Anatomy of the third and fourth psoas major and quadratus lumborum muscles for lumbar compartment block surgery

Abstract

Purpose The purpose of this study has yielded basic data for use in medical practice by evaluating the relationships between the psoas major, quadratus lumborum, and surrounding vertebrae, and determining landmarks for use during compartmental block surgery of the psoas major and quadratus lumborum. Methods Radiographic data analyses and cadaver psoas major dissections were performed for anatomical observations and relationship comparisons with the quadratus lumborum and vertebrae. Radiological measurement data for the psoas major were obtained, yielding 106 sets of data. Results The length of the psoas major measured from the spinous process of the third lumbar vertebra was significantly larger in males (60.5 ± 8.2 mm) than in females (48.8 ± 5.7 mm) (p < 0.05). also the length of the right psoas major of the fourth lumbar vertebra was significantly larger in males (73.5 ± 8.6 mm) than in females (60.7 ± 7.8 mm) (p < 0.05). The length of the quadratus lumborum of the third lumbar vertebra measured from the spinous process of the third lumbar vertebra was significantly larger in males (89.2 ± 8.1 mm) than in female (74.2 ± 7.7 mm) (p < 0.05). also the length of the quadratus lumborum of the fourth lumbar vertebra measured from the spinous process of the fourth lumbar vertebra was significantly larger in males (103.6 ± 10.6 mm) than in females (91.2 ± 9.9 mm) (p < 0.05). The lengths of the psoas major and quadratus lumborum of the third and fourth lumbar vertebrae decreased with age. Conclusion The accumulating research data of clinical studies of the psoas major, quadratus lumborum, and lumbar approaches will help clinicians to choose the most appropriate methods for treatment and rehabilitation.