Correction of post-traumatic kyphosis in the thoracolumbar spine through Ponté osteotomy and interbody fusion with impacted morsellized bone graft

Abstract

Objective To describe Ponte osteotomy and interbody fusion with impacted morsellized bone graft and to investigate the safety and efficacy for the correction of post-traumatic kyphosis (PTK) in the thoracolumbar spine.Methods From June 2010 to March 2013,13 patients with PTK in the thoracolumbar spine were treated through Ponte osteotomy and interbody fusion with impacted morsellized bone graft.There were 7 males and 6 females,aged from 32 to 78 years,average 54.5 years.The apex level of kyphosis was T11 in 1,T12 in 4,L1 in 5 and L2 in 3.There was failure of first surgery in seven patients,and inappropriate conservative treatment in six,that all suffered from pain,progressive deformity,and deteriorating neurologic status.During the operation,the intervertebral space was loosened radically through Ponte osteotomy and discectomy,and the kyphosis was firstly corrected using the morcellized impacted graft technique.Then the kyphosis was corrected using the correction rod technique with the hinge of the morcellized impacted graft.Radiographical assessments included localized kyphosis,thoracic kyphosis,lumbar lordosis,sacral tilt angle,sagittal vertical axis,bony fusion and the relative height of the interbody fusion vertebra.Visual analogue scale (VAS),Oswestry disability index (ODI) and ASIA were evaluated before and after surgery,and the operative duration,blood loss were recorded.Results All patients were successfully followed up for an average time of (20.0±9.1) months.Bony fusion was achieved in all patients at 12 months follow-up.Localized kyphosis was reduced from an average of 42.2° (26° to 54°) to 7.1° (-7° to 13°) with an correction rate of 83.2％ on average.Sagittal alignment from T1 to the sacrum became more physiologic from 2.91cm (-3.0 to 7.8 cm) to 1.35cm (-0.5 to 3.8 cm).Thoracic kyphosis,lumbar lordosis and sacral tilt angle all improved at followup.The average VAS score was 6.38±0.87 (range,5 to 8) before operation and 2.23±0.83 (range,1 to 4) at final follow-up.The average ODI score was 55.0± 12.1 (range,39 to 72) before operation and 20.6±7.3 (range,11 to 34) at final follow-up.Neurological function improved from C to D in two patients,from C to E in four patients,and from D to E in seven patients.Conclusion Application of Ponte osteotomy and interbody fusion with impacted morsellized bone graft for the correction of PTK in the thoracolumbar spine has several advantages:large angle correction,high fusion rate,mini-invasion,and little nerve complications. Key words: Thoracic vertebrae; Lumbar vertebrae; Spinal fractures; Kyphosis; Spinal fusion; Bone transplantation