Pedicle screw vs. pedicle screw-rod-hook direct repair for adolescent lumbar spondylolysis: a multicenter retrospective cohort study.

PURPOSE: To compare clinical outcomes, time to fusion, and post-fusion segmental ROM between pedicle screw (PS) direct repair and pedicle screw-rod-laminar hook (PSRH) repair in adolescents/young adults with non-spondylolisthetic lumbar spondylolysis. METHODS: We included patients aged 15-25 years treated from 2015 to 2022 at three centers. All patients had predominant low back pain, failed conservative treatment, no neurological symptoms, and no vertebral slip. The defect was decorticated and grafted with allograft. Patients underwent PS or PSRH repair. CT was obtained at 6, 12, 18, 24, and 28 months until fusion. Fusion was adjudicated by independent reviewers. After CT-confirmed fusion, implants were removed in all patients. Segmental ROM was measured on flexion-extension radiographs using the Cobb angle difference. RESULTS: Fifty-seven patients were included (PS 27; PSRH 30). Follow-up was similar (21.8 ± 3.39 vs. 21.4 ± 3.02 months; P = 0.660). The PS group had higher costs, longer hospital stay, and greater blood loss (all P < 0.05). Preoperative VAS and ODI were comparable. At final follow-up, VAS was similar (2.07 ± 0.87 vs. 1.83 ± 0.64; P = 0.23). ODI showed a borderline difference (9.51 ± 6.16 vs. 12.06 ± 3.11; P = 0.050). Time to fusion was shorter with PS repair (10.9 ± 2.90 vs. 13.0 ± 3.28 months; P = 0.013). After implant removal, ROM was smaller in the PS group (3.33 ± 1.03 vs. 5.46 ± 0.77; P = 0.001). Complications were infrequent in both groups. CONCLUSION: Both techniques improved pain and function with low complication rates. PS repair was associated with faster fusion but smaller post-fusion ROM after implant removal. Construct choice may influence fusion progression and post-fusion kinematics.