Aim of the study was to investigate dynamic radio-ulnar incongruence (dRUI) in the canine elbow joint comparing orthopedic healthy and dysplastic dogs in a prospective in vivo study design. In 6 orthopedic sound elbow joints (5 dogs, median age 17 months & mean body weight 27.9 kg) and 7 elbow joints with medial coronoid disease (6 dogs, median age 17.5 months & mean body weight 27.6 kg) 0.8 mm Ø tantalum beads were surgically implanted into radius, ulna and humerus for dynamic radiosteriometric analysis (RSA) using high-speed biplanar fluoroscopy with the dogs walking on a treadmill. dRUI, in the form of proximo-distal translation of the radius relative to the ulna, was measured for the first third of stance phase and compared between groups using unpaired t-testing. Healthy elbow joints exhibited a relative radio-ulnar translation of 0.7 mm (SD 0.31 mm), while dysplastic joints showed a translation of 0.5 mm (SD 0.30 mm). No significant difference between groups was detected (p = 0.2092, confidence interval -0.6 -0.2). Based on these findings dRUI is present in every canine elbow joint, as part of the physiological kinematic pattern. However, dysplastic elbow joints do not show an increased radio-ulnar translation, and therfore dRUI cannot be considered causative for medial coronoid disease.

Objective The aim of this study was to report the humeroulnar joint kinematics in a dog with medial coronoid process disease (MCPD) before and after dynamic proximal ulnar osteotomy (DPUO). Study Design A 15-month-old female Labrador Retriever with advanced MCPD was treated by DPUO and fragment removal. Bi-planar fluoroscopic kinematography of the affected joint was performed before and 12 weeks after DPUO along with computed tomography. Static axial radioulnar incongruence (sRUI), dynamic relative proximodistal radioulnar motion (dynamic RUI), axial humeroulnar rotation, as well as humeroulnar joint contact at the medial coronoid process (MCP) were calculated. Results Static axial radioulnar incongruence was reduced from 2.3 to 1.5 mm after DPUO but dynamic RUI remained unchanged (0.2 vs. 0.3 mm). Mean humeroulnar rotational amplitude increased from 2.6° (standard deviation 0.4) to 4.5° (standard deviation 2.0). Joint contact area at the MCP became substantially increased as well as broadly distributed among the MCP following DPUO (52.5 vs. 63.0%; p = 0.0012). Conclusion Dynamic proximal ulnar osteotomy failed to restore the radioulnar congruence and increased the humeroulnar rotational instability. No effect was observed on dynamic RUI. Nevertheless, joint contact area at the MCP was increased and became more homogeneously distributed, which might explain the beneficial effect of clinical outcome in this case.

ZusammenfassungEin 3 Monate alter, männlicher Shar Pei-Welpe wurde wegen Mattigkeit, Fieber und Hautödemen vorgestellt. Durch weiterführende Untersuchungen konnten eine oberflächliche Pyodermie mit Streptococcus canis und eine akute neutrophile Vaskulitis diagnostiziert werden. Es erfolgte eine symptomatische und antibiotische Therapie in Kombination mit Immunsuppressiva (initial Prednisolon, später Ciclosporin) Therapie. Im weiteren Verlauf traten Komplikationen in Form von Dyspnoe, Anämie, großflächigen Hautulzera, Nekrosen und eine Sekundärinfektion mit multiresistenten Bakterien auf. Durch intensivmedizinische Betreuung konnte der Hund nach 38 Tagen entlassen und in den folgenden Wochen die Dosis der Immunsuppressiva reduziert und die Medikamente nach 4 Monaten abgesetzt werden.

Summary Objective: To prospectively compare relative axial (internal-external) humero-ulnar rotation in normal and dysplastic canine elbow joints. Material and methods: Six normal elbows (five dogs) and seven joints (six dogs) with coronoid disease were examined. After implantation of 0.8 mm tantalum beads into humerus and ulna, biplanar x-ray movies of the implanted elbows were taken while dogs were walking on a treadmill. Based on the 2D bead coordinates of the synchronized x-ray movies virtual 3D humero-ulnar animations were calculated. Based on these, relative internal-external humero-ulnar rotation was measured over the first third of stance phase and expressed as maximal rotational amplitude. Amplitudes from three consecutive steps were averaged and groupwise compared using an unpaired t-test. Results: In normal elbow joints mean axial relative humero-ulnar rotation was 2.9° (SD 1.1). Dysplastic joints showed a significantly greater rotational amplitude (5.3°, SD 2.0; p = 0.0229, 95% confidence interval 0.4–4.4). Conclusion: Dysplastic elbow joints show greater relative internal-external humero-ulnar rotation compared to normal elbows, which might reflect rotational joint instability. Clinical relevance: Increased relative internal-external humero-ulnar rotation might alter physiological joint contact and pressure patterns. Future studies are needed to verify if this plays a role in the pathogenesis of medial coronoid disease.

Objective This study aimed to evaluate the correlation of static axial radioulnar incongruence (sRUI) measured under general anaesthesia with the real in vivo dynamic RUI (dRUI) during walking. Study design This was a prospective clinical study that included 6 sound elbows (5 dogs) and 7 medial coronoid process disease (MCPD) affected elbows (6 dogs). Materials and Methods Static axial radioulnar incongruence was measured using the sphere fitting technique on computed tomography-based three-dimensional (3D) models of radius and ulna. The in vivo pose of radius and ulna was derived from radiostereometric analysis during the walk and transferred onto previously calculated 3D models. Dynamic RUI was measured on those adjusted models using the sphere fitting technique, providing a measurement of RUI over time during walk. Results Mean sRUI was 0.2 mm (standard deviation [SD]: 0.30) in control and 1.4 mm (SD: 0.73) in elbow joints with MCPD; being significantly different (p = 0.0035; confidence interval [CI]: 0.4772–1.8824). Mean dRUI in controls (−0.4 mm; SD: 0.47) was significantly different (p = 0.0004; CI: 0.9918–2.5225) from dRUI in the affected elbows (1.4 mm; SD: 0.73). Comparison of sRUI and dRUI within each group showed difference in the control group (0.2 vs. −0.4 mm; p = 0.0138; CI: 0.1820–1.0014). In affected elbows, no difference between sRUI and dRUI was found (1.4 vs. 1.4 mm; p = 0.8963). Conclusion In normal elbow joints, sRUI does not represent the in vivo condition during weight bearing. Dynamic and slightly negative RUI occurs during loading (0.2 mm positive to −0.4 mm negative RUI). In MCPD affected elbows with sRUI, no dynamic change of RUI occurs during the walk.

Introduction Medial coronoid process disease is the most common manifestation of canine developmental elbow disease and a frequent cause of thoracic limb lameness (Van Ryssen and van Bree, 1997; Fitzpatrick et al., 2009a; Smith et al., 2013). This pathology can progress to a more severe medial compartment disease (MCompD) (Van Ryssen and van Bree, 1997; Vermote et al., 2009; Franklin et al., 2014), which is characterized by full-thickness cartilage loss of the medial coronoid process (MCP) and medial humeral condyle (modified Outerbridge scores 4 and 5) (Fitzpatrick et al., 2009b;

Objectives The objective of the first part of this retrospective multicentre study was to identify and classify common calcaneal tendon (CCT) injuries in a study population of 66 cats. Methods The medical records of five different small animal referral centres and veterinary teaching hospitals between 2010 and 2020 were reviewed. In addition to patient-specific data, CCT injuries were characterised in detail. Diagnostic modalities and further comorbidities were recorded. Results Sixty-six cats met the inclusion criteria. The mean age of the cats was 7.5 years (range 0.5–16.3) and their mean body weight (BW) was 4.6 kg (range 1.5–9.0). Thirty-four spayed females (51.5%), five intact females (7.6%) and 27 castrated males (40.9%) were included. Most cases involved closed injuries of the CCT (69.7%). Twenty-one of 46 cats had closed atraumatic injuries (45.7%). Open injuries (30.3%) were most commonly lacerations (65%). Twenty-one injuries were classified as atraumatic (31.8%), whereas 25 were traumatic (37.9%). With every year of age, the odds of having an atraumatic injury increased by a factor of 1.021. Cats with atraumatic injuries had a higher mean BW than cats with traumatic injuries, but the difference was not statistically significant. Acute injuries were recorded in 40.9% of cases, whereas 51.5% of cats had a subacute CCT injury and 7.6% had chronic lesions. Most acute lesions were Meutstege type I injuries (55.6%). Subacute and chronic lesions were more commonly Meutstege type IIc injuries (58.8% and 60%, respectively). Considering all CCT injuries, a Meutstege type IIc injury was most common (53%). Conclusions and relevance The most common type of injury was Meutstege type IIc. Cats with atraumatic injuries had a higher mean BW than cats with traumatic injuries, but the difference was not statistically significant. Older cats more commonly presented with atraumatic CCT injuries.

Objectives The aims of the second part of this retrospective multicentre study were to describe the surgical techniques used in the treatment of common calcaneal tendon (CCT) injuries, and evaluate the short- and long-term outcomes and complications. Methods The medical records of five different small animal referral centres and veterinary teaching hospitals between 2010 and 2020 were reviewed. Surgical vs conservative treatment was evaluated. Treatment type, type of postoperative immobilisation, and short- and long-term outcomes and complications were recorded. Minor complications were defined as not requiring surgical intervention. Long-term outcome was evaluated by an owner questionnaire. Results Sixty-six cats met the inclusion criteria. Mean time to surgery was 9.6 days (range 0–185). Most cats (83.3%) were treated surgically. Regardless of treatment modality, all limbs were immobilised for a mean time of 48.2 days (range 2–98). For 63 cats that had the temporary tarsal joint immobilisation technique recorded, a transarticular external skeletal fixator (ESF; 57.1%) or a calcaneotibial screw (33.3%) were used most commonly. The method of immobilisation had a notable, although non-significant, influence on the occurrence of short-term complications, with most complications being reported for the transarticular ESF group. The total short-term complication rate was 41.3%, the minor complication rate was 33.3% and the major complication rate was 7.9%, with pin tract infections being the most commonly occurring minor complication. Three cats (6%) had a total of four major complications over the long term. Most cats (86%) were free of lameness at the long-term evaluation, with an overall successful clinical long-term outcome of 84.9%, according to the owner questionnaire. Cats with traumatic injuries and injuries treated surgically had higher questionnaire scores than those with atraumatic injuries and those treated conservatively. Conclusions and relevance Outcome was generally good in cats with CCT injury, irrespective of the type of treatment. Complications included a high proportion of minor complications associated with the technique of tarsal joint immobilisation. ESF frames were more commonly involved in complications than other techniques. Surgically treated cats had a slightly better long-term outcomes.