Indirect neural decompression achieved by BKP followed by LLIF procedure and PPS-Rod fixation for osteoporotic lumbar vertebral fracture with spinal stenosis at the adjacent levels

<p>Introduction: We employed minimally invasive surgery (MIS), as an alternative to direct posterior decompression with instrumented fusion, for patients who had neurologic symptoms associated with osteoporotic lumbar vertebral fractures. This study assessed the CT- and MRI-evidence of indirect neural decompression achieved by an MIS strategy consisting of transpsoas lateral lumbar interbody fusion (LLIF), Balloon kyphoplasty (BKP), and percutaneous pedicle screw (PPS) -Rod fixation.</p><p>Methods: Four patients, who had neurologic symptoms associated with unhealed osteoporotic vertebral fracture of L4, underwent a single-stage MIS and had a minimum 2-year follow-up. The MIS consisted of three surgical techniques performed in the following order: (1) the BKP for the L4 fractured vertebral body in the prone position; (2) the LLIF for the adjacent intervertebral levels of the L3-L4 and L4-L5 in the lateral position; and (3) the PPS-Rod fixation at L3 through L5 in the prone position. We evaluated the indirect neural decompression at the LLIF levels with CT and MRI scans, and clinical results with the JOA score.</p><p>Results: As compared to preoperative values, the postoperative CT measurements at the LLIF levels revealed significant increases in disc height at the anterior (12.2±0.6 mm to 15.4±0.5 mm), middle (11.8±0.8 mm to 14.7±0.6 mm) and posterior edges (6.0±0.8 mm to 8.7±0.7 mm), and in bilateral foraminal height (13.8±0.9 mm to 18.3±0.6 mm on the left; 14.1±0.5 mm to 17.6±0.4 mm on the right). CT scans at 2-year follow-up continued to show significant increases of the values.</p><p>Also at the LLIF levels, axial T2-weighted MRIs demonstrated a significant progressive increase from the preoperative values to those 1-year and 2-year postoperatively in cross-section area of the dural sac (77.4±9.8 mm² to 146.2±15.1 mm² and 170.4±14.6 mm²). The corresponding T1-weighted MRIs showed significant progressive decreases of the ligamentum flavum in cross-sectional area (101.3±7.8 mm² to 70.2±5.5 mm² and 54.4±3.7 mm²) and thickness (4.1±0.2 mm to 2.9±0.3 mm and 2.3±0.3 mm on the left; 4.4±0.3 mm to 3.2±0.2 mm and 2.5±0.3 mm on the right). Two-year postoperative CT scans confirmed a solid interbody fusion at all 8 LLIF levels, and the JOA score significantly improved from 9 points preoperatively to 22.5 points postoperatively.</p><p>Conclusions: A combination of BKP, LLIF and PPS, if performed in this order, serves as an excellent MIS strategy for neurologic compromise associated with unhealed osteoporotic fracture of the lumbar spine, affording indirect neural decompression and spinal stabilization.</p>