Objective—To determine mass, center of mass (COM), and moment of inertia (ie, body segment parameters [BSPs]) of hind limb segments by use of a noninvasive method based on computerized tomography (CT) in Labrador Retrievers with and without cranial cruciate ligament (CCL) disease and to provide regression equations to estimate BSPs of normal, CCL-deficient, and contralateral hind limbs.
Animals—14 clinically normal and 10 CCL-deficient Labrador Retrievers.
Procedures—Bone, muscle, and fat areas were identified via CT. Mass, COM, and moment of inertia were determined on the basis of tissue densities in the thigh, crus, and foot segments. Regression models were developed to determine predictive equations to estimate BSP on the basis of simple morphometric measurements.
Results—The thigh and crus of CCL-deficient limbs weighed less than in contralateral segments. Thighs weighed less in CCL-deficient than in normal limbs. The thigh moment of inertia was less in CCL-deficient than in contralateral limbs. The crural COM was located more distally in normal limbs, compared with other limbs. Predictive equations to estimate BSP varied by parameter, body segment, and limb status.
Conclusions and Clinical Relevance—BSPs of the thigh and crus varied with segment and status of the hind limb in Labrador Retrievers with or without CCL disease. Equations to estimate BSP on the basis of simple morphometric measurements were proposed, providing a basis for nonterminal studies of inverse dynamics of the hind limbs in Labrador Retrievers. This approach may offer new strategies to investigate the pathogenesis of nontraumatic joint diseases.
Objective—To evaluate the effect of an osteoconductive
resorbable calcium phosphate cement (CPC) on
the holding power of bone screws in canine pelvises
and to compare the effect with that for polymethylmethacrylate
Sample Population—35 pelvises obtained from
Procedure—Each pelvis was sectioned longitudinally.
Within each pair of hemipelvises, one 4.0-mm cancellous
screw was placed in the sacroiliac (SI) region and
another in the iliac body. Similar regions on the contralateral-
matched hemipelvis were assigned 1 of 3 augmentation
techniques (CPC-augmented 4.0-mm cancellous
screws, PMMA-augmented 4.0-mm cancellous
screws, and CPC-augmented 3.5-mm cortical screws).
Pullout force was compared between matched screws
and between treatment groups prior to examination of
cross sections for evaluation of cement filling and noncortical
bone-to-cortical bone ratio.
Results—CPC and PMMA augmentation significantly
increased pullout force of 4.0-mm screws inserted in
the SI region by 19.5% and 33.2%, respectively, and
CPC augmentation significantly increased pullout force
of 4.0-mm cancellous screws inserted in the iliac body
by 21.2%. There was no difference in the mean percentage
augmentation between treatment groups at
either location. Cement filling was superior in noncortical
bone, compared with filling for cortical bone.
Noncortical bone-to-cortical bone ratio was significantly
greater in the sacrum (6.1:1) than the ilium (1.3:1).
Conclusions and Clinical Relevance—CPC and
PMMA improve the ex vivo holding strength of
4.0-mm cancellous screws in the SI and iliac body
regions and SI region, respectively. Cement augmentation
may be more effective in areas with greater
noncortical bone-to-cortical bone ratios. (Am J Vet Res