[Treatment of osteoporotic vertebral compression fractures with PMMA-augmented pedicle screw fixation].

BACKGROUND

Over the last few decades many innovative operation technique were developed due to the increase of porotic vertebral fractures. These new techniques aim to reach the required stability of the vertebral column. In case of significant instability, spinal canal stenosis or neural compression, decompressive intervention may be necessary, which results in further weakening of the column of the spine, the minimal invasive percutan vertebroplasty is not an adequate method to reach the required stability, that is why insertion of complementary pedicular screws is needed. Considering the limited screw-fixing ability of the porotic bone structure, with this new technique we are able to reach the appropriate stability of cement-augmented pedicle screws by dosing cement carefully through the screws into the vertebral body. We used this technique in our Institute in case of 12 patients and followed up the required stability and the severity of complications.

METHODS

Fifteen vertebral compression fractures of 12 patients were treated in our Institute. Using the classification proposed by Genant et al. we found that the severity of the vertebral compression was grade 3 in case of 13, while grade 2 in case of two fractures. The average follow up time of the patients was 22 months (12-39), during this period X-ray, CT and clinical control examinations were taken. During the surgery the involved segments were localised by using X-ray and after the exploration the canulated screws were put through the pedicles of the spine and the vertebral body was filled through the transpedicular screws with bone cement. Depending on the grade of the spinal canal stenosis, we made the decompression, vertebroplasty or corpectomy of the fractured vertebral body, and the replacement of the body. Finally the concerned segments were fixed by titanium rods.

RESULTS

In all cases the stenosis of spinal canal was resolved and the bone cement injected into the corpus resulted in adequated stability of the spine. In case of six patients we observed cement extravasation without any clinical signs, and by one patient--as a serious complication--pulmonary embolism. Neurological progression or screw loosening were not detected during the follow up period. Part of the patients had residual disability after the surgery due to their older ages and the problem of their rehabilitation process.

CONCLUSION

After the right consideration of indications, age, general health condition and the chance of successful rehabilitation, the technique appears to be safe for the patients. With the use of this surgical method, the stability of the spine can be improved compared to the preoperative condition, the spinal canal stenosis can be solved and the neural structures can be decompressed. The severity of complications can be reduced by a precise surgical technique and the careful use of the injected cement. The indication of the surgical method needs to be considered in the light of the expected outcome and the rehabilitation.