Proximal Curve Decompensation Following a Local Resection and Selective Fusion of Lumbar Spine Osteoblastoma with Scoliosis: A Case Report

Background: The recommended treatment for Osteoblastoma with scoliosis is surgical resection, correction of scoliosis with posterior spinal instrumentation and fusion. There were reported risk of recurrence of osteoblastoma but no published report on proximal curve decompensation when selective fusion of lumbar spine is chosen. Case presentation: A 12-year-old girl presented with low back pain for 3 years and was found to have back deformity. She was diagnosed with thoracolumbar scoliosis with apex at L2 vertebra with Cobb’s angle of 430 secondary to Osteoblastoma pedicles of left L2 and L3. Tumour excision with hemilaminectomy left L2 and L3, posterior instrumentation and selective fusion from T12 to L4 was done. Unfortunately, the Cobb’s angle worsened to 650 proximal to the upper instrumented vertebra (UIV) with proximal thoracic curve of 300 after 2 years follow up. An extension of posterior spinal instrumentation, curve correction and fusion up to T3 was performed. Latest review 6 months after the surgery revealed no aggravated curve or shift, no back pain and no neurological deficit. Conclusions: Scoliosis secondary to osteoblastoma need to be monitored closely following resection and selective fusion in skeletally immature patient. Risk of proximal curve decompensation, as well as secondary surgery, need to be aware of.