Pars interarticularis repair using pedicle screws and laminar hooks fixation technique in patients with symptomatic lumbar spondylolysis

Abstract

Study Design: Prospective case series. Purpose: To assess the outcomes of pars repair surgery using pedicle screws and laminar hooks. Methods: This study was conducted on 22 patients with symptomatic lumbar spondylolysis. Curettage of the fibrocartilage in the defect and drilling of the sclerotic bone ends were done, followed by impaction of cancellous bone graft. Pedicle screws were inserted bilaterally in the corresponding pedicles and connected to a laminar hook via rods (screw-rod-hook fixation). The intensity of back pain and the functional outcome were assessed using the visual analog scale (VAS) and the Oswestry disability index (ODI). Plain radiographs were performed immediately postoperatively and after 3 and 6 months. CT scan was done at the final follow-up to assess pars healing. The mean follow-up period was 27 months. Results: The mean preoperative VAS and ODI were 7.4 ± 0.8 and 64.8 ± 6.7, which improved to 2.4 ± 0.8 and 20 ± 6 respectively at the final follow-up (P < 0.001). Healing of the defect was found in 19 patients at the final follow-up. Non-fusion with graft resorption was noticed in the remaining 3 cases (13.6%). However, postoperative VAS and ODI values improved even in the radiologically non-fused patients. Level of evidence: Therapeutic study, Level IV. Conclusion: Pars repair using pedicle screws and laminar hooks is a relatively simple yet effective procedure.

Keywords

• pars repair
• pedicle screws
• laminar hooks
• screw-rod-hook fixation
• spondylolysis