Hock

Abstract: The clinical and radiologic features of osteochondritis dissecans in the knee and hock joint of horses are described. The material includes 91 horses, of which 43 had the lesion in one or both knee joints, and 48 in one or both hock joints. It was found that osteochondritis dissecans of the knee joint was more common than the one in the hock joint in thoroughbreds and halfbreds, while the lesion in the hock joint was most common in standardbred trotters. In the knee the lesion was most often located to the lateral trochlear ridge. In the hock joint the predilection site was the intermediate ridge of the tibia. The lesions were of obvious clinical importance and the knee joint was usually more severely affected than the hock joint. Prognosis was also more guarded in horses with knee joint involvement, regardless whether or not surgical treatment was instituted. Arthrotomy and removal of fragments in the osteochondral defects or of loose bodies was the standard surgical procedure. It was felt that this treatment improved prognosis somewhat, particularly in the horses with hock joint lesions. It was found that there are many similarities between osteochondritis dissecans in horses and in pigs and dogs. However, further investigation is needed to shed more light on etiology and pathogenesis and on the nature of osteochondritis dissecans in the horse.

Abstract: This article reviews the literature on hock lesions in dairy cattle, focusing in particular on their prevalence and associated clinical signs, as well as the scoring systems used to assess them and the data on risk factors. This analysis was limited to hock lesions where there was inflammation and damage of the skin and the subcutaneous tissue only without involvement of the joint. The presence of hock lesions, or tarsal peri-arthritis, is strongly related to time spent lying on abrasive surfaces, prolonged high local pressure or friction of the hock on hard surfaces, and collisions of the hock with cubicle fittings. Since hocks have almost no fatty tissue or muscles between the bones and skin, there is no protection against these types of trauma and skin damage occurs (resulting in hock lesions). The risk of these lesions becoming infected is strongly dependent on the hygiene of the lying area. The prevalence of hock lesions in dairy cows is generally reported as high (>50%). As hock lesions are often correlated with lameness, they are associated with economic losses and impaired welfare, as well as negative societal perception of the dairy sector. Alterations in cubicle characteristics, bedding material, pasture access and lameness prevention may all lower the prevalence of hock lesions; nevertheless, the actual relationship between housing design and other cow- and management-related risk factors on the occurrence of hock lesions appears to be complex and interrelated.

Abstract: Objectives: To quantify net joint moments, joint powers, and joint reaction forces (JRF) across the hock, stifle, and hip joints in Labrador Retrievers with and without cranial cruciate ligament (CCL) disease. To investigate differences in joint mechanics between normal, CCL deficient, and contralateral pelvic limbs. Study Design: Cross-sectional clinical study. Animals: Clinically normal (n=14) and CCL-deficient (n=9) Labrador Retrievers. Methods: Each limb was analyzed separately and classified as normal, CCL-deficient or sound contralateral limb. Kinematic, ground reaction force (GRF), and morphometric data were combined in an inverse dynamic approach to compute hock, stifle and hip net moments, powers and JRF, while trotting. Results: Vertical and braking GRF and JRF were significantly decreased in CCL-deficient limbs. In affected limbs, extensor moments at the hock and hip, flexor moment at the stifle and power in all 3 joints were less than normal. Kinetics also identified a greater joint moment and power of the contralateral limbs compared with normal, particularly of the stifle extensor muscles group. Conclusion: Lameness resulting from CCL disease affected predominantly reaction forces during the braking phase and the extension during push-off. A greater contribution of the contralateral limbs to propel the dog forward was identified. Clinical Relevance: Reductions in joint motion, loads, and muscle contraction were interpreted as modifications adopted to reduce or avoid painful mobilization of the injured stifle joint. The increased joint moment and power of the contralateral compensating side may correlate with the lameness observed, but also with the predisposition of contralateral limbs to CCL deficiency in dogs.

Abstract: Summary This study aimed to quantify the factors associated with the prevalence of the radiological signs of osteochondrosis (OC) and osteochondrosis dissecans (OCD) in South German Coldblood (SGC) horses. The prevalence of OC and OCD in fetlock and hock joints was analysed in 167 young coldblood horses with a mean age of 14 months. The presence of at least one osteochondrotic lesion (OC) in fetlock or hock joints was documented for 61.7% of the horses and 26.9% of the horses had osseus fragments. Osteochondrotic findings at the dorsal aspect of the sagittal ridge of the third metacarpal/metatarsal bone were seen in 53.9% of the horses and palmar/plantar osseous fragments in fetlock joints in 16.2% of the horses. Hock joint OC was found in 40.1% of the horses and hock OCD in 0.6%. Osteochondrotic findings in the distal part of the tibia were prevalent in 28.1% and in the lateral trochlea tali in 17.4% of the horses. The sex of the investigated horses significantly influenced the prevalence of OC in fetlock and hock joints, as well as the findings in the distal part of the tibia and lateral trochlea tali. Age at radiological examination was significant for the prevalence of OC in hock joints, palmar/plantar osseous fragments in fetlock joints and osteochondrotic findings in the distal part of the tibia. Female horses showed a 2-fold higher risk for OC in fetlock and hock joints than male horses. The distribution of the affected horses by age classes showed that radiographic signs of OC in fetlock and hock joints significantly increased at an age of about 1 year. We can conclude from our study that fetlock and hock OC is a prevalent radiographic finding in more than 1-year-old female and male SGC horses.