⅰ BDBO, all of which were lumbosacral hemivertebra. There were 9 cases of type Ⅱ and 14 cases of type Ⅲ, respectively, all of which were non-lumbosacral hemivertebra. Twenty-six patients underwent hemivertebra BDBO combined with pedicle screw fixation, while 6 patients underwent hemivertebra BDBO without instrumentation. The operative time was (200.1±57.1) min (range: 100 to 335 min), the intraoperative blood loss was (187.8±76.9) ml (range: 50 to 355 ml), and the number of instrumented segments was (2.8±1.0) segments (range: 2 to 4 segments). The follow-up duration was (76.9±45.1) months (range:25 to 191 months). The segmental scoliosis angle was corrected from 36.4°±5.4° preoperatively to 7.7°±5.1° postoperatively, with a correction rate of (79.6±10.8)%, and was 7.8°±3.5° at the latest follow-up (F=394.482, P<0.01). The main Cobb angle was corrected from 39.4°±8.0° preoperatively to 12.4°±8.6° postoperatively, with a correction rate of (69.9±13.1)%, and was 12.8°±9.1° at the latest follow-up (F=104.006, P<0.01). The compensatory cranial curve spontaneously corrected from 11.3°±5.5° preoperatively to 4.7°±2.8° postoperatively, with a correction rate of (55.6±21.5)%, and was 4.8°±2.9° at the latest follow-up (F=29.910, P<0.01). The compensatory caudal curve spontaneously corrected from 14.0°±9.7° preoperatively to 5.8°±5.1° postoperatively, with a correction rate of (51.1±32.0)%, and was 5.3°±4.0° at the latest follow-up (F=16.996, P<0.01). The segmental kyphosis angle was corrected from 20.4°±10.2° preoperatively to 6.6°±4.4° postoperatively, with a correction rate of (65.7±15.5)%, and was 7.1°±4.3° at the latest follow-up (F=41.434, P<0.01). Postoperative complications included transient nerve root injury in 2 cases, cerebrospinal fluid leakage in 2 cases, and delayed incision healing in 1 case. Conclusion: Hemivertebra BDBO effectively corrects CS caused by a single hemivertebra in children younger than 5 years old, with no significant loss of correction observed at mid-to long-term follow-up.