An 8-year-old Portuguese Water Dog presented with a 5-month history of left forelimb lameness. There was palmar pain. Ultrasonography revealed enlargement of the left median nerve. Subsequent MRI also showed enlargement of the median nerve in the distal palmar to the mid-forearm region. Rapid intraoperative diagnosis suggested malignant peripheral nerve sheath tumors (MPNST) and a neurotomy was performed. The lameness had almost disappeared in 1 month after surgery. Recurrence occurred 26 months postoperatively and the forelimb was amputated. At 950 days after the neurotomy, radiography revealed lung metastasis, and the dog died 988 days after the neurotomy. Neurotomy for MPNST should be performed with caution until more information is available regarding methods for early detection, margin determination, and indication determination for neurotomy.

BACKGROUND: Desmitis of the accessory ligament of the deep digital flexor tendon (ALDDFT) is a commonly reported injury. Despite the commonality of this injury, the literature is limited to small case series, with the reported success following treatment varying from 18% to 75%.
OBJECTIVE: To identify the prognosis and factors associated with a return to work following ALDDFT injury.
METHODS: Retrospective case series.
METHODS: Medical records of horses from four equine hospitals (January 2000 and December 2018) with a diagnosis of desmitis of ALDDFT were reviewed. Data retrieved included case detail, use, history, lameness treatment and follow-up. Success was defined as returning to work. Backward stepwise logistic regression was used to identify variables significantly associated with return to work.
RESULTS: Ninety-one horses were included. The mean age was 13.5 years (standard deviation 4.9 years). Thirty-four percent (28/91) of horses were sound at the initial presentation. Sixty-eight percent (62/91) of horses were managed using controlled exercise alone, 28% (29/91) were treated with intra-lesional injection, therapeutic ultrasound, extracorporeal shockwave therapy or desmectomy of the ALDDFT and 3% (3/91) were euthanased without treatment. Sixty-four percent (54/85) of horses returned to work. Horses that were lame at follow-up were less likely to return to work (odds ratio [OR] 107.93, 95% confidence interval [CI] 20.06-580.61, p < 0.001) than those that returned to soundness. Identification of adhesions on ultrasonography was also associated with having reduced odds for return to work when compared to horses without adhesions (OR 0.10, 95% CI 0.01-0.76, p = 0.03).
CONCLUSIONS: Retrospective nature of the study, the potential of selection bias with regards to follow-up.
CONCLUSIONS: Sixty-four percent (54/85) of horses returned to work following injury of the ALDDFT. Persistence of lameness and adhesion formation were significantly associated with a poor outcome.

UNASSIGNED: Dogs (n = 6) suffering from elbow-associated lameness for a median of 3.5 (min 2, max 12) months duration requiring arthroscopic exploration according to imaging results were prospectively included in this study.
UNASSIGNED: Dogs that met the inclusion criteria were of various breeds with a median body weight of 18 (min 13.2, max 34.5) kg and median age at presentation of 11 (min 6, max 96) months. Results of imaging modalities (radiographs and/or computed tomography (CT)) were consistent with developmental elbow disease in all of the dogs.
UNASSIGNED: Feasibility of the needle arthroscopy procedure was first assessed in a preliminary cadaveric study. Disease-free cadaveric forelimbs (n = 12) were collected from adult dogs (n = 6) euthanised for reasons unrelated to the present study. Elbow exploration was performed, beginning with needle arthroscopy (1 mm, 0° angle scope) followed by standard arthroscopy (2.4 mm, 30° angle scope) through a medial approach. The ease of introduction, range of motion and the quality of visualisation were assessed subjectively and the presence of iatrogenic introduction lesions and extent of field of vision (assessed by the number of anatomical structures visualised) were scored and statistically compared. Needle arthroscopy allowed inspection of all structures at risk for medial/caudal compartment disease in all joints considering the occasional need for multiple portals. In the clinical setting, elbow exploration was found to be similar to that in cadaver joints in 4/6 dogs. The lower quality of vision provided by needle arthroscopy was a limitation of the technique, and 2/6 clinical cases required conversion to standard arthroscopy for full visualisation of the joint. No introduction lesions were noted with needle arthroscopy in either the cadaveric or clinical studies.
UNASSIGNED: Needle arthroscopy allowed safe visualisation of all of the structures of the medial and caudal compartment in disease-free cadaveric elbows, suggesting that needle arthroscopy is an appropriate technique for diagnosis and assessment of lesions of developmental elbow disease. However, the low quality of vision provided by the 1 mm scope, and the small diameter of the sleeve, which limited fluid inflow, combined with fragility of the device were major drawbacks that prevented consistent full exploration of the joint and detailed lesion assessment in clinical situations. Improvement of the device is thus necessary before use of the technique in clinical practice can be recommended.
UNASSIGNED: CCD: Caudal compartment disease; CT: Computed tomography; DED: Developmental elbow disease; DJD: Degenerative joint disease; LCL: Lateral collateral ligament; LCP: Lateral coronoid process; LHC: Lateral part of the humeral condyle; MCD: Medial compartment disease; MCL: Medial collateral ligament; MCP: Medial coronoid process; MHC: Medial part of the humeral condyle; MRI: Magnetic resonance imaging.

Medial coronoid process disease is the most common manifestation of canine developmental elbow disease which can progress to a more severe medial compartment disease (MCompD) characterized by full-thickness cartilage loss of the medial coronoid process and the medial humeral condyle. Among others, the \"Canine Unicompartmental Elbow\" (CUE) has been reported to be an effective treatment strategy for MCompD, with full in 47.6% and acceptable function in 43.7% at 6 months or later of follow-up.
To report on our clinical experiences with the CUE system using the caudo-medial approach in terms of both complications and functional outcome.
Medical records of dogs that underwent CUE procedure using a caudo-medial approach over a 3-year period were retrospectively reviewed. This covered epidemiological data, bi-planar radiographs, subjective gait analysis, owner questionnaire, surgical reports, as well as second-look arthroscopic findings when available.
In total, 52 CUE procedures were performed in 44 dogs with a median age of 8.0 years (IQ: 5.0-10.0) and a median bodyweight of 31.9 kg (ranging 20-48 kg) at the surgery. Four cases never return for follow-up, but were included in the analysis to increase the number of cases with pre- and intra-operative data. Mean follow-up time available for the remaining 48 cases was 7.1 (SD: 5.2) months. Radiographic derived implant positioning and alignment proved to be satisfactory in the sagittal plane but parallelism in the frontal plane was only present in three cases. Second-look arthroscopy in five cases with delayed or disappointing functional improvement showed evidence of implant-related contact lesions and progressive erosion of the medial coronoid area in three elbows. Overall, complications occurred in 11 cases (21%), being major in eight (15%) and minor in three (6%). Major complications included refractory pain and lameness 6 to 12 months postoperatively in five cases. At last follow-up, 12 cases (25%) were considered to have full function, 35 cases (73%) acceptable function, and in one case, the function was considered unacceptable. As the only variable related to functional outcome, age had a negative predictive value for full function.
The CUE procedure appears to be an effective treatment option for patients with MCompD. Older dogs might be at risk of having an inferior clinical outcome when compared to young patients. The reason for this is unknown and will have to be evaluated in future studies. Compared to a CUE case series of 103 elbows operated through a medial approach, using a caudo-medial approach decreased the incidence of approach-related complication. Nevertheless, the functional outcome in the current case series was less favorable than previously reported. These conflicting findings as well as the occurrence of potentially implant mechanical conflict at the medial joint compartment despite CUE warrants further studies.

A frog jump is both simple and difficult to comprehend. The center-of-mass (COM) follows a two-dimensional (2D) path; it accelerates diagonally upward, then traces a predictable arc in flight. Despite this simplicity, the leg segments trace intricate trajectories to drive the COM both upwards and forwards. Because the frog sits crouched with sprawled legs, segments must pivot, tilt, and twist; they solve a long-recognized problem of converting non-linear 3D motion of the leg segments to linear 2D motion of the COM. I use mathematical approaches borrowed from robotics to address: How do frogs manipulate the flow of kinetic energy through their body to influence jump trajectory? I address (1) transfer of motion through kinematic transmission and (2) transfer of motion through dynamic coupling of segment mass-inertia properties. Using a multi-body simulation, I explore how segment acceleration induces rotations at neighboring segments (even without accounting for bi-articular muscles). During jumps, this inertial coupling mechanism is likely crucial for modulating the direction of travel. The frog case study highlights a useful computational framework for studying how limb joints produce coordinated motion.

暂无摘要。

Tetrapod limbs are serially homologous structures that represent a particularly interesting model for studies on morphological integration, i.e. the tendency of developmental systems to produce correlated variation. In newts, limbs develop at an early larval stage and grow continuously, including after the habitat transition from water to land following metamorphosis. However, aquatic and terrestrial environments impose different constraints and locomotor modes that could affect patterns of morphological integration and evolvability. We hypothesize that this would be the case for alternative heterochronic morphs in newts, i.e. aquatic paedomorphs that keep gills at the adult stage and adult metamorphs that are able to disperse on land. To this end, we analyzed patterns and strengths of correlations between homologous skeletal elements of the fore- and hindlimbs as well as among skeletal elements within limbs in both phenotypes in the alpine newt, Ichthyosaura alpestris. Our results showed that metamorphs and paedomorphs had similar, general patterns of limb integration. Partial correlations between homologous limb elements and within limb elements were higher in paedomorphs when compared to metamorphs. A decrease in partial correlation between homologous limb elements in metamorphs is accompanied with a higher evolvability of the terrestrial morph. All these results indicate that environmental demands shaped the patterns of morphological integration of alpine newt limbs and that the observed diversity in correlation structure could be related to a qualitative difference in the modes of locomotion between the morphs.

暂无摘要。

The greyhound is a dog breed highly specialized to run fast (17 m/s) over short distances (Usherwood and Wilson, 2005). As a result, there are many anatomical structures correlated with this sprinting function. The branching patterns of vasculature supplying blood to the head, forelimbs and thorax (subclavian arteries and its branches) were described in 34 adult greyhound cadavers (22 male, 12 female) (donated with owner consent and used under a memorandum of understanding with the University of Adelaide Animal Ethics Committee) from silicone casts of the arch of the aorta and the cranial arteries. Chi-squared analysis was used to test for pattern frequency differences, and t-tests were used to analyse the differences between sex and symmetry. All measurements were scaled to a fixed measure, the Open Thorax Length (OTL), to correct for size variation between individuals. Significant differences were found between the left and right subclavian arteries in the greyhound. The length to the first branch as a percentage of the OTL was greater in the right subclavian artery than the left subclavian artery (P < 0.001). The interval between the first and last branches (branching interval) as a percentage of the OTL was larger in the left subclavian artery than the right subclavian artery (P < 0.001). The reason for these differences remains unclear. Nonetheless, intraspecific variations of the branching patterns of the subclavian arteries have been described in the greyhound, thus suggesting that breed-specific variations in the cardiovascular system are likely to occur throughout domestic dogs.

Convergence in morphology can result from evolutionary adaptations in species living in environments with similar selective pressures. Here, we investigate whether the shape of the forelimb long bones has converged in environments imposing similar functional constraints, using musteloid carnivores as a model. The limbs of quadrupeds are subjected to many factors that may influence their shape. They need to support body mass without collapsing or breaking, yet at the same time resist the stresses and strains induced by locomotion. This likely imposes strong constraints on their morphology. Our geometric morphometric analyses show that locomotion, body mass and phylogeny all influence the shape of the forelimb. Furthermore, we find a remarkable convergence between: (i) aquatic and semi-fossorial species, both displaying a robust forelimb, with a shape that improves stability and load transfer in response to the physical resistance imposed by the locomotor environment; and (ii) aquatic and arboreal/semi-arboreal species, with both groups displaying a broad capitulum. This augments the degree of pronation/supination, an important feature for climbing as well as grasping and manipulation ability, behaviors common to aquatic and arboreal species. In summary, our results highlight how musteloids with different locomotor ecologies show differences in the anatomy of their forelimb bones. Yet, functional demands for limb movement through dense media also result in convergence in forelimb long-bone shape between diverse groups, for example, otters and badgers.