CT measures of lumbosacral paraspinal muscle size are not correlated with CT measures of lumbosacral stability in military working Labrador Retrievers

Abstract

Management of degenerative lumbosacral stenosis in military working dogs more frequently utilizes core conditioning exercise programs. Future research on the effectiveness of these programs may benefit from an improved understanding of relationships between paraspinal muscle size and lumbosacral stability. The aim of this retrospective, secondary analysis, cross-sectional study was to test the following hypotheses related to CT measures: (a) transverse paraspinal muscle area ratios differ between hip flexion and extension, (b) lumbosacral angle and lumbosacral range of motion differ by lumbosacral angle measurement technique, and (c) transverse paraspinal muscle area ratios are correlated with CT measures of lumbosacral stability (parasagittal and parasagittal oblique foraminal area changes) regardless of hip position and with lumbosacral range of motion within each hip position. Lumbosacral CT scans in hip flexion and extension were retrieved from a previous prospective study of military working Labrador Retrievers. A single observer performed triplicate measurements of transverse paraspinal muscle area ratios, parasagittal foraminal area, and parasagittal oblique foraminal area for each hip position and another observer independently performed triplicate measurements of lumbosacral angle and lumbosacral range of motion at L7-S1 using two published techniques. Thirty-nine dogs were analyzed and significant differences were identified between hip flexion and extension for all mean transverse paraspinal muscle area ratio values (P ≤ .05). Mean lumbosacral angles also significantly differed between the published techniques in both hip flexion and extension. When comparing mean lumbosacral range of motion values, one of the published techniques produced significantly smaller values. No significant correlation was found between transverse paraspinal muscle area ratios and parasagittal foraminal area changes, parasagittal oblique foraminal area changes, or lumbosacral range of motion. These results should be considered when designing studies using these CT measures in military working dogs.

Benign focal L5 nerve root enlargement in a dog

“…For comparative purposes, the sagittal IVF areas between L1 and L6 were measured as reported previously 10 . Data collected were compared to those obtained in a pilot study of skeletally mature and gender‐matched English Springer Spaniels (unpublished data).…”

CT measures of osseous cervicothoracic intervertebral foramina are repeatable and associated with CT measures of adjacent articular processes in horses

“…Previous studies reported that caudal cervical AP (from C5 to T1) were more frequently enlarged 5,9,14 . In companion animals and humans, the assessment of IF narrowing relies mainly on cross‐sectional imaging (CT or MRI) and various measurements have been described to objectively assess the dimensions of the IF; this includes the height, width, cross‐sectional area (CSA), and volume of the IF 15–24 . In humans, APCSA measured using MRI was a good predictor of cervical IF stenosis which was easy to use and fast to measure 25 .…”

“…5,9,14 In companion animals and humans, the assessment of IF narrowing relies mainly on crosssectional imaging (CT or MRI) and various measurements have been described to objectively assess the dimensions of the IF; this includes the height, width, cross-sectional area (CSA), and volume of the IF. [15][16][17][18][19][20][21][22][23][24] In humans, APCSA measured using MRI was a good predictor of cervical IF stenosis which was easy to use and fast to measure. 25 CT measurement of IFCSA in sagittal plane have been proven useful for diagnosing and to help predicting the operability of people with lumbosacral IF stenosis.…”