Analysis of Clinical and Radiological Outcomes of Posterior Dynamic Stabilization for Direct Repair of Bilateral L5 Pars Interarticularis Defect: Dynamic Assessment of Pars Fusion.

AIM: This study aimed to evaluate the satisfactory clinical and radiological outcomes of posterior dynamic stabilization for the direct repair of bilateral L5 pars interarticularis defects and pars fusion.

MATERIAL AND METHODS: This is a retrospective evaluation of postoperative follow-up results of 13 patients with bilateral L5 pars interarticularis defects without spondylolisthesis. The patients underwent dynamic transpedicular stabilization between 2013 and 2018. Our surgical criteria included unilateral or bilateral L5 spondylolysis; excessive low back pain; low back pain accompanied by leg pain without neurological findings; symptoms lasting at least six months despite conservative treatments, age 50 years; and lack of significant adjacent disc degeneration.

RESULTS: There were seven female and six male patients with a mean age of 38.9 years. All patients achieved satisfactory postoperative results during a mean follow-up period of 22 months. Preoperative visual analog scale score and Oswestry Disability Index value were 8.85 ± 0.69 and 54.46 ± 7.62, respectively, which decreased to 1.31 ± 0.48 and 9.85 ± 3.51, respectively, at the postoperative 24th month. In all patients, the bony fusion of the pars interarticularis at the stabilized segment was confirmed on the computed tomography scan at an average of 22 months postoperatively.

CONCLUSION: The posterior dynamic system ensures that the spine moves within physiological limits and carries the load by sharing it with the spine. The advantages of direct pars repair using our technique are the restoration of the posterior structures' normal anatomy, protection of the functional mobility segment, and early functional recovery without degeneration in the adjacent segment. Therefore, when there is no significant instability, patients with spondylolysis can be treated with posterior dynamic stabilization techniques with satisfactory clinical and radiological results.