Effectiveness Of Stepwise Corrective Surgery For Severe Kyphoscoliosis Deformities

Objective: Severe kyphoscoliosis deformities were usually accompanied byneurological abnormalities, as well as heart and lung dysfunction, digestive disordersand other organs dysfunction. Surgical treatment of the severe spinal deformitiesremains a challenge for spine surgeons. So we propose "stepwise corrective" surgery forsevere kyphoscoliosis deformities in order to improve the effect and reduce the risk ofsurgery. Meanwhile, we review the effectiveness of stepwise corrective surgery forsevere kyphoscoliosis deformities.Methods:24patients with severe kyphoscoliosis deformities were received stepwisecorrective surgery. There were9males and15females with an average age of18years.The average preoperative major coronal curve was (128.8±19.4)°, and the averagepreoperative kyphosis was (108.8±36.5)°. First step was performed on the concave sideby internal distraction of pedicle screws and rods through2invasive incisions;4.3months later, the final correction was performed by posterior osteotomy in all patients.During the surgery, the function of spinal cord was monitored intra-operatively bysomatosensory evoked potential (SEP) or motor evoked potential (MEP) in all patients.Results: The mean major coronal curve was corrected by40.6%after the first operationand by65.6%after the second operation. The mean kyphosis was corrected by41.3%after the first operation and by70.1%after the second operation. The percentage ofpredictive FEV1and FVC was63.9±12.2%（range32.3-83.1%）and62.0±13.4%（range29.0-85.4%）before the first operation, and increased to79.6±12.6%（range58.3-121.0%） and72.1±10.8%（range57.3-103.8%） before the second operation, respectively. All patients were followed by9.2months, with final63.5%correction inmajor coronal curve and67.0%correction in kyphosis curve. No severe complicationwas noticed in this series. One case had superior mesenteric artery syndrome after thefinal correction. Two cases had transient nerve root palsies. One case had occurred onepedicle screw failure after the first step surgery.Conclusions: The stepwise corrective surgery for the treatment of severe kyphoscoliosisdeformities provides safe and satisfactory outcomes in this patient population.