Surgical arthrodesis for the treatment of osteoarthrosis of the proximal intertarsal, distal intertarsal and tarsometatarsal joints in 30 horses: a comparison of four different techniques

Over a period of seven years, 30 horses were treated by surgical arthrodesis for lameness resulting from osteoarthrosis of the proximal intertarsal, distal intertarsal and tarsometatarsal joints (bone and occult spavin). Twenty-five horses were affected in one hock only and five were affected bilaterally. Four different techniques for achieving arthrodesis were used. Fourteen out of 18 horses (78 per cent) with involvement of the distal intertarsal and tarsometatarsal joints only and six out of 11 horses (55 per cent) in which the proximal intertarsal joint was also involved became sound following surgery. The status of one other horse, with involvement of the proximal intertarsal joint, is not known.     

Determination of the anatomic communications among compartments within the carpus, metacarpophalangeal and metatarsophalangeal joints, stifle joint, and tarsus in llamas

OBJECTIVE: To determine the anatomic communications among compartments within the carpus, metacarpophalangeal and metatarsophalangeal joints, stifle joint, and tarsus in llamas. SAMPLE POPULATION: 88 limbs from 22 llamas necropsied because of reasons unrelated to disease of the carpus; tarsus; or metacarpophalangeal, metatarsophalangeal, or stifle joints. PROCEDURE: 1 compartment (randomly assigned) of each joint was injected with blue latex solution. Communication between joint compartments was determined by observation of latex in adjacent compartments following frozen sectioning. RESULTS: Of the 44 carpi, 30 (68%) had anatomic separation between the radiocarpal and middle carpal joints, whereas the remaining 14 (32%) had communication between the radiocarpal and middle carpal joints. In the metacarpophalangeal or metatarsophalangeal joints, medial and lateral joint compartments remained separate in 83 of 88 (94%) joints injected. The tibiotarsal and proximal intertarsal joints communicated in all tarsi examined, whereas 14 of 38 (37%) communicated between the proximal intertarsal and distal intertarsal joints. Communication between the distal intertarsal and tarsometatarsal joints was detected in 17 of 25 (68%) specimens; all 4 tarsal joints communicated in 11 of 42 (26%) specimens examined. Examination of 33 stifle joints that were successfully injected revealed communication between the femoropatellar, medial femorotibial, and lateral femorotibial joints. CONCLUSIONS AND CLINICAL RELEVANCE: These data suggest that it is important to determine the joint communications specific to each llama prior to treatment of septic arthritis. The metacarpophalangeal or metatarsophalangeal joint compartments may be considered separate, although the lateral and medial compartments infrequently communicate along the proximal palmar or plantar aspect.     

Lead poisoning in sandhill cranes.

Seven Florida sandhill cranes (Grus canadensis pratensis) and 6 greater sandhill cranes (Grus canadensis tabida) were exposed to lead-base paint containing 27% lead. One bird of each subspecies died enroute to the hospital, with a clinical history of anorexia, weakness, and open-mouth breathing of 36 hours' duration. There were no gross lesions, and microscopic lesions were limited to focal hepatic necrosis and hemosiderosis. Two of each subspecies of cranes developed clinical signs of lead poisoning, which included anorexia, weakness, green diarrhea, regurgitation, and open-mouth breathing. Diagnosis of lead poisoning was confirmed on the basis of blood lead concentrations ranging from 146 microgram/100 ml to 378 microgram/100 ml. These 4 cranes were treated successfully with calcium disodium edetate intramuscularly. Seven of the birds remained clinically normal despite high blood lead levels, especially in the greater sandhill cranes.     

Chemical arthrodesis of the distal tarsal joints using sodium monoiodoacetate in 104 horses

OBJECTIVE: To evaluate chemical arthrodesis using sodium monoiodoacetate for treatment of degenerative joint disease of the tarsometatarsal and distal intertarsal joints. DESIGN: Retrospective clinical study. METHOD: Horses were diagnosed with degenerative joint disease of one or more of the tarsometatarsal or distal intertarsal joints based on history, lameness examination, radiographic findings and, in some cases, response to intra-articular anaesthesia or medication. Intra-articular injections of sodium monoiodoacetate were performed using 23 gauge needles in the sedated, standing horse. Positive contrast arthrography of the distal intertarsal joint was performed in all horses to evaluate needle placement and the presence or absence of communication with other synovial structures. The mean intra-articular dose of sodium monoiodoacetate was 192 mg. Horses were subject to a graded exercise program commencing 7 to 10 days after treatment. Where possible, follow up lameness examination and radiography was performed at 3, 6, 12 and 24 months after treatment. RESULTS: At 3, 6, 12 and 24 months after treatment, respectively, 0/57, 14/55, 41/50, and 29/34 of horses were sound. At 3, 6, 12 and 24 months after treatment, respectively, 5/55, 24/38, 26/30 and 18/18 of horses had radiographic evidence of ankylosis of treated joints. Post injection pain was marked in 6.7% of horses and significant complications requiring further treatment occurred in 3.8% of horses. CONCLUSIONS: Chemical arthrodesis using sodium monoiodoacetate was an effective treatment method for degenerative joint disease of the distal tarsal joints. The technique was performed in the sedated standing horse and required minimal equipment. Results were comparable to those achieved following surgical arthrodesis. The risk of significant complications was minimised through good technique using an appropriate injection volume and concentration.     

Correlation of ultrasonographic observations with anatomic features and radiography of the elbow joint in dogs

OBJECTIVE: To define the ultrasonographic appearance of the elbow joint of dogs and to develop an ultrasonographic imaging protocol to reliably accomplish complete evaluation of that joint. ANIMALS: 11 clinically normal mixed-breed dogs. PROCEDURE: Ultrasonographic observations (by use of a 5 to 10 MHz linear array probe) were made of 22 elbow joints in cadaveric forelimbs from clinically normal dogs. Images in standard anatomic planes were recorded with a multi-image camera, on videotape, or onto a computer. The anatomic plane of the ultrasonographic beam and position of the ultrasonographic probe were also recorded. Dissection of each elbow joint was performed, and anatomic features were correlated with ultrasonographic images. RESULTS: Structures clearly identified ultrasonographically included the lateral and medial humeral epicondyles, the humeroradial and humeroulnar joints, anconeal process, medial coronoid process, hyaline cartilage covering the proximal articular surface of the radius, collateral ligaments, tendons of triceps brachii and supinator muscles, and the supinator tendon and sesamoid in the supinator cartilage. An ultrasonographic imaging protocol for examination of the elbow joint was developed. CONCLUSIONS AND CLINICAL RELEVANCE: Precise correlations were established between the gross anatomic appearance of the elbow joint and the ultrasonographic images of its component structures. The ultrasonographic imaging protocol will enable complete examination of all regions of the joint for detection of pathologic lesions.     

ULTRASONOGRAPHIC ANATOMY OF THE TEMPOROMANDIBULAR JOINT IN HEALTHY PURE-BRED SPANISH HORSES

The objective was to describe the normal ultrasonographic appearance of the soft tissue and bony structures of the temporomandibular joint in Pure-Bred Spanish horses using frozen and plastinated sections performed as anatomical references. The temporomandibular joint of five healthy Pure-Bred Spanish horses and the head specimens from 12 Pure-Bred Spanish cadavers that were subjected to euthanasia for reasons other than temporomandibular joint problems were studied sonographically and anatomically. An 11 MHz linear-array transducer was used to obtain longitudinal ultrasonographic images of the temporomandibular joint from rostral, lateral, and caudal approaches. For anatomic study, a gross dissection was performed on six temporomandibular joints. The other six head specimens were first frozen at -30 degrees C for 48h and then, at -70 degrees C for a week. Three millimeter thick anatomic sections were collected in the same plane as the sonographic planes. These sections were plastinated, photographed, and compared with the corresponding ultrasonographic images. The articular surfaces, the articular cartilage, the disc, the intra-articular fat tissue, the joint capsule, and other structures were clearly visualized sonographically. Structures identified on the ultrasonographic images were in accordance with those identified on the corresponding anatomic sections. We confirmed the appearance of structures of the equine temporomandibular joint that have been described previously but we also identified the caudal fibrous expansion of the disc, the caudal compartment of the dorsal synovial pouch, and the lateral ligament. Our results define a reference that will aid in sonographic evaluation of the equine temporomandibular joint region.     

In Vivo Investigation of Communication Between the Distal Intertarsal and Tarsometatarsal Joints in Horses and Ponies

The frequency of communication between the tarsometatarsal and distal intertarsal joints was investigated in 27 horses and 12 ponies. After the injection of diluted latex into the tarsometatarsal joints using the plantarolateral approach, the horses and ponies were walked for 200 meters. Latex was found in the distal intertarsal joints of 19 of 73 tarsi (26% communication) at necropsy. In 3 tarsi, latex was also found in the proximal intertarsal and tar-socrural joints.     

Kinematics of the hind limb in trotting horses after induced lameness of the distal intertarsal and tarsometatarsal joints and intra-articular administration of anesthetic

OBJECTIVE: To identify hind limb and pelvic kinematic variables that change in trotting horses after induced lameness of the distal intertarsal and tarsometatarsal joints and after subsequent intra-articular administration of anesthetic. ANIMALS: 8 clinically normal adult horses. PROCEDURE: Kinematic measurements were made before and after transient endotoxin-induced lameness of the distal intertarsal and tarsometatarsal joints and after intra-articular administration of anesthetic. Fourteen displacement and joint angle (metatarsophalangeal [fetlock] and tarsal joints) measurements were made on the right hind limb, sacrum, and the right and left tubera coxae. Kinematic measurements were compared by general linear models, using a repeated measures ANOVA. Post hoc multiple comparisons between treatments were evaluated with a Fisher least squared difference test at alpha = 0.05. RESULTS: After lameness induction, fetlock and tarsal joint extension during stance decreased, fetlock joint flexion and hoof height during swing increased, limb protraction decreased, and vertical excursion of the tubera coxae became more asymmetric. After intra-articular administration of anesthetic, limb protraction returned to the degree seen before lameness, and vertical excursion of the tubera coxae became more symmetric. CONCLUSIONS AND CLINICAL RELEVANCE: Increased length of hind limb protraction and symmetry of tubera coxae vertical excursion are sensitive indicators of improvement in tarsal joint lameness. When evaluating changes in tarsal joint lameness, evaluating the horse from the side (to assess limb protraction) is as important as evaluating from the rear (to assess pelvic symmetry).     

Evolutionary and Functional Anatomy of the Pelvic Limb in Fossil and Recent Equidae (Perissodactyla, Mammalia)

In Equidae, the limb structure adapted for fore and aft running motion first developed during late Paleocene (Hyracotherium). Since then, almost all the modifications contributed in developing a limb structure in which flexion and extension were primary movements. In Hyracotheriinae and Anchitheriinae, the hip and stifle joints were more flexed and had stronger semitendinosus muscles for fore and aft motion of the limb than in Equinae. Hyracotheriinae and Anchitheriinae had unstable hock joint and had significant intertarsal movement. In Hemphillian and earlier Equinae, the intertarsal movement was considerably reduced and in post Hemphillian Equinae it was negligible because of the presence of strong intertarsal ligaments. In the evolution of the horse the development of intertarsal ligaments, reduction of lateral digits and shortening of the astragalar neck contributed in providing the stability at the hock joint. Four types of limb structures are recognized in Equidae: (1) Hyracotheriinae, (2) Anchitheriinae, (3) Tridactyl Equinae, and (4) Monodactyl Equinae. Monodactyl tendencies appeared for the first time in Hemingfordian Parahippus (reduced metatarsals II and IV and their phalanges). The foot structure of this group is more like Equinae rather than Anchitheriinae, and is considered one of the Equinae in this paper. Early Clarendonian Pliohippus was the first equid to achieve monodactylism, but is not in the directancestry of Equus. Dinohippus became monodactyl at about the same time and has more in common with Equus (skull and dental characters) than Pliohippus.     

Prevalence of Radiographic Signs of Osteoarthritis in Lusitano Purebred Horses

Radiographic prevalence and correlation of radiographic findings has not been performed in Lusitano Purebred horses. The aim of this study was to (1) evaluate the prevalence of primary osteoarthritis radiographic findings in Lusitano Purebred horses; (2) to assess correlations between radiographic findings in different joints of the same limb and different limbs; and (3) elucidate the effect of age in the radiographic findings. A radiographic protocol of the stifle, tarsi, fetlocks and distal limbs was done in 98 Lusitanos and the classification of the radiographs was performed using a 0-4 scale developed and applied blindly by three veterinarians. The distal interphalangeal, proximal interphalangeal, metacarpophalangeal, metatarsophalangeal, tarsometatarsal, distal intertarsal, proximal intertarsal/, tibiotarsal and femorotibial-patellar joints were evaluated. Most joints presented no abnormal findings or minor abnormal radiographic findings (82.86% grade ≤1). The most affected joint was tarsometatarsal and more severe lesions were found in tarsometatarsal and distal intertarsal. Femorotibial-patellar radiographic changes were rare (2.13%). A strong/moderate correlation was found between contralateral joints with exception hindlimb fetlocks. A moderate correlation was found between fore and hindlimbs for distal limb joints. When analyzing ipsilateral as well as diagonal distal limbs, a strong/moderate correlation was also found. The total score progressed in 0.2 score points per each year of age, revealing that age can be a statistically significant predictor for radiographic changes. Overall, Lusitano horses presented a low prevalence of severe radiographic sings of primary osteoarthritis. Findings in contralateral joints tend to be correlated.     

Suspected fusariomycotoxicosis in sandhill cranes (Grus canadensis): clinical and pathological findings

In 1985 and 1986, large-scale natural die-offs of sandhill cranes in Texas were attributed to fusariomycotoxicosis. These birds demonstrated a progressive loss of motor control to the neck, wings, and legs. Based on necropsy and/or histopathology of 31 cranes, the most common lesions involved skeletal muscle and included hemorrhages, granulomatous myositis, thrombosis, and vascular degeneration. Serum chemistry results revealed that levels of creatinine kinase, aspartate aminotransferase, and alanine aminotransferase were above published normals. However, only alanine aminotransferase was higher in clinically affected cranes than in normal cranes collected from the same area.     

Surgical treatment of tarsometatarsal joint luxation in a miniature horse foal

A 2-week-old Miniature Horse foal was referred for evaluation and treatment of a luxated right tarsometatarsal joint. Treatment consisted of closed reduction and internal fixation using two partially threaded Steinmann pins placed in normograde fashion through the tuber calcis into the proximal third metatarsus. Traumatic luxation has been reported to occur in the tarsocrural, proximal intertarsal and tarsometatarsal joints within the equine tarsus. Treatment for luxation of the distal intertarsal joint has not been documented. The treatment method most commonly suggested for tarsal luxation is closed reduction and cast immobilisation. Internal fixation using lag screws and plating has also been described. A combination of internal fixation and external coaptation is thought to achieve maximal stability and allow faster convalescence in cases of tarsal luxation. This case report describes for the first time a technique using two Steinmann pins to achieve successful internal fixation of a traumatic tarsometatarsal joint luxation in a 2-week-old Miniature Horse foal.     

Mortality of captive whooping cranes caused by eastern equine encephalitis virus

Of 39 captive whooping cranes (Grus americana), 7 died during a 7-week period (Sept 17 through Nov 4, 1984) at the Patuxent Wildlife Research Center, Laurel, Md. Before their deaths, 4 cranes did not develop clinical signs, whereas the other 3 cranes were lethargic and ataxic, with high aspartate transaminase, gamma-glutamyl transferase, and lactic acid dehydrogenase activities, and high uric acid concentrations. Necropsies indicated that the birds had ascites, intestinal mucosal discoloration, fat depletion, hepatomegaly, splenomegaly, and visceral gout. Microscopically, extensive necrosis and inflammation were seen in many visceral organs; the CNS was not affected. Eastern equine encephalitis (EEE) virus was isolated from specimens of the livers, kidneys, lungs, brains, and intestines of 4 of the 7 birds that died, and EEE virus-neutralizing antibody was detected in 14 (44%) of the 32 surviving birds. Other infectious or toxic agents were not found. Morbidity or mortality was not detected in 240 sandhill cranes (Grus canadensis) interspersed among the whooping cranes; however, 13 of the 32 sandhill cranes evaluated had EEE virus-neutralizing antibody. Of the 41 wild birds evaluated in the area, 3 (4%) had EEE virus-neutralizing antibody. Immature Culiseta melanura (the most probable mosquito vector) were found in scattered foci 5 km from the research center.     

Pathological and histopathological findings in the joints of fattening turkeys

This paper reports on pathological and histopathological findings in the joints of male turkeys (B.U.T. Big 6) reared in two different housing systems. Pathological investigations were conducted on all animals which died between the 6th week of life and the end of fattening (585 birds, 1170 hip, knee and intertarsal joints) from four fattening periods with 3000 birds each. This study included 297 birds kept in a conventional housing system (barn 2) with a stocking density of 2.8 birds/m2, and 288 birds from a barn (1) from which the animals had access to an outdoor scratching area (stocking density 2.5 birds/m2). In all, 157 (26.5%) of the 585 fallen turkeys (barn 1:93; barn 2:70) showed at least one pathological joint alteration. and there were macroscopically detectable changes in 274 (7.8%) of the 3510 investigated joints: 152 (7.8%) of the 1728 joints from barn 1, and 122 (8.8%) of the 1782 from barn 2. In both housing systems the most frequent pathological alterations were in the intertarsal joint affecting 16% (188) of these 1170 joints (barn 1:106; barn 2:82); next most frequent were changes in the knee joint with 4.5% (53) of the 1170 joints affected (barn 1:26; barn 2:27). In both barns, synovial alterations occurred predominantly in the intertarsal and the knee joints. Bacteriological investigation of altered synovial fluids (83) most frequently showed an infection with Staphylococcus spp. (44) and E. coli (15). Macroscopic investigation showed alterations in 31 (2.7%) of the 1170 hip joints (barn 1:19; barn 2:12); 2% (22) of these showed cartilage degenerations of the femoral head (barn 1:15; barn 2:7). Histological investigation of these cartilage lesions showed that they were predominantly (70%) due to osteochondrosis with complete epiphyseolysis affecting 16 femoral heads (barn 1:10; barn 2:6). Partial epiphysiolysis was found in 24% (5) of the femoral heads (barn 1:4; barn 2:1). Furthermore, 43% (9) of the 22 femoral heads with cartilage degeneration also had osteomyelitis and osteochondritis, as well (barn 1:6; barn 2:3). Histological investigation of the 104 femoral heads with no macroscopic findings (barn 1:56; barn 2:48), revealed osteochondrosis in 11 cases (10.6%) (barn 1:6; barn 2:5). Osteomyelitis and osteochondritis were found in 17 (16.3%) of these femoral heads (barn 1:9; barn 2:8). There were no significant (p < 0.05) differences between the two housing systems in the incidence and frequency of joint alterations. It is to be assumed that these joint alterations were the cause of acute, chronic pain.     

Efficacy of selected coccidiostats in sandhill cranes (Grus canadensis) following challenge.

The anticoccidial efficacy of amprolium, clazuril, and monensin were studied in sandhill cranes (Grus canadensis) infected with a mixture of Eimeria spp. oocysts. Five groups of four 1-day-old sandhill crane chicks were maintained on a crumbled ration containing no coccidiostat, amprolium at 2.2 ppm, clazuril at 1.1 ppm, clazuril at 5.5 ppm, or monensin at 99 ppm. After 2 wk on their respective feeding regimens, birds in each of the five groups were administered 25 x 10(3) pooled sporulated Eimeria spp. oocysts per os and observed for another 3 wk. A sixth group of four chicks served as nonmedicated, nonchallenged control during the study. Clinical signs and lesions consistent with disseminated visceral coccidiosis were observed in all challenged controls and birds fed amprolium and clazuril. Birds in these groups died 9-10 days after challenge. In contrast, only one monensin-medicated bird had clinical signs of disseminated visceral coccidiosis, and it died 13 days after challenge (DAC). This and an asymptomatic bird that were necropsied at study termination had less-severe gross and microscopic lesions of disseminated visceral coccidiosis. Two of three monensin-treated birds that survived challenge passed from 50 to 500 coccidial oocysts 11 to 18 DAC but were negative at study termination. Of the coccidiostats tested, monensin, at the dietary level of 99 ppm, was the only anticoccidial drug that provided protection against experimentally induced disseminated visceral coccidiosis in sandhill cranes.     

Clinical evaluation of dogs after surgical and nonsurgical management of osteochondritis dissecans of the talus

Osteochondritis dissecans of the medial aspect of the talus was diagnosed in 17 joints in 11 dogs. In 10 of the 11 dogs, intermittent lameness had persisted after initial diagnosis and therapy. Radiographs made during the initial examination showed a widening of the medial tarsocrural joint space, with osteophyte formation involving the medial and caudal tarsocrural joint. The follow-up radiographs showed greatest change in the increase in reactive bone formation, especially involving the medial and caudal aspects of the tarsocrural joint and the medial aspect of the talus. Arthrotomy for flap removal and curettage was performed on 11 joints; 6 joints did not receive surgery. After a mean period of 34 months following diagnosis, the dogs were examined clinically and the affected joints were radiographed. The degree of lameness, range of motion, and stability of the tarsocrural joint were graded for each limb. Radiographic determinants that were assessed included: width of the medial tarsocrural joint space, medial tarsocrural osteophyte formation, lateral tarsocrural osteophyte formation, caudal tarsocrural osteophyte formation, medial talus osteophyte formation, lateral talus osteophyte formation, intertarsal osteophyte formation, subchondral sclerosis of the distal end of the tibia, presence of joint bodies, and periarticular soft-tissue thickness. On the basis of clinical and radiographic evaluations, the surgical procedures described in this report did not modify progression of osteoarthritic changes.     

Ultrasonographic examination of the equine sacroiliac region

REASONS FOR PERFORMING STUDY: Little information exists about the normal ultrasonographic appearance of the equine sacroiliac region, but knowledge of the ultrasonographic anatomy is necessary to understand the possible pathological changes in sacroiliac diseases. OBJECTIVES: The normal ultrasonographic appearance of soft tissues and bony structures of the sacroiliac region in horses was studied in order to establish clinically relevant reference parameters. METHODS: Thirteen cadaver specimens were examined using a transcutaneous approach above the tubera sacrale to image the dorsal sacroiliac ligament and the tendon of the longissimus dorsi muscle. A rectal approach was used to outline the sacroiliac joint and its adjacent structures. Thirteen sound horses with no history of back pain were examined following the same protocol as for the post mortem examinations. RESULTS: The tendon of the longissimus dorsi muscle can clearly be distinguished from the dorsal sacroiliac ligament, especially in longitudinal images. Transrectal examination of the sacroiliac joint consists of evaluation of the bony surfaces of the sacrum and ilium in comparison with the contralateral side. CONCLUSIONS: Ultrasonographic examination of the sacroiliac region provided clear images of the caudomedial border of the sacroiliac joint and its adjacent structures and is a useful aid in the diagnosis of sacroiliac joint diseases and adjacent lesions. The study has shown ultrasonography to be a useful method for examining and differentiating the longissimus dorsi muscle and the dorsal sacroiliac ligament at the level of the tubera sacrale. POTENTIAL RELEVANCE: Diagnostic ultrasound is available to most practitioners. These reference ultrasound parameters may help to improve the diagnosis of sacroiliac diseases.