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- Author or Editor: Charles E. DeCamp x
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Abstract
Objective—To describe the abnormal gait of dogs with hip dysplasia by use of kinematic gait analysis.
Animals—19 large-breed dogs with moderate to severe clinical and radiographic evidence of hip dysplasia and 10 clinically normal dogs (controls).
Procedure—Kinematic and force plate data were collected, and degree of coxofemoral joint abductionadduction, mediolateral foot movement, distance between hind feet, maximum hind foot elevation, mediolateral pelvic movement, and coxofemoral joint angular acceleration were calculated. Essential Fourier coefficients were determined and used to reconstruct mean angular acceleration curves. Fourier coefficients and foot and pelvic movement data were compared between groups.
Results—Dogs with hip dysplasia had a greater degree of coxofemoral joint adduction and range of abduction-adduction and greater lateral pelvic movement, compared with controls. Foot movement variables did not differ significantly between groups. Coxofemoral joint angular acceleration was greater in the middle to end of the stance phase, whereas deceleration was greater in the late stance to early swing phase and middle to end of the swing phase in dogs with hip dysplasia, compared with controls.
Conclusions and Clinical Relevance—Differences in degree of coxofemoral joint abduction-adduction, amount of mediolateral pelvic movement, and coxofemoral joint angular acceleration between clinically normal dogs and dogs with hip dysplasia may indicate a compensation in gait of affected dogs as a result of discomfort or biomechanical effects attributable to hip dysplasia and degenerative joint disease. Information gained from kinematic and kinetic gait analyses may be useful in evaluating treatments for hip dysplasia in dogs. (Am J Vet Res 2000;61:974–978)
Summary
Limb symmetry was evaluated by measuring ground reaction forces in 2 groups of normal-gaited dogs at a trot. Data were collected from 2 groups of 21 dogs trotted at dog/handler velocities of 1.25 to 1.55 m/s and 1.85 to 2.05 m/s, respectively. Of these dogs, 9 participated in both groups to allow comparison of data at both velocities. Additionally, 16 of the dogs in group 1 were measured in 2 directions of movement to determine whether directional dependence was present. Collected data were then applied to 3 described symmetry indices.
Each index was easy to calculate, but all had limitations. A major limitation was variation in magnitude of ground reaction forces measured between the different axes and the effect of this variation on precision of the derived indices. Vertical ground forces provided the most consistent symmetry indices, in part because of their large magnitude. The indices indicated that no dog had perfect right-to-left symmetry during a trotting gait. Statistical differences were not found in any of the measurements of directional dependence. Likewise, comparing symmetry data in dogs trotted at both velocities indicated no significant differences in any axis.
However, further analysis of the data revealed the actual amount that a variance attributable to right-left limb variation was negligible. Most of the variance was attributable to trial variation. Thus, the aforementioned indices, which use nonconsecutive footfall methods to evaluate limb symmetry, actually measure principally trial variation and not limb-to-limb variation.
Abstract
Objective—To compare structural properties of a plate-rod combination–bone construct (PRCbc) and interlocking nail–bone construct (ILNbc) by use of an experimentally induced gap fracture in canine tibiae.
Sample Population—12 paired canine tibiae.
Procedure—Specimens were implanted with a plate-rod combination consisting of a 3.5-mm, limited-contact, dynamic-compression plate combined with an intramedullary rod or 6-mm interlocking nail. Ostectomy (removal of 10-mm segment) was performed. Paired constructs were loaded for bending, compression, or torsion measurements (4 constructs/group). Compliance was determined by fitting regression lines to the load-position curves at low (initial compliance) and high (terminal compliance) loads.
Results—Bending compliances did not differ significantly between constructs. For the ILNbc, initial compliance was greater than terminal compliance in compression and torsion. Initial compliance and terminal compliance for the PRCbc were similar in compression and torsion. Initial compliance in compression and torsion was greater for the ILNbc, compared with initial compliance for the PRCbc. Maximum deformations in bending and compression were similar between constructs; however, maximum torsional angle was significantly greater for the ILNbc, compared with values for the PRCbc.
Conclusions and Clinical Relevance—The study documented that for an experimentally induced gap fracture in canine tibiae, a plate-rod combination is a significantly less compliant fixation method in torsion and compression, compared with an interlocking nail. Considering the deleterious effects of torsional deformation on bone healing, a plate-rod combination may represent a biomechanically superior fixation method, compared with an interlocking nail, for the treatment of dogs with comminuted tibial diaphyseal fractures. (Am J Vet Res 2005;66:1536–1543)
Abstract
Objective—To compare the biomechanical properties of pantarsal arthrodesis achieved with a dorsal bone plate-alone (BPA) or pin-plate combination (PPC).
Sample Population—8 pairs of cadaver canine tarsi.
Procedure—Within a pair, 1 tarsus was arthrodesed by use of a 13-hole 3.5-mm broad dynamic compression bone plate applied to the dorsal aspect of the tarsus; the paired tarsus received an identical plate similarly applied, with the addition of an intramedullary pin filling approximately 40% of the tibial medullary canal, spanning the tibiotarsal joint. Plates were instrumented with strain gauges proximal and distal to the solid portion of the plate. Specimens were mounted on a servo-hydraulic testing machine and loaded at 20%, 40%, and 80% of body weight for 10 cycles at 1 Hz. Construct compliance, angular deformation, and plate strain were determined during the 10th cycle.
Results—PPC specimens were less compliant than BPA specimens at all loads and had significantly less angular deformation than BPA specimens at loads of 40% and 80% of body weight. Tibiotarsal gauge microstrain was significantly less in PPC specimens, compared with BPA specimens, regardless of loads. Maximal strains were 33.5% to 40.5% less in PPC than BPA specimens.
Conclusions and Clinical Relevance—For pantarsal arthrodesis in dogs, our results indicate that the PPC construct is biomechanically superior to the BPA construct. By improving construct stability, addition of an intramedullary pin to the traditional BPA technique may lessen implant-related complications and improve plate fatigue life. A subsequent decrease in postoperative morbidity may occur with little addition of time or complexity to the surgical procedure. (Am J Vet Res 2005;66:125–131)
Abstract
Objective
Noninvasive, computer-assisted, three-dimensional kinematic gait analysis was used to describe lameness in a chronic model of cranial cruciate ligament rupture (CCLR) in dogs.
Design
Hind limb lameness was evaluated prior to and at 1, 3, and 6 months after transection of the cranial cruciate ligament.
Animals
Seven clinically normal large dogs.
Procedure
Dynamic flexion and extension angles and angular velocities were calculated for the coxofemoral, femorotibial, and tarsal joints. Distance and temporal variables were determined. Essential Fourier coefficients were used to develop mean flexion extension curves for all joints and to compare changes in movement that developed with CCLR over time.
Results
Each joint had a characteristic pattern of flexion and extension movement that changed with CCLR. The femorotibial joint angle was more flexed throughout stance and early swing phase of stride and failed to extend in late stance. Angular velocity of the femorotibial joint was damped throughout stance phase, with extension velocity almost negligible. The coxofemoral and tarsal joint angles, in contrast to the femorotibial joint angle, were extended more during stance phase. These changes were documented as differences noted in the essential Fourier coefficients. Stride length and frequency also varied significantly after CCLR.
Conclusions
Cranial cruciate ligament rupture affects movement of the coxofemoral and tarsal joints, as well as the femorotibial joint, in gait. A pattern of joint movement may be discerned in which the coxofemoral and tarsal joints compensate for the dysfunction of the femorotibial joint.
Clinical Relevance
Methods were developed that will improve objective evaluation of CCLR and its treatment in dogs. (Am J Vet Res 1996;57:120-126)
Abstract
Objective
To define alterations of movement in dogs with hip dysplasia by use of noninvasive, 3-dimensional, computer-assisted kinematic gait analysis.
Design
Kinematic and force plate data were collected at the trot from clinically normal dogs and from dogs with hip dysplasia.
Animals
12 large adult dogs of various breeds with clinical and radiographic evidence of hip dysplasia, and 12 clinically normal adult large dogs of various breeds with body weight similar to that of the dogs with hip dysplasia.
Procedure
Dynamic flexion and extension angles and angular velocities were calculated for the coxofemoral, femorotibial, and tarsal joints. Temporal and distance variables were also computed. Essential Fourier coefficients were determined and used to reconstruct mean dynamic flexion and extension curves for all joints, and to compare differences in movement between dogs with hip dysplasia and clinically normal dogs.
Results
Dogs with hip dysplasia had subtle characteristic changes in dynamic flexion and extension angles and angular velocities of each joint, verified by significant differences in essential Fourier coefficients between the 2 study groups. Stride length was increased and peak vertical force was decreased in dogs with hip dysplasia. Subject velocity, maximal foot velocity, stance duration, stride frequency, and impulse area did not differ between the 2 groups.
Conclusions
Kinematic gait analysis indicated that hip dysplasia is associated with alterations in movement of the coxofemoral, femorotibial, and tarsal joints. Computer-assisted kinematic gait analysis provided a noninvasive, objective tool with which to evaluate these complex motion alterations.
Clinical Relevance
The information obtained may be useful in future evaluations of various modes of treatment for hip dysplasia. (Am J Vet Res 1996;57:966–971)
Abstract
Objective
To describe intratrial differences in hind limb symmetry in healthy dogs at the trot, using non-invasive, computer-assisted, three-dimensional kinematic gait analysis.
Animals
8 clinically normal large-breed adult dogs.
Procedure
Dynamic flexion and extension angles and angular velocities were calculated for the coxofemoral, femorotibial, and tarsal joints of dogs at the trot. Temporal and distance variables were computed. Essential Fourier coefficients were used to determine mean flexion and extension curves for all joints and to compare differences in movement between right and left hind limbs. Variances attributable to limb, dog, and trial were determined.
Results
Each joint had a characteristic pattern of flexion and extension movement that was used to compare intratrial symmetry of hind limb gait. Significant differences were not detected in temporal or distance variables between the right and left hind limbs. Significant differences were not noted in essential Fourier coefficients used to characterize coxofemoral, femorotibial, and tarsal joint angles and angular velocities, with the exception of the cosine-0 coefficient for coxofemoral angular velocity. Variation in joint angle and angular velocity measurements were attributable to individual dog and trial. Variation attributable to limb was negligible.
Conclusions
Intratrial evaluation of right-left hind limb symmetry, using kinematic gait analysis, indicated objectively that hind limb movement is symmetrical at the trot in healthy large-breed dogs.
Clinical Relevance
Documentation of hind limb symmetry at the trot will help provide a basis for direct comparison of both hind limbs in future studies evaluating gait and treatment of dogs with musculoskeletal disease. (Am J Vet Res 1998;59:680-685)
Summary
A noninvasive computer-assisted kinematic gait analysis was used to describe flexion and extension movements of 6 joints in Greyhounds at a trot. Distinct patterns of movements were described for each joint studied. The coxofemoral and carpal joints were characterized by a single peak of maximal extension. The femorotibial, tarsal, scapulohumeral, and cubital joints had 2 peaks of maximal extension, with 1 peak preceding stance phase and a second peak within stance phase. A two-factor repeated-measures anova was used to determine the variance in measurement of joint angles in degrees that was attributable to trial repetitions and to differences between dogs. The coxofemoral, femorotibial, tarsal, scapulohumeral, and cubital joints had a mean variance attributable to trial repetition of 6.6 (range, 1.7 to 12.9), and a mean variance attributable to differences between dogs of 5.1 (range, 0.9 to 9.2). The carpus had more variance, with a mean variance attributable to trial repetition of 16.3 (range, 13.3 to 20.5), and that attributable to differences between dogs of 31.8 (range, 20.5 to 46.7). Kinematic gait analysis provided a reliable description of flexion and extension movements in Greyhounds with minimal variance attributable to trial repetitions and to differences between dogs.
Abstract
Objectives
To use computer-assisted kinematic analysis to describe the walk in healthy dogs and to adapt Fourier transformation for analysis of the data.
Design
Evaluation of normal walk in dogs, using kinematic and force plate analysis.
Sample Population
15 healthy large-breed dogs.
Procedure
Morphometric data were collected to describe the sample population. Temporal and distance variables were measured to describe the walk. Flexion and extension movements were described for the scapulohumeral, cubital, carpal, coxofemoral, femorotibial, and tarsal joints. Fourier transformation was adapted to facilitate analysis of the joint angle waveforms.
Results
Unique and complex patterns of flexion and extension movements were observed for each joint studied. The walk had consistency of movement in the sample population in temporal and distance variables and joint movements. Variances attributable to intra- and interdog differences were similar and 1 to 2 orders of magnitude smaller than the mean Fourier coefficients from which they were calculated for all 6 joints. The number of essential Fourier coefficients required to represent the joint angle waveforms was 3 for the coxofemoral joint, 5 each for the femorotibial, scapulohumeral, cubital, and carpal joints, and 6 for the tarsal joint.
Conclusions
Computer-assisted kinematic gait analysis proved to be a reliable and consistent technique for assessment of movement at the walk in dogs, and Fourier transformation was shown to be an effective tool for analysis of the kinematic data.
Clinical Relevance
The database derived from the normal sample population in this study can be used as a model of musculoskeletal function at the walk for future comparisons with disease and treatment.(Am J Vet Res 1996;57:381-388)
Abstract
Objective
To determine whether use of hemoglobin glutamer-200 (bovine) as a partial blood volume replacement in dogs undergoing cemented total hip replacement caused any deleterious effects on the bone-cement or cement-prosthesis interface, exerted any deleterious effects on body organs, or caused any complications during the anesthetic, immediate recovery, or long-term recovery period.
Animals
9 adult dogs.
Methods
Dogs were anesthetized, and 15% of the blood volume was removed. Simultaneously, lactated Ringer's solution was infused, and 6 dogs were given hemoglobin glutamer (1 g/kg of body weight, IV). Unilateral total hip replacement was performed. Limb use was assessed visually, and force-plate and radiographic evaluations were performed before, and 8 weeks after, surgery. Eight weeks after surgery, dogs were euthanatized, necropsies were performed, and prosthetic component pullout forces were determined.
Results
There were no significant differences between treated and control dogs in regard to biomechanical (visual assessment of gait, force-plate analysis, femoral and acetabular component pullout forces) and pathologic evaluations (physical examination, CBC, serum biochemical analyses, necropsy, and histologic evaluations). Radiographic signs of loosening of the femoral component were seen in 4 dogs treated with hemoglobin glutamer.
Conclusions and Clinical Relevance
Administration of hemoglobin glutamer as a blood substitute did not appear to have any deleterious effects in dogs undergoing total hip arthroplasty. The radiographic findings, which were discordant with the biomechanical results, merit further investigation. (Am J Vet Res 1999;60:1337–1340)