Musculature adaption in patients with lumbosacral transitional vertebrae: a matched-pair analysis of 46 patients

Abstract

Objective Even though lumbosacral transitional vertebrae (LSTV) are one of the most common congenital anomalies of the spine, their effect on surrounding soft tissues is not well-studied. We therefore aimed at analyzing the association between LSTV and changes in volume, mass, symmetry, and degeneration of lumbar and trunk muscles. Materials and methods Abdomen–pelvis CT scans were analyzed in patients with LSTV and a matched control group. LSTV were classified according to the Castellvi classification. Muscles were segmented from the remaining soft tissue and their cross-sectional area and volume were examined at five defined levels. Threshold segmentation was used to differentiate between muscle fibers and fat tissue. Matched pairs were compared using Wilcoxon rank sum tests. For comparison of categorical data, chi-squared tests were performed and for associations between the degree of fusion and muscle size and degeneration, Spearman’s correlation coefficients were calculated. Inter- and intrarater reliabilities were evaluated by computing intraclass correlation coefficients. Results Forty-six patients with LSTV and 46 controls were included. Muscle volume of the paraspinal and trunk muscles was significantly lower (707.0 cm3 vs. 809.7 cm3, p < 0.001) and fatty muscle changes were significantly increased in all but the caudal paravertebral muscles of LSTV patients (M. psoas p < 0.04, M. quadratus lumborum p < 0.001, paravertebral muscles p = 0.011, M. rectus abdominis p < 0.001, M. obliquus abdominis p < 0.001). Correlations between the degree of Castellvi classification and muscle volume were significant (p = 0.001). Conclusion LSTV are associated with a reduction in muscle volume and an increase in muscle degeneration of both lumbar and trunk muscles.

Approach-related anatomical differences in patients with lumbo-sacral transitional vertebrae undergoing lumbar fusion surgery at level L4/5

“…However, approach in our collective of patients with 6LV was not hampered because of a lower seated iliac crest compared to the control group. In line with the literature, our study shows that a change in bony anatomy is accompanied by a change in soft tissue anatomy [3,12,17]. For an LLIF, the psoas muscle must be dissected for exposure of the intervertebral disc space.…”

“…Procedures coming from ventral retroperitoneal such as anterior lumbar interbody fusion (ALIF), lateral retroperitoneal approaches such as oblique (OLIF) or lateral lumbar interbody fusion (LLIF), dorsal procedures such as posterior (PLIF) or transforaminal lumbar interbody fusion (TLIF) as well as combined procedures with transpedicular screw fixation are commonly used for this purpose [16]. The literature shows that changes in bone anatomy in LSTV are accompanied by changes in soft tissue anatomy, which can significantly complicate approaches, especially for retroperitoneal procedures, in which the large abdominal vessels are exposed [3,12,17].…”

Referred Muscle Pain, Some Considerations of Its Significance in Practice

“…In cases in which no morphological substrate is found in these structures, low back pain may be caused by thoracolumbar fascia and/or compartment syndrome, paravertebral muscles (mm. iliocostalis and longissimus dorsi) or by m. psoas and/or m. quadratus lumborum, ligaments and insertions in the form of enthesopathy, ligaments, (facet) joints, sacroiliac joints, in osteoporosis of vertebral bodies (Todorov, 2014;Becker et al, 2021) morphological and/or functional changes in the hip muscles, such as mm. gluteii, m. piriformis m. psoas major (Pourahmadi et al, 2020) and others.…”

Lumbosacral transitional vertebrae alter the distribution of lumbar mobility–Preliminary results of a radiographic evaluation

“…These differences may result from a tissue alteration in the cadaveric study of Golubovsky et al, the analysis of asymmetric LSTV only, and an isolated view on the osteo-ligamentous structures without inclusion of the musculature in their study. At the same time, the literature reports significant muscular adaptions in patients with LSTV [ 26 , 27 ]. Recent evidence also indicates significant differences for the spinopelvic anatomy between LSTV and a control group, which might also affect the mutual interaction between the pelvis and lumbar spine [ 20 ].…”