To describe methods to measure the 3-D orientation of the proximal, diaphyseal, and distal segments of the canine radius by use of computer-aided design software (CADS) and to compare the repeatability and reliability of measurements derived by those methods.
31 canine radii with biapical deformities and 24 clinically normal (control) canine radii.
Select CT scans of radii were imported into a CADS program. Cartesian coordinate systems for the humerus and proximal, diaphyseal, and distal radial segments were developed. The orientation of each radial segment in the frontal, sagittal, and transverse planes was measured in triplicate by 3 methods. The repeatability and reliability of those measurements were calculated and compared among the 3 measurement methods.
The mean ± SD within-subject repeatability of radial angular measurements for all 3 methods was 1.40 ± 0.67° in the frontal plane, 3.17 ± 2.21° in the sagittal plane, and 3.01 ± 1.11° in the transverse plane for control radii and 2.56 ± 1.95° in the frontal plane, 3.59 ± 2.39° in the sagittal plane, and 3.47 ± 1.19° in the transverse plane for abnormal radii. Mean ± SD bias between radial measurement methods was 1.88 ± 2.07° in the frontal plane, 6.44 ± 6.80° in the sagittal plane, and 2.27 ± 2.81° in the transverse plane.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that use of CADS to assess the 3-D orientation of the proximal, diaphyseal, and distal segments of normal and abnormal canine radii yielded highly repeatable and reliable measurements.
Objective—To evaluate the reliability of goniometry
by comparing goniometric measurements with radiographic
measurements and evaluate the effects of
sedation on range of joint motion.
Animals—16 healthy adult Labrador Retrievers.
Procedure—3 investigators blindly and independently
measured range of motion of the carpus, elbow,
shoulder, tarsus, stifle, and hip joints of 16 Labrador
Retrievers in triplicate before and after dogs were
sedated. Radiographs of all joints in maximal flexion
and extension were made during under sedation.
Goniometric measurements were compared with
radiographic measurements. The influence of sedation
and the intra- and intertester variability were evaluated;
95% confidence intervals for all ranges of
motion were determined.
Results—Results of goniometric and radiographic
measurements were not significantly different.
Results of measurements made by the 3 investigators
were not significantly different. Multiple measurements
made by 1 investigator varied from 1 to 6°
(median, 3°) depending on the joint. Sedation did not
influence the range of motion of the evaluated joints.
Conclusions and Clinical Relevance—Goniometry
is a reliable and objective method for determining
range of motion of joints in healthy Labrador
Retrievers. (Am J Vet Res 2002;63:979–986)
Objective—To describe and evaluate a new radiographic
view of the elbow joint in dogs that would
potentially enhance observation of the medial coronoid
Sample Population—20 cadaver limbs from 10 dogs
and clinical examination of 100 elbow joints of 53 dogs.
Procedure—Twenty elbow joints from 10 cadavers
were imaged by use of mediolateral, flexed mediolateral,
craniocaudal, craniolateral-caudomedial oblique
(Cr15L-CdMO), and distomedial-proximolateral oblique
(Di35M-PrLO) radiographic views before and after
placement of 3 lead pellets placed on the cranial,
medial, and craniodistal aspect of the MCP. Three
examiners independently reviewed these radiographs.
One hundred elbow joints of 53 dogs with
forelimb lameness and signs of pain elicited on palpation
of the elbow joint were examined. These joints
were radiographed and treated by use of arthroscopy.
Three examiners independently graded the radiographs.
Results—The MCP was identified on all Di35M-PrLO
views made during the anatomic study. The Di35M-PrLO
view had the largest area under the receiving
operating characteristic (ROC) curve for detection of
abnormalities of the MCP. Fractured and nonfractured
MCP could only be significantly differentiated on
Di35M-PrLO and mediolateral views. The Di35M-PrLO
view had a higher agreement between examiners
than other radiographic views for detection of
fractures of the MCP.
Conclusion and Clinical Relevance—The Di35M-PrLO
view enhances the identification of anomalies
and fragmentation of the MCP in dogs, compared
with other radiographic views. The Di35M-PrLO view
may be of benefit for early screening of dogs potentially
affected with elbow dysplasia. (Am J Vet Res
Objective—To design and manufacture custom titanium bone plates and a custom cutting and drill guide by use of free-form fabrication methods and to compare variables and mechanical properties of 2 canine tibial plateau leveling methods with each other and with historical control values.
Sample Population—10 canine tibial replicas created by rapid prototyping methods.
Procedures—Application time, accuracy of correction of the tibial plateau slope (TPS), presence and magnitude of rotational and angular deformation, and replica axial stiffness for 2 chevron wedge osteotomy (CWO) methods were assessed. One involved use of freehand CWO (FHCWO) and screw hole drilling, whereas the other used jig-guided CWO (JGCWO) and screw hole drilling.
Results—Replicas used for FHCWO and JGCWO methods had similar stiffness. Although JGCWO and FHCWO did not weaken the replicas, mean axial stiffness of replicas after JGCWO was higher than after FHCWO. The JGCWO method was faster than the FHCWO method. Mean ± SD TPS after osteotomy was lower for FHCWO (4.4 ± 1.1°) than for JGCWO (9.5 ± 0.4°), and JGCWO was more accurate (target TPS, 8.9°). Slight varus was evident after FHCWO but not after JGCWO. Mean postoperative rotation after JGCWO and FHCWO did not differ from the target value or between methods.
Conclusions and Clinical Relevance—The JGCWO method was more accurate and more rapid and resulted in more stability than the FHCWO method. Use of custom drill guides could enhance the speed, accuracy, and stability of corrective osteotomies in dogs.
Objective—To compare 5 radiographic views for the detection of osteochondritis dissecans (OCD) in dogs with signs of elbow joint pain.
Animals—53 dogs (100 elbow joints) with forelimb lameness and signs of elbow joint pain.
Procedures—Mediolateral (ML), flexed ML, craniocaudal (CC), craniolateral-caudomedial oblique (Cr15L-CdMO), and distomedial-proximolateral oblique (Di35M-PrLO) radiographic views of the 100 elbow joints were obtained. Four examiners graded radiographs with regard to elbow joint OCD. Joints were assessed by use of arthroscopy. Receiver operating characteristic (ROC) curves, kappa measure of agreement, and Fisher exact tests for association between median diagnostic value and actual status were computed.
Results—47 joints had an abnormal medial aspect of the humeral condyle (MAHC), and among them, 11 had OCD. The presence of fractures of the medial coronoid process was significantly and positively correlated with the presence of abnormalities of the MAHC (r = 0.40), but was negatively correlated with the presence of OCD (r = −0.32). At 95% specificity, median sensitivities to detect OCD were 57% for Cr15L-CdMO, 56% for CC, 10% for flexed ML, 7% for ML, and 4% for Di35M-PrLO views. The areas under the ROC curves were significantly larger for the Cr15L-CdMO and CC views than for the ML, flexed ML, and Di35M-PrLO views for the detection of OCD. Only the Cr15L-CdMO and CC views allowed accurate detection of OCD.
Conclusions and Clinical Relevance—In dogs with signs of elbow joint pain, the Cr15L-CdMO view is excellent and the CC view was good for detection of OCD.
Objective—To evaluate effects of tibial plateau leveling osteotomy (TPLO) on canine stifle joint biomechanics in a cranial cruciate ligament (CrCL)–deficient stifle joint by use of a 3-D computer model simulating the stance phase of gait and to compare biomechanics in TPLO-managed, CrCL-intact, and CrCL-deficient stifle joints.
Sample—Computer simulations of the pelvic limb of a Golden Retriever.
Procedures—A previously developed computer model of the canine pelvic limb was used to simulate TPLO stabilization to achieve a tibial plateau angle (TPA) of 5° (baseline value) in a CrCL-deficient stifle joint. Sensitivity analysis was conducted for tibial fragment rotation of 13° to −3°. Ligament loads, relative tibial translation, and relative tibial rotation were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints.
Results—TPLO with a 5° TPA converted cranial tibial translation to caudal tibial translation and increased loads placed on the remaining stifle joint ligaments, compared with results for a CrCL-intact stifle joint. Lateral collateral ligament load was similar, medial collateral ligament load increased, and caudal cruciate ligament load decreased after TPLO, compared with loads for a CrCL-deficient stifle joint. Relative tibial rotation after TPLO was similar to that of a CrCL-deficient stifle joint. Stifle joint biomechanics were affected by TPLO fragment rotation.
Conclusions and Clinical Relevance—In the model, stifle joint biomechanics were partially improved after TPLO, compared with CrCL-deficient stifle joint biomechanics, but TPLO did not fully restore CrCL-intact stifle joint biomechanics. Overrotation of the tibial fragment negatively influenced stifle joint biomechanics by increasing caudal tibial translation.
Objective—To investigate the influence of varying morphological parameters on canine stifle joint biomechanics by use of a 3-D rigid-body canine pelvic limb computer model that simulated an intact and cranial cruciate ligament (CrCL)–deficient stifle joint across the stance phase of gait at a walk.
Sample—Data from computer simulations.
Procedures—Computer model morphological parameters, including patellar ligament insertion location, tibial plateau angle (TPA), and femoral condyle diameter (FCD), were incrementally altered to determine their influence on outcome measures (ligament loads, relative tibial translation, and relative tibial rotation) during simulation of the stance phase of gait at a walk. Outcome measures were assessed for each scenario and compared between an intact and CrCL-deficient stifle joint with the sensitivity index (the percentage change in outcome measure divided by the percentage change in input parameter).
Results—In a CrCL-intact stifle joint, ligament loads were most sensitive to TPA. In a CrCL-deficient stifle joint, outcome measures were most sensitive to TPA with the exception of caudal cruciate ligament and lateral collateral ligament loads, which were sensitive to FCD and TPA. Relative tibial translation was sensitive to TPA and patellar ligament insertion location, whereas relative tibial rotation was most sensitive to TPA.
Conclusions and Clinical Relevance—The computer model sensitivity analyses predicted that individual parameters, particularly TPA and FCD, influence stifle joint biomechanics. Therefore, tibial and femoral morphological parameters may affect the likelihood, prevention, and management of CrCL deficiency.
OBJECTIVE To investigate the influence of 4 biomechanical parameters on canine cranial cruciate ligament (CrCL)-intact and -deficient stifle joints.
SAMPLE Data for computer simulations of a healthy 5-year-old 33-kg neutered male Golden Retriever in a previously developed 3-D rigid body pelvic limb computer model simulating the stance phase during walking.
PROCEDURES Canine stifle joint biomechanics were assessed when biomechanical parameters (CrCL stiffness, CrCL prestrain, body weight, and stifle joint friction coefficient) were altered in the pelvic limb computer simulation model. Parameters were incrementally altered from baseline values to determine the influence on stifle joint outcome measures (ligament loads, relative tibial translation, and relative tibial rotation). Stifle joint outcome measures were compared between CrCL-intact and -deficient stifle joints for the range of parameters evaluated.
RESULTS In the CrCL-intact stifle joint, ligament loads were most sensitive to CrCL prestrain. In the CrCL-deficient stifle joint, ligament loads were most sensitive to body weight. Relative tibial translation was most sensitive to body weight, whereas relative tibial rotation was most sensitive to CrCL prestrain.
CONCLUSIONS AND CLINICAL RELEVANCE In this study, computer model sensitivity analyses predicted that CrCL prestrain and body weight influenced stifle joint biomechanics. Cranial cruciate ligament laxity may influence the likelihood of CrCL deficiency. Body weight could play an important role in management of dogs with a CrCL-deficient stifle joint.
Objective—To evaluate factors associated with lameness severity and hip joint range of motion in dogs with hip dysplasia and to assess the association between hip joint range of motion and degree of lameness.
Design—Prospective case series.
Animals—60 client-owned Labrador Retrievers with hip dysplasia.
Procedures—Owners completed a questionnaire regarding their dogs' daily exercise duration and type (ie, low impact vs high impact) and lifestyle. Range of motion of affected hip joints was measured with a transparent plastic goniometer. The presence of subluxation or luxation of hip joints as a consequence of hip dysplasia and the size of the largest osteophytes or enthesophytes of hip joints on ventrodorsal radiographic images of the pelvis were recorded. Multivariate analyses were performed to identify factors associated with lameness, loss of hip joint flexion, and loss of hip joint extension and to identify factors associated with the presence of large osteophytes.
Results—Exercise was associated with a decrease in the severity of lameness in dogs with hip dysplasia. The strength of this inverse relationship increased with longer exercise duration. Lameness was more severe in dogs with hip joint luxation than in dogs without luxation. Hip joint extension was 1° lower for each year of age, and osteophyte or enthesophyte size was 1 mm larger with each 3-year increase in age.
Conclusions and Clinical Relevance—Longer daily exercise duration was associated with lower lameness scores in dogs with hip dysplasia. Dogs with hip joint luxation secondary to hip dysplasia had higher lameness scores than did dogs without hip joint luxation.