Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired Objectives
Materials and Methods
The purpose of this study was to determine whether
patients with a burst fracture of the thoracolumbar spine treated
by short segment pedicle screw fixation fared better clinically
and radiologically if the affected segment was fused at the same
time. A total of 50 patients were enrolled in a prospective study
and assigned to one of two groups. After the exclusion of three
patients, there were 23 patients in the fusion group and 24 in the
non-fusion group. Follow-up was at a mean of 23.9 months (18 to
30). Functional outcome was evaluated using the Greenough Low Back
Outcome Score. Neurological function was graded using the American
Spinal Injury Association Impairment Scale. Peri-operative blood transfusion requirements and duration of
surgery were significantly higher in the fusion group (p = 0.029
and p <
0.001, respectively). There were no clinical or radiological
differences in outcome between the groups (all outcomes p >
0.05).
The results of this study suggest that adjunctive fusion is unnecessary
when managing patients with a burst fracture of the thoracolumbar
spine with short segment pedicle screw fixation.
This review of the literature presents the current understanding of Scheuermann’s kyphosis and investigates the controversies concerning conservative and surgical treatment. There is considerable debate regarding the pathogenesis, natural history and treatment of this condition. A benign prognosis with settling of symptoms and stabilisation of the deformity at skeletal maturity is expected in most patients. Observation and programmes of exercise are appropriate for mild, flexible, non-progressive deformities. Bracing is indicated for a moderate deformity which spans several levels and retains flexibility in motivated patients who have significant remaining spinal growth. The loss of some correction after the completion of bracing with recurrent anterior vertebral wedging has been reported in approximately one-third of patients. Surgical correction with instrumented spinal fusion is indicated for a severe kyphosis which carries a risk of progression beyond the end of growth causing cosmetic deformity, back pain and neurological complications. There is no consensus on the effectiveness of different techniques and types of instrumentation. Techniques include posterior-only and combined anteroposterior spinal fusion with or without posterior osteotomies across the apex of the deformity. Current instrumented techniques include hybrid and all-pedicle screw constructs.
