Age and sex correlate with bony changes and anatomic variations of the lumbosacroiliac region of the vertebral column in a mixed population of horses

Abstract

OBJECTIVE To provide a postmortem description of anatomic variations and changes of the lumbosacroiliac region in horses. The authors hypothesized that lesion severity would increase with age and body weight and correlate to anatomic variations. SAMPLES Lumbosacroiliac vertebral specimens from 38 horses (mean age, 16 years; range, 5 to 30 years) that died or were euthanized for reasons unrelated to the study between November 2019 and October 2021. PROCEDURES The lumbosacroiliac region of the vertebral column was removed from each cadaver. After dissection, disarticulation, and boiling, the anatomic specimens were examined for anatomic variations and osseous changes of the articular process joints (APJs), intertransverse joints (ITJs), and sacroiliac joints (SIJs). The lengths of L6-S1 intertransverse articular surfaces were measured and their ratios calculated. Descriptive statistics were obtained, and the χ2 test was used to assess differences in anatomic variations and abnormal changes of the APJs, ITJs, and SIJs. RESULTS The most common anatomic variation was a sacrum-like shape of the transverse processes of L6 (29/38 [76%]) and converging orientation of dorsal spinous process of L6 (33/38 [87%]). The highest prevalence of bony changes was detected at L5-L6 (right, 34/38 [89%]; left, 33/38 [87%]) and L6-S1 APJs (right, 38/38 [100%]; left, 37/38 [97%]) and at SIJs (right, 32/38 [86%]; left, 31/38 [82%]). The shape of L6 transverse processes differed between breed (P = .01) and was associated with presence of L4-L5 ITJs (P < .01). CLINICAL RELEVANCE Age and sex were associated with changes of the sacral dorsal spinous processes, ITJs, and APJs. The clinical significance of these findings could not be confirmed based on the study limitations.

Post‐mortem ultrasonographic and computed tomographic features of the anatomical variations and acquired pathological bony changes of the lumbosacroiliac region in a mixed population of horses

“…Furthermore, variability in the disc (normal, thinner, or thicker) was recorded. 6 The presence of unilateral or bilateral APBCs and symmetry of the lesions at the level of the ventral aspect of the lumbosacral ITJs were scored using the readapted grading system adopted in a previous anatomical study of the lumbosacral region 24 where grade 0 = mild, osseous changes affecting less than 25% of the articular or periarticular surfaces; grade 1 = moderate, osseous changes affecting 25%-50% of the articular or periarticular surfaces; grade 2 = severe, osseous changes affecting over 50% of the articular or periarticular surfaces; and grade 3 = ankylosis, with osseous proliferation with partial or complete bridging of the articular processes.…”

“…The normal CT appearance of the spinous process (SP) (i.e., dorsal spinous process) of the last lumbar vertebra and S1, lumbosacral articular process joints (APJs) and lumbosacral ITJs and vertebral bodies was described using reference specimens 5 and 36, which had no APBCs or anatomical variations of the lumbosacroiliac region evaluated during the anatomical dissection performed in our previous study. 24 On CT, the specimens were evaluated for anatomical variations and APBCs of the lumbosacroiliac area. The SP of the last lumbar vertebra was categorised as converging, perpendicular, or diverging based on the orientation relative to the spinal column.…”

Computed tomographic study analysing functional biomechanics in the thoracolumbar spine of horses with and without spinal pathology

“…Whilst there is no evidence for radiographic changes in the area of the spinous processes (SPs) in Warmblood foals, ORSPs were detected in untrained Thoroughbred yearlings (Pressanto et al., 2023; Sinding & Berg, 2010). Fused SPs are found more frequently in older horses (Scilimati, Beccati, et al., 2023). A developmental or genetic component of the condition is the subject of current debate (Patterson Rosa et al., 2022; Pressanto et al., 2023).…”

Osseous pathologic changes in the thoracic region of the equine vertebral column: A descriptive post-mortem study in three breeds.

“…Thoracolumbar pathology has since long been related to poor performance in horses, [1][2][3] and most work on prevalence has been done in the caudal thoracic and lumbar region of Thoroughbreds, 4,5 French trotters 6 and in populations with a mixture of breeds. [7][8][9][10][11][12][13][14][15] A few of these studies also included the cranial thoracic vertebrae. 7,8,12 However, hardly any data exits on thoracic pathology in Warmbloods 8 , the major horse breed for equestrian sports other than racing.…”

“…17 It was further hypothesized that there would be a positive correlation between the occurrence and severity of pathologies and age in line with our earlier study on the lumbar region in these specimen 17 and other studies on bony changes in the lumbosacroiliac region of the vertebral column in a mixed population of horses. 9,14,15 2 MATERIAL AND METHODS…”