Wang Chongyan1, Xuyang Zhang1, Shengyun Li1, Junhui Liu1, Zhi Shan1, Jiasheng Wang1, Jian Chen1, Shunwu Fan1, Fengdong Zhao2. 1. Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Rd, Hangzhou 30016, PR China. 2. Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 East Qingchun Rd, Hangzhou 30016, PR China. Electronic address: zhaofengdong@zju.edu.cn.
Abstract
BACKGROUND CONTEXT: Intravertebral clefts (IVCs) are vacuum-like cavities commonly associated with osteoporotic vertebral compression fractures (OVCFs). IVCs promote cement leakage during kyphoplasty, suggesting a physical link with the basivertebral foramen, although this is uncertain. PURPOSE: The present study aims to create IVCs in mechanical experiments on cadaveric spines in order to clarify their pathogenesis, structure, and links with the basivertebral foramen. STUDY DESIGN AND METHODS: In total, 15 three-vertebra lumbar specimens from five cadavers aged 68 to 71 years were subjected to axial compressive overload followed by cyclic loading in flexion and extension to create an OVCF together with an IVC. Computed tomography scans and radiographs were used to confirm structural changes and micro-CT was used to measure trabecular bone properties in five specimens. Unipedicular vertebroplasty was then performed on 10 damaged specimens until fluoroscopy revealed extravasation of cement. RESULTS: In every specimen, loading created an OVCF with an IVC. Dissection and imaging showed that the IVC was always connected with the basivertebral foramen. The central vertebral region, including the IVC, had the lowest connectivity density, trabecular number, and bone volume fraction, and the highest trabecular separation. Vertebroplasty caused cement leakage through the basivertebral foramen in nine specimens and into an adjacent disc in one specimen. CONCLUSION: Cyclic loading in flexion and extension applied to a fractured osteoporotic vertebra can create an IVC, which then allows cement leakage via the basivertebral foramen.
BACKGROUND CONTEXT: Intravertebral clefts (IVCs) are vacuum-like cavities commonly associated with osteoporotic vertebral compression fractures (OVCFs). IVCs promote cement leakage during kyphoplasty, suggesting a physical link with the basivertebral foramen, although this is uncertain. PURPOSE: The present study aims to create IVCs in mechanical experiments on cadaveric spines in order to clarify their pathogenesis, structure, and links with the basivertebral foramen. STUDY DESIGN AND METHODS: In total, 15 three-vertebra lumbar specimens from five cadavers aged 68 to 71 years were subjected to axial compressive overload followed by cyclic loading in flexion and extension to create an OVCF together with an IVC. Computed tomography scans and radiographs were used to confirm structural changes and micro-CT was used to measure trabecular bone properties in five specimens. Unipedicular vertebroplasty was then performed on 10 damaged specimens until fluoroscopy revealed extravasation of cement. RESULTS: In every specimen, loading created an OVCF with an IVC. Dissection and imaging showed that the IVC was always connected with the basivertebral foramen. The central vertebral region, including the IVC, had the lowest connectivity density, trabecular number, and bone volume fraction, and the highest trabecular separation. Vertebroplasty caused cement leakage through the basivertebral foramen in nine specimens and into an adjacent disc in one specimen. CONCLUSION: Cyclic loading in flexion and extension applied to a fractured osteoporotic vertebra can create an IVC, which then allows cement leakage via the basivertebral foramen.
Authors: Maria Tzika; George K Paraskevas; Maria Piagkou; Apostolos K Papatolios; Konstantinos Natsis Journal: Surg Radiol Anat Date: 2021-02-17 Impact factor: 1.246