Management and treatment of feline tarsal injuries

Radiomorphometric analysis of the metapodial bones in the Scottish fold cats

Scottish Fold cats (Felis catus, Linnaeus 1758) are one of the most well-known and popular cat breeds in the world, characterized by their folded ears attached to the head. Very frequently, cats fall prey of different trauma and accidents that can cause bone fractures especially in the metapodial bones. The method of radiometry is used in veterinary practice to visualize and measure different parts of the animal skeleton. The aim of this study was to assess the linear parameters derived from radiographic images of the metacarpals and metatarsals in Scottish Fold cats and additionally detecting potential sexual dimorphism. Radiographic images of 24 adult Scottish Fold cats (12 male and 12 females) of different ages and weights were analysed. Six linear measurements of the metapodial bones were evaluated to investigate any differences between the sexes. The linear radiometric measurements of the five metacarpals (MC1-5) and the four metatarsals (MT2-5) bones were larger in male metapodial bones than that of female cats. The maximum length (Ml) of the MC1 and MC2 was statistically different between sex, respectively, (p = 0.001) and (p = 0.05). The others metacarpal bones were different in mostly all linear parameters but not statistically significant. The most significant differences between sexes were observed in the parameter of width proximal end (Wp) of MC1-3 (p = 0.001) and MC4 (p = 0.05). More statistical different was MT2 and less MT3. The linear parameter of Bd of the MT4 was the most different statistically between sex (p = 0.001). The results of the study will be useful in function of comparative anatomy, in veterinary clinical practice, in zoo archaeology and in the veterinary forensic investigation.

Equine Talocalcaneal subluxation

A Quarter horse filly was evaluated for a two-week old wound of the right hind cannon bone after the mare stepped on her. A sequestrum was noted radiographically and was surgically debrided. After continued follow-up a left hind varus deformity was noted and was corrected with a lateral transphyseal screw in the distal left tibia. After the varus deformity was improved, a lateromedial radiograph was taken of the distal left tibia and tarsus and talocalcaneal subluxation was seen. The same view was taken of the right tarsus and the same deformity was noted. After finding no case reports on the condition with information on treatment or surgical correction, humane euthanasia was elected. A few months later, the same owner brought a two-month-old colt out of the same mare to the hospital for an elective procedure. Tarsal radiographs were taken due to the owner's previous experience, although the colt had no clinical history or any traumatic incidents. A lateromedial view of the right tarsus revealed talocalcaneal subluxation.

Short-term outcome after treatment of talocrural instability in cats using modified type II transarticular external skeletal fixation

Transarticular external skeletal fixation (TESF) is repeatedly used for temporary stabilisation of tarsal joint in cats. Hence, this study aimed to evaluate the use of temporary modified type II TESF for management of talocrural instability (TCI) in cats without joint arthrodesis and to rate short-term outcomes and complications. Medical records of all cats treated for TCI between January 2012 and December 2021 were reviewed. Information was collected including signalment, degree of lameness, type of TCI, accompanying soft tissue and bone injuries, and post-operative follow-up assessment including time of frame removal, complications, degree of lameness, range of joint motion and ankylosis. Surgical management didn't involve debridement of the articular cartilage. Eighty-five percent of cats had satisfactory joint stability at the time of frame removal. Eighteen cats exhibited minor complications, six cats had major complications, and 8 cats showed persistent lameness. All cats showed reduction of joint motion range by 20°-30° directly after frame removal while returned to normal in 79% of cats 4 weeks later. Variable degrees of joint ankylosis were reported. In conclusion, this study supports the use of temporary modified type II TESF for management of TCI in cats without joint involvement as an excellent alternative to tarsal arthrodesis.

Stress radiographic assessment of collateral ligament constraints on the feline tarsocrural joint

INTRODUCTION

This cadaveric study describes the collateral ligament constraints on the feline tarsocrural joint using stress radiography.

METHODS

Thirty-six feline cadaveric hindlimbs free of orthopaedic disease were placed in a custom-made jig and controlled stress radiography was performed before and after transection of one, or both collateral ligaments. Changes in varus and valgus deviation and pronation and supination were measured at three limb angles (extension, 120^o flexion and 90^o flexion).

RESULTS

There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulocalcaneal ligament at all limb positions (extension: 41%, 120°: 78%, 90°: 63%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulotalar ligament at extension (14%). There was a significant positive percentage change in the mean angle of varus deviation after transection of both fibulocalcaneal and fibulotalar ligaments at all limb positions (extension: 58%, 120°: 67%, 90°: 67%), and in the mean angle of valgus deviation (100%) and supination (89%) at 90 degrees flexion. There was a significant positive percentage change in the mean angle of valgus deviation after transection of the tibiocentral ligament at all limb positions (extension: mean 79%, 120°: 43%, 90°: 49%) and the mean angle of pronation at 120 degrees flexion (10%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the tibiotalar ligament at extension (11%) and at 90 degrees flexion (54%) and in the mean angle of pronation at all limb positions (extension: 11%, 120°: 19%, 90°: 32%). There was a significant positive percentage change in the mean angle of valgus deviation (extension: 255%, 120°: 172%, 90°: 176%) and pronation (extension: 58%, 120°: 134%, 90°: 76%) after transection of the tibiocentral and tibiotalar ligaments at all limb positions and in the mean angle of varus deviation at extension (13%) and 90 degrees flexion (69%).

CONCLUSION

The medial collateral ligaments prevent against excessive valgus deviation and pronation, and the lateral collateral ligaments prevent against excessive varus deviation and supination. At 90 degrees flexion subluxation of the talus occurs on the ipsilateral side of the ligament injury resulting in an additional direction of instability.

A pilot study: Can calcaneus radiographic image be used to determine sex and breed in cats?

This study examined whether radiographic images measurements of the calcaneus in cats are determinative of sex and breed. For this purpose, radiographic images of 70 cats (37 male and 33 females) of different ages (from one to 18 years) and different breeds (41 mix-breed, 18 Scottish Fold and 11 British Shorthair cats) without orthopaedic problems were used. Right tarsal joint radiographs of these orthopaedically healthy cats were taken. Four linear measurements and two angle values of the calcaneus were obtained from the radiographic images. The MANOVA result showed that the most determining factor between the three groups was the greatest width (p value = 0.001). Calcaneal body length, calcaneal greatest length and calcaneal shortest depth were higher in mix-breed cats. Calcaneal tuber length was higher in Scottish Fold cats. The only statistically significant difference between Scottish Fold and British Shorthair was in the calcaneal tuber length (p value = 0.04). In the comparison made between the sexes regardless of species, the linear measurements in males were higher than in females. It was determined that these parameters are statistically significant in terms of sex differentiation in cats. Dorsal and plantar calcaneal angles are not sex determinants in cats. The effect of age on other measurements was analysed by correlation test. However, the effect of age on the measurements was not statistically significant. Mix-breed cats were examined in four groups according to their colour (grey, black-white, yellow, tri-colour). No statistically significant difference was found between calcaneal measurements of cats with different skin colour genotypes. In this study, calcaneus measurements were both determinative between breeds and sexes in cats.

Traumatic joint luxations in cats: Reduce, repair, replace, remove

PRACTICAL RELEVANCE

Traumatic joint luxations are usually associated with significant trauma and there may be concomitant systemic injury. Joints are unstable as a result of injury to one or more supporting structures and the clinician should aim to determine which structures are damaged with physical examination, diagnostic imaging and careful assessment under sedation/anaesthesia. The aim is to reduce the joint back to its anatomical position, and then to maintain this through repair of damaged structures. However, where this is not possible, replacement or removal (arthrodesis/excision arthroplasty) of the joint remain viable options.

CLINICAL CHALLENGES

Owing to the small size of feline joints and the severity of damage often seen, surgical management of these cases can be challenging. The first priority is to ensure the patient is systemically well before embarking on any specific surgical treatment of a luxated joint. Cats also present challenges in the postoperative period and a lack of patient and owner compliance can be detrimental to postoperative outcomes.

AIMS

This article aims to help the reader diagnose joint luxations and to assist decision-making with an overview of the management and treatment options available.

EVIDENCE BASE

There are a number of original articles and textbook chapters in the literature covering aspects of different joint luxations, particularly for the more common luxations. This article draws on information from key feline research and, where necessary, extrapolates from relevant canine research. The authors also offer practical guidance based on their own clinical experience.

Biomechanical comparison of knotted and knotless stabilization techniques of the tarsal medial collateral ligament in cats: A cadaveric study

OBJECTIVE

To compare mechanical properties of intact feline medial collateral ligaments and three techniques for treatment of feline medial tarsal instability.

STUDY DESIGN

Controlled laboratory study.

SAMPLE POPULATION

Forty-eight normal, adult feline tarsi.

METHODS

Three repairs were tested: a bone tunnel with polypropylene (PP) suture, a bone tunnel with polyethylene (PE) cord, and a knotless anchor technique with PE cord. A cyclic (6-N preload; 5-N amplitude; 2-Hz frequency) tensile test (600 cycles) was performed on feline tarsi with either the long or the short medial tarsal ligament intact, with each reconstruction technique followed by a single-cycle load-to-failure test (0.5 mm/s) with a failure point at 2 mm of displacement. Total elongation, peak-to-peak elongation, stiffness, and maximum load to failure point were compared with the intact condition.

RESULTS

No differences in stiffness, total elongation, or peak-to-peak elongation were found between specimens repaired with the knotless technique and intact controls (P > .04), whereas tarsi repaired with the tunnel technique and PP were weaker (P < .008). Total and conditioning elongation were greater after tunnel reconstruction with PP than after knotless reconstruction (P = .005). Mean load to 2 mm of displacement tended (P = .03) to be higher after knotless than after knotted PP repairs and did not differ (P = .47) between tarsi repaired with the tunnel or anchor repairs with PE.

CONCLUSION

The mechanical properties of intact tarsi were superior to those of tarsi repaired with tunnel techniques and PP but were similar to those of tarsi repaired with knotless techniques with PE.

CLINICAL SIGNIFICANCE

Feline tarsal stabilization with the knotless technique for tarsal medial collateral ligament insufficiency may reduce the requirement for or duration of postoperative coaptation.

Computed tomography and magnetic resonance imaging study of a normal tarsal joint in a Bengal tiger (Panthera tigris)

Background

In this research, using computed tomography (CT) and magnetic resonance imaging (MRI), we provide a thorough description of the standard appearance of a right tarsal joint in a Bengal tiger (Panthera tigris). CT scans were performed using a bone and soft tissue window setting, and three-dimensional surface reconstructed CT images were obtained. The MRI protocol was based on the use of Spin-echo (SE) T1-weighted and Gradient-echo (GE) STIR T2-weighted pulse sequences. Magnetic resonance (MR) images were taken in the transverse, sagittal and dorsal planes. We also performed anatomical dissections to facilitate the interpretation of the different structures of the tarsus joint and allow comparisons with CT and MRI images.

Results

The CT images allowed us to observe differences between the bones and soft tissues of the tarsal joint. When applying the bone window setting, the obtained footage showed the anatomy between the medulla and cortex. Additionally, the trabecular bone was delineated. By contrast, the soft tissue window allowed the main soft tissue structures of the tarsal joint, including ligaments, muscles and tendons, to be differentiated. Footage of the main anatomical structures of the standard tiger tarsus was obtained through MRI. The SE T1-weighted images showed the best evaluation of the cortical, subchondral and trabecular bone of the tibia, fibula, tarsus and metatarsus bones. Nonetheless, the GE STIR T2-weighted images allowed us to better visualize the articular cartilage and synovial fluid. In both MRI pulse sequences, the ligaments and tendons appeared with low signal intensity compared with muscles that were visible with intermediate signal intensity.

Conclusions

The results of this CT and MRI study of the Bengal tiger tarsal joint provide some valuable anatomical information and may be useful for diagnosing disorders in this large non-domestic cat.