ABSTRACT
The authors reviewed factors related to the surgical techniques attributed to surgeon-errors which result in failures of the construct of the internal fixation of thoracolumbar fractures through transpedicular screws systems, and how these could be avoided. The authors reviewed 280 consecutive patients with traumatic thoracolumbar fractures who underwent spinal surgical fixation with short segment transpedicular screw instrumentation at two institutions, between January 1997 and June 2005. All patients in this series were victims of high-force trauma. Among this series, 30 patients had a construct failure attributed to surgeon-related errors. Clinical evaluation of the patients was performed on admission and at postoperative period using ASIA scale. All patients were radiologically investigated by plane x-rays and computerized tomographic scan spine on admission and occasionally MRI and 3D CT scan of the spine when required. We used McAfee classification of thoracolumbar injuries. Surgical treatment was indicated in cases of biomechanical instability of the spine and/or if a neurologic deficit was imminent or already present, the patients were followed-up as regard to clinical and radiological evidence of construct failure. Thirty patients out of 280 patients with post-traumatic thoracolumbar injuries had construct failures. Main clinical presentation of construct failure was severe pain and inability to walk at postoperative period. Radiologically there was progressive spinal deformity with and without implant failures. The locations of the fractures in order of frequency were as follows: L1 in 18 cases, L2 in 7 cases, T12 in 5 cases. The construct failure was in the form of screw binding in 6 patients, screw breakage in 12 patients, screw/rod dislodgement in 3 patients, progressive kyphosis in 5 patients, disengaged screw's cup in 2 patients, and broken rods in 2 patients. Successful use of transpedicular screws in traumatic thoracolumbar fractures is predicated on understanding of biomechanical properties of both the spine and implants. Great attention must be directed to maintain the sagittal and coronal balances of the spine over the sacrum through reconstruction of comminuted anterior vertebral column and appropriate distraction of the construct. In spite of routine use of pedicle, screw has not been free of complications; the majority of construct failures is not actually device failures but instead is surgeon-related errors