Degenerative lumbar scoliosis patients with proximal junctional kyphosis have lower muscularity, fatty degeneration at the lumbar area

Abstract

Purpose To assess the lumbar muscle conditions on the incidence of proximal junctional kyphosis (PJK) after long-level correction and instrumentation surgery for degenerative lumbar scoliosis (DLS) patients with a minimum 2-year follow-up. Methods Eighty-four DLS patients undergoing long instrumented fusion surgery (≥ 5 vertebrae) were retrospectively studied. According to the occurrence of PJK at the final follow-up, patients were divided into the PJK group and the Non-PJK group. Patient characteristics, surgical variables and radiographic parameters were analyzed statistically. The lumbar muscularity (cross-sectional area of muscle-disc ratio × 100) and fatty degeneration (signal intensity of muscle-subcutaneous fat ratio × 100) were evaluated on magnetic resonance imaging . Results The prevalence of PJK was 20.24%. Gender, age at surgery, body mass index, uppermost instrumented vertebrae level, fusions extending to the sacrum, and levels fused were not significantly different between the groups. Lower bone mineral density, smaller functional cross-sectional area (FCSA) of paraspinal extensor muscles (PSE), higher lean muscle-fat index and total muscle-fat index of PSE, greater preoperative thoracolumbar kyphosis (TLK), smaller preoperative sacral slope (SS), larger preoperative sagittal vertical axis were identified in PJK group. Logistic regression analysis showed that osteoporosis, preoperative TLK > 15°, SS > 24°, FCSA of PSE > 138.75, and total muscle-fat index of PSE > 4.08 were independently associated with PJK. The final follow-up VAS score for back pain was higher, and SRS-22 subcategories of pain, function, self-image, and total score were significantly lower in the PJK group. Conclusion Osteoporosis, lower lumbar muscularity and higher fatty degeneration, preoperative greater TLK and smaller SS were found to be strongly associated with the presence of PJK in DLS.

The predictive value of preoperative paraspinal muscle morphometry on complications after lumbar surgery: a systematic review

“…Of the 16 included studies, three studies investigated participants with lumbar spinal stenosis (LSS) [20][21][22], three studies investigated degenerative lumbar scoliosis (DLS) [21,23,24], one study investigated degenerative flat back [25], one study investigated spondylolisthesis [26] and 9 investigated multiple degenerative lumbar diseases [27][28][29][30][31][32][33][34][35]. Three studies examined the effect of preoperative paraspinal muscles on bone nonunion [20,27,28], two studies examined screw loosening [23,29], four studies examined ASD [26,30,32,35], five studies examined PJK [21,24,31,33,34], and two studies examined studies examined sagittal imbalance [22,25]. For paraspinal muscle morphometry, 6 investigated muscle CSA only [20,27,29,30,33,34], 2 investigated FI only [26,28] and 8 investigated both [21-25, 31, 32, 35].…”

“…All included studies examined paraspinal muscle morphology on MRI. There were 12 case-control studies [20,23,24,[26][27][28][29][31][32][33][34][35], 1 cohort studies [21] and 3 case series studies [22,25,30]. In line with assessment of risk of bias, all studies were rated as high quality (Table 2).…”

The Association of Lumbar Disc Herniation with Lumbar Volumetric Bone Mineral Density in a Cross-Sectional Chinese Study

“…Several earlier studies have appraised the relationship between intervertebral disc disease and lumbar and/or multipoint BMD [ 21 , 22 , 23 , 24 ]. However, they did not focus on the association between LDH and lumbar BMD in both men and women.…”

“…Previous studies have investigated lumbar vertebral BMD in patients with spinal disorders such as scoliosis [ 21 , 22 ], intervertebral disc degeneration [ 22 ] and osteoarthritis [ 23 , 24 ], and theories had been introduced to explain why the pathogenesis of LDH might be related to lumbar intervertebral disc degeneration (LDD) [ 25 , 26 , 27 , 28 ]. Although disc herniation is most commonly caused by mechanical injury and the consequent rupture of the fibrous annulus, some extent of initial degeneration is necessary to allow the pulpous nucleus to herniate through the fibrous bands of the annulus into the vertebral canal [ 29 ].…”

Paraspinal Muscle Degeneration as an Independent Risk for Loss of Local Alignment in Degenerative Lumbar Scoliosis Patients After Corrective Surgery

“…21 PJK was defined as proximal junctional angle 10 or greater and at least 10 greater than the corresponding preoperative measurement. 22 Back pain visual analog scale (VAS) score, Oswestry disability index (ODI), Japanese Orthopedic Association (JOA) score (29 points) were employed to evaluate symptoms and functional status preoperatively.…”