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ObjectiveEvaluate whether total elbow replacement (TER) through a lateral approach is accurate and stable.Animals12 skeletally mature large-breed dog cadavers were used.MethodsLimb alignment, elbow joint motion, and collateral ligament laxity were evaluated preoperatively. The order of surgery (left or right) and the approach (lateral or medial) were randomly selected for TER in each dog. The other approach was used in the contralateral elbow. Intraoperative technical difficulties, duration of surgery, and anatomic complications were recorded. Limb alignment, elbow joint motion, collateral ligament laxity, and prosthetic component alignment were evaluated after surgery. Data were collected from June 11 to 15, 2023.ResultsThe duration of surgery using a lateral or medial approach did not differ (P = .499). Anatomic complications were not observed. The lateral approach resulted in 8° more elbow extension (P = .003), 1.58° less lateral collateral ligament constraint (P = .033), 2.80° less medial collateral ligament constraint (P = .002), 4.38° less frontal plane constraint (P = .004), 8° greater humeral component inclination (P = .033), and 5.6° greater radioulnar component varus (P = .001) than the medial approach. Varus of the radius, mechanical axis deviation, limb supination, elbow flexion, mediolateral humeral component and craniocaudal radioulnar component orientation did not differ among joints operated using a lateral or medial approach. In normal cadaveric elbows, a lateral approach for TER appears feasible, producing equivalent limb alignment, joint laxity, and joint motion to normal elbows and to TER placed using a medial approach.Clinical relevanceIn dogs, TER can be performed using a lateral surgical approach.

ObjectiveTo evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening.AnimalsSixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8).MethodsIntact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening.ResultsTMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs.Clinical relevanceA novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.

ObjectiveThe objective of this study is to compare drilling variables and torsional mechanical properties of rabbit femora after bicortical drilling with a 1.5-mm standard surgical drill bit, acrylic drill bit, and K-wire.Samples24 pairs of rabbit femora.MethodsAfter drilling under controlled axial displacement rate, each bone was biaxially loaded in compression followed by rapid external torsion to failure. Maximum axial thrust force, maximum drill torque, integral of force and displacement, change in temperature, maximum power spectral density of the torque signal, torque vibration, and torque and angle at the yield and failure points were collected. Pre- and postyield stiffness, yield and failure energies, and postyield energy were calculated.ResultsThe work required to drill through the cis- and transcortices (integral of force and displacement) was greater for the K-wire, followed by the acrylic and then standard drill bits, respectively. The K-wire demonstrated higher maximum torque than the drill bits at the ciscortex, and the force of drilling was significantly greater. The vibration data was greater with the acrylic and standard drill bits than the K-wire. There was no difference in torsional strength between drilling types.Clinical relevanceMechanical differences exist between different drill bits and K-wire and demonstrate that the K-wire is overall more damaging than the surgical drill bit.

ObjectiveTo objectively measure the current demographic makeup of the American College of Veterinary Surgeons (ACVS) diplomates and to develop a survey tool to be used as a metric to measure future changes in the ACVS demographic profile.Sample737 ACVS diplomates.MethodsA 14-item electronic survey was sent to 2,199 ACVS diplomates between August 25 and September 9, 2021, via email. Survey items included demographic information as well as perceptions about the ACVS and diversity, equity, and inclusion (DEI). Responses were quantitatively and qualitatively analyzed.ResultsThe survey response rate was 34% (737/2,199). The median age category among respondents was 45 to 54. The median years in practice as a diplomate was 11 to 15. The majority of respondents identified as white/Caucasian and heterosexual, with male and female respondents being similarly represented. Most respondents identified English as their first language. Few considered themselves first-generation college graduates or identified as disabled. Many respondents considered DEI to be an important initiative to promote in the ACVS.Clinical relevanceFindings suggested that the majority of ACVS respondents are supportive of DEI efforts. This study also serves as an objective analysis that can be reassessed in the future to determine the success of such initiatives.

ObjectiveDetermine whether dogs with well-functioning orthopedic metal implants can develop metal reactivity.SampleClient-owned dogs that had tibial plateau leveling osteotomy (TPLO) or total hip replacement (THR) implants for 12 months or more and control dogs with no implants.ProceduresLymphocyte transformation testing was performed by exposing peripheral blood lymphocytes to nickel (Ni), chromium (Cr), cobalt (Co), or a combination of these metals. Lymphocyte proliferation was assessed with flow cytometry. Lymphocyte stimulation indexes (SIs) were calculated. A SI > 2 was considered reactive. Median SIs of dogs in response to metal exposure were compared statistically.ResultsSamples from 10 dogs with TPLO, 12 dogs with THR, and 7 control dogs were analyzed. Six dogs out of 22 with metal implants had a reactive SI to 1 or more metals, while 2 of 7 control dogs had a SI > 2 when exposed to nickel only. When all metals were considered, no differences in metal reactivity were found between TPLO, THR, and control groups.Clinical relevanceMetal reactivity is present in dogs and can be identified using lymphocyte transformation testing. Reactivity to Ni is present in dogs with and without metal implants. Reactivity to Co and Cr occurs in some dogs with metal implants.

ObjectivesTo evaluate the effects of the chondrodystrophy-associated FGF4L2 retrogene on intervertebral disc (IVD) calcification and vertebral geometry.Animals22 Nova Scotia Duck Tolling Retrievers (NSDTR) with no FGF4L2 retrogene (n = 7, wild-type dogs), 1 retrogene copy (8, heterozygous dogs), or 2 retrogene copies (7, homozygous dogs).ProceduresComputed tomography (CT) scans of the vertebral column were analyzed using computer-aided design (CAD) software. IVD calcification, vertebral column length, and vertebral geometry of the third cervical (C3), 13th thoracic (T13), and first lumbar (L1) vertebrae were compared.ResultsIVD calcification was not found in wild-type dogs. IVD calcification was more frequent in homozygous dogs than heterozygous (P = .008) or wild-type dogs (P < .001) and in heterozygous dogs compared to wild-type dogs (P < .001). Four IVDs were subclinically herniated in 3 dogs (2 homozygous, 1 heterozygous). Calcified IVD had a greater volume and surface area in heterozygous dogs than homozygous dogs. C3 vertebral canal height-to-width ratio was greater in homozygous dogs than heterozygous dogs (P = .044) and wild-type dogs (P = .010).Clinical relevanceIVD calcification and vertebral geometry can be analyzed using CAD software. The presence of 1 or 2 FGF4L2 copies in the absence of the FGF4L1 retrogene has an additive effect on the number of calcified IVD and a minor effect on vertebral geometry in NSDTR dogs. Data support the use of FGF4L2 phenotyping to reduce clinical disease in segregating breeds and to monitor the introduction of wild-type alleles into fixed breed populations.

ObjectiveTo understand relative frequency of adverse health events, defined as injuries or infectious diseases, in dogs participating in agility and to determine health research priorities of agility dog owners.ProceduresAn internet-based questionnaire distributed to agility dog owners included items related to experiences with infectious diseases and injuries in agility dogs, reasons for retirement of dogs from competition, and ranking of health research priorities. Frequencies of infectious diseases in US geographic regions were compared with Chi-square tests. Research priority rankings were determined as median and interquartile range (IQR) for each topic. Rank-based tests (Kruskal Wallis and Mann-Whitney) compared rankings between participants in different agility organizations, between veterinarian and non-veterinarian competitors, and between respondents who had competed in national championship events and other respondents.ResultsThere were 1,322 respondents who had competed in canine agility in the previous 6 months, with those respondents reporting a median time competing in the sport of 13 years (IQR = 8-20 years); 50% of respondents had competed in at least one national championship agility event in the preceding 5 years. Overall, 1,015 respondents (77%) indicated that one or more of their dogs had been injured and approximately one-third (n = 477, 36%) indicated that one or more dogs had likely acquired one or more infectious diseases as a result of agility activities. Specific types of infectious diseases acquired varied by geographic region in the US. Research priority rankings were similar regardless of preferred agility organization or respondent experience. The highest-ranking research topics were identification of risk factors for specific types of injuries, improvements in equipment and understanding of safe course design, and physical conditioning programs to prevent injury.Conclusions and clinical relevanceAgility competitors prioritize research in areas that advance understanding of injury prevention in their dogs. Research priorities are nearly uniform among competitors regardless of their preferred agility organization or level of experience, providing a strong rationale for agility organizations to collaborate in research initiatives that improve safety and well-being for dogs competing in the sport. There has been little published research focusing on the high-priority research areas identified by competitors.

BackgroundCranial cruciate ligament rupture (CCLR) is one of the most common causes of pelvic limb lameness in dogs. Risk factors for CCLR include breed (especially large and giant breeds), body weight, gender and spay/neuter status, and age. Few studies have evaluated physical activity and fitness indicators, however, as risk factors for disease. This study used an online questionnaire distributed primarily via social media to assess risk factors for CCLR in dogs actively engaged in agility training or competition to determine demographic and physical activity factors associated with rupture.ResultsData from 260 dogs with CCLR were compared to similar data from 1006 dogs without CCLR. All dogs were actively training or competing in agility at the time of CCLR or the time of data submission, respectively. Physical characteristics associated with increased risk of CCLR included younger age, spayed female sex, greater body weight, and greater weight to height ratio. Agility activities associated with increased odds ratios included competition in events sponsored by the North American Dog Agility Council (NADAC), competing at novice and intermediate levels, and competing in fewer than 10 events/year. Odds ratios were lower in dogs that competed in events sponsored by United Kingdom Agility International (UKI). Other activities associated with increased odds ratio for CCLR included involvement in flyball activities and short walks or runs over hilly or flat terrain on a weekly basis. Activities associated with decreased odds ratio included involvement in dock diving, barn hunt, nosework, or lure coursing/racing activities and participation in core balance and strength exercises at least weekly.ConclusionsThese results are consistent with previous studies demonstrating that body weight and spay/neuter status are risk factors for CCLR in dogs. This is the first report to demonstrate that risk of CCLR in agility dogs is decreased in dogs that engage in regular core strengthening exercises, compete more frequently, compete at higher levels, and compete in more athletically challenging venues.

ObjectiveTo compare osteoarthritis scores assigned through radiographic evaluation of 18 anatomic regions in the elbow joint with scores assigned through evaluation of 3-D maximum intensity projection (MIP), 3-D surface rendering (TSR), and multiplanar reconstructed (MPR) CT images, and to evaluate intraobserver and interobserver agreement of radiographic and CT scoring.SampleRadiographic and CT images of 39 elbow joints in 20 dogs.ProceduresImages were anonymized and graded independently by 5 observers. One observer graded 12 elbow joints 3 times. Intraobserver consistency and repeatability, interobserver agreement, consistency among methods, and bias between methods were calculated.ResultsThe most severe changes were observed at the proximal aspect of the anconeal process, and the medial and cranial aspects of the medial coronoid process. Intraobserver consistency was moderate or better for 11/16 regions with MIP images, 11/16 regions with TSR images, 17/18 regions with MPR images, and 14/18 regions with radiographic images. Interobserver agreement was moderate or better for 5/16 regions with MIP images, 9/16 regions with TSR images, 12/18 regions with MPR images, and 6/18 regions with radiographic images. Mean scores from CT-based methods were higher than mean radiographic scores.Clinical relevanceAssessments of osteoarthritis severity in the elbow joints of dogs obtained by examining radiographic images were generally consistent with assessments obtained by examining CT scans. MPR scores were more consistent and more comparable to radiographic scores than were MIP or TSR scores.

Two FGF4 retrogenes (FGF4L1 on chromosome 18 and FGF4L2 on chromosome 12) have been identified to cause dwarfism across many dog breeds. Some breeds are nearly homozygous for both retrogenes (e.g., Dachshunds) and others are homozygous for just one (e.g., Beagles and Scottish Terriers). Since most breeds do not segregate both of these retrogenes, it is challenging to evaluate their individual effects on long bone length and body size. We identified two dog breeds selected for hunting ability, the Alpine Dachsbracke and the Schweizer Niederlaufhund, that segregate both of these retrogenes. Using individual measurements of height at the shoulder, back length, head width, thorax depth and width, and thoracic limb measurements, we evaluated the combined effects of FGF4 retrogenes within these breeds. We applied multivariable linear regression analysis to determine the effects of retrogene copy numbers on the measurements. Copy numbers of both retrogenes had significant effects reducing height at the shoulders and antebrachial length, with FGF4L1 having a much greater effect than FGF4L2. FGF4L1 alone influenced the degree of carpal valgus and FGF4L2 alone increased head width. Neither retrogene had an effect on thorax width or depth. Selectively breeding dogs with FGF4L1 and without FGF4L2 would likely lead to a reduction in the FGF4L2-related risk of intervertebral disc herniation while maintaining the reduction in leg length resulting from FGF4L1.

This study in dogs explored the feasibility of using cartilage fragments removed and discarded during routine palliative surgery for osteochondritis dissecans (OCD) as a source of primary chondrocytes for scaffold-free cartilage tissue-engineering. Primary chondrocytes were obtained from three OCD donors and one age-matched healthy articular cartilage (HAC) donor. After monolayer expansion of primary cells, a three-dimensional spherical suspension culture was implemented. Following this stage, cells were seeded at a high density into custom-made agarose molds that allowed for size and shape-specific constructs to be generated via a method of cellular self-assembling in a scaffold-free environment. Fifty-eight neocartilage constructs were tissue-engineered using this methodology. Neocartilage constructs and native cartilage from shoulder joint were subjected to histological, mechanical, and biochemical testing. OCD and HAC chondrocytes-sourced constructs had uniformly flat morphology and histology consistent with cartilage tissue. Constructs sourced from OCD chondrocytes were 1.5-times (32%) stiffer in compression and 1.3 times (23%) stronger in tension than constructs sourced from HAC chondrocytes and only 8.7-times (81%) less stiff in tension than native tissue. Constructs from both cell sources consistently had lower collagen content than native tissue (22.9%/dry weight [DW] for OCD and 4.1%/DW for HAC vs. 51.1%/DW native tissue). To improve the collagen content and mechanical properties of neocartilage, biological and mechanical stimuli, and thyroid hormone (tri-iodothyronine) were applied to the chondrocytes during the self-assembling stage in two separate studies. A 2.6-fold (62%) increase in compressive stiffness was detected with supplementation of biological stimuli alone and 5-fold (81%) increase with combined biological and mechanical stimuli at 20% strain. Application of thyroid hormone improved collagen content (1.7-times, 33%), tensile strength (1.8-times, 43%), and stiffness (1.3-times, 21%) of constructs, relative to untreated controls. Collectively, these data suggest that OCD chondrocytes can serve as a reliable cell source for cartilage tissue-engineering and that canine chondrocytes respond favorably to biological and mechanical stimuli that have been shown effective in chondrocytes from other animal species, including humans.

ObjectiveTo evaluate the diagnostic value of still images of needle arthroscopy (SNAR), still images of traditional arthroscopy (STAR), and computed tomography (CT) to diagnose medial coronoid process (MCP) pathology.Study designProspective clinical trial.AnimalsDogs (n = 17) presented for evaluation of elbow dysplasia.MethodsFor each case, two SNAR and STAR images of the MCP were reviewed independently and in random order by three board-certified surgeons. Computed tomographic images were reviewed by one board-certified radiologist. Reviewers were blinded to surgical and clinical findings. Surgical findings from real-time TAR with palpation were used as the gold standard. Receiver operating characteristic (ROC) curves and concordance statistics tests for the diagnostic accuracy of MCP fissure, MCP fragment, medial compartment condition, and cartilage score were calculated.ResultsImages of 27 elbows joints were reviewed. For MCP fissure detection, areas under the ROC curves for CT (0.84), STAR (0.73), and SNAR (0.57) did not differ. For the detection of MCP fragment, STAR had a larger area under the ROC curve (0.93) compared with SNAR (0.74, P = .015) and CT (0.54, P

ObjectiveTo describe methods to measure the 3-D orientation of the proximal, diaphyseal, and distal segments of the canine radius by use of computer-aided design software (CADS) and to compare the repeatability and reliability of measurements derived by those methods.Sample31 canine radii with biapical deformities and 24 clinically normal (control) canine radii.ProceduresSelect CT scans of radii were imported into a CADS program. Cartesian coordinate systems for the humerus and proximal, diaphyseal, and distal radial segments were developed. The orientation of each radial segment in the frontal, sagittal, and transverse planes was measured in triplicate by 3 methods. The repeatability and reliability of those measurements were calculated and compared among the 3 measurement methods.ResultsThe mean ± SD within-subject repeatability of radial angular measurements for all 3 methods was 1.40 ± 0.67° in the frontal plane, 3.17 ± 2.21° in the sagittal plane, and 3.01 ± 1.11° in the transverse plane for control radii and 2.56 ± 1.95° in the frontal plane, 3.59 ± 2.39° in the sagittal plane, and 3.47 ± 1.19° in the transverse plane for abnormal radii. Mean ± SD bias between radial measurement methods was 1.88 ± 2.07° in the frontal plane, 6.44 ± 6.80° in the sagittal plane, and 2.27 ± 2.81° in the transverse plane.Conclusions and clinical relevanceResults indicated that use of CADS to assess the 3-D orientation of the proximal, diaphyseal, and distal segments of normal and abnormal canine radii yielded highly repeatable and reliable measurements.

ObjectiveTo assess the accuracy of three-dimensionally (3-D) printed drill guides in constraining the trajectory of drill tracts for implants in canine thoracic vertebrae.Study designExperimental ex vivo study.Sample populationFive canine thoracic vertebral column specimens.MethodsGuides to constrain drill trajectories were designed on the basis of computed tomographic (CT) imaging of six thoracic vertebrae (T8-T13) and were 3-D printed. The guides were used to create drill tracts in these vertebrae by both an experienced and a novice surgeon, and CT imaging was repeated. The entry point and angulation of actual and planned drill tracts were compared for both surgeons. Unintended cortical violations were also assessed by using a modified Zdichavsky classification.ResultsFifty-eight drill tracts were created in 30 vertebrae. Mean entry point deviation was 1.4 mm (range, 0.4-3.4), and mean angular deviation was 5.1° (range, 1.5°-10.8°). There were no differences between surgeons in entry point deviation (P = .07) or angular deviation (P = .22). There were no unintended cortical bone violations, and all drill tracts were classified as modified Zdichavsky grade I.ConclusionThe 3-D printed guides used in the current study yielded drill tracts with small linear and angular errors from intended paths and 100% accuracy for placement within vertebral pedicles and bodies. This technique was conveniently used by both an experienced and a novice surgeon.Clinical significanceThis technique might be immediately applicable to clinical cases requiring thoracic vertebral stabilization and may allow safe and accurate implant placement for surgeons with varying experience levels.

Abstract Objective This study aimed to report the adverse drug events and treatment outcome of systemic linezolid therapy to manage multi-drug resistant orthopaedic surgical site infection in dogs. Materials and Methods Retrospective case review of four dogs that received linezolid to treat surgical site infections after orthopaedic surgery. Reevaluations consisted of a clinical examination or a telephone interview. Results Serum drug concentrations varied. All dogs showed a temporary resolution of clinical signs of surgical site infection. Two dogs that received linezolid at the previously reported dose developed drug-associated side effects. The side effects were anorexia, nausea, vomiting and regenerative anaemia. All side effects resolved after the discontinuation of linezolid. Surgical site infection recurred in two dogs 52 and 177 days after discontinuing linezolid respectively. Clinical significance Adverse drug events occurred in dogs receiving oral linezolid at the dosage of 10 to 20 mg/kg. Oral linezolid therapy failed to resolve deep orthopaedic surgical site infections in two out of four dogs. As a tertiary antimicrobial, linezolid should only be used in carefully selected cases while monitoring for drug-associated side effects.

Objective: To evaluate the short-term efficacy and safety of cold compression therapy (CCT) relative to a soft padded bandage (SPB) in dogs undergoing surgery to manage cranial cruciate ligament injury. Methods:Dogs were randomized into groups that received CCT or SPB after surgery. Weight bearing was measured using a weight distribution platform before and the day after surgery. Stifle joint flexion and extension were measured using a goniometer before and the day after surgery. Rectal temperatures were measured every 15 min for 2 h after surgery and the morning after surgery. Mechanical nociceptive thresholds (MNT) were measured using an algometer the day after surgery. Findings in both groups were compared using a mixed model ANOVA. Results:20 dogs were enrolled: 10 in the CCT and 10 in the SPB group. Dogs undergoing CCT had more stifle joint flexion (P = 0.008) and weight bearing (P < 0.001) after surgery than dogs with SPB. MNT after surgery correlated statistically with stifle joint flexion after surgery (r = -0.315, P = 0.014), extension after surgery (r = 0.310, P = 0.016), and weight bearing after surgery (r = 0.314, P = 0.003). Return to normothermia was delayed in the CCT group, with temperatures ~0.5°C (1.0°F) lower 105 (P = 0.018) and 120 min (P = 0.013) after surgery. Conclusion:Relative to bandaging, CCT had a positive short-term impact on stifle flexion and weight bearing. CCT delayed warming after surgery but dogs were only mildly hypothermic [0.5°C [1.0°F]].

Chondrodystrophy results in predictable and progressive biochemical and structural changes to the intervertebral disc, resulting in early onset degeneration and dystrophic mineralization of the disc. Accelerated degeneration and mineralization of the intervertebral disc are common in multiple dog breeds and can result in compromised function, herniation, pain, and a variety of neurological sequelae. A mutation responsible for chondrodystrophy in dogs has been identified as an aberrant fibroblast growth factor 4 (FGF4) retrogene insertion on chromosome 12 (CFA12) and is associated with short stature of the Nova Scotia Duck Tolling Retriever. Segregation of the CFA12 FGF4 retrogene in this dog breed provides an opportunity to examine the effect of retrogene presence on radiographic and histologic appearance of chondrodystrophic disc degeneration within a single breed. Here we found that in the intervertebral discs isolated from 2 dogs with the CFA12 FGF4 genotype, the nucleus pulposus was largely replaced by cartilaginous tissue, and physaliferous notochordal cells were rarely if ever identified. These findings are in contrast to the normal histologic findings in 2 breed-matched dogs lacking the mutation. The findings are consistent with premature chondroid degeneration of the intervertebral disc and suggest that the presence of the CFA12 FGF4 retrogene is sufficient to cause the chondrodystrophic phenotype.

ObjectiveTo evaluate accuracy of articular surfaces determined by use of 2 perpendicular CT orientations, micro-CT, and laser scanning.Sample23 cat cadavers.ProceduresImages of antebrachia were obtained by use of CT (voxel size, 0.6 mm) in longitudinal orientation (CTLO images) and transverse orientation (CTTO images) and by use of micro-CT (voxel size, 0.024 mm) in a longitudinal orientation. Images were reconstructed. Craniocaudal and mediolateral length, radius of curvature, and deviation of the articular surface of the distal portion of the radius of 3-D renderings for CTLO, CTTO, and micro-CT images were compared with results of 3-D renderings acquired with a laser scanner (resolution, 0.025 mm).ResultsMeasurement of CTLO and CTTO images overestimated craniocaudal and mediolateral length of the articular surface by 4% to 10%. Measurement of micro-CT images underestimated craniocaudal and mediolateral length by 1%. Measurement of CTLO and CTTO images underestimated mediolateral radius of curvature by 15% and overestimated craniocaudal radius of curvature by > 100%; use of micro-CT images underestimated them by 3% and 5%, respectively. Mean ± SD surface deviation was 0.26 ± 0.09 mm for CTLO images, 0.30 ± 0.28 mm for CTTO images, and 0.04 ± 0.02 mm for micro-CT images.Conclusions and clinical relevanceArticular surface models derived from CT images had dimensional errors that approximately matched the voxel size. Thus, CT cannot be used to plan conforming arthroplasties in small joints and could lack precision when used to plan the correction of a limb deformity or repair of a fracture.

ObjectivesOsseointegrated prostheses are increasingly used for amputees, however, the lengthy rehabilitation time of these prostheses remains a challenge to their implementation. The aim of this study was to investigate the ability of locally applied vibration or low-intensity pulsed ultrasound (LIPUS) to accelerate osseointegration and increase peri-implant bone volume.MethodsA 4-week and 8-week rodent study were conducted in a femoral intramedullary implant model (control, vibration, LIPUS, and combined treatment) to determine effects on healing. Osseointegration was evaluated quantitatively through mechanical, µCT and histological evaluations.ResultsMaximum pushout load at 4 weeks increased with LIPUS relative to control (37.7%, P=0.002). Histologically, LIPUS and vibration separately increased peri-implant bone formation after 4 weeks relative to control. Vibration resulted in greater peri-implant bone after 8 weeks than all other groups (25.7%, P

ObjectiveThis study assessed femur properties in 80 adult female rats exposed to a range of whole body vibration amplitudes at 45 Hz over five weeks. Our hypothesis was that an optimal amplitude for whole body vibration would be apparent and would result in increased bone strength.MethodsAnimals were treated in five amplitude groups (0 g, 0.15 g, 0.3 g, 0.6 g, and 1.2 g peak), for 15 minutes per day, five days per week, for five weeks. Femur strength was assessed via: (1) three-point bending of the shaft, (2) cantilever bending of the neck, and (3) indentation of distal cancellous bone. Femoral bone mineral density, plasma prostaglandin E2 (PGE2) concentrations, cartilage thickness, and histopathologic properties were measured.ResultsVibration doubled (P=0.039) cancellous bone stiffness in the 0.6 g and 1.2 g groups and induced a 74% increase in PGE2 concentrations (P=0.007). However, femoral densitometry and strength of the neck and shaft were unchanged and the cancellous bone indentation strength did not differ statistically (P=0.084). Cartilage thickness of vibrated groups at the medial condyle did not increase significantly (P=0.142) and the histopathologic grade did not change. There was no definitive optimal vibration amplitude.ConclusionThe benefits of vibration therapy over five weeks were confined to cancellous bone.

ObjectivesTo evaluate the accuracy of detection of temperature differences among skin sites of lay individuals and manual physical therapists.MethodsForty-four manual physical therapists and 44 lay individuals were recruited. Subjects palpated two temperature-controlled surfaces that ranged in temperature between 30 and 35 °C and varied randomly by 1, 2, 3, 4, or 5 °C for 10 s. The subjects were then asked to identify the warmer pad.ResultsAccuracy increased with larger temperature differences. Accuracy of detection of 1 and 3 °C temperature differences was higher in manual physical therapists than lay individuals.DiscussionPalpation can be used to accurately detecting temperature differences between sites and is more accurately performed by an experienced practitioner.Level of evidence3b.

OBJECTIVE To identify potential risk factors for digit injuries in dogs training and competing in agility events. DESIGN Internet-based, retrospective, cross-sectional survey. ANIMALS 1,081 dogs training or competing in agility events. PROCEDURES Data were collected for eligible animals via retrospective surveys distributed electronically to handlers of dogs participating in agility-related activities. Variables evaluated included demographic (handlers) and signalment (dogs) information, physical characteristics of dogs, and injury characteristics. A separate survey of dogs competing in similar agility-related activities but without digit injuries was also administered. Multivariable logistic regression was used to develop a model for assessment of risk factors. RESULTS Data were collected from 207 agility dogs with digit injuries and 874 agility dogs without digit injuries. Factors associated with significantly increased odds of injury included Border Collie breed (OR, 2.3; 95% confidence interval [CI], 1.5 to 3.3), long nails (OR, 2.4; 95% CI, 1.3 to 4.5), absence of front dewclaws (OR, 1.9; 95% CI, 1.3 to 2.6), and greater weight-to-height ratio (OR, 1.5; 95% CI, 1.1 to 2.0). Odds of injury decreased with increasing age of the dog (OR, 0.8; 95% CI, 0.76 to 0.86). CONCLUSIONS AND CLINICAL RELEVANCE Results should be cautiously interpreted because of potential respondent and recall bias and lack of review of medical records. Nevertheless, results suggested that retaining healthy dewclaws, maintaining lean body mass, and trimming nails short for training and competition may decrease the likelihood of digit injuries. Research to investigate training practices, obstacle construction specifcations, and surface considerations for dogs competing in agility activities is indicated.

ObjectiveTo assess the influence of a 50% distal ulnectomy on mediolateral carpal stability in the dog.Study designCanine cadaveric study.Sample populationSeven canine thoracic limbs METHODS: Thoracic limbs were placed in a jig to mimic weight bearing with a load representing 30% of body weight. Carpal extension angle was standardized at 190° ± 5°. Frontal plane carpal angles were measured with the limb loaded on craniocaudal radiographs before and after ulnectomy. Valgus and varus stress radiographs with the limb loaded were acquired before and after ulnectomy. The limbs were palpated and were subjectively graded for valgus or varus instability by 2 investigators before and after ulnectomy.ResultsMean (±SD) valgus angulation increased after ulnectomy (2.1° ± 1.7°; P = .017; CI95  = 0.5°-3.7°) when the limb was loaded without valgus or varus stress applied. Mean valgus angulation increased after ulnectomy (2.7° ± 2.8°; P = .032; CI95  = -0.2°-5.5°) when valgus stress was applied to the loaded limb. Varus angulation was unchanged after ulnectomy (0.6° ± 4.6°; P = .383; CI95  = -4.2°-5.3°) when varus stress was applied to the loaded limb. Palpation detected increased valgus score after ulnectomy.ConclusionDistal ulnectomy with excision of the lateral styloid process induces a slight increase in valgus in canine cadaver carpi. The clinical consequences of that valgus on carpal function and health should be assessed in clinical patients.

OBJECTIVE To assess 3-D geometry of the humerus of dogs and determine whether the craniocaudal canal flare index (CFI) is associated with specific geometric features. SAMPLE CT images (n = 40) and radiographs (38) for 2 groups of skeletally mature nonchondrodystrophic dogs. PROCEDURES General dimensions (length, CFI, cortical thickness, and humeral head offset), curvature (shaft, humeral head, and glenoid cavity), version (humeral head and greater tubercle), and torsion were evaluated on CT images. Dogs were allocated into 3 groups on the basis of the craniocaudal CFI, and results were compared among these 3 groups. The CT measurements were compared with radiographic measurements obtained for another group of dogs. RESULTS Mean ± SD humeral head version was -75.9 ± 9.6° (range, -100.7° to -59.4°). Mean mechanical lateral distal humeral angle, mechanical caudal proximal humeral angle, and mechanical cranial distal humeral angle were 89.5 ± 3.5°, 50.2 ± 4.5°, and 72.9 ± 7.8°, respectively, and did not differ from corresponding radiographic measurements. Mean humeral curvature was 20.4 ± 4.4° (range, 9.6° to 30.5°). Mean craniocaudal CFI was 1.74 ± 0.18 (range, 1.37 to 2.10). Dogs with a high craniocaudal CFI had thicker cranial and medial cortices than dogs with a low craniocaudal CFI. Increased body weight was associated with a lower craniocaudal CFI. Radiographic and CT measurements of craniocaudal CFI and curvature differed significantly. CONCLUSIONS AND CLINICAL RELEVANCE CT-based 3-D reconstructions allowed the assessment of shaft angulation, torsion, and CFI. Radiographic and CT measurements of shaft curvature and CFI may differ.

Osseointegrated implants transfer loads from native bone to a synthetic joint and can also function transdermally to provide a stable connection between the skeleton and the prostheses, eliminating many problems associated with socket prostheses. Additive manufacturing provides a cost-effective means to create patient-specific implants and allows for customized textures for integration with bone and other tissues. Our objective was to compare the osseointegration strength of two primary additive manufacturing methods of producing textured implants: electron beam melting (EBM) (mean Ra = 23 μm) and direct metal laser sintering (DMLS) (mean Ra = 10 μm). Due to spatial resolution, DMLS can produce surfaces with a roughness comparable to EBM. Two cohorts of Sprague-Dawley rats received bilateral, titanium implants in their distal femurs and were followed for 4 weeks. The first-cohort animals received EBM implants transcortically in one femur and a DMLS implant in the contralateral femur. The second cohort received DMLS implants (either fine textured or coarse textured to mimic EBM) in the intramedullary canal of each femur. Osseointegration was evaluated through mechanical testing and micro-computed tomography (bone volume fraction [BV/TV] and bone-implant contact [BIC]). The fixation strength of coarse textured implants provided superior interlocking relative to fine textured implants without affecting BV/TV or BIC in both cohorts. Coarse EBM implants in a transcortical model demonstrated an 85% increase in removal torque relative to the fine DMLS textured implants. The thrust load in the intramedullary model saw a 35% increase from fine to coarse DMLS implants.

BackgroundAvailable information suggests a mismatch between radiographic and orthopedic examination findings in cats with DJD. However, the extent of the discrepancy between clinical and radiographic signs of OA in companion animals has not been described in detail. This study aimed to evaluate the relationship between orthopedic examination findings, joint goniometry, and radiographic signs of DJD in 100 cats, in a prospective observational design. Cat temperament, pain response to palpation, joint crepitus, effusion and thickening were graded. Radiographs of appendicular joints and the axial skeleton were made under sedation. Joint motion was measured by use of a plastic goniometer before and after sedation. Associations between radiographic degenerative joint disease (DJD) and examination findings were assessed to determine sensitivity, specificity and likelihood estimations.ResultsPain response to palpation was elicited in 0-67% of the joints with DJD, with a specificity ranging from 62-99%; crepitus was detected in 0-56% of the joints and its specificity varied between 87 and 99%; for effusion, values ranged between 6 and 38% (specificity, 82-100%), and thickening, 0-59% (specificity, 74-99%). Joints with DJD tended to have a decreased range of motion. The presence of pain increased the odds of having DJD in the elbow (right: 5.5; left: 4.5); the presence of pain in the lower back increased the odds of spinal DJD being present (2.97 for lumbar; 4.67 for lumbo-sacral).ConclusionsRadiographic DJD cannot be diagnosed with certainty using palpation or goniometry. However, negative findings tend to predict radiographically normal joints. Palpation and goniometry may be used as a tool to help to screen cats, mostly to rule out DJD.