[Treatment of a hip and patella luxation in a toy dog]. / Behandlung einer Hüftgelenks- und Kniescheiben-Luxation bei einer Zwerghunderasse.

INTRODUCTION: The present case report describes the surgical treatment of a traumatic craniodorsal luxation of the hip and a concomitant medial congenital luxation of the patella (3rd grade) in an 11-year-old Yorkshire Terrier. First the hip luxation was corrected with a cemented hip prosthesis. The femoral stem was inserted in slight anteversion (15°) with respect to the preoperative condition (5°), this contributed contrasting the medial traction of the femoral quadriceps on the patella, improving patellar luxation from 3rd to 2nd grade. However, the persistent patellar luxation and intermittent lameness reduced limb function and made a second intervention necessary. Four weeks after prosthetic surgery, a femoral trocleoplasty and lateral transposition of the tibial crest were performed to definitively re-establish a correct replacement of the patella in the femoral trochlea. No perioperative complications were found. At the final examination the patient did not show any lameness or pain that could be evoked when manipulating the surgically corrected limb. The surgical treatment allowed a restoration of the hip function and the alignment of the extensor mechanism of the femoral quadriceps and ensured a complete return to normal motor activities.

INTRODUCTION: Nous décrivons le traitement chirurgical d'une luxation traumatique cranio-dorsale de la hanche et d'une luxation patellaire de degré 3 concomitante chez un chien Yorkshire Terrier âgé de 11 ans. La luxation de la hanche a d'abord été traitée avec une prothèse totale cimentée. L'insertion de la tige fémorale en légère antéversion (15°) par rapport à l'état préopératoire (5°) contrecarrait la traction médiale des muscles quadriceps sur la rotule et réduisait la luxation patellaire du degré 3 au degré 2. Cependant la présence d'une boiterie intermittente due à la luxation patellaire de degré 2 persistante a réduit la fonction du membre et a rendu nécessaire une seconde intervention chirurgicale. Quatre semaines après le remplacement total de la hanche, une trochléoplastie fémorale et une transposition latérale de la crête tibiale ont été réalisées afin d'établir définitivement un alignement correct de la rotule dans la trochlée fémorale. Aucune complication périopératoire n'a été rencontrée. Lors de dernier contrôle, le patient ne présentait pas de boiterie ni de douleur lors de la manipulation du membre opéré Le traitement chirurgical a permis de rétablir la fonction de la hanche et d'aligner correctement le mécanisme extenseur des muscles quadriceps, tout en garantissant un retour complet du patient à une activité physique normale.

Complex segregation analysis of canine hip dysplasia in German shepherd dogs.

Complex segregation analyses were carried out to clarify the mode of inheritance of canine hip dysplasia (CHD) in German shepherd dogs. Data were used from 8,567 animals examined for CHD from 20 families with three to four generations. The existence of a major gene in addition to polygenic gene effects was detected. In the present study, a mixed model with a dominant major gene effect seemed to be most probable for dichotomous encoding (0: dogs without signs of CHD; 1: dogs with borderline/slight to severe CHD). In addition, mixed major gene inheritance was shown for a binary trait where borderline was assigned to dogs scored free from CHD and for a trichotomously encoded trait (0: dogs without signs of CHD; 1: borderline CHD; 2: mild to severe CHD). Although only small frequencies were found for the unfavorable homozygotic genotype AA, the probability of the AB genotype was high in affected animals. Selection schemes to reduce the frequency of the allele A should therefore efficiently improve existing breeding programmes in German shepherd dogs.

Estimation of genetic population variables for six radiographic criteria of hip dysplasia in a colony of Labrador Retrievers.

OBJECTIVE: To estimate genetic population variables for 6 radiographic criteria of canine hip dysplasia (CHD). ANIMALS: 664 full- and half-siblings from a colony of Labrador Retrievers. PROCEDURE: Heritability estimates and genetic correlations were calculated for 6 radiographic criteria of CHD. Two evaluation protocols were compared: the grade of the most severely affected hip joint and the sum of the scores for both hip joints. The predictive performance of estimated breeding values was also evaluated. RESULTS: The overall prevalence of CHD (Federation Cynologique Internationale grades C, D, and E) was 29.6%. Median age at radiographic examination was 377 days. Heritability for the total CHD grade, Norberg angle (NA), coverage of the femoral head (COV), craniodorsal acetabular rim (ACR), subchondral bone sclerosis (SUBCH), shape of the femoral head and neck (FHN), and osteoarthritic changes at the insertion site of the joint capsule (JC) was estimated as follows: 0.44, 0.43, 0.46, 0.37, 0.32, 0.21, and 0.05, respectively. Heritability estimates were slightly higher for the sum of the scores for both hip joints. If NA and COV were included as fixed effects in the model for the dependent variables ACR, SUBCH, FHN, and JC , then heritability of these traits significantly decreased (0.08 to 0.15). High scores of NA and COV lead to a significant increase of the scores of the remaining criteria. CONCLUSIONS AND CLINICAL RELEVANCE: Canine hip dysplasia is heritable to a moderate degree. Signs of subluxation revealed the highest heritability estimates. The criteria ACR, SUBCH, FHN, and JC were strongly influenced by NA and COV.

Radiographic features of feline joint diseases.

Feline joint disorders are often overlooked, possibly because cats are extremely agile and appear to cope with pathologic changes within their joints better than their canine counterparts. There is a growing awareness that osteoarthritis occurs more frequently than previously anticipated in cats, and recently we have seen the emergence of hip dysplasia as an entity of concern in some purebred cats. There are also several poorly understood conditions that affect the joints of cats, such as synovial osteochondromatosis, that invite further study. In recent years we have seen an expansion in the knowledge of immune-mediated and infectious arthropathies and their inter-relationship with infective agents. This article describes the radiographic changes seen in many of the currently recognized joint disorders of domestic cats.

Hip dysplasia: a feline population study.

The study population consisted of cats presented to the University of Missouri-Columbia Veterinary Medical Teaching Hospital from January 1, 1991 through December 31, 1995. Ventrodorsal radiographs including the pelvic region were evaluated for radiographic evidence of hip dysplasia. Each radiograph was evaluated independently by three board-certified veterinary radiologists and a consensus normal of dysplastic evaluation was determined. There were 684 cats from 12 breeds. The data derived from this study indicate the frequency of feline hip dysplasia in this population to be about 6.6% (45/684) and that the incidence appears to be breed dependent. Also, the radiographic appearance of hip dysplasia in cats is different than in dogs. A shallow acetabulum with remodeling and proliferation involving the cranio-dorsal acetabular margin were the most common radiographic signs. Minimal remodeling of the femoral neck was seen.

Hip dysplasia in the cat: a report of three cases.

Hip dysplasia was diagnosed in three cats. Two were presented with a history of hindlimb lameness and the other had a history of constipation. All were confined for two weeks and showed considerable clinical improvement. At follow-up examination the cats were free of clinical signs despite the deterioration in the radiological appearance of their hips. Luxation or subluxation of the hips, insufficient development of the craniolateral acetabular edges, loss of the arched shape of the cranial subchondral acetabular bones, shallow acetabula and secondary degenerative changes on the femoral heads and necks were the main radiological findings in the affected cats.

Clinical evaluation of intertrochanteric osteotomy for treatment of dogs with early-stage hip dysplasia: 37 cases (1980-1987).

Between May 1980 and May 1987, intertrochanteric osteotomy was performed on 43 hips of 37 dogs (6 bilateral procedures) with early-stage hip dysplasia, with the objectives of improving hip biomechanics and reducing discomfort. Clinical evaluation consisted of: questionnaire, and/or orthopedic examination, and/or report from owner(s) via telephone. At least 1 form of evaluation was conducted for 42 of 43 hips (98%). On the basis of orthopedic examination findings, 27 of 33 hips (84%) were functionally good or normal at postoperative month 15 (on average). On the basis of owner report, 19 of 28 hips (68%) were functionally good or normal at postoperative month 11 (on average). On the basis of questionnaire data, 17 of 24 hips (70%) were functionally good or normal at postoperative year 1. Before surgery, only 11 of 37 hips (30%) had been evaluated as functionally good or normal. Of 36 owners, 33 (91.6%) reported that they would have the procedure performed again if the circumstances were the same. From the good to excellent clinical results, we concluded that intertrochanteric osteotomy is a beneficial treatment for dogs with early-stage hip dysplasia.

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.

Radiographic evaluation of nonanesthetized and nonsedated dogs for hip dysplasia.

The use of chemical or gas restraint was unnecessary in most large breed dogs being evaluated radiographically for hip dysplasia. Of 100 large-breed dogs, 97 were successfully radiographed for hip dysplasia evaluation without the use of sedation or anesthesia.

Inheritance of associated ocular and skeletal dysplasia in Labrador retrievers.

A breeding colony was established to investigate the inheritance of associated ocular and skeletal dysplasia in Labrador Retrievers; 124 pups were produced. These pups were evaluated for the presence of ocular lesions, including cataracts, vitreous strands, persistent hyaloid remnants, retinal folds, retinal dysplasia, peripapillary hyperreflectivity, and rhegmatogenous retinal detachments, and skeletal abnormality, which was recognized by shorter than normal forelimbs and an abnormal morphologic appearance of the radius and ulna. Analysis of the distribution of lesions in pups indicated that the syndrome is caused by one abnormal gene, which has recessive effects on the skeleton and incompletely dominant effects on the eye. This would suggest that suspect carrier dogs could be identified by test matings with a known homozygote.