The Association between Imaging Parameters of the Paraspinal Muscles, Spinal Degeneration, and Low Back Pain

Abstract

This narrative review investigated imaging parameters of the paraspinal muscles and their association with spinal degenerative features and low back pain (LBP) found in the literature. Three principal signs of muscle degeneration were detected on imaging: decreased muscle size, decreased radiographic density, and increased fat deposits. Men have a higher density of paraspinal muscles than women, younger individuals have a higher density than older ones, and lean individuals have a higher density than those with an increased body mass index. Fatty infiltration appears to be a late stage of muscular degeneration and can be measured noninvasively by an MRI scan. Fatty infiltration in the lumbar multifidus is common in adults and is strongly associated with LBP, especially in women, independent of body composition. Fatty infiltration develops in areas where most degenerative changes are found. MR spectroscopy studies have corroborated that the lumbar multifidus in LBP subjects has a significantly higher fat content than asymptomatic controls. There is a strong need for establishing uniform methods of evaluating normal parameters and degenerative changes of the paraspinal muscles. Additional imaging studies are needed to improve the understanding of the association and causal relationships between LBP, spinal degeneration, and changes in the paraspinal muscles.

Rotator Cuff Fibro‐Adipogenic Progenitors Demonstrate Highest Concentration, Proliferative Capacity, and Adipogenic Potential Across Muscle Groups

“…Interestingly, our results also showed PS muscles had high percentages of FAPs of which were more adipogenic and had greater cell proliferation rates compared to the hindlimb muscles. Clinically, PS muscles are known to develop FI in a number of spine conditions such as degenerative disc disease and scoliosis . Most studies of PS FI center on imaging quantification of FI and correlation to clinical outcomes.…”

“…Although FI is common in RC tears, this pattern of pathology is not ubiquitous across all types of musculotendinous injuries at all anatomic locations, with the exception of some genetic condition, such as muscular dystrophies, and more global metabolic disturbances such as obesity and type 2 diabetes . Multiple studies have observed high degrees of FI in paraspinal muscles in patients with congenital and degenerative spine diseases . Conversely, the development of intramuscular fibrosis rather than FI appears to be the hallmark of volumetric muscle injuries that involve the extremities .…”

Muscle Control and Non-specific Chronic Low Back Pain

“…Changes to the MF apparent with MRI imaging are strongly associated with back pain, but the diagnostic value in individual patients of such changes is limited, since back pain of any cause can lead to changes of the MF cross sectional area and amount of fat infiltration (79). Prolonged bed rest in the absence of back pain can also lead to atrophy of the MF seen on imaging (80) and the atrophy can be reversed with appropriate exercises (81).…”

The Implications of Paraspinal Muscle Atrophy in Low Back Pain, Thoracolumbar Pathology, and Clinical Outcomes After Spine Surgery: A Review of the Literature

“…There is limited literature assessing paraspinal muscle atrophy with regard to thoracolumbar pathology. Kalichman et al 8 suggest an association between paraspinal muscle atrophy and spondylolisthesis, facet joint osteoarthropathy, and disc space narrowing. A study composed of patients with moderate (ODI < 42) and severe (ODI !…”