Abstract
BACKGROUND: This study aimed to assess the preoperative radiographic factors and specific surgical interventions in both degenerative and lytic lumbar spondylolisthesis patients, who underwent single level lumbar fusion surgery, with a focus on evaluating the predictors of postoperative restoration of segmental lumbar lordosis(SLL) and spinopelvic balance. METHODS: A single-centre, retrospective study on 74 patients with degenerative and lytic lumbar spondylolisthesis who underwent single level transforaminal lumbar interbody fusion (TLIF) surgery between August 2020 and July 2022 with a minimum follow up of 1 year. Radiographic measures included disc angle(DA), SLL, lumbar lordosis(LL), anterior/posterior disc height(ADH/PDH), spondylolisthesis percentage(SP) and pelvic parameters like pelvic incidence(PI), pelvic tilt(PT) and sacral slope(SS). Surgery-related measures included cage position, spondylolisthesis reduction rate, rod contouring and disc height restoration rate(DHRR). For analysis, change in SLL ≥ 8° indicated increased segmental lumbar lordosis(ISLL), and < 8° indicated unincreased segmental lumbar lordosis(UISLL). RESULTS: The mean age of the entire cohort was 42.4 years, with 76% of the patients being female. In our study 62% patients had UISLL and 38% had ISLL. In lytic listhesis group, on multivariate analysis the LL, DA, cage position were significant predictors of restoration of SLL. In degenerative listhesis, age and preoperative SP were significant factors. DHRR was the only significant predictor for restoring good PI-LL(Pelvic incidence minus Lumbar lordosis). CONCLUSION: Preoperative LL, DA and intraoperative cage position emerged as significant predictive factors. Surgeons should place the cage more anteriorly, with efforts to restore disc height to maximise the restoration of SLL and to attain a good PI-LL. CLINICAL TRIAL NUMBER: Not applicable.