Few complications, less blood loss seen with percutaneous pedicle screw fixation

Adult patients with spine deformity had better 2-year outcomes after circumferential fusion with minimally invasive lateral interbody fusion and posterior instrumentation than patients who had after open surgery with posterior instrumentation, according results of a study.

“For well-balanced, moderate, symptomatic thoracolumbar deformity, circumferential fusion with [minimally invasive surgery] MIS lateral interbody fusion and posterior instrumentation is an effective technique for pain relief and radiographic deformity correction,” Alexander A. Theologis, MD, said.

The MIS procedure is associated with minor complications, less operative time and blood loss and more deformity correction at 2-years follow- up among adult patients with spine deformity, according to a presentation he gave at the International Society for the Study of the Lumbar Spine Annual Meeting.

Open vs percutaneous screws

The primary goal of adult spinal deformity surgery is to restore sagittal and coronal alignment to improve function, as well as quality of life, according to Theologis.

Theologis and colleagues analyzed the results of 155 adult spinal deformity patients who underwent circumferential fusion via a MIS approach. The cohort was divided to receive either an open or percutaneous approach for placement of posterior pedicle screw instrumentation.

In all, 60 patients underwent the procedure with open-type (hybrid) posterior pedicle screws and 90 patients underwent the procedure with percutaneous posterior pedicle screws (cMIS). The groups were statistically similar in terms of age, sex and BMI.

One difference between the groups, however, was the cMIS cohort had smaller preoperative Cobb angles of 36.9° ± 14.3° compared with Cobb angles of 43.9° ± 16.9° in the hybrid group.

Results with percutaneous screws

Following surgery, both groups experienced statistically significant improvements in Oswestry Disability Index (ODI) scores, VAS scores, Cobb angle, lumbar lordosis, lumbopelvic mismatch and leg pain scores, according to Theologis.

However, he noted that patients with percutaneous posterior pedicle screws experienced fewer overall complications than patients with open posterior pedicle screws (33.3% vs 53.8%).

“After operation, there were significant improvements in ODI for both groups, but in the cMIS group, they did have statistically significant improvements in ODI when compared to the hybrid group and a lower ODI score at 2-year follow-up,” Theologis said.

The cMIS cohort experienced significantly less estimated blood loss (536 mL ± 532 mL) compared to 1199 cc ± 946 mL for the hybrid cohort. The average operative times were also shorter for the cMIS cases at 440 minutes ± 190 minutes compared to 627 minutes ± 246 minutes for the hybrid cases.

Safe, effective procedure

Based on the results of the study, the cMIS cohort had a 0% minor radiographic complication rate compared to a 9% rate for the hybrid cohort.

Compared to open posterior instrumentation, percutaneous pedicle screw fixation resulted in fewer complications, less blood loss, shorter operative times and less disability at 2-years follow-up, Theologis and colleagues concluded. – by Robert Linnehan

Reference:
Theologis AA, et al. Paper #49. Presented at: International Society for the Study of the Lumbar Spine Annual Meeting; June 8-12, 2015; San Francisco.

For more information:
Alexander A. Theologis, MD, can be reached at Department of Orthopaedic Surgery, University of California, San Francisco, 2550 23rd St., Building 9, 2nd Floor, San Francisco, CA 94110; email: alekos.theologis@ucsf.edu.

Disclosure: Theologis reports no relevant financial disclosures.