Influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb of the horse
The influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb was investigated in a group of eight sound horses. The degree of lameness after the flexion test was scored by a standard clinical classification, and by measuring the angle of maximum fetlock extension by means of the infrared light-based MacReflex gait analysis system. There was a good correlation between the clinical score and this electronically recorded kinematic parameter (r = 0.96). Both the force applied and the period of application affected the outcome of the test. Increasing the force applied by 25 per cent led to three horses being judged positive, instead of two when the normal force was applied. Doubling the time to 120 seconds resulted in four horses rather than two being classified as lame after the test. Reducing the force to 75 per cent or the time to 30 seconds resulted in all the horses being classified as sound. A flexion test lasting five minutes, either at 100 per cent force or at 75 per cent, classified six of the eight horses as lame. It is concluded that the flexion test should be defined more precisely in terms of these two factors in order to make its results more consistent and hence more useful.
Association between clinical signs and histopathologic changes in the synovium of the tarsocrural joint of horses with osteochondritis dissecans of the tibia.
OBJECTIVE
To develop a scoring system for histopathologic changes in the synovium of tarsocrural joints (TCJs) of horses with osteochondritis dissecans (OCD) and to test for association between histopathologic changes and joint effusion or lameness.


ANIMALS
93 horses with OCD of the intermediate ridge of the tibia of 1 or both TCJs (134 joints) and 38 control horses without disease of TCJs (38 joints).


PROCEDURES
For OCD-affected horses, pretreatment lameness, TCJ effusion, and results of pelvic limb flexion test were scored. Synovial biopsy specimens were obtained from TCJs of OCD-affected horses during arthroscopy, and similar postmortem tissue specimens were obtained from control horses through a small arthrotomy. Histologic signs of synovitis in 172 biopsy specimens were scored by 2 pathologists (A and B) by use of 2 criteria: synoviocyte proliferation and cellular infiltration.


RESULTS
Analysis of scoring revealed good to very good intraobserver agreement within pathologist A (weighted kappa [WK], 0.76 to 0.81), and moderate to good agreement within pathologist B (WK, 0.56 to 0.63). Interobserver agreement for synoviocyte proliferation (WK, 0.34 to 0.52) and cellular infiltration (WK, 0.38 to 0.48) scores was fair to moderate. Joint effusion and synoviocyte proliferation were significantly associated, as were joint effusion and cellular infiltration. There was no association between histopathologic changes and the other clinical signs evaluated.


CONCLUSIONS AND CLINICAL RELEVANCE
The scoring system was helpful for evaluating synovial inflammation caused by OCD of the intermediate ridge of the tibia in horses. Histopathologic signs of synovial inflammation were associated with effusion but not with lameness.
Current veterinary therapy : food animal practice 3
(Abbreviated): Special Therapy and Procedures. Neonatal Diseases and Disease Management. Herd Health Management. Dietary Management. Metabolic Disorders. Physical and Chemical Disorders. Viruses, Chlamydiae, And Mycoplasma. Bacterial and Fungal Diseases. Protozoal and Rickettsial Diseases. Diseases of the Respiratory System. Diseases of the Circulatory System. Diseases of the Digestive System. Diseases of the Reproductive Tract. Diseases of the Urinary System. Diseases of the Eye. Neurologic Diseases of Food Animals. Diseases of the Musculoskeletal System. Dermatologic Diseases.