Biomechanical assessment of the effects of decompressive surgery in non-chondrodystrophic and chondrodystrophic canine multisegmented lumbar spines

Abstract

PurposeDogs are often used as an animal model in spinal research, but consideration should be given to the breed used as chondrodystrophic (CD) dog breeds always develop IVD degeneration at an early age, whereas non-chondrodystrophic (NCD) dog breeds may develop IVD degeneration, but only later in life. The aim of this study was to provide a mechanical characterization of the NCD [non-degenerated intervertebral discs (IVDs), rich in notochordal cells] and CD (degenerated IVDs, rich in chondrocyte-like cells) canine spine before and after decompressive surgery (nucleotomy).MethodsThe biomechanical properties of multisegmented lumbar spine specimens (T13–L5 and L5–Cd1) from 2-year-old NCD dogs (healthy) and CD dogs (early degeneration) were investigated in flexion/extension (FE), lateral bending (LB), and axial rotation (AR), in the native state and after nucleotomy of L2–L3 or dorsal laminectomy and nucleotomy of L7–S1. The range of motion (ROM), neutral zone (NZ), and NZ stiffness (NZS) of L1–L2, L2–L3, L6–L7, and L7–S1 were calculated.ResultsIn native spines in both dog groups, the greatest mobility in FE was found at L7–S1, and the greatest mobility in LB at L2–L3. Surgery significantly increased the ROM and NZ, and significantly decreased the NZS in FE, LB, and AR in both breed groups. However, surgery at L2–L3 resulted in a significantly larger increase in NZ and decrease in NZS in the CD spines compared with the NCD spines, whereas surgery at L7–S1 induced a significantly larger increase in ROM and decrease in NZS in the NCD spines compared with the CD spines.ConclusionsSpinal biomechanics significantly differ between NCD and CD dogs and researchers should consider this aspect when using the dog as a model for spinal research.

Caracterización de lesiones en columna vertebral mediante tomografía computarizada en canes de Lima, Perú

“…Dentro de estas, la hernia discal medial fue la de mayor presentación (32.8%), probablemente debido a la particular estructura anatómica del disco intervertebral. El anillo fibroso es más grueso en ventral y lateral que en dorsal, el núcleo pulposo tiene una localización excéntrica orientada hacia dorsal y el ligamento longitudinal dorsal es más frágil en comparación al ligamento longitudinal ventral, todo lo cual favorece la presentación dorsal o paramedial de las hernias (Smolders et al, 2013).…”

A Canine Gait Analysis Protocol for Back Movement Assessment in German Shepherd Dogs

“…Outcomes of the recent studies on measuring and evaluating the ground reaction forces [20][21][22][23][24][25][26] demonstrate the importance of providing normative data and we are providing the most crucial parameters related to kinetics -anterior, posterior and anterior posterior vertical ground reaction forces normalized by body weight (See Supplementary Material Table S1 to access the normative data of force platforms, for all subjects). Static acquisitions measure the quadrupedal posture and the results of this study from healthy dogs can be used as a baseline to measure the amount of deviation from the normative data for pathological dogs.…”

“…The position of a virtual marker (MidIC)-defined as the midpoint between the two ICs-was also computed (Figure 1). Marker locations on the spine were chosen so that data on the physiological spine movements characterized by major flexion/extension, lateral bending and axial rotation in the thoraco-lumbar transition area [12] and in L7-S1 segments, could be collected [22].…”

In vitrobiomechanical evaluation of internal fixation techniques on the canine lumbosacral junction

“…Surgical management is recommended for patients with severe or recurrent pain that is not responsive to medical management or when neurologic deficits are present ( Johnston & Tobias, 2012a ). Common surgical options for DLS include dorsal laminectomy alone or in combination with a partial discectomy, dorsal laminectomy combined with fixation and fusion or lateral foraminotomy ( Meij et al, 2007 ; Hankin et al, 2012 ; Smolders et al, 2012a ; Smolders et al, 2012b ). Two previous biomechanical studies have shown that a dorsal laminectomy with partial discectomy increases lumbosacral movement, which may lead to instability ( Smolders et al, 2012a ; Early et al, 2013 ).…”