Treatment of unstable osteoporotic fractures of the thoracolumbar spine by short transpedicular instrumentation and vertebral cement augmentation using vertebroplasty or kyphoplasty
Abstract
Introduction: A retrospective study of 26 patients treated between 1/2010 and 6/2016 with unstable osteoporotic fracture of the thoracolumbar spine treated with short transpedicular fixation and vertebroplasty of the affected vertebra is presented. Material and Method: The patients were operated in a prone position with the insertion of transpedicular screws, fracture reduction followed by insertion of Jamshidi needles in the case of vertebroplasty or balloon expander in the case of kyphoplasty and subsequent filling of the vertebral body with polymethylmethacrylate cement and addition of posterolateral fusion.
Results: From an average JOA preoperative score of 11,7 (+/- 1,48), 1 year postoperative improvement was evaluated at 15,6 (+/- 1,62) (p=0,02). The assessment of subjective pain with a VAS score went from a preoperative value of 5,2 (+/- 1,8) to 2,56 (+/- 1,49) 1 year postoperatively (p=0,003).
A total of three patients (11,5%) had a neurological deficit before surgery. All improved postoperatively by one step.
Restoring the sagittal balance by measuring the modified Cobb angle in the sagittal plane was achieved by correcting from a preoperative value of 18,9 (+/- 3,4) to 8,8 (+/- 2,3) postoperatively, followed by a deterioration to 14,1 (+/- 2,6) degrees 1 year after surgery. B-type cement leakage with leakage of small amounts of cement into the spinal canal without the need of surgical revision was found in one patient.
Type S leakage without neccesity of the revision surgery without pulmonary embolism manifestation was found in one patient. Type C leakage was found in total of ten patients, 2x the spinal canal and 8x in the intervertebral disc.
Only one patient in the group, with leakage of cement into the spinal canal and worsening of neurological status, was revised immediately without postoperative improvement. Instrumental failure at 1 year after surgery was found in four patients, in 3 of these cases, the transpedicular screws migrated, and in one patient the screw broke.
Manifestation of a new pathological vertebral fracture adjacent to the operated segment was found in two patients. Discussion: The results of the study confirm, that the advantage of the surgical technique is reduction and stabilisation of the fractured vertebra in one step, indirect decompression of the spinal canal and the possibility of correcting the sagittal balance.
The disadvantage is the risk of cement leakage with subsequent development of serious clinical complications, the risk of loss of correction of sagittal balance, instrumentation failure and the development of pathological fracture of the adjacent vertebra.