Objective: The authors reviewed factors related to the surgical techniques resulting in failure
of the construct of the internal fixation of thoracolumbar fractures through transpedicular
screw systems and how to be avoided. Patients and Methods: The authors reviewed 280
consecutive patients with traumatic thoracolumbar fractures who underwent spinal surgical
fixation with short segment transpedicular screw instrumentation at three institutions,
between January 1997 and June 2005. All patients in this series were due to high-energy
trauma. Among this series, 30 patients had a construct failure attributed to surgical technique
causes. Clinical evaluation of the patients was performed on admission and at post-operative
period using ASIA scale. All patients were radiologically investigated by plain X-rays and
computerized tomographic (CT) scan spine on admission and occasionally MRI and 3D CT
scan of the spine when required. The patients were followed up as regard to clinical and
radiological evidences of construct failure. Results: 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 post-operative period.
Radiologically there was progressive spinal deformity with implant failures. The locations of
the fractures in order of frequency were as follows: L-1 in 18 cases, L-2 in 7 cases, T-12 in 5
cases. The construct failure was in the form of screws malposition in 13 patients, screws
breakage in 10 patients, screw/rod dislodgement in 3 patients, disengaged screw's cup in 2
patients, and broken rods in 2 patients. Conclusion: 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 screws, it has not been free of complications. The
majority of construct failures is not actually device failures but instead is surgical technique
causes. |
