Standardized translaminar spinal tethering to prevent proximal junctional kyphosis in adult spinal deformity correction surgery

Purpose:This study evaluated whether standardized proximal translaminar spinal tethering at the upper instrumented vertebra (UIV) +1 and UIV+2 reduces the incidence of proximal junctional kyphosis (PJK) and the need for revision surgery in patients undergoing thoraco-lumbar deformity correction for adult spinal deformity (ASD). Methods:A retrospective cohort study was conducted on 59 adult patients who underwent thoraco-lumbar deformity correction surgery between October 2019 and August 2023. Patients were categorized into tethered (T) and non-tethered (NT) groups. Radiographic measurements were performed preoperatively, early postoperatively (≤3 months), and late postoperatively (>3 months) to assess PJK, defined as a proximal junctional angle (PJA) ≥ 10° and ≥ 10° greater than the corresponding preoperative measurement. Results:Overall, 18 patients (30.5%) developed PJK, with no significant difference between tethered (12%) and non-tethered (20.5%) patients within the first 3 months (p=0.384). However, at late follow-up, the PJK rate was significantly higher in non-tethered (41.1%) compared to tethered (16%) patients (p=0.037), with non-tethered patients being 3.67 times more likely to develop PJK (95% CI = 1.03-13.07). Kaplan-Meier analysis showed a significant reduction in time-dependent PJK development for tethered patients (p=0.027). Revision surgery was required in 11.8% of non-tethered patients compared to 4% of tethered patients (p=0.289). Conclusion:Proximal translaminar tethering at UIV+1 and UIV+2 effectively reduces the incidence of PJK in patients undergoing thoraco-lumbar deformity correction. However, the effect on surgical revision rates due to PJK remains unclear, warranting further long-term prospective studies.