Objective—To determine biomechanical and biochemical
properties of the medial meniscus in a semistable
stifle model and in clinical patients and to
determine the effect of canine recombinant somatotropin
hormone (STH) on those properties.
Animals—22 healthy adult dogs and 12 dogs with
meniscal damage secondary to cranial cruciate ligament
Procedure—The CCL was transected in 15 dogs, and
stifles were immediately stabilized. Implants releasing
4 mg of STH/d were placed in 7 dogs, and 8
received sham implants. Seven dogs were used as
untreated controls. Force plate analysis was performed
before surgery and 2, 5, and 10 weeks after
surgery. After 10 weeks, dogs were euthanatized, and
menisci from surgical and contralateral stifles were
harvested. The torn caudal horn of the medial meniscus
in dogs with CCL rupture comprised the clinical
group. Creep indentation determined aggregate modulus
(HA), Poisson's ratio (v), permeability (k), and percentage
recovery (%R). Water content (%W), collagen
content (C), sulfated glycosaminoglycan (sGAG)
content, and collagen type-I (cI) and -II (cII) immunoreactivity
were also determined.
Results—Surgical and clinical groups had lower HA, k,
%R, C, sGAG, cI, and cII and higher %W than the nonsurgical
group. Surgical stifles with greater weight bearing
had stiffer menisci than those bearing less weight.
Collagen content was higher in the surgical group
receiving STH than the surgical group without STH.
Conclusions and Clinical Relevance—Acute stabilization
and moderate weight bearing of the CCL-deficient
stifle appear to protect stiffness of the medial
meniscus. Normal appearing menisci from CCL-deficient
stifles can have alterations in biomechanical and
biochemical properties, which may contribute to
meniscal failure. (Am J Vet Res 2002;63:419–426)
Objective—To assess the impact of partial immersion in water on vertical ground reaction force (vGRF) and vGRF distribution in dogs.
Animals—10 healthy adult dogs.
Procedures—Weight placed on each limb of each dog was measured 3 times (1 scale/limb). Dogs were then immersed in water to the level of the tarsal, stifle, and hip joints, and vGRFs were measured. Coefficients of variation for triplicate measurements were calculated. Mixed-effects ANOVAs were used to compare the vGRF for thoracic versus pelvic limbs and the vGRF at various immersion levels as well as the vGRF distributions among limbs at various immersion levels.
Results—Mean ± SD vGRF before immersion was 249 ± 34 N. It was significantly decreased by 9% after immersion to the tarsal joints (227 ± 32 N), by 15% after immersion to the stifle joints (212 ± 21 N), and by 62% after immersion to the hip joints (96 ± 20 N). The vGRFs were significantly higher for the thoracic limbs than for the pelvic limbs before immersion and at all immersion levels. Dogs placed 64% of their weight on the thoracic limbs before immersion. That ratio did not differ significantly after immersion to the tarsus (64%) or stifle (63%) joints, but was significantly larger after immersion to the hip joints (71%).
Conclusions and Clinical Relevance—vGRF decreased as the depth of immersion increased. The thoracic limb-to-pelvic limb vGRF ratio was unchanged in dogs after immersion to the tarsal or stifle joints, but it increased after immersion to the hip joints.
Objective—To compare the 3-D motion of the pelvic limb among clinically normal dogs and dogs with cranial cruciate ligament (CCL)–deficient stifle joints following tibial plateau leveling osteotomy (TPLO) or lateral fabellar–tibial suture (LFS) stabilization by use of an inverse dynamics method.
Animals—6 clinically normal dogs and 19 dogs with CCL-deficient stifle joints that had undergone TPLO (n = 13) or LFS (6) stabilization at a mean of 4 and 8 years, respectively, prior to evaluation.
Procedures—For all dogs, an inverse dynamics method was used to describe the motion of the pelvic limbs in the sagittal, frontal, and transverse planes. Motion and energy patterns for the hip, stifle, and tibiotarsal (hock) joints in all 3 planes were compared among the 3 groups.
Results—Compared with corresponding variables for clinically normal dogs, the hip joint was more extended at the beginning of the stance phase in the sagittal plane for dogs that had a TPLO performed and the maximum power across the stifle joint in the frontal plane was greater for dogs that had an LFS procedure performed. Otherwise, variables in all planes were similar among the 3 groups.
Conclusions and Clinical Relevance—Gait characteristics of the pelvic limb did not differ between dogs that underwent TPLO and dogs that underwent an LFS procedure for CCL repair and were similar to those of clinically normal dogs. Both TPLO and LFS successfully provided long-term stabilization of CCL-deficient stifle joints of dogs with minimal alterations in gait.
Objective—To use an inverse dynamics method to describe the motion of the canine pelvic limb in 3 dimensions.
Animals—6 healthy adult dogs.
Procedures—For each dog, 16 anatomic and tracking markers were used to define the center of rotation for the pelvic limb joints and a kinematic model was created to describe the motion of the pelvic limb. Kinetic, kinematic, and morphometric data were combined so that an inverse dynamics method could be used to define angular displacement, joint moment, and power of the hip, stifle, and tibiotarsal (hock) joints in the sagittal, frontal, and transverse planes.
Results—Movement and energy patterns were described for the hip, stifle, and hock joints in the sagittal, frontal, and transverse planes.
Conclusions and Clinical Relevance—Knowledge of the 3-D movement of the pelvic limb can be used to better understand its motion, moment, and energy patterns in healthy dogs and provide a referent with which gaits of dogs with pelvic limb injuries before and after surgical repair or rehabilitation can be compared and characterized. This information can then be used to guide decisions regarding treatment options for dogs with pelvic limb injuries.