Lumbar lordosis morphology correlates to pelvic incidence and erector spinae muscularity

Abstract

The retrospective study aimed to investigate the relationship between lumbar lordosis morphology, pelvic incidence and paraspinal muscle. It enrolled asymptomatic adult volunteers aged between 18 and 45 years old. Lumbar lordosis morphology, consisting of total lumbar lordosis (LL), proximal lumbar lordosis (PLL), distal lumbar lordosis (DLL), lumbar lordosis apex (LLA) and inflexion point, was evaluated, as well as pelvic incidence (PI) and muscularity of erector spinae (ES) and multifidus. Pearson correlation was performed to analyze the relationship between each other parameter. Cases were stratified according to pelvic incidence (very low < 30°, low 30°–45°, moderate 45°–60°, and high > 60°), comparison between groups was performed by univariance analysis. 87 asymptomatic adult volunteers (33 females and 54 males) were included in the study. PLL revealed a correlation with LLA (r = 0.603, p = 0.002) and inflexion point (r = 0.536, p = 0.004), but did not DLL with LL apex (r = 0.204, p = 0.058) or inflexion point (r = 0.210, p = 0.051). PI revealed a greater correlation with PLL (r = −0.673, p < 0.001) than with DLL (r = −0.237, p = 0.045). Linear stepwise regression analysis also exhibited the correlation between PI and PLL (R2 = 0.452, PLL = 16.2–0.61 * PI, p < 0.001). ES muscularity correlated with LL apex (r = −0.279, p = 0.014) and inflexion point (r = −0.227, p = 0.047). Stratification by PI demonstrated PLL increased across groups (p < 0.001), but DLL was comparable between low and moderate PI group (p = 0.329). Lumbar lordosis morphology appears to accommodate to pelvic incidence and erector spinae muscularity. Proximal lumbar lordosis has a bigger correlation with pelvic incidence than the distal lumbar lordosis. The results are helpful for restoring a rational lumbar lordosis shape in long fusion surgery.

Lumbar Lordosis Distribution in Asymptomatic Adult Volunteers: A Systematic Review

“…Pesenti et al [16] reported that age was negatively strongly correlated with PLL and PI was positively strongly correlated with proximal lordosis. Li et al [13] revealed that PI had a great correlation with proximal lordosis and the muscularity of erector spinae and multifidus were not correlated with proximal lordosis.…”

Change in Pelvic Incidence Associated With Sacroiliac Joint Dysfunction: A Case Report

“…PI = SS + PT. As the sacrum is the entire weight of the spine to rest on, PI is the angle correlating with lumbar lordosis through SS and consequent spine degeneration [ 21 , 24 ]. Although PI has been considered as a static parameter in health individuals, it can be seen that when the sacral inclination changes in destabilized conditions, PI changes [ 4 ].…”

The Level of Conus Medullaris in 629 Healthy Japanese Individuals

“…Recent retrospective studies suggested that distal LL (L4-S1) is comparable between low to moderate and high PI groups. Proximal LL (L1-L4), however, is significantly influenced by the PI value (greater PI, and greater proximal lumbar lordosis) [ 14 , 15 ]. Furthermore, not only does the LL magnitude increase in cases of a larger PI but also the LL apex and inflection point are located more toward the cranial side [ 14 ].…”

“…Proximal LL (L1-L4), however, is significantly influenced by the PI value (greater PI, and greater proximal lumbar lordosis) [ 14 , 15 ]. Furthermore, not only does the LL magnitude increase in cases of a larger PI but also the LL apex and inflection point are located more toward the cranial side [ 14 ]. Thus, in cases with a large PI the local lordosis around L1, where the conus medullaris is often located [ 1 , 2 , 3 , 4 , 5 , 6 ], might be greater, and the conus medullaris might be located more toward the cranial side in the twisted spinal canal.…”