To evaluate changes in ground reaction forces (GRFs) in relation to gait velocity using 2 force plates (FPs) for healthy Beagles.
18 healthy Beagles were included (body weight, 10.45 ± 1.28 kg; age, 26 ± 11 months).
Ten GRF parameters were measured at three gait velocities (walk, 0.9 to 1.2 m/s; trot 1, 1.6 to 2.0 m/s; and trot 2, 2.1 to 2.5 m/s): peak lateral force (PLF), peak medial force (PMF), lateral impulse (LI), medial impulse (MI), peak propulsive force (PPF), peak braking force (PBF), propulsive impulse (PI), braking impulse (BI), peak vertical force (PVF), and vertical impulse (VI).
As velocity increased, the PVF of all limbs increased, the VI of all limbs decreased, and the PPF of the forelimbs increased. At all velocities, PBF and BI were significantly higher than the PPF and PI in forelimbs; however, PBF and BI were significantly lower than the PPF and PI in hindlimbs. There were no significant differences in the PLF, PMF, LI, and MI of the forelimbs and hindlimbs among all velocities. The PLF was significantly higher than the PMF of forelimbs during trot 1 and trot 2.
These results may be useful when comparing healthy Beagles with diseased ones when premorbid data are not available. Because the forelimbs are mainly responsible for the braking force, it is suggested that weight bearing is more stable in the forelimbs than in the hindlimbs, which are mainly responsible for the propulsive force, and that a greater force is generated laterally than medially during trot.
To investigate the effects of intervertebral distraction screw (IDS) fixation of the lumbosacral joint (LSJ) on the intervertebral foraminal area (IFA) and intervertebral stabilization of the LSJ and adjacent lumbar segments in dogs.
7 healthy Beagles.
Dorsal laminectomy was performed at the LSJ in each dog to expose the intervertebral disk. The IDS was then inserted into the L7-S1 disk. Computed tomography was performed before and after laminectomy and after IDS insertion (intact, laminectomy, and IDS conditions, respectively) to measure the intervertebral range of motion (ROM) and intervertebral distance (ID) at L7-S1, L6-7, and L5-6 with the LSJ in a flexed and extended position. The intervertebral foramina stenosis rate was calculated from the intervertebral foramina area in entrance, middle, and exit zones. Results were compared among conditions.
The ROM at L7-S1 after IDS insertion was lower than that observed before and after laminectomy; no other differences were identified among conditions. With the LSJ in the flexed position, the ID at L7-S1 was larger after IDS insertion than before and after laminectomy; no other differences in ID were identified. In all evaluated zones, the stenosis rate was lower after IDS insertion than before and after laminectomy. No differences in ROM, ID, and stenosis rate were identified among conditions at L6-7 or L5-6.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested that IDS fixation of the LSJ restricted lumbosacral ROM and prevented decreases in lumbosacral ID and IFA in healthy dogs. There were no changes at L6-7 and L5-6.
To retrospectively review the efficacy of combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate as treatment for dogs with degenerative lumbosacral stenosis (DLSS).
21 client owned dogs diagnosed with DLSS and treated surgically.
Based on clinical records, signalments, clinical signs, findings from orthopedic and neurological examinations, imaging findings, and postoperative complications were evaluated at the following time points: preoperatively, postoperatively, and 3, 6, 12, 24, and 36 months after surgery.
In all 21 cases, clinical signs were alleviated, proprioceptive deficits were improved from 3 months after surgery, and no recurrence of clinical signs was observed during the observation period. Minor complications were observed in 6 cases (28.6%), including implant failure in 2 (9.5%), delayed healing of surgical wounds in 2 (9.5%), seroma in 1 (4.8%), and swelling of the affected area in 1 (4.8%). There was no case with major complications.
Combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate is a useful treatment that can improve long-term clinical signs in dogs with DLSS.
To investigate the effect of an excessive tibial plateau angle (TPA) and change in compressive load on tensile forces experienced by the cranial cruciate, medial collateral, and lateral collateral ligaments (CCL, MCL, and LCL, respectively) of canine stifle joints.
16 cadaveric stifle joints from 16 orthopedically normal Beagles.
Stifle joints were categorized into unchanged (mean TPA, 30.4°) and excessive (mean TPA before and after modification, 31.2° and 41.1°, respectively) TPA groups. The excessive TPA group underwent a TPA-increasing procedure (curvilinear osteotomy of the proximal aspect of the tibia) to achieve the desired TPA. A robotic system was used to apply a 30- and 60-N compressive load to specimens. The craniomedial band of the CCL, caudolateral band of the CCL, MCL, and LCL were sequentially transected; load application was repeated after each transection. Orthogonal force components were measured in situ. Forces on ligaments were calculated after repeated output force measurements as the contribution of each component was eliminated.
Increasing the compressive load increased tensile forces on the craniomedial and caudolateral bands of the CCL, but not on the MCL or LCL, in specimens of both groups. At the 60-N load, tensile force on the craniomedial band, but not other ligaments, was greater for the excessive TPA group than for the unchanged TPA group.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that stress on the CCL may increase when the compressive load increases. The TPA-increasing procedure resulted in increased tensile force on the CCL at a 60-N compressive load without affecting forces on the MCL or LCL.