The Importance of Spinopelvic Parameters in Recurrent Lumbar Disk Herniation

Study Design: Retrospective clinical study. Objectives: We aimed to investigate preoperative spinopelvic mismatch as a risk factor for recurrent lumbar disk herniation (RLDH) in patients undergoing lumbar disk herniation (LDH) surgery. Summary of Background Data: Spinopelvic parameters have been associated with lumbar degenerative diseases, particularly LDH. However, the relationship between these parameters and RLDH has yet to be studied. Materials and Methods: Data of 1453 patients aged ≥18 who underwent single-level, unilateral fenestration microdiscectomy for the first time in our hospital between 2013 and 2019 were reviewed. The study group comprised 88 patients who underwent surgery for RLDH. The control group comprised 101 randomly selected patients who underwent surgery for LDH but not RLDH. Age, sex, body mass index, occupational activity level, operative level, Roussouly classification type, and time to recurrence were recorded. Moreover, pelvic incidence, lumbar lordosis (LL), interverteberal disk height (IDH), segmental lordosis, sacral slope (SS), pelvic tilt (PT), and sacral table angle (ST) were measured for each patient. Pelvic mismatch was calculated. Results: Mean age was 46.5±11.4 y (range, 20–70). Both groups were similar concerning age, sex, body mass index, occupational activity level, and level of surgery. The mean time to recurrence was 167.3±36.6 d (range, 62–363). Measurements in the RLDH group were as follows: IDH=7.6±1.5 mm, pelvic incidence =54.4°±10.1°, LL=47.3°±13°, segmental lordosis =9.3°±5°, SS=35.1°±9.9°, and PT=19.3°±7.3°. Mean IDH was significantly lower in the RLDH group ( P =0.02). Less LL and lower PT at L3–4 level and increased SS at L5–S1 level were considered risk factors for RLDH. Conclusion: This study showed that preoperative low IDH is at higher risk for RLDH in patients undergoing LDH surgery. LL, PT, and SS may be risk factors for specific levels.