Bilateral dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation in an alpaca

CASE DESCRIPTION A 14-month-old female alpaca presented with a 3-week history of acute left hind limb lameness and swelling of the left tarsal region. CLINICAL FINDINGS Radiography revealed intermittent dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation. TREATMENT AND OUTCOME In an attempt to stabilize the talus, screws were placed in the distomedial aspect of the talus and the plantaromedial aspect of the central tarsal bone, and a stainless-steel wire was placed around the screws in a figure-eight pattern. The screw head of the proximal screw broke within 4 weeks after surgery, but subluxation did not recur, and the lameness resolved. Seven months later, the same condition was diagnosed in the opposite hind limb and was treated similarly. Implants remained intact on this side, but the animal started to show signs of pain and inability to flex the tarsal joint, prompting removal of the distal screw. Subsequently, the animal became sound and produced 2 healthy crias, but was euthanatized 4 years after the second surgery because of coccidiosis. CLINICAL RELEVANCE Dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation is a sporadic condition in New World camelids. This report provides the first account of successful treatment by surgical stabilization of the medial aspect of the proximal intertarsal joint.

Late middle Miocene caviomorph rodents from Tarapoto, Peruvian Amazonia

Miocene deposits of South America have yielded several species-rich assemblages of caviomorph rodents. They are mostly situated at high and mid- latitudes of the continent, except for the exceptional Honda Group of La Venta, Colombia, the faunal composition of which allowed to describe the late middle Miocene Laventan South American Land Mammal Age (SALMA). In this paper, we describe a new caviomorph assemblage from TAR-31 locality, recently discovered near Tarapoto in Peruvian Amazonia (San Martín Department). Based on mammalian biostratigraphy, this single-phased locality is unambiguously considered to fall within the Laventan SALMA. TAR-31 yielded rodent species found in La Venta, such as the octodontoid Ricardomys longidens Walton, 1990 (nom. nud.), the chinchilloids Microscleromys paradoxalis Walton, 1990 (nom. nud.) and M. cribriphilus Walton, 1990 (nom. nud.), or closely-related taxa. Given these strong taxonomic affinities, we further seize the opportunity to review the rodent dental material from La Venta described in the Ph.D. volume of Walton in 1990 but referred to as nomina nuda. Here we validate the recognition of these former taxa and provide their formal description. TAR-31 documents nine distinct rodent species documenting the four extant superfamilies of Caviomorpha, including a new erethizontoid: Nuyuyomys chinqaska gen. et sp. nov. These fossils document the most diverse caviomorph fauna for the middle Miocene interval of Peruvian Amazonia to date. This rodent discovery from Peru extends the geographical ranges of Ricardomys longidens, Microscleromys paradoxalis, and M. cribriphilus, 1,100 km to the south. Only one postcranial element of rodent was unearthed in TAR-31 (astragalus). This tiny tarsal bone most likely documents one of the two species of Microscleromys and its morphology indicates terrestrial generalist adaptations for this minute chinchilloid.

Radiological tarsal bone morphology in adolescent age of congenital clubfeet treated with the Ponseti method

Background Major abnormalities of tarsal bone shape after surgical clubfoot treatment are well known from the literature. The Ponseti method has gained widespread acceptance in primary treatment of congenital clubfeet. Despite the longtime experience, data regarding the development of tarsal bones after this treatment are still rare. The aim of the study was therefore to evaluate radiographic parameters describing tarsal bone shape of clubfeet after Ponseti treatment and compare them to age-matched healthy feet. Methods Twenty two consecutive severe clubfeet in 14 patients were investigated by repeated diagnostic ultrasound during the corrective process. Extent and temporal course of correction were documented with standardized X-rays after a mean follow-up of 12 years (between the ages of 10–14 years) and compared to a group of age-matched normal feet. Results Reliability testing for all X-ray parameters showed good to excellent results. In comparison to the control group, all parameters except the radius of the trochlea (RT) were significantly altered in clubfeet with highest differences shown for the anterior talar motion segment (ATM), talonavicular coverage (TNC) and the talometatarsal index (TMT-Index). Differentiation between minor and major deformities showed significant differences only for the front tarsal index (FTI). Conclusions Tarsal bone shape of clubfeet treated by the Ponseti method differs significantly from normal feet. One of the most pronounced and clinically relevant difference of the clubfoot talus compared to the normal talus is the markedly reduced anterior talar motion segment.

Calcaneonavicular coalition resection

Tarsal coalition is an abnormal connection between tarsal bones, caused by an embryogenic failure. Its most common forms are calcaneonavicular and talocalcaneal coalition, which are present in 53% and 37% of the cases, respectively. The onset of symptoms is related to tarsal bone ossification, and mean age for this event is estimated at 16 years for calcaneonavicular coalition. Surgical treatment is indicated for patients who did not improve symptoms with conservative treatment. The aim of this study is to present a surgical technique as a treatment option for resection of calcaneonavicular coalition associated with abnormal cuboid-navicular joint. Level of Evidence V; Therapeutic Studies; Expert Opinion.

Medial Bone Plating for Management of Type V Central Tarsal Bone Fractures in Six Dogs

Objective The aim of this study was to report the surgical technique and outcomes of dogs with type V central tarsal bone (CTB) fractures stabilized with a bone plate applied to the medial aspect of the tarsus and metatarsus. Study Design This study was a retrospective review of dogs with type V CTB fractures diagnosed with computed tomography and stabilized using a medial bone plate. Follow-up included clinical examination and radiography 8 to 10 weeks postoperatively and/or a long-term owner questionnaire. Results Six dogs were identified. All fractures occurred during exercise without external trauma and all dogs had additional tarsal fractures. Five dogs returned for clinical follow-up; all had no or mild lameness and evidence of fracture healing on radiography. A suspected surgical site infection occurred in one dog and resolved with medical management. Suspected contact between the plate and medial malleolus in one dog, and loosening of a talar screw in another, were identified, though not treated. Five owners completed the questionnaire, a median of 88 months postoperatively. No further complications were reported, limb function was reportedly acceptable, and all owners were very satisfied with the surgery. Conclusion Medial bone plate stabilization of highly comminuted CTB fractures resulted in evidence of fracture healing, and a low incidence of complications in six non-racing dogs.

Bone Bruises of the Ankle and Mid-foot Often Associate with Ankle Sprain

Background: Ankle sprains are one of the most common musculoskeletal injuries. However, they may be more serious than commonly believed since many patients reportedly experience chronic problems afterwards. It is necessary to improve the treatment, such as the method and duration of fixation, of sprained ankles.Methods: Magnetic resonance imaging of 70 patients with acute moderate or advanced ankle sprains presenting consecutively between November 2014 and December 2019 were reviewed for analysis of bone bruising associated with ankle sprains. The patients were treated conservatively with a solid splint or cast until walking pain could be resolved without external fixation. In cases with pain at the time of weight bearing after solid fixation, crutches were prescribed for pain relief. The fixation period ranged from 8 days to 72 days (mean: 29.5 days). Afterwards, 54.0% of patients had walking pain and required the use of crutches. The ankle joint pain disappeared after conservative treatment in all patients.Results: The incidence of bone bruises detected by magnetic resonance imaging in the ankle and midfoot associated with ankle sprain was 81.4%. Bone bruises of the midfoot, including the tarsal bone and Chopart joint, were found in 34.3% of ankle sprains. Bone bruises of the talus were the most common, being present in 60% of ankle sprains. Bone bruises were also evident in the tibia (44.3%), the calcaneus (21.4%), and the tarsal bone (25.7%). There was a significant association between bone bruises of the talocrural joint surface and use of the crutches after fixation (P=0.041). Multiple regression analysis adjusted for age and gender revealed that bone bruises of the talocrural joint surface of the talus was a significant independent predictor of crutch use (P=0.045), with an odds ratio (95% confidence interval) of 3.03 (1.03-8.94).Conclusion: Bone bruises of the ankle and midfoot are often present in ankle sprains. In moderate or advanced cases of ankle sprain, external solid fixation of both the ankle and midfoot should be performed. In cases with pain at weight bearing following solid fixation, crutches are advised for pain relief and proper ligament and bone healing.

Radiographic Recognition of Tarsal Malformation in 8- to 9-Week-Old Bernese Mountain Dogs

Introduction Tarsal malformation is a skeletal malformation of unknown aetiology associated with a variety of morphologic changes to the tarsal and metatarsal bones of the dog. Objective The aim of this study was to determine if early diagnosis and prevalence of tarsal malformation could be obtained at approximately 8 to 9 weeks of age in multiple litters of Bernese Mountain dogs. Methods A prospective study of 51 Bernese Mountain dog puppies were evaluated from 12 litters in northern Italy. Dorsoplantar radiographic views of the tarsus were obtained at 60 ± 5 days of age. Tarsal malformation was defined as an abnormal extension of the central tarsal bone on its medial side, or the presence of ectopic bone located medially to the central tarsal bone, talus and second metatarsal bones (proximomedial, distomedial and metatarsal ossification sites respectively). Results All puppies were found to be clinically normal. Thirty-nine of the 51 puppies showed ossification sites medial to the tarsus as defined. A metatarsal ossification was present in all dogs with either a proximo- or distomedial ossification site. No central tarsal bone extensions were observed. The remainder of the tarsometatarsal joints were normal. Clinical Significance Tarsal malformation can be identified in the 8- to 9-week-old Bernese Mountain dog. The clinical significance of tarsal malformation remains to be determined, either as an incidental finding or a precursor to the development of other clinically relevant and related issues in the tarsus.

Tarsal fractures: part 2

Both calcaneal and central tarsal bone fractures are commonly encountered in the racing greyhound. While isolated fractures of the numbered tarsal bones are uncommon, malleolar fractures are encountered frequently in small animal practice. Fractures of the central tarsal bone or calcaneal fractures in both dogs and cats may be either fatigue or stress fractures, or associated with Knees and Teeth Syndrome, which may alter the typically expected presentation and prompt assessment for additional fractures, both in the tarsus and elsewhere. Surgical stabilisation is often the treatment of choice, particularly for fractures with an articular component. In many cases, surgical stabilisation leads to a positive outcome, with Greyhounds often being able to return to racing. However, it is important to be aware that fractures in non-racing dogs tend to be more complex and that this good prognosis may not be appropriate to extrapolate. Depending on the nature and severity of injuries, joint preservation may not always be a realistic goal. If the joint cannot be preserved, arthrodesis may become necessary.

The occurrence of tarsal injuries in male mice of C57BL/6N substrains in multiple international mouse facilities

Dislocation in hindlimb tarsals are being observed at a low, but persistent frequency in adult male mice from C57BL/6N substrains. Clinical signs included a sudden onset of mild to severe unilateral or bilateral tarsal abduction, swelling, abnormal hindlimb morphology and lameness. Contraction of digits and gait abnormalities were noted in multiple cases. Radiographical and histological examination revealed caudal dislocation of the calcaneus and partial dislocation of the calcaneoquartal (calcaneous-tarsal bone IV) joint. The detection, frequency, and cause of this pathology in five large mouse production and phenotyping centres (MRC Harwell, UK; The Jackson Laboratory, USA; The Centre for Phenogenomics, Canada; German Mouse Clinic, Germany; Baylor College of Medicine, USA) are discussed.