Joint Lameness Research Articles

Arthrocentesis approaches to the phalangeal joints of the one humped camel (Camelus dromedarius)

Irrespective of the exceptional adaptation of dromedaries to harsh environmental conditions, they remain highly susceptible to joint lameness resulting from a range of diverse factors and conditions. The joints most often affected by traumatic osteoarthritis in dromedaries are the metacarpophalangeal and metatarsophalangeal joints. A comprehensive understanding of joint anatomy and topography of the dromedary is required to perform arthrocentesis correctly on affected joints. Forty-two distal limbs were taken from 28 camels and studied by gross dissection, casting, ultrasonography, and computed tomography (CT). Representative three-dimensional models of the joint cavities, recesses, and pouches were obtained using different casting agents. This study provides a detailed description of dorsally, axially, and abaxially positioned joint recesses, as well as palmar/plantar positioned joint pouches. The safety and feasibility of the different arthrocentesis approaches were evaluated. The traditional dorsal arthrocentesis approach of the metacarpophalangeal, metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joints, has limitations due to the risk of damaging the tendon structures and articular cartilage, which can lead to joint degeneration. A lateral arthrocentesis approach via the proximal palmar/plantar pouches of the metacarpophalangeal/metatarsophalangeal and proximal interphalangeal joints is recommended. This approach eliminates the potential needle injury to the articulating joint cartilage and other surrounding joint structures, such as tendons, blood vessels, and nerves.

A Double-Blinded Positive Control Study Comparing the Relative Efficacy of 2.5% Polyacrylamide Hydrogel (PAAG) Against Triamcinolone Acetonide (TA) And Sodium Hyaluronate (HA) in the Management of Middle Carpal Joint Lameness in Racing Thoroughbreds

The purpose of this prospective double-blinded positive control study was to compare the efficacy of 2.5% polyacrylamide hydrogel (2.5% PAAG) in the management of middle carpal joint lameness in Thoroughbreds against treatments of triamcinolone acetonide (TA) or sodium hyaluronate (HA). A total of 31 flat-racing Thoroughbreds with lameness (grade 1-3/5) localized to the carpus by intra-articular analgesia were selected. Following a radiological assessment of the carpi confirming the absence of fragment/fracture, the horses were randomly assigned for intra-articular treatment with either 2 ml of 2.5% PAAG, 12 mg TA or 20 mg HA (followed by two further intravenous treatments of 40 mg, at weekly intervals in the HA group only), by a treating veterinarian. All horses were rested for 48 hours post-treatment and then re-entered an unaltered training regimen. Subsequent examinations at 2, 4, and 6 weeks were performed by a blinded examining veterinarian for all groups, while horses treated with 2.5% PAAG were monitored for 12 weeks for recurrence of lameness. Significantly more joints treated with 2.5% PAAG were lame free (83%) at 6 weeks compared to TA (27%; P = .007) and to HA (40%; P = .04). There was no significant difference between TA and HA groups at any time. All the joints treated within 2.5% PAAG that were lame free at 6 weeks (10/12) were still lame-free at 12 weeks. In conclusion, treatment with 2.5% PAAG led to statistically superior results compared to TA and HA in the management of selected middle carpal joint lameness in flat-racing Thoroughbreds, with therapeutic effects persisting up to 12 weeks.

Correction of Valgus Dislocation of the Radio-Carpal Joint in a Dog through Ligament Reconstruction with Synthetic Wire: an Alternative to Arthrodesis

Background: Radio-carpal dislocations are normally related to situations of trauma and may be treated with open or closed reduction, reconstruction of injured structures or arthrodesis. The treatment aims to eliminate pain, abnormal joint movement and restore member functions, avoiding or minimizing the development of arthrosis. Notwithstanding the literature on the treatment options, few of them explain the restorative technical applications and their evolution in a later postoperative period. The aim of the present report is to discuss extra-articular joint reconstruction with nylon wire in a canine patient with radio-carpal joint dislocation and ligament rupture.Case: A 10-year-old mixed-breed bitch, weighing 10 kg, after an 8-meter fall, received care at Animal Care Barueri Clínica Veterinária. The animal presented left thoracic member functional impotence and radio-carpal joint valgus dislocation, pain and joint swelling. The patient was sedated and medium-lateral and dorso-palmar X-rays of the distal area of the thoracic member were performed, showing radio-carpal dislocation and a slight radiotransparent line in caudal cortical of the middle third of the left radium, possibly related to an incomplete fracture due to compaction. At this point, the choice was for a closed reduction performed by means of traction followed by internal rotation of the distal extremity of the member. An immobilization device was placed using a vinyl splint for 4 days, until the date of the surgery. For the surgical procedure, a dorso-medial access was opened in the left radio-carpal joint, restoring the short radium collateral joint with nylon 0 suture, anchored on 3 pathways opened in the bones (2 pathways in the radium and 1 in the carpo-radial bone), forming one knot. The subcutaneous tissue was closed and sutured using absorbable wire of 2-0 polyglycolic acid. The skin was sutured using nonabsorbable wire of 3-0 nylon. The immediate postoperative X-rays showed the pathways created, conservation of the bone structures and restoration of the anatomic axis of the radio-carpal joint. The member was again immobilized for 70 days and, 30 days after removal of the splint, the animal could already bear load over the member, without lameness. At 10 months after the surgery, the patient performed X-rays of the medium-lateral and dorso-palmar projections, showing absence of the signs of arthrosis or any joint impairment. There was also absence of lameness and pain, however with reduction in joint movement amplitude, with total extension but more limited flexion.Discussion: Through comparison with the literature it was possible to find similarities with the joint injury approach reported, mainly regarding the form of the suture and the clinical alterations observed, such as short radium collateral ligament rupture related to joint valgus deviation. The treatment strategy in the case combined temporary closed reduction of the joint, immobilization, later joint access and restoration with synthetic wire and long-term immobilization. The postoperative results obtained showed favorable evolution, without signs of joint degeneration, pain or lameness. Possible unwanted consequences related to arthrodesis make the options for reconstruction techniques seem more interesting; however, further information of their application and the combination of its variations in a more directed fashion are still required. Understanding the types of injuries, together with the development of research that assess their diagnosis and evolution, may help treatments to show even better perspectives.Keywords: dislocation, joint, radio-carpal, reconstruction, ligament.Título: Correção de luxação valga da articulação rádio-cárpica em um cão através da reconstrução ligamentar com fio sintético: uma alternativa à artrodeseDescritores: luxação, articulação, rádio-cárpica, reconstrução, ligamento.

Efficacy of tight suturing for shortening healing scar tissues in repair of Myerson type III old rupture of Achilles tendon

Objective To investigate the clinical efficacy of tight suturing for shortening healing scar tissues in repair of Myerson type III old rupture of Achilles tendon. Methods A retrospective case series study was performed to analyze the clinical data of 16 patients with Myerson III type chronic Achilles tendon ruptures admitted to Sports Hospital Affiliated to Chengdu Sport University from January 2015 to December 2017. All of the patients were males with sports injuries, aged 19-71 years (mean, 40.6 years). The Achilles tendon defect was 5-7 centimeter (mean, 5.2 centimeter). The patients received tight suturing and shortening healing scar tissue for the repair. The operation time and surgical wound size were recorded. The clinical efficacy was evaluated by Amer-Lindholm standard and American 0rthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. Meanwhile, the complications such as wound infection, Achilles tendon re-rupture, heel lifting weakness, muscle strength decline, ankle dysfunction, lameness and symptoms of sural nerve injury were recorded. Results All patients were followed up for 11-41 months, with an average of 26 months. The operation time ranged from 25-51 minutes, with an average of 37 minutes. The incision was 4-12 cm, averaging 7 cm. According to the Amer-Lindholm standard, 14 patients were graded as excellent and two were graded as good, with the excellent and good rate of 100%. AOFAS ankle-hindfoot score increased from (42.7±6.8)points before operation to (95.1±4.9)points at the last follow-up (P<0.05). During the follow-up, there were no complications such as infection, Achilles tendon rupture, heel lifting weakness, muscle strength decline, ankle joint dysfunction, lameness and gastrocnemial nerve injury. Conclusion For Myerson type III old rupture of Achilles tendon, tight suturing for shortening healing scar tissue can increase the postoperative function scores without wound infection or complications. Key words: Achilles tendon; Wounds and injuries; Cicatrix; Tight suture

Tibial Plateau Leveling Osteotomy for Cranial Cruciate Ligament Rupture in Canines: Patient Selection and Reported Outcomes.

Cranial cruciate ligament (CCL) rupture is one of the most common causes of pelvic limb lameness in dogs. In a CCL deficient stifle, joint lameness develops from cranial tibial translation in relation to the distal femoral condyles. The tibial plateau leveling osteotomy (TPLO) is a well-described surgical procedure that neutralizes tibiofemoral shear force by altering the tibial plateau via a proximal tibial osteotomy, and subsequently restores normal limb function. Current literature for the TPLO was reviewed and used to describe the optimal patient selection and to report clinical outcome with the TPLO in comparison to other surgical options for CCL rupture. The clinical outcomes reported to date, particularly those utilizing objective outcome data, support the TPLO as being able to consistently return dogs to normal limb function with a low risk for long-term morbidity. The TPLO procedure was found to be widely applicable to dogs ranging from small breed to large and giant breed, and does not appear to have some of the limitations that exist with alternative surgical options. This review concludes that the TPLO is an excellent treatment option for any dog with CCL rupture due to the excellent long-term outcome and high rate of owner satisfaction previously reported. Despite these conclusions, it is important to remember that treatment selection for CCL rupture remains dependent on multiple considerations including patient factors, surgeon experience, and costs.

Effect of circadian rhythm, age, training and acute lameness on serum concentrations of cartilage oligomeric matrix protein (COMP) neo-epitope in horses.

SummaryBackgroundMolecular serum markers that can identify early reversible osteoarthritis (OA) in horses are lacking.ObjectivesWe studied serum concentrations of a novel cartilage oligomeric matrix protein (COMP) neo‐epitope in horses subjected to short‐term exercise and with acute lameness. The effects of circadian rhythm and age were also evaluated.Study designLongitudinal studies in healthy horses and cross‐sectional comparison of lame and non‐lame horses.MethodsSera were collected from five horses before and after short‐term interval exercise and during full‐day box rest. Sera from 32 acutely lame horses were used to evaluate age‐related effects. Independent samples from control horses (n = 41) and horses with acute lameness (n = 71) were included. COMP neo‐epitope concentrations were analysed using custom‐developed inhibition ELISAs validated for equine serum. The presence of COMP neo‐epitope was delineated in healthy and osteoarthritic articular cartilage with immunohistochemistry.Results COMP neo‐epitope concentrations decreased after speed training but returned to baseline levels post‐exercise. No correlations between age and serum COMP neo‐epitope concentrations were found (r = 0.0013). The mean (±s.d.) serum concentration of COMP neo‐epitope in independent samples from non‐lame horses was 0.84 ± 0.38 μg/mL, and for lame horses was 5.24 ± 1.83 μg/mL (P<0.001). Antibodies against COMP neo‐epitope did not stain normal articular cartilage, but intracytoplasmic staining was found in superficial chondrocytes of mild OA cartilage and in the extracellular matrix of moderately osteoarthritic cartilage.Main limitations ELISA was based on polyclonal antisera rather than a monoclonal antibody. There is a sex and breed bias within the groups of horses, also it could have been of value to include horses with septic arthritis and tendonitis and investigated joint differences.ConclusionsThis COMP neo‐epitope can be measured in sera, and results indicate that it could be a biomarker for pathologic fragmentation of cartilage in connection with acute joint lameness.

Use of a 2.5% Cross-Linked Polyacrylamide Hydrogel in the Management of Joint Lameness in a Population of Flat Racing Thoroughbreds: A Pilot Study

Osteoarthritis is one of the most common disease processes effecting equine athletes, causing up to 60% of all lameness. This prospective longitudinal study reports on the effect of treatment of carpal and metacarpophalangeal joint lameness with 2.5% cross-linked polyacrylamide hydrogel (PAAG). A total of 49 flat-racing Thoroughbreds at a single training facility were included in the study. The results show a significant improvement in lameness grades at weeks 1 (P < .01), 4 (P < .001), 12 (P < .001), and 24 (P < .001) when compared to baseline lameness at week 0. This pilot study suggests that 2.5% cross-linked PAAG is a safe and effective joint treatment for managing joint lameness in Thoroughbred racehorses and warrants further blinded and controlled studies to fully evaluate the efficacy of the 2.5% cross-linked PAAG and its mode of action.

A dose response study of monosodium iodoacetate induced femorotibial osteoarthritis in Wistar rats

In the present study, 18 female rats were randomly divided into 3 different groups. Each group consisted of 6 female rats. The right femorotibial joint of rats of the group I, II, III received 1, 3 and 5 mg monosodium iodoacetate (MIA), respectively at dose volume of 50 il/joint. The left femorotibial joint of rats of the group I, II, III received 50 il normal saline and served as control. Three rats from each group were euthanized on day 15 and 30 post injection. The clinical sign and histopathologic changes were clearly dose dependent. 5 mg MIA/joint produced marked joint swelling, lameness and lesions viz., degeneration and necrosis of chondrocytes, atrophy of articular cartilage, exposure of subchondral bone, fibrosis in marrow cavity and chondro-osteophyte formation on day 15 and 30. The rats of 3 mg MIA/joint showed similar clinical signs and lesions of milder severity. In 3 mg MIA/joint, chondro-osteophyte formation was seen on day 30. In 1 mg MIA/joint showed mild swelling, lameness and minimal necrosis of chondrocytes as compared to 3 and 5 mg groups. On basis of above findings it is concluded that 3 mg MIA/joint produced ideal osteoarthritisrat model.

Involvement of mitochondrial dysfunction and ER-stress in the physiopathology of equine osteochondritis dissecans (OCD)

Osteochondrosis (OC) is a developmental bone disorder affecting several mammalian species including the horse. Equine OC is described as a focal disruption of endochondral ossification, leading to osteochondral lesions (osteochondritis dissecans, OCD) that may release free bodies within the joint. OCD lesions trigger joint swelling, stiffness and lameness and affects about 30% of the equine population. OCD is considered as multifactorial but its physiopathology is still poorly understood and genes involved in genetic predisposition are still unknown. Our study compared two healthy and two OC-affected 18-month-old French Trotters diagnosed with OCD lesions at the intermediate ridge of the distal tibia. A comparative shot-gun proteomic analysis of non-wounded cartilage and sub-chondral bone from healthy (healthy samples) and OC-affected foals (predisposed samples) identified 83 and 53 modulated proteins, respectively. These proteins are involved in various biological pathways including matrix structure and maintenance, protein biosynthesis, folding and transport, mitochondrial activity, energy and calcium metabolism. Transmission electron microscopy revealed typical features of mitochondrial swelling and ER-stress, such as large, empty mitochondria, and hyper-dilated rough endoplasmic reticulum, in the deep zone of both OC lesions and predisposed cartilage. Abnormal fibril organization surrounding chondrocytes and abnormal features at the ossification front were also observed. Combining these findings with quantitative trait loci and whole genome sequencing results identified about 140 functional candidate genes carrying putative damaging mutations in 30 QTL regions. In summary, our study suggests that OCD lesions may result from defective hypertrophic terminal differentiation associated with mitochondrial dysfunction and ER-stress, leading to impaired cartilage and bone biomechanical properties, making them prone to fractures. In addition, 11 modulated proteins and several candidate mutations located in QTL regions were identified, bringing new insight into the molecular physiopathology and genetic basis of OCD.

Effect of anesthetizing individual compartments of the stifle joint in horses with experimentally induced stifle joint lameness

To evaluate the effects of sequential anesthesia of the individual compartments of the equine stifle joint on lameness induced by intra-articular deposition of interleukin (IL)-1β. 6 horses. For each horse, baseline hind limb lameness was first evaluated. A randomly selected compartment of 1 stifle joint was then injected with IL-1β to induce synovitis and lameness; subsequently, the same compartment was anesthetized with 2% mepivacaine hydrochloride, and lameness was reevaluated. Two weeks later, baseline lameness was evaluated, and lameness was similarly induced; thereafter, the 2 synovial compartments of the stifle joint not injected with IL-1β were anesthetized sequentially in random order (ie, first and second blocks); lameness was evaluated after each block. Finally, the IL-1β-treated compartment was anesthetized (third block); lameness was again evaluated. This second experiment was repeated for the contralateral stifle joint 2 weeks later. Throughout the study, lameness was quantified objectively by assessing vertical pelvic movement asymmetry with a wireless, inertial sensor-based system. Intra-articular deposition of IL-1β induced lameness in all injected limbs. In the first experiment, anesthesia of the compartment injected with IL-1β resulted in a significant decrease in lameness, with vertical pelvic movement asymmetry approaching baseline. In the second experiment, lameness improved significantly after the second and third blocks and was almost completely abolished after all 3 synovial compartments were anesthetized. In horses, lameness caused by a lesion in 1 compartment of a stifle joint can be improved more by instillation of local anesthetic solution into that compartment than by anesthesia of the other compartments.

Long-Term Study on the Health Status of Polish Breeding Goat Population

Three questionnaire surveys were carried out in 1996, 2002 and 2007 in breeding goat herdsin Poland to identify disorders which posed an important health problem in breeding goat herds inPoland, and to track the variations in the frequency of occurrence of disorders observed between 1996and 2007. In this period strong tendency to reduce the number of herds and increase their size wasevident. The complete set of answers regarding health problems in herds was obtained in 73 herds in1996, 59 in 2002 and 45 in 2007 (177 complete questionnaires in all). Only four disorders wereidentified as important health problems in breeding goat herds in 1996, while as many as ten in 2007.In 1996 external parasites, superficial abscesses, diarrheas in adult goats and mastitis were foundproblematic by the owners.Those four conditions remained important in 2007 but six new emerged: joint swelling,lameness, injuries and fractures, respiratory signs, fetal loss and wasting. Eleven disorders had becomesignificantly more prevalent over the 10-year period of the study: superficial abscesses, lameness,injuries and fractures, joint swelling, respiratory signs in adults and in kids, diarrheas in kids, fetalloss, neurological signs, dystocia and weight loss. This shows how the health problems change alongwith the development of goat industry and can help to prepare effective control programs.

Anaesthetic arthrography of the shoulder joint in dogs

To evaluate the use of intra-articular anaesthesia combined with positive contrast arthrography (collectively called 'anaesthetic arthrography' [AA]) in the shoulder in order to identify and confirm the source of pain in lame dogs. Anaesthetic arthrography was performed in 30 dogs with shoulder joint lameness with a mixture of contrast medium (iohexol: 240 mg I/ml) and a local anaesthetic (mepivacaine 2%: 20 mg/ml). The effect of intra-articular anaesthesia was evaluated by an objectified visual scoring system and the arthrograms were evaluated for their diagnostic value. This study showed that AA was positive in 28 out of 30 dogs. Dilution of the contrast medium with a local anaesthetic produced an arthrogram of good quality for each shoulder joint. In 16 out of 18 cases of osteochondritis dissecans, a cartilage flap could be identified following arthrography. In all cases the flap was not identified from plain radiographs. Biceps brachii tendon pathology was diagnosed on arthrography in seven dogs but was missed in two dogs. Calcification at the caudal rim of the glenoid cavity was diagnosed in three dogs, but was of clinical importance in only two dogs. In addition one infection was diagnosed during synovial aspiration. Anaesthetic arthrography of the shoulder is a simple, safe, and reliable diagnostic test to confirm shoulder joint pain and simultaneously identify a lesion. This procedure may be of particular importance in cases of occult shoulder joint lameness when clinical findings and plain radiographs are inconclusive.

Efficacy of intramuscular polysulfated glycosaminoglycan in a controlled study of equine carpitis

Twelve healthy horses were subject to the monoioidoacetate (MIA) carpitis model, which was allowed to develop for 7 days. The horses were then randomly divided into two groups. Group A (control) received an intramuscular injection of normal saline every 4 days for a total of seven injections while group B received 500 mg of a PSGAG (SYNTEX CSY36) intramuscularly every 4 days for seven treatments. Efficacy of the PSGAG was evaluated by three clinical outcomes: lameness score, carpal circumference and maximum carpal flexion. Clinical outcomes were measured on days -8 (previous to carpitis induction), 0 (previous to drug treatment), 7, 14, 21, 28 and 35. Areas under the curve clinical outcome as function of time were built and used as variables for the statistical analysis. There was less joint circumference enlargement and lameness and greater carpal flexion in PSGAG-treated horses compared with that in controls. The studied compound has demonstrated to be efficacious on the treatment of a chemically induced carpitis in horses.

BONE SCINTIGRAPHY FOR THE DIAGNOSIS OF AN ABNORMAL MEDIAL CORONOID PROCESS IN DOGS

Few reports have been published regarding the use of scintigraphy in the diagnosis of elbow joint lameness in dogs. Some authors have speculated about the potential use of bone scintigraphy and its suspected high sensitivity for the early diagnosis of abnormalities of the medial coronoid process (MCP) in dogs. Scintigraphy is used routinely in our institution in dogs presented for thoracic limb lameness and/or suspected of abnormalities of the MCP when radiographic findings were equivocal. Radiographic, scintigraphic, and surgical findings of the elbow joints of 17 dogs with elbow joint lameness were compared with radiographic, scintigraphic, and necropsy findings of the elbow joints of 12 clinically healthy Labrador Retrievers. Quantitative evaluation of scintigraphic images was performed to determine relative radiopharmaceutical uptake in the region of the MCP. Maximum relative uptake of the coronoid process in the normal dogs was taken as a threshold value to classify elbows as positive or negative for an abnormal MCP after all 24 elbows of the 12 healthy dogs were confirmed as being normal at necropsy. All 17 elbows from lame dogs were positive on scintigraphy and confirmed as having chondromalacia, a fissure, or fragmentation of the MCP. Based on our results, bone scintigraphy may be a valuable diagnostic tool for the diagnosis of abnormalities of the MCP in dogs, and particularly in older dogs where clinical and radiographic changes may be ambiguous.

Patellar Blastomycosis in a Dog

A 4-year-old, spayed female, mixed-breed dog was presented for evaluation of chronic left hind-limb lameness. Lytic lesions were observed in the left patella on radiographs of the stifle. A biopsy of the patella led to a histopathological diagnosis of blastomycosis. Surgical debridement followed by a 90-day course of itraconazole and physical rehabilitation resolved the clinical signs and stopped the progression of radiographic lesions. Blastomycosis should be considered as a differential diagnosis for stifle joint lameness with lytic lesions in the patella.

Evaluation of clinical, radiographical and cytological findings compared to arthroscopic findings in shoulder joint lameness in the dog

Forty-two dogs with lameness emanating from the shoulder joint were studied by clinical examination, radiographic examination, joint fluid analysis, and arthroscopic examination, following a set protocol. Dogs with mild clinical signs, absent or mild radiographic signs of osteoarthrosis, and without or with very mild changes in the synovial fluid, may still have moderate to severe degenerative pathological changes in the shoulder joint.

Centrodistal joint lameness in dogs

Lameness attributable to pathology of the centrodistal joint was investigated in five racing greyhounds, five Border collies and two other dogs. Diagnosis was made by the induction of pain from rotationally stressing the medial aspect of the tarsus, and by the exclusion of tarsal fractures and instabilities. Radiographic changes included plantar ligament entheslopathy and centrodistal joint osteophytosis. In many of the cases, the lameness was poorly responsive to rest and non-steroidal anti-inflammatory drugs. One dog was managed conservatively and became sound. In 10 of 11 cases, surgical promotion of centrodistal ankylosis was associated with a return to soundness.

Radiographic evaluation of sclerosis of the third carpal bone associated with exercise and the development of lameness in Standardbred racehorses.

Sclerosis of the third carpal bone is a common radiographic finding in both lame and sound racehorses, but there are no guidelines correlating degree of sclerosis and incidence of lameness. To develop a protocol for describing subchondral bone sclerosis in C3 on dorsoproximal-dorsodistal oblique (DPr-DDiO) radiographs of the carpus and to correlate these changes with exercise history and carpal lameness. One hundred and six Standardbreds entering their first year of training (exercise group) and 7 age-matched Standardbreds at pasture (controls) were examined at approximately 3 month intervals over 12-18 months. Examinations consisted of lameness evaluation and carpal radiographs (DPr-DDiO and flexed lateromedial projections). A grading system (very mild, mild, moderate and severe) for C3 sclerosis seen on the DPr-DDiO radiograph was developed that utilised a combination of the criteria of trabecular thickening (trabecular score; TS) and total percent area of the C3 radial facet affected (TAA). Exercise group horses showed significant increase in TS and TAA throughout training compared to control horses. Middle carpal joint lameness developed in 32/106 (30%) exercise group horses and none of the control horses. Incidence of middle carpal joint (MCJ) lameness was lower in horses with mild (2/30, 6.7%) than moderate (10/32, 31.2%) and severe (20/44, 45.4%) sclerosis throughout training. Horses with higher grades of sclerosis, as defined by this novel grading system, were more likely to develop MCJ lameness at some point of training. The proposed grading system gave a quantitative assessment of radiographic sclerosis that could then be used to correlate increasing severity of sclerosis with increasing incidences of lameness. These results serve as a basis for further investigation into determining the degree of C3 sclerosis at which pathological changes and lameness can be expected.

Three-dimensional kinematics of the tarsal joint at the trot.

The tarsal joint is a common site of injury for many sport horses. Understanding the biomechanics of this complex joint begins with developing a clear picture of the kinematics during normal locomotion. This study describes the 3D kinematics of the tarsal joint by measuring the motion of the tibia and third metatarsus in 4 sound Quarter Horses with targets attached directly to the bones via steel pins. The objective was to determine if the tarsus had significant motion outside the tarsocrural joint. Two Steinmann pins were inserted into the lateral side of the right hindlimb and marker triads were fixed to the end of each pin. 3D motion of the bones was recorded as each subject trotted in hand. Three rotations were expressed using an attitude vector based on the finite helical angle method. Three translations were calculated as the motion of the tibia relative to the third metatarsus. Angular and translation data were mostly coupled with flexion angle. Internal/external rotation during stance and translations during swing showed evidence of noncoupled motion. Although the majority of tarsal motion occurs in the tarsocrural joint, there is evidence that translations and rotations occur in other locations within the tarsal joint and that some of these are related to the tarsal joint 'snapping' phenomenon. This research provides a set of reference 3D kinematics which will aid in the study of the aetiology and mechanical effects of tarsal joint lameness.

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

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. 8 clinically normal adult horses. 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. 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. 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).