Felix Michael Duerr

This double-blind, positive-controlled clinical trial was designed to evaluate the tolerance and efficacy of a commercially available collagen-elastin hydrogel microparticle (CEHM) injectate. Thirty-five client-owned dogs with naturally occurring bilateral elbow osteoarthritis (OA) were randomized into two study groups and received a single intra-articular injection in both elbows: Triamcinolone (TA) + CEHM or TA only. Eighteen dogs were treated with TA + CEHM; 17 were treated with TA only. All patients were required to be on a consistent regimen of nonsteroidal anti-inflammatory drugs (NSAIDs) at the time of enrollment and were instructed to discontinue them before injection. The patients were evaluated at seven time points over a one-year period. Outcome measures included veterinary assessment, objective gait analysis (OGA), accelerometry, and clinical metrology instruments (Canine Brief Pain Inventory and Client Specific Outcome Measures). Individual patient success was predefined based on previous literature as demonstrating specific improvements in four out of five of the following outcome measures: Veterinary assessment, OGA, accelerometry, Canine Brief Pain Inventory Pain Interference Score, and Canine Brief Pain Inventory Pain Severity Score. Thirty-three patients were included for at least partial data analysis. Adverse effects associated with TA + CEHM included three mild and two moderate cases of transient soreness. Two mild cases of transient soreness were reported in the TA group. All adverse events resolved without treatment. There was insufficient evidence to conclude a difference between groups for any of the response variables. As expected, clinical metrology instruments improved significantly in both groups. In total, 82% (14/17) of dogs in the TA + CEHM group resumed NSAID treatment, compared to 56% (9/16) of dogs in the TA group. The proportion of dogs achieving individual patient success was low and ranged from 0 to 29% across the study time points. Given the lack of difference between groups, further research, with larger sample sizes, is needed to justify the use of these products in dogs for the treatment of elbow OA.

BackgroundCanine prostheses have been commercially available for many years but are still in early stages of research, development, and clinical application. ObjectiveTo prospectively investigate mid-term clinical outcomes of partial limb amputation with a socket prosthesis (PLASP) in canine patients via a descriptive prospective clinical case series and to describe a clinical protocol for PLASP. MethodsClient-owned dogs (n = 12) with distal limb pathology for which total limb amputation was recommended were enrolled. Partial limb amputation was performed and a socket prosthesis was moulded and fitted to the limb. Complications, clinical follow-up, and objective gait analysis (OGA) were recorded for at least 6 months. An online survey was completed by owners after study completion. ResultsTen dogs with thoracic limb pathology and two with pelvic limb pathology were included. The most common site of amputation was mid-radius (n = 5). Eleven of 12 dogs demonstrated quadrupedal gait on OGA with mean per cent body weight distribution (%BWD) of 26% on thoracic limb prostheses and a %BWD of 16% for the one pelvic limb prosthesis that OGA data were available for. Complications included prosthesis suspension difficulties (n = 5), pressure sores (4), bursitis (4), postoperative infection (3), prosthesis aversion (2), dermatitis (1), and owner noncompliance (1). Two owners elected to discontinue prosthesis use. ConclusionsPLASP allowed restoration of quadrupedal gait patterns in most patients. Owners reported overall positive satisfaction, though a high complication rate was observed. PLASP should be considered in select cases as an alternative to total limb amputation for dogs with distal limb pathology.

Introduction: Accurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II).Materials and methods: Phase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set.Results: Phase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point.Discussion/Conclusion: The VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

The COVID-19 pandemic has catalyzed the use of novel teaching modalities to enhance the provision of remote veterinary education. In this study, we describe the use of immersive virtual reality (iVR) as a teaching aid for veterinary medicine students during their orthopedics clinical rotation. Student sentiments were assessed using voluntary electronic surveys taken by veterinary students before and after the rotation. The most noteworthy benefits students reported were improved engagement with the course content, information retention, radiographic interpretation, and clinical reasoning skills. Obstacles encountered during the initial stages of the program included financial and temporal investment in equipment and content development, technical troubleshooting, and motion sickness. Though it is unlikely that iVR will ever fully replace hands-on learning experiences, it presents an educational opportunity to supplement traditional learning methods, motivate students, and fill information gaps. As iVR technology continues to evolve and improve, potential applications in the veterinary curriculum grow, making the modality’s use progressively more advantageous. Although this study describes its application in an orthopedic setting, the versatility of the iVR modality lends the potential for it to be implemented in a number of clinical and didactic settings.

A formal screening of self-complementary adeno-associated virus (scAAV) vector serotypes in canine joint tissues has not been performed to date. Selecting appropriate serotypes is crucial for successful treatment due to their varying levels of tissue tropism. The objective of this study is to identify the most optimal scAAV vector serotype that maximizes transduction efficiencies in canine cell monolayer cultures (chondrocytes, synoviocytes, and mesenchymal stem cells) and tissue explant cultures (cartilage and synovium). Transduction efficiencies of scAAV serotypes 1, 2, 2.5, 3, 4, 5, 6, 8, and 9 were evaluated in each culture type in three different vector concentrations by encoding a green fluorescent protein. It was found that scAAV2 and 2.5 showed the overall highest transduction efficiency among serotypes with dose-response. Since possible immune response against conventional AAV2 was previously reported in dogs, the chimeric scAAV2.5 may be more suitable to use. Evaluation of the safety and efficacy of the scAAV2.5 vector with an appropriate therapeutic gene in vivo is indicated.

Introduction: The use of orthoses and prostheses is expanding in veterinary medicine. However, research evaluating the efficacy and complications of these devices in veterinary patients is limited. The primary objective of this study was to prospectively determine the complications and outcomes associated with custom orthosis and prosthesis use in the canine patient.Materials and Methods: This was a prospective, clinical trial that followed patients for 12 months following device fitting. Owner-perceived complications, clinical metrology instruments, and objective gait analysis were used as outcome measures at various time points. The patients were grouped into the following four major categories: Patients with a carpal orthosis, patients with a stifle orthosis, patients with a tarsal orthosis, and patients with a prosthetic device.Results: Forty-three patients were included in the study. Thirty-nine out of 43 patients (91%) experienced at least one complication, with 7/7 (100%) prosthesis patients experiencing at least one complication. At least one skin complication was reported for the following patient groups during the first 3 months of use: 8/14 (58%) stifle orthoses, 9/10 (90%) carpal orthoses, 6/10 (60%) tarsal orthoses, and 4/7 (58%) prostheses. Patient non-acceptance of the device was identified in 2/15 (14%) stifle orthoses, 1/10 (10%) tarsal orthoses, and 4/7 (55%) prostheses. One out of 15 (7%) stifle orthoses, 4/10 (40%) carpal orthoses, 4/10 (40%) tarsal orthoses, and 1/7 (15%) prostheses experienced mechanical device problems necessitating repair. The majority of patients with carpal and stifle orthoses showed improvement on objective gait analysis in percent body weight distribution of the affected limb between baseline and the most recent follow-up without the device donned: 83% (n = 6) of patients with carpal orthoses, 100% (n = 11) of patients with stifle orthoses. None of the patients with tarsal orthoses showed a similar improvement (0%; n = 4).Discussion and conclusion: Three major complications associated with canine orthosis and prosthesis use were identified in this study as follows: Skin complications (abrasions, loss of hair, and sores), mechanical device problems, and patient non-acceptance of the device. Owners should be notified of these potential complications prior to pursuing orthoses or prostheses as a potential treatment option. Although clinical improvement was noted in the majority of patients with stifle and carpal pathology, given the lack of a control group, it is unknown how much of this improvement can be attributed to the orthoses.

Background: Monitoring changes in appendicular skeletal muscle mass is frequently used as a surrogate marker for limb function. The primary objective of this study was to review scientific information related to the assessment of appendicular skeletal muscle mass in dogs. The secondary objective was to develop practical recommendations for serial evaluation of muscle mass.Methods: A scoping review was conducted with a systematic search of PubMed, Web of Science, CAB abstract, and Cochrane from inception to June 2021. The following modalities were included in the search: limb circumference, diagnostic ultrasound, computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry.Results: A total of 62 articles that measured appendicular skeletal muscle mass in dogs were identified. Limb circumference (55 articles) was the most commonly used modality. Its reliability was investigated in five studies. Several factors, including measuring tape type, body position, joint angles, and the presence of hair coat, were reported as variables that can affect measurements. Diagnostic ultrasound (five articles) was validated in three articles, but there is scarce information about observer reliability and variables affecting the measurement. Computed tomography (four articles) and magnetic resonance imaging (one article) have been used to validate other modalities at a single time point rather than as a clinical tool for serial muscle mass monitoring. Dual-energy x-ray absorptiometry (two articles) has been used to quantify specific skeletal muscle mass but was mainly used to evaluate body composition in dogs.Conclusion: Limb circumference and ultrasound are likely the main modalities that will continue to be used for serial muscle mass measurement in the clinical setting unless a new technology is developed. The reliability of limb circumference is questionable. Several key factors, including measuring tape type, body position, joint angles, and coat clipping, need to be controlled to improve the reliability of limb circumference measurements. Ultrasound may provide a reasonable alternative, but further studies are required to evaluate the reliability of this modality and identify factors that influence ultrasound measurements.

This double-blind, randomized, prospective clinical trial was conducted to obtain exploratory data comparing the efficacy of intra-articular allogeneic mesenchymal stem/stromal cells (MSC) to high molecular weight hyaluronic acid (HA) for the treatment of pain associated with canine osteoarthritis (OA). Objective gait analysis (%Body Weight Distribution, %BWD), accelerometry, clinical metrology instruments and veterinary exams were used as outcome measures during various time points throughout the 48-week study period. Fourteen dogs with elbow or coxofemoral OA were enrolled and assigned in a 2:1 ratio to the treatment groups. Each patient received a set of two injections 4 weeks apart. Self-limiting joint flare was observed in seven patients, with six of these in the MSC group. Ten patients completed all follow-up appointments. Both treatment groups showed evidence of mild improvement following the treatment, but the results were inconsistent among the various outcome measures assessed. Overall, dogs enrolled in the HA group showed greater improvement compared to the MSC group. The primary outcome measure, %BWD, showed evidence of improvement, when compared to baseline values, at 36 weeks after injection for the HA group only (p = 0.048, estimated difference: 4.7). Similarly, when treatment groups were compared, evidence of a difference between treatment groups (with the HA-group showing greater improvement) were identified for weeks 24 and 36 (p = 0.02 and 0.01, respectively). The small sample size of this exploratory study does not allow firm conclusions. However, until studies with larger sample sizes are available, the current literature combined with our data do not support the clinical use of intra-articular MSC therapy over high molecular weight HA for the treatment of canine OA at this time.

The objective of this study was to provide preliminary data describing the safety and effect of cannabidiol (CBD) for symptom relief of canine osteoarthritis-associated pain in a clinical setting using objective outcome measures. Twenty-three client-owned dogs with naturally occurring osteoarthritis of appendicular joints completed this prospective, double-blinded, crossover, placebo-controlled study. Baseline data were acquired for 4 wk, followed by random allocation to either placebo or CBD treatment for 6 wk, followed by 6 wk with the opposite treatment. Outcome measures included objective gait analysis, activity counts (via accelerometry) and clinical metrology instruments. There were no differences noted between groups at any time point for any of the recorded outcome measures. Adverse events associated with CBD administration included elevation in liver enzymes (n = 14) and vomiting (n = 2).