Clinical outcome of collateral ligament injuries of the tarsus

The significance of collateral ligament desmitis of the tarsocrural joint is often clinically underestimated, because it is an uncommon injury with a guarded prognosis for athletic soundness. The objective of this study was to describe the clinical presentation, treatment, and outcome of 12 horses with collateral ligament desmitis, along with tarsocrural joint synovitis secondary to hemarthrosis. Criteria for inclusion in this study included clinical signs of tarsocrural joint synovitis and sonographic evidence of collateral ligament desmitis. This retrospective study evaluated horses over an 8-year period. Median follow-up after treatment was 5.5 years. Four horses in the study returned to their previous level of performance, 6 horses remained lame due to pain in the tarsus, 1 was euthanized, and 1 is in convalescence. This study highlights the importance of collateral ligament desmitis, and emphasizes the need for early, aggressive treatment to prevent the development of osteoarthritis.

Trauma resulting in hemarthrosis and long medial collateral ligament desmitis of the tarsocrural joint in a horse

A horse was initially diagnosed with hemarthrosis and desmitis of the long medial collateral ligament of the right tarsus and later developed prominent enthesiophytosis at the site of insertion of the ligament's deep portion. Hemarthrosis due to intra- or peri-articular pathology can cause recurrent lameness, even without evident external trauma.

Nonrigid external fixation of the elbow, coxofemoral, and tarsal joints in dogs

Nonrigid external fixation of a joint is designed to restrict abnormal joint movement and facilitate healing of traumatized ligaments and capsule tissue with minimizing the impact of immobilization on articular homeostasis and cartilage metabolism. Weight bearing and joint motion minimize muscle atrophy and loss of bone mineral and allow controlled loading of the ligaments, thereby improving their strength and functionality. This article describes simple, cost effective techniques for the percutaneous application of external fixators to the elbow, coxofemoral, and tarsal joint of dogs.

Central tarsal bone fracture in the border collie

Fracture of the plantar process of the central tarsal bone together with a dorsomedial displacement of the body of the bone was seen in six border collies. All injuries occurred during free exercise, with no extrinsic trauma. Three dogs had concomitant tarsal fractures. Primary treatment was by lag screwing the central tarsal bone to the fourth tarsal bone. All cases eventually made an excellent recovery. The superficial radiographic appearance was of a luxation of the bone as reported in a previous series, but appraisal of the radiographs showed evidence of fracture in all cases. A cadaver study to assess the mechanism of luxation showed that it is unlikely to occur naturally.

Arthrodesis of the tarsometatarsal joint, using type II ESF with acrylic connecting bars in four dogs

Hyperextension injury of the tarsometatarsal joint (TMTJ) is a debilitating injury and arthrodesis of this joint is often the only procedure that can result in full return to function. Most surgical procedures described for arthrodesis of the tarsometatarsal joint necessitate the use of external, splint or cast, to protect the implants used from fatigue failure. This report describes the successful use of type II external fixator that spans the tarsometatarsal joint in four dogs with hyperextension injury of the tarsometatarsal joint. This technique enables the patient to bear weight on the limb immediately after surgery until bony fusion is achieved, without the need for an additional protecting splint.

Prevalence of Osseous Fragments in Distal and Proximal Interphalangeal, Metacarpo- and Metatarsophalangeal and Tarsocrural Joints of Hanoverian Warmblood Horses

The prevalence of osseous fragments in different limb joints was analysed in 3749 young Warmblood riding horses, which were pre-selected for sale at auction from 1991 to 1998 by the Association of Hanoverian Warmblood Breeders (Verband hannoverscher Warmblutzüchter e.V.) in Verden (Aller), Germany. The evaluation of these horses was based on a standardized radiological examination, including the distal interphalangeal (DIJ), the proximal interphalangeal (PIJ), the metacarpo- and metatarsophalangeal (MC/MTJ) and the tarsocrural joints (TCJ). In 32% of all horses at least one osseous fragment was found on these radiographs. TCJ were affected in 9.6% of the horses and MC/MTJ in 20.7%. The percentage of horses affected in the MTJ was significantly higher (13.7%) than that of horses affected in the MCJ (9.5%). The prevalences of osseous fragments were considerably lower in DIJ (4.5%) and PIJ (0.9%). Osseous fragments only occurred either in DIJ or PIJ or MC/MTJ or TCJ in 87% of the affected horses. Depending on the joint type, osseous fragments were found in analogous joints in the front and the hind limbs in up to 26% of the affected horses, whilst bilateral affection occurred in between 10% and 46% of the horses. Distribution of osseous fragments in the limb joints investigated here did not differ significantly between male and female horses. There was a significant increase in the percentage of horses with osseous fragments in MC/MTJ during the study period. The results of this study indicate the need to act against the high prevalences of osseous fragments in the limb joints of young Warmblood riding horses.

Chip fractures from the distal lateral trochlear ridge of the talus of a quarter horse gelding: a veterinary medicine clinical report

An eighteen-month old quarter horse gelding was diagnosed with chip fractures from the distal lateral trochlear ridge of the talus. The horse presented with the symptom of persistent synovitis. The diagnosis was based on radiographic evidence. The horse was treated initially with arthroscopic surgery. He was given a non-steroidal anti-inflammatory agent, and a chondroprotective agent to prevent further damage to, and aid in the healing of, the damaged joint.

Bioartificial bone grafting: Tarsal joint fusion in a dog using a bioartificial composite bone graft consisting of beta-tricalciumphosphate and platelet rich plasma--a case report

Grafting of large bone defects caused by trauma or tumor resection still remains a problem to solve. In experimental studies as well as in human dentistry, osteoconduction and biodegradation of the beta-tricalciumphosphate Cerasorb as well as osteoinductive capabilities of platelet rich plasma have been proven. In case of luxation of the right tarsal joint, including a compressive fracture of the forth tarsal bone, the recommended use of autologous cancellous bone to support osseous fusion was replaced by the use of a bioartificial bone graft. Biodegradation of the bone graft was proven clinically and radiographically. Complete osseous fusion of the intertarsal joint occurred. The use of the beta-tricalciumphosphate Cerasorb in combination with platelet rich plasma to support a partial arthrodesis of the tarsal joint in a dog did not impede the healing process but led to full recovery of the patient, indicating that this concept of bioartificial bone grafting could support bone healing.

Retrospective study of 24 cases of septic calcaneal bursitis in the horse

REASONS FOR PERFORMING STUDY

Wounds to the plantar aspect of the tarsus present a diagnostic and treatment challenge. This study was undertaken to describe specific features of traumatic wounds involving the calcaneal bursa, with a view to determining which clinical examination findings and diagnostic tests results could provide reliable indicators of prognosis.

OBJECTIVES

To report clinical presentation, diagnostic findings, treatment and outcome of 24 cases of septic calcaneal bursitis; and to determine the importance of the involvement of specific anatomical structures in relation to the prognosis for survival and return to athletic function.

METHODS

Records of 24 horses that had suffered traumatic wounds involving the calcaneal bursae were reviewed and divided into 3 groups, based on the bursa involved and presence or absence of involvement of the tuber calcanei. Clinical, diagnostic imaging and surgical findings were recorded for each case. Differences between groups and outcome were examined for significance with Chi-squared, Fisher's Exact or Kruskal-Wallis tests, as appropriate.

RESULTS

Wounds involving only the subcutaneous bursa had an excellent prognosis for survival. Seventy-five percent of horses with wounds involving the intertendinous calcaneal bursa survived. Involvement of the tuber calcanei presented a fair to guarded prognosis, with only 44% of horses with involvement of this structure surviving.

CONCLUSIONS

In contrast to other studies of septic synovial structures, the time between initial injury and referral did not affect the outcome. Correct identification of invasion of the calcaneal bursa(e) and/or tuber calcanei in wounds to the plantar aspect of the tarsus allows for more accurate pronostication. Damage to the tuber calcanei presents a poorer prognosis than for cases that involve only the soft tissue structures in the region.

POTENTIAL RELEVANCE

This study demonstrates the importance of correct anatomical identification of structures involved in wounds in the region of the calcaneal bursa. The use of radiography, ultrasonography and synoviocentesis are essential in these cases to provide the most appropriate treatment for the horse and accurate prognosis for the owner.

Dorsal tarsal instability in three racing greyhounds

Rupture of the dorsal ligaments of the tarsus in the greyhound is a rare racing injury. This case report describes dorsal tarsal instability in three greyhounds. A stumble and somersault were observed in two cases and were thought to have caused the injury. Previous reports advocate partial intertarsal arthrodesis as the preferred treatment for dorsal instability of the proximal intertarsal joint, but not all dogs returned to successful racing. In these three cases, stability was restored by the insertion of a wire tension band anchored to two bone screws, allowing the development of periarticular fibrosis. The dogs raced again with no loss of form.

Wedge-shaped conformation of the dorsolateral aspect of the third tarsal bone in the Thoroughbred racehorse is associated with development of slab fractures in this site

Anecdotal evidence suggested that many cases of third tarsal bone (T3) fracture encountered clinically were associated with an abnormal shape to this bone. The radiographs of 10 normal horses and 10 horses affected with slab fracture of T3 were therefore examined to ascertain if any pre-existent radiological abnormality was present in cases of fracture. Measurement of the maximum and minimum width between the proximal and distal articular surfaces of the dorsolateral aspect of this bone was carried out on a standardised dorso-50 degrees medial-palmarolateral radiographic projection of the tarsus of each horse. To avoid artefacts produced by possible image magnification, ratios of these values were used for comparison between horses. The results showed that wedge shaped conformation of T3, in which the articular surfaces of the bone converge and then diverge again on the dorsolateral aspect, was over-represented in the population of horses sustaining T3 fracture when compared to controls. This information may be important in making judgements on the suitability of horses during prepurchase examination for racing.

Asymmetric densitometric and mechanical adaptation of the left fifth metacarpal bone in racing greyhounds

The densitometric and mechanical structural properties of the left and right fifth metacarpal bones of 10 racing greyhounds with a fracture of the central tarsal bone and 10 without a fracture were investigated by dual energy x-ray absorptiometry and a servo-hydraulic materials testing machine. In all the greyhounds the bone mineral density of the left fifth metacarpal bone was significantly greater than that of the right (P<0.001), but there was no significant difference between the degree of asymmetry in bone mineral density in the two groups. The ultimate torque and energy-to-failure of the left fifth metacarpal bone of the greyhounds with a fracture of the right central tarsal bone were significantly higher than in the right fifth metacarpal bone and higher than in both the left and right fifth metacarpal bones of the greyhounds with no fracture (P<0.05). The ultimate torque and energy-to-failure were significantly related to bone mineral density (P<0.005), and 22 per cent of the variation in these structural properties could be explained by variations in bone mineral density. Fifth metacarpal remodelling in response to asymmetric cyclic loading is bone-specific, and structural properties are enhanced in the left fifth metacarpal of greyhounds with a fracture of the right central tarsal bone.

Tarsal shearing injuries in the dog

Images

Fractures of the central tarsal bone in eight racing greyhounds

The case records of eight greyhounds that had undergone a surgical repair of either a type III or type IV fractured central tarsal bone were reviewed. In some cases difficulties were encountered which resulted in less than ideal fixation methods being used, but the fractures healed satisfactorily by intertarsal ankylosis and were radiographically complete after four to six months. For a successful outcome it was not necessary to preserve functional intertarsal joints by interfragmentary reconstruction and compression. The absence of dorsal slab fixation, poor dorsal screw positioning, or loss of the dorsal fragment, had no influence on the results. It took from six months to one year for the dogs to return to racing.

Use of contoured bar transhock external fixators in 17 cats

Seventeen cats with injuries involving the distal tibia, talocrural joints, tarsus and metatarsus were treated with contoured connecting bar transhock external fixators as either primary or secondary fixation. The assemblies stabilised all the injuries successfully. Fracture union was achieved in 11 out of 12 cases. Excellent results were achieved in eight cats and the outcome was satisfactory in a further five. Those cats with injuries involving talocrural joint luxation with displacement and significant periarticular soft tissue disruption had poorer long-term results. Complications occurred in seven cases.

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.

Fractographic examination of racing greyhound central (navicular) tarsal bone failure surfaces using scanning electron microscopy

The greyhound is a fatigue fracture model of a short distance running athlete. Greyhounds have a high incidence of central (navicular) tarsal bone (CTB) fractures, which are not associated with overt trauma. We wished to determine whether these fractures occur because of accumulation of fatigue microdamage. We hypothesized that bone from racing dogs would show site-specific microdamage accumulation, causing predisposition to structural failure. We performed a fractographic examination of failure surfaces from fractured bones using scanning electron microscopy and assessed microcracking observed at the failure surface using a visual analog scale. Branching arrays of microcracks were seen in failure surfaces of CTB and adjacent tarsal bones, suggestive of compressive fatigue failure. Branching arrays of microcracks were particularly prevalent in remodeled trabecular bone that had become compact. CTB fractures showed increased microdamage when compared with other in vivo fractures (adjacent tarsal bone and long bone fractures), and ex vivo tarsal fractures induced by monotonic loading (P < 0.02). It was concluded that greyhound racing and training often results in CTB structural failure, because of accumulation and coalescence of branching arrays of fatigue microcracks, the formation of which appears to be predisposed to adapted bone.

Asymmetric adaptive modeling of central tarsal bones in racing greyhounds

Fatigue fracture of the cuboidal bones of the foot, especially the navicular tarsal bone, is common in athletes and dancers. The racing greyhound is a naturally occurring animal model of this injury because both microcracking and complete fracture occur in the right central (navicular) tarsal bone (CTB). The right limb is on the outside when racing in a counter-clockwise direction on circular tracks, and is subjected to asymmetric cyclic compressive loading. We wished to study in more detail adaptive modeling in the right CTB in racing greyhounds. We hypothesized that cyclic asymmetric loading of a cuboidal bone induced by racing on a circular track would induce site-specific bone adaptation. We also hypothesized that such an adaptive response would be attenuated in greyhounds that were retired from racing and no longer subjected to cyclic asymmetric loading. Central tarsal bones from racing greyhounds (racing group, n = 6) and retired greyhounds being used for breeding (nonracing group, n = 4) were examined using quantitative computed tomography (CT). Bone mineral density (BMD) was determined in a 3-mm diameter region-of-interest (ROI) in six contiguous 1-mm-thick sagittal CT slices of each CTB. Bones were subsequently examined histomorphometrically and percentage bone area (B.Ar./T.Ar., %) was determined in 10 ROI from dorsal to plantar in a transverse plane, mid-way between the proximal and distal articular surfaces. The BMD of the right CTB was greater than the left in all greyhounds (p < 0. 001). In comparing ipsilateral limbs between groups, BMD of the racing group was greater than the nonracing group for each side (p < 0.005). In sagittal plane histologic sections, bone in the dorsal region of the right CTB had undergone adaptive modeling, through thickening and compaction of trabeculae. B.Ar./T.Ar., % in the right CTB of the racing group was greater than in the contralateral CTB (p < 0.001), and the ipsilateral CTB of the nonracing group (p < 0.001). In the nonracing group, B.Ar./T.Ar., % in the right CTB was not significantly different from left CTB (p > 0.8; power = 80% at Delta = 48%). It was concluded that greyhounds racing on circular tracks develop site-specific bone adaptation with compaction of trabecular bone and increase in BMD in the right CTB in particular, the most common site for fatigue fracture. Our data also suggested that partial reversal of this adaptive process occurred in retired, nonracing greyhounds, after cessation of asymmetric cyclic loading at racing speed. Racing greyhounds provide a model in which to study fatigue fracture and adaptation of cuboidal foot bones subjected to cyclic loading.

[The syndrome of external ligament sprain in the horse]

The treatment of acute complete (grade III) tears of the lateral ligaments of the ankle has generated much controversy in the medical literature. Functional treatment has become the standard treatment as it has been shown that there is no significant difference in long term results whatever the treatment (operative repair and cast, cast alone, or early controlled mobilization). Functional treatment includes only a short period of protection by tape bandage or brace and allows early weight-bearing. Major trauma with avulsion of bone and severe ligamentous damage on both medial and lateral sides of the ankle is however an indication for surgical treatment in the acute phase. Secondary operative reconstruction can be performed in case of persistent instability and laxity of the ankle. Secondary anatomic repair as proposed by Brodström, Duquennoy et al. and Karlsson et al. has a high rate of success and avoids the potential morbidity of harvesting partially or totally the peroneus brevis or other tendon grafts. Evaluation of the injured ankle has improved and in selected patients ultrasonography, arthrography, magnetic resonance imaging or bone scintigraphy may be useful for further evaluation of the injury. The frequency of associated injuries has probably been underestimated. Although ankle sprain is often thought of as an injury involving only the lateral ankle ligaments, there are varied and multiple components to the common sprained ankle. This condition would perhaps more appropriately be designated as the sprained ankle syndrome.

Talar neck fractures in five cats

Five cats with fracture of the talar neck were treated using external skeletal fixation (ESF). In four of the cases, ESF was the only fixation technique used and this was applied in a closed manner coupled with traction. In the remaining cat, ESF was used in combination with a lag screw. All the fractures eventually healed, demonstrating that ESF provided a simple and effective method of treatment for these cases.

Tarsometatarsal subluxation in dogs: partial arthrodesis by plate fixation

In a retrospective study of tarsometatarsal joint subluxation in eight dogs, secondary fractures were identified in six dogs, particularly of the fourth tarsal bone and the proximal fifth metatarsal bone. Common causes of tarsometatarsal joint injury included jumping or falling and direct trauma to the foot. Partial tarsal arthrodesis, with the use of bone-plate stabilization and cancellous bone grafting of joint spaces after removal of articular cartilage, led to progressive bone healing in all dogs. Implant breakage did not occur in any dog.

Evaluation of joint stabilization for treatment of shearing injuries of the tarsus in 20 dogs

Medical records of 20 dogs with 23 shearing injuries of the tarsus leading to joint instability were reviewed. A transarticular external skeletal fixation device or prosthetic ligament was used to stabilize the joints. The most common complications were fixator failure and implant infection. The median times for wound healing and maximal joint function were 10 and 12 weeks, respectively. Clinical outcome was excellent in 22%, good in 56%, and poor in 22%. Comparison of the two stabilization methods showed no statistically significant differences in healing time, time to regain function, or clinical outcome.

Nutritional secondary hyperparathyroidism in free-living fledgling American crows (Corvus brachyrhynchos brachyrhynchos)

From June 1994 to June 1996, 18 fledgling American crows (Corvus brachyrhynchos brachyrhynchos) from multiple locations on Long Island, New York, were presented with signs of metabolic bone disease characterized by folding fractures of the proximal tibiotarsus. Plasma alkaline phosphatase levels were elevated, and the calcium/phosphorus ratio and 25-hydroxycholecalciferol (25-(OH)D3) levels were decreased. The histopathologic diagnosis was parathyroid hyperplasia and generalized osteodystrophia fibrosa. A diet low in bioavailable calcium and/or vitamin D3 was the probable cause. Also, exposure to xenobiotics could have contributed to the depression of 25-(OH)D3 levels.

Outcome and racing performance after internal fixation of third and central tarsal bone slab fractures in horses. A review of 20 cases

Twenty horses with central and third tarsal bone slab fractures, were treated internal fixation. Eighteen of the 20 cases were Standardbred trotters, one was a Thoroughbred racehorse and one a Swedish Warmblood. The central tarsal bone (CT) was involved in 12 cases and the third tarsal bone (T3) in 8 cases. The fractures were treated by lag screw fixation with one (18 cases) or two (2 cases) 3.5 or 4.5 mm cortical screws. Horses were confined to stall rest for one month and then put on a gradually increasing exercise programme. Convalescence time was 3-8 months until the fracture had healed and training could be resumed. Fifteen of the horses regained athletic soundness. Thirteen of the horses (72%) raced after surgery (12 Standardbreds and 1 Thoroughbred). Nine (69%) of these 13 horses won races after surgery.

Tibiotarsal fracture repair in a scarlet macaw using external skeletal fixation

Surgical repair of a fractured tibiotarsus in a scarlet macaw (Ara macao) is described. The forces imposed on the fracture site are discussed and the unique features of avian bone emphasised. Advantages of external skeletal fixation and specific details of the frame construction are highlighted.

Radiographic, computed tomographic and magnetic resonance imaging evaluation of a chronic long digital extensor tendon avulsion in a dog

Long digital extensor tendon avulsion is reported in a 5 month old Great Dane. Clinically the dog presented with a unilateral weight-bearing pelvic limb lameness. Joint effusion was present and there was pain and crepitance associated with flexion of the stifle. Orthopedic evaluation and radiographs were suggestive of a long digital extensor tendon injury which was confirmed by computed tomography and magnetic resonance imaging. The injury was surgically repaired with screw and spiked washer fixation.

Soft tissue injuries of the tarsus

Contrast radiography provides a clear survey of the size, shape, and location of extratendovaginal fluid-filled cavities, distended bursa, and tendon sheaths and demonstrates intersynovial communication. Ultrasonography effectively demonstrates Achilles tendon injury, slippage of the SDFT off the summit of the calcaneus, assorted ligamentous injuries, and cystic or solid extratendovaginal masses. It will also demonstrate distended bursae and tendon sheaths, but it is not as effective in demonstrating a synovial herniation, or a narrow synovial fistula. Contrast radiography may prove to be the imaging modality of choice for examination of fluctuating swellings, whereas ultrasonography is preferred for the assessment of firm swellings. Routine radiographic evaluation in the clinical assessment of soft tissue injuries in the hock region continues to play an invaluable diagnostic role.

Use of a full-thickness autograft on the tarsus of an ostrich

Full-thickness, cutaneous autografting was successfully performed on an adult female ostrich to heal a granulomatous wound on the right tarsus. With surgical techniques used in domestic species such as dogs and horses, skin grafting is an alternative in avian species when conventional wound closure is not appropriate.

Tarsocrural joint luxation in a horse

A 14-year-old Quarter Horse x Thoroughbred gelding was admitted to the teaching hospital because of inability to bear weight on its right hind limb, associated with a severe deviation of the tarsus. The provisional diagnosis was tarsal joint luxation or fracture. Radiography revealed complete luxation of the tarsocrural joint. The luxation was reduced, using minimal force. The horse was confined to a box stall and was maintained in a full-length hind-limb cast for 33 days. Box stall confinement was continued for 3 months after removal of the cast. On reexamination 18 months after the injury, the horse had only mild lameness (grade 1 of 5), but had marked reduction in the range of motion of the tarsus. Radiography revealed extensive changes indicative of severe degenerative joint disease. The horse was still used occasionally as a light pleasure riding horse and maintained itself on pasture well.

Use of a flexed dorsoplantar radiographic view of the talocrural joint to evaluate lameness in two dogs

A flexed dorsoplantar radiographic view of the talocrural joint was a useful additional view to diagnose abnormalities of the lateral trochlear ridge of the talus of 2 dogs. This view outlined the subchondral bone of both trochlear ridges of the talus and the apposing cochlea tibiae of the distal portion of the tibia. The tarsus was flexed at the level of the talocrural joint, and an x-ray beam was centered on the joint. With this additional view, fractures of the lateral trochlear ridge were readily diagnosed. This view would help to demonstrate osteochondral lesions of the lateral trochlear ridge.

Tarsal fractures in a heifer and a bull

Tarsal fractures were diagnosed in a heifer and a bull. In both cases, radiography confirmed intra-articular fractures, with subluxation of the fracture fragment. Sudden, nonreducible hock flexion was a clinical sign in both cases. This sign may be highly suggestive of intra-articular fracture when diagnosis must be made without radiography.

Central tarsal implant in a racing greyhound

Although most type IV fractures in dogs can be treated with screw fixation, type V fractures usually lead to an unsuccessful clinical result. A central tarsal replacement composed of a titanium alloy was developed by our investigation team to treat type V fractures. The implant was used to successfully treat a greyhound and to allow it to return to racing. Continual development of this new surgical procedure hopefully will give the veterinarian predictable and reliable clinical results and return injured greyhounds to active racing.

Clinical, radiographic, and scintigraphic findings associated with enthesitis of the lateral collateral ligaments of the tarsocrural joint in standardbred racehorses

Injury of the lateral collateral ligaments of the tarsocrural joints was diagnosed in nine Standardbred pacers. The average age was 4.9 years. The severity of the lameness varied from severe to subtle and joint effusion was seen in eight of 10 tarsocrural joints. A positive hindlimb flexion test was seen in four of six cases in which results were recorded. The identification of the site of involvement was based on a focal intense 'hot spot' seen on scintigraphy, and new bone formation seen radiographically at the anatomical sites of insertion of the long lateral collateral ligament of the tarsocrural joint in nine limbs and the short lateral collateral ligament of one limb. The authors believe this injury to be enthesitis caused by the cyclic trauma of training and racing speed. The primary therapy was rest. Of six cases which returned to training, three raced as well or better than before injury.

Use of lag screw fixation for repair of a central tarsal bone fracture in a horse

An 8-year-old Thoroughbred gelding was determined to have a sagittal fracture of the central tarsal bone. Lag screw fixation of the fracture enabled the horse to return to jumping, although degenerative arthritis of the distal intertarsal joint was apparent radiographically 17 months after the injury.

Traumatic tarsal luxation repaired without internal fixation in three horses and three ponies

Three horses and three ponies were treated for traumatic luxation of the proximal intertarsal or tarsometatarsal joint. In each case, there were fractures of one or more tarsal bones. Three of the animals had disruption of one of the collateral ligaments. Five animals were treated by closed reduction and external coaptation. One pony was treated by open curettage, a cancellous bone graft, and cast immobilization. No internal fixation was used in any of these animals. From this series of cases, it would appear that closed reduction and external coaption alone is adequate treatment for most cases of tarsal luxation.

Fractures of the calcaneus in racing greyhounds

Fifty-one calcaneus fractures associated with (41) or without (10) central tarsal bone (Tc) fractures in racing greyhounds were evaluated and categorized. All calcaneal fractures with no Tc fractures had a plantar proximal intertarsal subluxation. No subluxations were found in dogs with both calcaneal and central tarsal fractures. The calcaneal fractures were treated either with coaptation splints or surgical repair. Surgical techniques included a Steinmann pin with a figure eight tension band device or screw or plate fixation as primary techniques supplemented by Kirschner wires and cerclage wires. In all calcaneal fractures associated with plantar proximal intertarsal subluxation, an arthrodesis of the calcaneoquartal joint was performed. All 22 surgically repaired fractures in dogs available for physical and radiographic reexamination had healed within 1 to 6 months. Eight dogs with fractures of the calcaneus associated with fractures of Tc returned to a racing career. None of the dogs with plantar proximal intertarsal subluxation raced again. Based on the orientation of the fracture lines and on dissection of two tarsi with calcaneal fractures, a hypothesis on the pathogenesis of calcaneal fractures in racing greyhounds was formulated.