Reference intervals of adjacent disc height in fresh osteoporotic vertebral compression fractures and the association with postoperative adjacent segment complications: a quantitative study in Chinese postmenopausal women.

Background: Preoperative adjacent disc height (DH) was found as an independent risk factor for adjacent segment degeneration (ASD) after percutaneous kyphoplasty (PKP), indicating the preoperative status of the adjacent intervertebral discs may be closely related to adjacent segment complications. To establish the reference intervals (RIs) for adjacent DH of fresh osteoporotic vertebral compression fracture (OVCF) in Chinese postmenopausal women, and investigate the association with adjacent segment complications after PKP.

Methods: Consecutive inpatients diagnosed with fresh OVCF between November 2015 and August 2023 were reviewed. The enrolled patients were divided into subgroups based on injured vertebral level; then, the cranial and caudal DH were measured. The characteristics of DH among subgroups were identified, and specific RIs were established using the indirect Hoffmann method. The associations between DH and adjacent segment complications were assessed using multivariate analysis.

Results: The DH of the cranial disc was significantly lower than the corresponding caudal disc in all vertebral levels, which showed an increasing trend from T11 to L4. The RIs of DH were as follows: T11 (cranial), 2.14-5.14 mm; T11 (caudal), 2.64-5.89 mm; T12 (cranial), 2.69-5.77 mm; T12 (caudal), 3.18-6.57 mm; L1 (cranial), 3.05-6.59 mm; L1 (caudal), 3.40-8.29 mm; L2 (cranial), 3.68-8.36 mm; L2 (caudal), 4.57-9.78 mm; L3 (cranial), 4.53-8.92 mm; L3 (caudal), 5.26-10.07 mm; L4 (cranial), 4.70-11.42 mm; and L4 (caudal), 5.52-12.12 mm. Increased risks of adjacent segment complications after PKP were observed in patients with decreased adjacent DH.

Conclusion: The estimated vertebral level and disc level-specific RIs for adjacent DH of fresh OVCF were established in the Chinese postmenopausal women population. A decrease in adjacent DH posed high risks of adjacent segment complications after PKP for treating OVCF.