Determinants of passive hip range of motion in adult Greyhounds

OBJECTIVE: To determine the ranges of normal pelvic limb range of motion in adult Greyhound dogs, and to explore which factors influence hip range of motion in a population bred to meet the specific demands of racing. Design A cross-sectional study design. METHOD: Thirty-two dogs (17 male and 15 female) 13 to 81 months old were randomly selected from a local pool of 160 Greyhounds. Goniometric measurements of hip, stifle and hock range of motion were recorded in triplicate. Signalment information collected included sex, weight and age of each Greyhound. The outcome factors for the study were range of hip flexion and hip extension. The theorised exposures, age, sex, weight, racing history and hock and stifle range of motion, were modelled against the outcome variables by linear regression analysis. RESULTS: Male dogs were significantly heavier (P < 0.001) and older (P < 0.002) than female dogs. Mean hip flexion was 71.75 degrees and mean hip extension 128.10 degrees. The determinants of hip flexion were sex (P = 0.008) and range of stifle flexion (P = 0.002). Race training did not influence the range of hip flexion in the sample. Determinants of hip extension included range of stifle extension (P = 0.015), history of race training (P = 0.004) and hock flexion. The mean hip extension of raced Greyhounds was 134.95 degrees compared with 121.25 degrees for unraced Greyhounds (mean difference -13.70, 95% confidence interval -18.12, -9.29; P < 0.001). CONCLUSIONS: This study has reported isolated pelvic limb joint range of motion in the racing Greyhound. Hip range of motion was affected by stifle range of motion, sex and race training. Dogs that had received race training had greater flexibility, possibly due to training having an active stretching role on muscles, tendons and other structures limiting the hip range of motion.     

Laminectomy for treatment of cauda equina syndrome in a cat

A 16-year-old spayed female Siamese cat was presented with a history of paraparesis and obstipation. The cat's impaired function was attributed to malalignment of the L7-S1 spine (cauda equina syndrome) and to traumatic fracture of the left femoral neck, with severe degenerative arthritis. Laminectomy resolved the cauda equina problem, and the hip joint was not treated.     

Effect of anaesthesia and stress on the radiographic evaluation of the coxofemoral joint

A pelvic radiographic examination was performed on 15 large breed dogs without history and clinical sign of hip dysplasia. The effect of anaesthesia and of two stress-radiographic methods on the coxofemoral subluxation was evaluated. With anaesthesia a mild coxofemoral subluxation was seen in 31 per cent of the dogs, which all appeared radiographically normal when sedated. The Norberg angle was significantly decreased in anaesthetised dogs (P < 0–05). When dogs with a radiographically normal coxofemoral joint conformation were submitted to a stress-radiographic examination there was a shift towards an increased coxofemoral subluxation. Subluxation was seen in 70 per cent of the dogs when the knee fixation method of positioning was applied and in 100 per cent of the dogs when the wedge method was used. Correspondingly the Norberg angle decreased significantly when the coxofermoral joints were stressed (P_kneefix < 0–00003; P_wedge= 0–000008). The study concludes that the currently used procedure for evaluation of the hip joints does not necessarily disclose whether or not a dog has hip dysplasia.     

Total hip replacement in two dogs with unsuccessful femoral head ostectomy

An English setter (case 1) and a Tibetan mastiff (case 2) presented with intermittent weight-bearing lameness on the right hind limb when trotting. The dogs had a history of femoral head and neck ostectomy (FHNO). Orthopedic examination revealed pain and crepitus on the right hip joint. The dogs underwent total hip replacement (THR). At the 2-year (case 1) and 1-year (case 2) follow-up, both dogs had resumed normal activity without lameness. The muscle mass and range of motion were significantly improved in the affected hind limb. In conclusion, FHNO with poor functional outcomes can be successfully ameliorated with THR.     

COMPARISON OF CLINICAL, RADIOGRAPHIC, COMPUTED TOMOGRAPHIC, AND MAGNETIC RESONANCE IMAGING METHODS FOR EARLY PREDICTION OF CANINE HIP LAXITY AND DYSPLASIA

The purpose of the study was to use two palpation methods (Bardens and Ortolani), a radiographic distraction view, three computed tomography (CT) measurements (dorsolateral subluxation score, the lateral center-edge angle, and acetabular ventroversion angle) and two magnetic resonance (MR) imaging hip studies (synovial fluid and acetabular depth indices) in the early monitoring of hip morphology and laxity in 7–9 week old puppies; and in a follow-up study to compare their accuracy in predicting later hip laxity and dysplasia. The MR imaging study was performed with the dog in dorsal recumbency and the CT study with the animal in a weight-bearing position. There was no association between clinical laxity with later hip laxity or dysplasia. The dorsolateral subluxation score and the lateral center-edge angle were characterized by a weak negative correlation with later radiographic passive hip laxity (−0.26< r <−0.38, P <0.05) but its association with hip dysplasia was not significant. There was an association between early radiographic passive hip laxity and synovial fluid index with later passive hip laxity (0.41< r <0.55, P <0.05) and this was significantly different in dysplastic vs. nondysplastic hips ( P <0.05). There was no association between the remaining variables and later hip laxity or dysplasia. The overlapping ranges of early passive hip laxity and synovial fluid index for hip dysplasia grades and the moderate correlations with the later passive hip laxity make the results of these variables unreliable for use in predicting hip laxity and dysplasia susceptibility.     

von Willebrand heterotopic osteochondrofibrosis in Doberman pinschers: five cases (1980-1987)

Five cases involving female Doberman Pinschers, each with a mass composed of osseous, chondrous, or fibrous tissue, or a combination thereof, formed in or around the muscles of the hip, were reviewed. In each dog, the mass severely limited the coxofemoral joint range or motion, especially when the joint was extended. Surgical debulking resulted in a favorable outcome. All dogs tested had plasma concentrations of von Willebrand factor antigen below established normal limits. We believe that the low concentrations of von Willebrand factor antigen commonly found in Doberman Pinschers may predispose them to the development of this condition and its resulting pelvic limb lameness, presumably because of increased risk of microvascular bleeding. This association is presumptive because 2 dogs in our study had a history of excessive bleeding either before or after being treated for the hip condition. Trauma was associated in 2 cases. All 5 dogs, however, bled more than usual during the curative surgery. These 5 cases, plus additional reported cases, confirm this syndrome, which warrants recognition. The name von Willebrand heterotopic osteochondrofibrosis of Doberman Pinschers was selected because it identified the basic features of the syndrome.     

Effect of trotting velocity on work patterns of the hind limbs of Greyhounds

OBJECTIVE: To quantify the effects of trotting velocity on joint angular excursions, net joint moments, and powers across the hind limb joints in Greyhounds. ANIMALS: 5 healthy Greyhounds with no history of lameness of the hind limbs. PROCEDURES: Small reflective markers were applied to the skin over the joints of the hind limbs, and a 4-camera kinematic system was used to record positional data at 200 Hz in tandem with force platform data while the dogs trotted on a runway at slow, medium, and fast velocities. Breed-specific morphometric data were combined with kinematic and force data in an inverse-dynamics solution for net joint moments and powers at the hip, stifle, tarsal, and metatarsophalangeal joints. RESULTS: Angle, moment, and power patterns at the various joints were conserved among the 3 velocities. With increasing velocity, moments and powers at the tarsal, stifle, and hip joints during the stance phase were increased in amplitude, whereas amplitudes during the swing phase were not. The main contributors to increased velocity were the hip extensors and stifle flexors during the early part of the stance phase and the tarsal extensors during the late part of the stance phase. CONCLUSIONS AND CLINICAL RELEVANCE: Increases in trotting velocity in Greyhounds do not alter the basic patterns of work and power for various joints of the hind limbs, but local burst amplitudes during the stance phase increase incrementally.     

Effect of dam and sire qualitative hip conformation scores on progeny hip conformation

OBJECTIVE: To determine in dogs what effect using hip conformation scores assigned by the Orthopedic Foundation for Animals (OFA) as a criterion for breeding selections would have on hip conformation scores of the progeny. DESIGN: Longitudinal study. ANIMALS: English Setters, Portuguese Water Dogs, Chinese Shar-peis, and Bernese Mountain Dogs for which OFA hip conformation scores were known. PROCEDURE: Pedigree data were obtained from the national breed clubs and the American Kennel Club and merged with data from the OFA hip conformation score database. An ANOVA was used to evaluate the effects of sex, age at the time of radiographic evaluation, and year of birth on the variation in hip conformation scores among the progeny. Heritability was estimated by use of within-year midparent offspring regression analyses. RESULTS: Significant differences in progeny hip conformation scores between sexes were not detected, but age at the time of radiographic evaluation and year of birth had a significant effect on hip joint conformation of the progeny. Estimated heritability (mean +/- SE) was 0.26 +/- 0.03, and dam and sire hip conformation scores had a significant effect on progeny hip conformation scores. Annual decreases in percentage of dysplastic progeny and increases in percentages of progeny and breeding dogs with phenotypically normal hip joint conformation were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that hip conformation scores have moderate heritability in dogs and selection of breeding stock with better hip conformation scores will increase the percentage of progeny with phenotypically normal hip joint conformation.     

Canine hip dysplasia: study of heritability in 401 litters of German Shepherd dogs

Heritability of hip dysplasia was estimated to be about 0.4 to 0.5 when based on the radiographic evaluations of the hip joints of 2,404 German Shepherd Dogs born at The Armed Forces Dog Training Center in Sweden. The material included all dogs in 401 litters born at the Center from 1965 through 1973 that reached the age of 15 months. To be expected with such high heritability, frequency of hip dysplasia in the offspring was shown to be affected by the hip joint status of sire and dam as well as by the hip joint status of their parents and littermates. Even matings between sires with normal hip joints and dams with only slight dysplasia resulted in significantly higher frequency of hip dysplasia in the offspring, when compared with the frequency if both sires and dams had normal hip joints. Frequency of hip dysplasia in the progeny of sires with normal hip joints varied greatly. Since 1973, selection of the breeding stock has been based on hip joint status (phenotype) of the breeding animals and of their relatives as well as on what had become known about frequency of hip dysplasia in the litters already born (progeny testing). In this way, frequency of hip dysplasia in 347 dogs born at the Center during 1975 was lowered to 28%. This figure should be compared with the figure of 50%, which represents the frequency of hip dysplasia in the kennel up to 1970, when selection was not as strict as could be expected in a well-controlled kennel.     

Relationships between results of the Ortolani method of hip joint palpation and distraction index, Norberg angle, and hip score in dogs

OBJECTIVE: To determine whether results of the Ortolani method of hip joint palpation in dogs were related to distraction index (DI), Norberg angle, or radiographic hip score. DESIGN: Cross-sectional study. ANIMALS: 459 clinically normal dogs. PROCEDURE: Dogs were sedated for radiography and palpation of the hip joints. Results of hip joint palpation were classified as negative, mild positive, moderate positive, or severe positive. Distraction indices were measured for all dogs. Norberg angles were measured for 380 dogs for which ventrodorsal hip-extended radiographic projections were available. Hip scores assigned by the Orthopedic Foundation for Animals (OFA) were available for 95 dogs. RESULTS: Age, weight, and sex were not significantly associated with results of hip joint palpation. There was moderate correlation between results of hip joint palpation and DI (r = 0.636), low-moderate correlation between results of hip joint palpation and OFA hip scores (rs = 0.437), and weak negative correlation (r = -0.236) between results of hip joint palpation and Norberg angle. For joints without degenerative joint disease (DJD), there was a significant linear relationship between results of hip palpation and DI; however, for joint with DJD, there was not. Results of hip joint palpation were 5.3-fold as likely to be negative for dogs with DJD as for dogs without. CLINICAL IMPLICATIONS: Results of hip joint palpation were at best moderately correlated with radiographic measures of hip joint laxity. Therefore, hip joint palpation should be combined with hip-extended and stress radiography when assessing hip joint quality.     

Purulent Necrotic Dislocation of the Hip Joint Associated with Umbilical Infection in a Foal

A 42-day-old heavy draft horse fell into sudden astasia. Significant swelling and heat sensation of the left femoral region were observed. Because of a friction sound in the left hip, we supposed that the hip joint was dislocated or the hip bone was fractured. Computed Tomography (CT) examination showed that the left hip joint was dislocated and the left femoral head was disjunct. We carried out a pathological autopsy, and made a diagnosis of the foal as fracture of the hip bone and femoral head with suppurative umbilical arteritis. Pathologic changes in the umbilical artery and hind leg were completely unilateral, suggesting that left umbilical arteritis spread to the blood circulation, causing arthritis and dislocation of the hip bone.     

New concepts of coxofemoral joint stability and the development of a clinical stress-radiographic method for quantitating hip joint laxity in the dog

From mechanical principles and postmortem observations of coxofemoral joints of dogs, a hydrostatic mechanism influencing hip joint stability was discovered. This discovery led to the development of a stress-radiographic positioning method to quantitate hip joint laxity in dogs. The method incorporated 2 views with the dog in supine position and hips at neutral flexion/extension angle: a compression view, with the femoral heads fully seated in the acetabula; and a distraction view, with the femoral heads at maximal lateral displacement. An index measurement method was formulated to quantitate the relative degree of joint laxity appearing in either the compression or distraction view. Clinical evaluation of 6 dogs was done to compare the compression/distraction method with the standard hip-extended radiographic method. Also, the stress-radiographic method was performed on 16-week-old Borzoi and German Shepherd Dogs to compare the characteristics of inherent hip joint laxity in these breeds. In all dogs tested, hip joint laxity was masked by the standard hip-extended view as indicated by a 2.5-fold improvement in sensitivity to hip joint laxity of the new method (P less than 0.00001). Moreover, the mean hip joint laxity of 16-week-old German Shepherd Dogs exceeded the mean hip joint laxity of Borzois by 79% (P less than 0.00001). Reports in the literature document the incontrovertible association of hip joint laxity to the development of hip dysplasia in dogs. We believe the ability to accurately quantitate hip joint laxity will provide key diagnostic and prognostic criteria for the selection of pet dogs, and more importantly, breeding stock.     

Assessment of the hip reduction angle for predicting osteoarthritis of the hip in the Labrador Retriever

Hip palpation has been used to provide semiquantitative information regarding passive joint laxity and susceptibility to hip dysplasia. The purpose of this study was to: (1) evaluate the intra- and inter-examiner repeatability of the hip reduction angle measured at 4 months of age by three examiners using manual goniometry and an electromagnetic tracking system; (2) compare the hip reduction angle measured with manual goniometry to the hip reduction angle measured with the electromagnetic tracking system; and (3) evaluate the hip reduction angle, distraction index and Ortolani manoeuvre at 4 months of age as predictors of the development of hip osteoarthritis at 12 months of age in 11 Labrador Retriever dogs. Intra- and inter-examiner repeatability was demonstrated for both the manual and electromagnetic goniometric measurement of the hip reduction angle (coefficient of variation < 4.3% and < 6.1%; and P = 0.163 and P = 0.836 respectively). The hip reduction angle measured by manual goniometry was moderately correlated to the hip reduction angle measured by the electromagnetic tracking system (r = 0.603, P < 0.0000). The hip reduction angle measured by manual and electromagnetic goniometry was a poor predictor of osteoarthritis at 12 months of age (r = 0.231, P < 0.062, and r = 0.321, P < 0.01). The distraction index was moderately correlated with the development of osteoarthritis by 12 months of age (r = 0.493, P < 0.0000). The Ortolani sign was sensitive (100%) but not specific (41%) for the development of osteoarthritis at 12 months of age. The hip reduction angle did not further quantify the Ortolani manoeuvre as a predictor of osteoarthritis in Labrador Retrievers.     

Total hip arthroplasty in the horse: Overview,technical considerations and case report

A total hip arthroplasty was performed in a small equine patient with a history of traumatic subluxation of the coxofemoral joint during infancy resulting in severe degenerative changes to the femoral head and acetabulum. The transtrochanteric surgical approach used to expose the joint, as well as the technique and technology to replace the joint, is described. The patient was weightbearing within 24 h of surgery and walking successfully without sling support 4 days post operatively. On the fifth post operative day, the patient abruptly deteriorated and succumbed to multiple pulmonary thromboemboli and a jejunal infarction. Despite the systemic complications in this case, the initial short‐term success of this treatment option indicate its potential to be considered in the management of equine coxofemoral joint disease/lesions.     

Osteolytic osteomyelitis associated with visceral leishmaniasis in a dog

A dog was examined with a history of weight loss and lameness of the left hind limb. A painful response to examination of the left hip joint, and lymphadenopathy were noted. Amastigote forms of Leishmania sp. were observed by cytology in samples from the popliteus lymph node, and anti-Leishmania sp. antibodies at a titer of 1:640 were detected in serum by indirect immunofluorescence. Radiological changes included osteolysis and a periosteal proliferative reaction in the left femoral greater trochanter. These changes were histologically characterized as an osteolytic granulomatous osteomyelitis associated with amastigotes within macrophages. Non-decalcified fragments of the periosteum were processed for immunohistochemistry, observed with prominent immunolabelling of amastigotes of Leishmania sp. within macrophages. The diagnosis was further confirmed by positive PCR for Leishmania sp., belonging to the Leishmania donovani complex.     

Genetic evaluation of elbow scores and the relationship with hip scores in UK Labrador retrievers

A linear mixed model analysis of elbow and hip score data from UK Labrador retrievers was used to estimate the heritability of elbow score (0.16-0.19) and to determine a moderate and beneficial genetic correlation with hip score (0.40). A small improvement in the genetic trend of elbow score was observed during the years 2000-2008, equivalent to avoiding only the worst 3-4% of scored dogs for breeding, but close to what may have been anticipated if the current British Veterinary Association-approved guidelines were followed. Calculations suggested that a correlated response to indirect selection on hip score may elicit a greater response than direct selection on elbow score and that the genetic trend in elbow score may be explained as a consequence of the stronger selection pressure that has been placed on hip score. Increases in the accuracy of estimated breeding values for elbow score of 4-7% for dogs with elbow data only and 7-11% for dogs with both hip and elbow score were observed from bivariate analysis of elbow and hip data. A selection index confirmed the benefits of bivariate analysis of elbow and hip score data by identifying increases in accuracy (directly related to the response to selection) of 14% from the use of optimum coefficients compared to use of hip data only. The quantified genetic correlation means that hip score effectively acts as a 'secondary indicator' of elbow score in this breed and the preponderance of hip data means that it acts as a major source of information that may be used to improve the accuracy of estimates of genetic risk for elbow dysplasia.     

PUPPY LINE, METAPHYSEAL SCLEROSIS, AND CAUDOLATERAL CURVILINEAR AND CIRCUMFERENTIAL FEMORAL HEAD OSTEOPHYTES IN EARLY DETECTION OF CANINE HIP DYSPLASIA

Ventrodorsal extended hip radiographs were analyzed from Foxhounds, Irish setters, Greyhounds, and Labrador retrievers radiographed four to seven times between 8 and 110 weeks of age. Occurrence in these 91 dogs of a puppy line, an ill-defined zone of proximal femoral metaphyseal sclerosis, a femoral neck linear sclerosis, or circumferential linear femoral head osteophytosis at 15–17 weeks of age were compared with hip joint laxity, as measured by distraction index, and to later findings of caudal curvilinear femoral neck osteophytes, circumferential femoral head osteophytes, hip incongruity consistent with hip dysplasia and degenerative joint disease by 52 weeks of age. A puppy line and/or femoral metaphyseal sclerosis was common at 15–17 weeks of age for dogs at mimimal risk (Greyhounds) and high risk (Foxhounds) of developing early degenerative joint disease associated with canine hip dysplasia. Though 44% of Greyhound hips had puppy lines and 28% had femoral metaphyseal sclerosis at 15–17 weeks of age, no Greyhound had a caudolateral curvilinear osteophyte or circumferential femoral head osteophyte at 24–27 or 52 weeks of age. No significant relationship was found between occurrence of a puppy line, a circumferential femoral head osteophyte or femoral metaphyseal sclerosis at 15–17 weeks and canine hip dysplasia or degenerative joint disease incidence at 42–52 weeks. Presence of a caudolateral curvilinear osteophyte in at least one hip at 24–27 weeks was significantly related to the diagnosis of canine hip dysplasia by 42–52 weeks. When both a caudolateral curvilinear osteophyte and a circumferential femoral head osteophyte were present in a hip at 24–27 weeks, degenerative joint disease was evident in all such hips by 42–52 weeks of age.     

Heritability and epidemiology of canine hip-dysplasia score and its components in Labrador retrievers in the United Kingdom

Hip-dysplasia (malformation of the coxofemoral joint) in dogs is a major health problem. Under the British Veterinary Association/Kennel Club's voluntary hip-dysplasia scheme, dog-owners/breeders submit radiographs from animals >1-year-old, to ensure adequate skeletal maturity. An overall hip score quantifies the degree of malformation in the hip joints of these animals, by summing the scores for nine components of the radiographs of both the left and right joints. The hip score data for 29,610 Labrador retrievers (registered with The Kennel Club, UK) were merged with the Kennel Club pedigree database for 472,435 Labrador retrievers. The merged data included the animal's identity, date of birth, sex and hip score and similar records for the dog's relatives, including the hip score if the relative had been tested.In recent years, breeding had been increasingly from tested parents. The mean hip score for male Labradors was significantly higher than that for females. Regression modelling showed a significant, positive dependence of the hip score of the offspring upon the hip scores of its sire, dam and grandparents. Genetic heritability (using data from 13,382 Labrador retrievers comprising 718 litters) was highly significant: 0.34 from the two parents, 0.41 from sire alone and 0.30 from dam alone. Using components data from 2038 offspring Labrador retrievers comprising 1248 litters, three similar estimates of heritability were significant for three major components (Norberg angle, cranial acetabular edge and subluxation); for other components, heritability was significant from the sire but not from the dam. Offspring hip score could be reduced substantially by using only parents with zero hip score.     

Heritability and epidemiology of canine hip-dysplasia score in flat-coated retrievers and Newfoundlands in the United Kingdom

Hip dysplasia (malformation of the coxofemoral joint) in dogs is a major health problem for which the British Veterinary Association (BVA) had set up a control scheme in 1965. Based on scoring nine components of the radiographs of both the left and right joints, the degree of hip joint malformation is now quantified by an overall hip score (a measure of the condition of the hip joint). The hip scores of 1258 flat-coated retrievers and 1566 Newfoundlands (registered with The Kennel Club in the United Kingdom) were analysed after merging with Kennel Club pedigree data for 19036 flat-coated retrievers registered by 1995 and 14336 Newfoundlands registered by 1997. The merged data included the animal's identity, date of birth, sex and hip scores and also similar records for the dog's relatives including the hip score if the relative had been tested. In recent years, breeding has been increasingly from tested parents. There has been some reduction in offspring hip scores - presumably because breeders avoided breeding from males with very high scores. However, a much greater reduction in offspring hip score would be achieved by stricter science-based selection of potential sires and dams. Regression modelling quantified the positive relationship between offspring and parental hip scores. The genetic heritability of hip scores was large and significant in both breeds (particularly from dams). The breeders in UK tended to use healthy sires for breeding but they have taken less care in selecting dams. Our regression models emphasise the need for both sires and dams, particularly dams, to be healthy with very small hip scores.