Applications of 3-dimensional printing in small-animal surgery: A review of current practices.

Three-dimensional (3D) printing, also called rapid prototyping or additive manufacturing, transforms digital images into 3D printed objects, typically by layering consecutive thin films of material. This technology has become increasingly accessible to the public, prompting applications in veterinary surgery. Three-dimensional prints provide direct visualization of complex 3D structures and also haptic feedback relevant to surgery. The main objective of this review is to report current applications of 3D printing in small-animal surgery, including surgical education, preoperative planning, and treatment of tissue defects. The reported uses of 3D prints, their proposed advantages, and current limitations are discussed considering published evidence. Aspects of the manufacturing process specific to each application are described, along with current practices in veterinary surgery.

Evaluation of a laparoscopic abdominal simulator assessment to test readiness for laparoscopic ovariectomy in live dogs.

OBJECTIVE: To predict readiness for laparoscopic ovariectomy of live dogs on the basis of performance on a high-fidelity laparoscopic abdominal simulator and to determine interrater reliability of the assessment. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Seventeen fourth-year veterinary students. METHODS: After a standardized laparoscopic training course, each participant performed a laparoscopic ovariectomy with a simulator. This performance was scored in real time by two evaluators using a rubric. Participants achieving a score of 112 of 160 performed a laparoscopic ovariectomy in a live dog, supervised by an instructor in the room. Two evaluators scored video recordings of each procedure using the rubric. Participants' opinions about the simulator were collected with a survey. RESULTS: All participants scored above the threshold (range, 126-151) and successfully completed laparoscopic ovariectomy in a live dog, with an average of 10 of 17 participants requiring verbal guidance and 5 of 17 participants requiring intervention from the instructor. Interrater concordance was excellent for the rubrics used to score performance on the simulator (R = 0.91) and in vivo (R = 0.81). All participants agreed that the simulator should be used to assess trainee readiness prior to surgery in a live dog. CONCLUSION: Participants achieving a score of at least 126 of 160 on the simulator were able to perform a laparoscopic ovariectomy in a live dog under supervision. The scoring system for the simulator had excellent interrater concordance. CLINICAL SIGNIFICANCE: This simulator and scoring system can be used in laparoscopic training programs to assess readiness for progression to the operative setting.

Biocompatibility of allogenic canine fascia lata: In vitro evaluation and small case series.

OBJECTIVE: To evaluate the biocompatibility of canine fascia lata (FL) in vitro and after FL allograft implantation in dogs with clinical disease. STUDY DESIGN: In vitro experiment and small case series. SAMPLE POPULATION: Six dogs treated with allogenic freeze-dried FL. METHODS: Fibroblasts were cultured on disks of FL, polypropylene mesh (PM; negative control), and porcine small intestinal submucosa (SIS; positive control). Constructs were compared at 3, 7, and 14 days for water content, DNA amounts, scanning electron microscopy, and histology. Records of dogs treated with FL allografts with follow-up examination were reviewed for signalment, indication for surgery, surgical procedure, and outcomes. All owners were invited to complete a standardized questionnaire for long-term follow-up. RESULTS: Water content was greater in FL and SIS than in PM (P = .03). Fascia lata constructs contained more DNA compared with PM constructs at days 7 and 14 (P < .05), whereas SIS constructs did not differ from FL or PM. Fibroblasts appeared spherical and distributed throughout FL constructs, whereas they appeared stellate and remained on the surface of SIS and PM. Fascia lata allografts were implanted in six dogs with surgical conditions. No incisional complications were noted. All dogs had good to excellent long-term outcomes, except one that experienced recurrence of a perineal hernia 2 years after repair. CONCLUSION: In vitro, canine FL allowed attachment and proliferation of fibroblasts throughout layers of the graft. Canine allogenic FL was clinically well tolerated in this small population of dogs. CLINICAL SIGNIFICANCE: Allogenic FL is biocompatible and can be considered an alternative to SIS for soft tissue augmentation in dogs.

The effect of body condition on postoperative recovery of dachshunds with intervertebral disc disease treated with postoperative physical rehabilitation.

OBJECTIVE: To determine the impact of obesity on postoperative recovery from thoracolumbar hemilaminectomy in dachshunds treated with rehabilitation. STUDY DESIGN: Prospective observational trial. ANIMALS: Thirty-two dachshunds with thoracolumbar intervertebral disk disease and pain perception. METHODS: Dachshunds were entered into the study after unilateral thoracolumbar hemilaminectomy. Lean muscle and fat contents were measured with dual-energy x-ray absorptiometry (DEXA) at the beginning and at week 12 of the study. Aggressive rehabilitation was performed 1, 2, 4, and 6 weeks after surgery. Logistic regressions were used to determine the odds ratios between potential risk factors (age, duration of clinical signs, weight, body condition score, percentage body fat, percentage lean muscle mass, and disability index [DI] score at presentation) and return benchmarks of recovery. RESULTS: Body condition score, percentage body fat, percentage lean muscle mass, weight, and age did not influence the odds ratio for recovery. An increase in preoperative DI score was associated with increased risk of a slow postoperative recovery (P < .05). The odds ratios were 2.5, 4.8, and 1.8 for >7 days until standing, > 30 days until strong ambulation, and failure to return to normal within the study period, respectively. On average, dogs lost weight (2.2 kg) and body fat (2.4%) but gained muscle mass (3.0%) over the study period (P < .05). CONCLUSION: Preoperative disability but not body condition was a risk factor for a slow recovery after thoracolumbar hemilaminectomy in dachshunds with rehabilitation. CLINICAL SIGNIFICANCE: A slower recovery is likely with increased preoperative disability, but body condition does not seem to affect the postoperative prognosis of dachshunds treated with rehabilitation.

Effect of Short- Versus Long-Term Video Game Playing on Basic Laparoscopic Skills Acquisition of Veterinary Medicine Students.

The objective of this study was to investigate the effect of playing video games on the performance of basic laparoscopic skills. The study was an experimental pre-test-post-test comparison group design. Fifty-two students (31 from the Western University of Health Sciences College of Veterinary Medicine and 21 from the Colorado State University College of Veterinary Medicine) completing their first or second year of the veterinary curriculum were randomized into two intervention groups. The intervention consisted of playing the video game Marble Mania on a Nintendo Wii. group L (long) played 18 hours over 6 weeks and group S (short) played 3 hours during the last week of the 6-week intervention period. Before and after the intervention, basic laparoscopic skills for both groups were assessed using a modified McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) instrument. Participants performed two laparoscopic tasks. Results showed that the performance of students improved in both group S and L (p < .05) on both laparoscopic tasks. Both groups showed statistically significant improvement in their post-intervention scores (group L, N = 25, z = -3.711, p < .001, r = 0.742; group S, N = 27, z = -3.016, p < .003, r = 0.580). There was no significant difference in the degree of improvement between group S and group L. The results suggest that playing Marble Mania on a Wii for any time duration could be an effective method for veterinary medicine students to improve basic laparoscopic skills, and indicate the needs for additional studies.

Radiographic, computed tomographic, and arthroscopic diagnosis of radioulnar incongruence in dogs with medial coronoid disease.

OBJECTIVE: To characterize radioulnar incongruence (RUI) in large dogs with medial coronoid disease (MCD) and determine the agreement between radiography, computed tomography (CT), and arthroscopy. STUDY DESIGN: Prospective observational case series. ANIMALS: Twenty-four large-breed dogs under 3 years of age with confirmed MCD. METHODS: MCD and incongruence were evaluated by radiographs and CT. RUI was measured along the ulnar commissure, mid-body, and apex of the medial coronoid process (MCP) by CT and arthroscopy. Joints with RUI ≥ 2 mm were considered incongruent. Variables recorded during arthroscopic treatment included type of MCD, RUI, and modified Outerbridge score. Agreement between the 3 diagnostic imaging techniques was evaluated, and the association between RUI and cartilage damage was analyzed. RESULTS: Single fragmentation was the most common MCD according to CT and arthroscopy. RUI was associated with degenerative joint disease according to CT and with cartilage damage according to arthroscopy. RUI was diagnosed in 26% of elbows by radiography, in 35% of elbows by CT, in 78% of elbows according to CT measurements of RUI ≥ 2 mm, and in 57% of joints by arthroscopy. RUI was most commonly detected at the ulnar commissure with CT and at the apex of the MCP with arthroscopy. Imaging modalities were in poor to fair agreement with arthroscopy when evaluating RUI. CONCLUSION: CT and arthroscopy provided similar detection of MCD and cartilage disease but disagreed in the assessment and localization of RUI. CLINICAL SIGNIFICANCE: CT does not reliably predict arthroscopic assessment of RUI and associated treatment decisions for MCD.

Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in Labrador retrievers.

OBJECTIVE: To determine repeatability of and correlation between 2 radiographic measurements of femoral anteversion angles (FAA) and to determine their influence on a score derived from tibial plateau angle (TPA) and FAA to predict the risk of cranial cruciate ligament disease (CCLD). STUDY DESIGN: Prospective clinical study. ANIMALS: Forty-eight Labrador retrievers with or without CCLD. METHODS: FAA and CCLD scores were calculated for each limb from extended pelvic radiographs (t-FAA) or angled (a-FAA) projections of the femur by 3 investigators. One investigator repeated measurements twice. Data were analyzed for repeatability, correlation between t-FAA and a-FAA, and their influence on CCLD scores. RESULTS: FAA correlated most strongly with the distance between the femoral head and the femoral axis on mediolateral radiographs, a measurement with excellent repeatability. t-FAA and a-FAA correlated with each other (r > 0.79, P < .0001), although t-FAA were about 1° greater than a-FAA (P = .01). Intrainvestigator and interinvestigator repeatability of the CCLD score was fair when derived from t-FAA and good to excellent when derived from a-FAA. CCLD scores differed between radiographic techniques but led to different predictions in only 9 (10%) limbs, all with lower TPA and CCLD scores than the rest of the population. CONCLUSION: a-FAA correlated strongly with t-FAA and improved the repeatability of CCLD scores within and between investigators. CLINICAL SIGNIFICANCE: A craniocaudal angled beam projection of the femur is a suitable alternative to a ventrodorsal pelvic radiograph when measuring FAA and may improve the repeatability and positive predictive value of CCLD scores.

Factors contributing to the variability of a predictive score for cranial cruciate ligament deficiency in Labrador Retrievers.

BACKGROUND: We recently reported that a conformation score derived from the tibial plateau angle (TPA) and the femoral anteversion angle (FAA), best discriminates limbs predisposed to, or affected by cranial cruciate ligament disease (CCLD), from those that are at low risk for CCLD. The specificity and sensitivity of this score were high enough to support further investigations toward its use for large-scale screening of dogs by veterinarians. The next step, which is the objective of the current study, is to determine inter-observer variability of that CCLD score in a large population of Labrador Retrievers. A total of 167 Labradors were enrolled in this cross-sectional study. Limbs of normal dogs over 6 years of age with no history of CCLD were considered at low risk for CCLD. Limbs of dogs with CCLD were considered at high risk for CCLD. Tibial plateau and femoral anteversion angles were measured independently by two investigators to calculate a CCLD score for each limb. Kappa statistics were used to determine the extent of agreement between investigators. Pearson's correlation and intraclass coefficients were calculated to evaluate the correlation between investigators and the relative contribution of each measurement to the variability of the CCLD score. RESULTS: The correlation between CCLD scores calculated by investigators was good (correlation coefficient = 0.68 p < 0.0001). However, interobserver agreement with regards to the predicted status of limbs was fair (kappa value = 0.28), with 37% of limbs being assigned divergent classifications. Variations in CCLD scores correlated best with those of TPA, which was the least consistent parameter between investigators. Absolute interobserver differences were two times greater for FAAs (4.19° ± 3.15) than TPAs (2.23° ± 1.91). CONCLUSIONS: The reproducibility of the CCLD score between investigators is fair, justifying caution when interpreting individual scores. Future studies should focus on improving the reproducibility of TPA and FAA measurements, as strategies to improve the agreement between CCLD scores.

Evaluation of a scoring system based on conformation factors to predict cranial cruciate ligament disease in Labrador Retrievers.

OBJECTIVE: To determine the association of a radiographic score derived from tibial plateau angle (TPA) and femoral anteversion (FAA) with an outcome of cranial cruciate ligament deficiency (CCLD) in large dogs. STUDY DESIGN: Cross-sectional study. ANIMALS: 167 Labrador Retrievers. METHODS: Hind limbs of sound Labrador Retrievers over 6 years of age were considered at low risk for CCLD. Limbs were considered high risk for CCLD if they were affected or predisposed (sound contralateral limb in dogs with unilateral CCLD). The radiographic CCLD score was calculated for each limb. The TPA, FAA, and CCLD scores were compared between limbs of the same dog and between risk categories. A contingency table was used to evaluate the association of the CCLD score with the CCLD status of limbs. RESULTS: TPA, FAA, and CCLD scores were greater in limbs categorized as high risk for CCLD than in normal limbs. The sensitivity and specificity of the CCLD score was 87% and 79%, respectively. The positive predictive value was 69% and the negative predictive value was 92%. Scores were similar between paired right and left limbs, but did not agree for predicted status in 14/106 dogs. DISCUSSION: Our study supports an association between TPA, FAA, and CCLD in Labrador Retrievers. The negative predictive value of the CCLD score supports its application for screening dogs considered at low risk for CCLD. Positive CCLD scores should be interpreted with caution and the status of a dog may be undetermined if scores obtained on each limb disagree.

Technical difficulties during the training phase for Tightrope® and percutaneous lateral fabellar suture techniques for cranial cruciate ligament repair.

OBJECTIVE: To compare level of difficulty, deviations from technical description and postoperative assessment during the training of veterinary students, small animal surgical residents, and a board certified surgeon for Tightrope® (TR) and percutaneous lateral fabella suture (pLFS) techniques for cranial cruciate ligament (CCL) repair. STUDY DESIGN: Prospective study. SAMPLE POPULATION: Cadaveric canine pelvic limbs (n = 32). METHODS: Sixteen 3rd year veterinary students, 6 small animal surgical residents and a Diplomate of the American College of Veterinary Surgeons performed the TR and pLFS techniques on paired limbs. Perceived level of difficulty, duration of surgery, and technical deviations were assessed by questionnaire, radiographs, and dissection. Results were compared between techniques with McNemar's test. RESULTS: The TR procedure was perceived as more technically demanding than the pLFS by veterinary students and residents. Technical deviations were overall more common after TR than pLFS, and in limbs repaired by students, regardless of procedure. The most difficult aspect of the TR consists of the bone tunnels whereas for pLFS it was passing the suture around the femorofabellar ligament. The sensitivity of radiographs for detection of technical deviations was 39% after TR and 50% after pLFS. CONCLUSION: Technical deviations are more common during the training phase of TR than pLFS, and the sensitivity of radiographs to detect those is low. Repeated practice on cadavers followed by dissection is recommended before use in patients.

Radiographic evaluation of femoral torsion and correlation with computed tomographic techniques in labrador retrievers with and without cranial cruciate ligament disease.

OBJECTIVES: To (1) develop a technique to determine the anteversion angle (AA) of the femur on a single radiograph; (2) determine the correlation between this technique and other published radiographic and computed tomographic (CT) methods; and (3) compare the diagnostic outcome of these methods in determining the level at which femoral torsion occurred in Labrador Retrievers with cranial cruciate ligament (CCL) deficiency. STUDY DESIGN: Cross-sectional clinical study. ANIMALS: Mature pure-bred Labrador Retrievers (n = 30). METHODS: Pelvic limbs (n = 28) of 14 dogs without CCL deficiency were classified as control, whereas limbs of 16 dogs (18 limbs) with CCL deficiency were considered as diseased. Femoral torsion was evaluated using radiography and CT and variables were compared among limb groups by use of a mixed-model ANOVA, with P < .05 considered significant. RESULTS: There was a significant association between biplanar and lateral plane AAs but neither correlated with CT assessment of femoral torsion. On CT, a significant correlation was identified between overall AA and each of the distal, proximal, and femoral head trochanteric angles. Biplanar and lateral plane AAs did not differ between normal and CCL deficient limbs. On CT, overall and distal AAs were increased in CCL deficient limbs compared to control. CONCLUSION: Biplanar determination of femoral torsion can be estimated based on a single lateral radiograph but the results will be inaccurate as only CT identified and localized the site of femoral torsion.

Short- and long-term outcomes after arthroscopic treatment of young large breed dogs with medial compartment disease of the elbow.

OBJECTIVES: To report short- and long-term outcomes after arthroscopic treatment in young large breed dogs affected by medial coronoid process disease (MCPD) and identify variables affecting outcome. STUDY DESIGN: Prospective observational case series. ANIMALS: Large breed dogs <3 years old (n = 15; 23 elbows). METHODS: MCPD was confirmed by radiography, computed tomography, and arthroscopy. Dogs were treated by arthroscopy. Variables recorded at time of treatment included radioulnar incongruity (RUI) and degree of cartilage erosion. Variables recorded before, 6 weeks, and ≥23 months after surgery included radiographic score for osteoarthritis, trochlear notch sclerosis, muscle circumference, range of motion (ROM), and the load distribution of vertical ground reaction forces between thoracic and pelvic limbs. RESULTS: A greater load distribution to the pelvic limbs was identified preoperatively in dogs with RUI than in dogs with congruent elbows. Load distribution was not significantly improved at 6 weeks compared with preoperatively. Muscle circumference and vertical impulse distributions were improved at long-term evaluation despite an increased osteoarthritis score. This improvement was more obvious in dogs with RUI or a high degree of cartilage erosion at initial presentation. CONCLUSION: Some evidence of improvement in long-term function was found in dogs with MCPD after arthroscopic treatment. RUI and cartilage erosion at the time of diagnosis were associated with more lameness preoperatively but did not affect the final gait assessment or osteoarthritis score in this small cohort.

Comparison of two minimally invasive approaches to the thoracolumbar spinal canal in dogs.

OBJECTIVE: To describe 2 minimally invasive approaches to the spinal canal for treatment of intervertebral disc disease and compare their efficacy to conventional hemilaminectomy. STUDY DESIGN: Experimental; randomized, controlled design. ANIMALS: Canine cadavers (n = 10; 5 small and 5 large dogs). METHODS: Barium-impregnated agarose gel (BA-gel) was injected into the spinal canal at 3 intervertebral spaces of the thoracolumbar spine in each cadaver. Sites were randomly assigned to 1 of 3 approaches: conventional (standard) hemilaminectomy (SH), endoscopic foraminotomy (EF), or foraminotomy via an illuminated port (FP). Computed tomographic scans were performed before and after the procedures. Procedures were compared for duration, bone window size, incision length, complications and percentage of BA-gel removed via repeated measures ANOVA. RESULTS: The incisions created during EF and FP were similar and smaller to that of a SH. The duration of EF was prolonged compared to FP and SH. The size of the vertebral window created was greater after SH in large dogs, while no difference was found between procedures in small dogs. The amount of simulated disc material removed from the spinal canal did not differ between procedures, regardless of the size of the dog. CONCLUSIONS: The two minimally invasive approaches were feasible in small and large dogs. Both techniques allowed similar removal of simulated disc material and may decrease soft tissue morbidity compared to SH.

Ability of the Tightrope® and percutaneous lateral fabellar suture techniques to control cranial tibial translation.

OBJECTIVE: To compare the ability of the Tightrope® (TR) cranial cruciate ligament (CCL) technique, percutaneous lateral fabella suture (pLFS) technique, and normal CCL to control cranial tibial translation (CTT). STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Cadaveric canine pelvic limbs (n = 18 pairs). METHODS: Six small animal surgical residents (1 pair each) and a Diplomate of the American College of Veterinary Surgeons (10 pairs) performed TR and pLFS techniques on paired limbs. Two intact limb pairs served as controls. Limbs were assessed by palpation, radiographs, and dissection before mechanical testing of resistance to CTT. Forces resisted during displacement were compared between groups with a mixed ANOVA and post hoc tests. RESULTS: With 5 mm of displacement, the pLFS resisted 72 ± 45 N and the TR resisted 66 ± 48 N of load. The intact CCL resisted 400 ± 35 N. The intact CCL resisted displacement significantly more than either surgical technique. CONCLUSIONS: TR and pLFS had similar ability to resist CTT but neither restored the biomechanical properties of an intact CCL.

Risk factors and diagnostic accuracy of clinical findings for meniscal disease in dogs with cranial cruciate ligament disease.

OBJECTIVE: To determine the risk factors for meniscal disease and diagnostic accuracy of physical examination in dogs with cranial cruciate ligament (CCL) deficiency. STUDY DESIGN: Prospective cohort study. ANIMALS: Stifles (n = 80) of dogs with CCL deficiency. METHODS: Each dog was evaluated preoperatively for factors that may increase the risk of, or aid in the diagnosis of meniscal disease including presence of pain on extension and flexion of the affected stifle, range of motion during flexion and extension, thigh circumference, positive cranial-drawer test, positive tibial compression test, tibial plateau angle, complete tear of the CCL, presence of a meniscal click, and gait analysis. Odds ratios were calculated for each of the factors and a multivariate approach was used to create an ROC curve. Subsequent sensitivity, specificity, and area under the curve was used to determine the diagnostic value of clinical tests. RESULTS: Dogs with pain upon flexion of the stifle were 4.3 times more likely to have medial meniscal disease than those without flexion pain and dogs with a complete CCL tear were 9.6 times more likely to have medial meniscal disease than those with partial tears. A meniscal click increased the likelihood of medial meniscal disease by a factor of 11.3. The diagnostic accuracy using a meniscal click and pain upon stifle flexion was 76%. CONCLUSION: Combining the presence of a meniscal click and pain during flexion of the stifle provide a more accurate diagnosis of medial meniscal disease in dogs with CCL disease over individual examination variables.

Validation of a novel 3D printed positioning device and dynamic radiographic technique to quantify rotational laxity of the stifle in dogs.

Cranial cruciate ligament deficiency (CCLD) results in internal rotational instability of the stifle (RLS). By contrast, tibial torsion (TT) is an anatomical feature of the tibia along its longitudinal axis. The objective of this study was to validate a dynamic radiographic technique to measure internal rotational laxity of the stifle and differentiate it from TT. Models included transection of the CCL for RLS and an osteotomy for TT. One limb within eight pairs of canine cadaveric hind limbs was randomly assigned to CCLD. The contralateral limb underwent TT, followed by CCLD. Neutral and stress radiographs were taken with the limb in a custom rotating 3-D printed positioning device before and after each modification. The position of the calcaneus on neutral views and the magnitude of its displacement under standardized torque were compared within limbs and between groups. Transection of the CCL increased the magnitude of displacement of the calcaneus by 1.6 mm (0.3-3.1 mm, p < 0.05) within limbs. The lateral calcaneal displacement (dS-dN) tended to be greater when CCLD limbs were compared to limbs with intact CCL. A magnitude of calcaneal displacement of 3.45 mm differentiated limbs with RLS from intact limbs with 87.5% sensitivity and 68.7% specificity. The calcaneus was displaced further laterally by about 3 mm on neutral radiographs (dN) when limbs with experimental TT were compared to those without TT (p < 0.05). A calcaneus located at least 3.25 mm from the sulcus differentiated limbs with TT from intact limbs with 87.5% sensitivity and 87.5% specificity. The technique reported here allowed detection of RLS, especially within limbs. A calcaneus located at least 3.25 mm on neutral radiographs of large dogs should prompt a presumptive diagnosis of TT.

Veterinarian burnout demographics and organizational impacts: a narrative review.

Burnout is a work-related syndrome of physical and emotional exhaustion secondary to prolonged, unresolvable occupational stress. Individuals of different demographic cohorts may have disparate experiences of workplace stressors and burnout impacts. Healthcare organizations are adversely affected by burnt out workers through decreased productivity, low morale, suboptimal teamwork, and potential impacts on the quality of patient care. In this second of two companion reviews, the demographics of veterinary burnout and the impacts of burnout on affected individuals and work environments are summarized, before discussing mitigation concepts and their extrapolation for targeted strategies within the veterinary workplace and profession.

A narrative review of the physiology and health effects of burnout associated with veterinarian-pertinent occupational stressors.

Chronic workplace stress and burnout are serious problems in veterinary medicine. Although not classified as a medical condition, burnout can affect sleep patterns and contributes to chronic low grade systemic inflammation, autonomic imbalance, hormonal imbalances and immunodeficiencies, thereby increasing the risks of physical and psychological ill health in affected individuals. Cultural misconceptions in the profession often lead to perceptions of burnout as a personal failure, ideas that healthcare professionals are somehow at lower risk for suffering, and beliefs that affected individuals can or should somehow heal themselves. However, these concepts are antiquated, harmful and incorrect, preventing the design of appropriate solutions for this serious and growing challenge to the veterinary profession. Veterinarians must first correctly identify the nature of the problem and understand its causes and impacts before rational solutions can be implemented. In this first part of two companion reviews, burnout will be defined, pathophysiology discussed, and healthcare and veterinary-relevant occupational stressors that lead to burnout identified.

Pelvic limb kinetic and kinematic analysis in Labrador Retrievers predisposed or at a low risk for cranial cruciate ligament disease.

OBJECTIVE: To compare kinematics, net moments, powers, ground and joint reaction forces (GRF, JRF) across the hock, stifle and hip joints in Labrador Retrievers at low risk or predisposed to cranial cruciate ligament disease (CCLD). STUDY DESIGN: Cross-sectional clinical study. ANIMALS: Clinically normal Labradors predisposed (n = 11) or at low risk for CCLD (n = 9). METHODS: Right pelvic limbs were classified as predisposed or not to CCLD using a predictive score equation based on combining tibial plateau angle (TPA) and femoral anteversion angle (FAA) measured on radiographs. Kinematic, GRF, and morphometric data were combined in an inverse dynamics approach to compute hock, stifle and hip kinematics, net moments, powers, and JRF while trotting. RESULTS: The extensor moment of the hock joint was greater in predisposed limbs compared with nonpredisposed limbs (0.37 versus 0.28 Nm/kg). The power generated around the hock and stifle joints in predisposed limbs was increased (0.69 versus 0.44 W/kg for the hock, 1.59 versus 1.05 W/kg for the stifle). Trotting velocity, stance time, vertical and craniocaudal GRF and JRF did not differ between groups. CONCLUSIONS: Extensor moment at the hock was increased in predisposed limbs compared with nonpredisposed limbs. Predisposed limbs generated more energy than nonpredisposed limbs around the hock and stifle joints.

Bone resorption markers and dual-energy x-ray absorptiometry in dogs with avascular necrosis, degenerative joint disease, and trauma of the coxofemoral joint.

OBJECTIVES: To compare the ability of N-terminal telopeptide (NTx) assays and dual-energy x-ray absorptiometry (DEXA) to detect bone resorption in dogs with nonneoplastic bone lysis and evaluate the correlation between these diagnostic tools. STUDY DESIGN: Prospective, cross-sectional clinical study. ANIMALS: Dogs (n = 35; 39 femoral heads) that had femoral head and neck ostectomy and 6 cadaver specimens from healthy immature small dogs. METHODS: Small dogs with avascular necrosis (n = 12), a reference group of small dogs (7), large dogs with degenerative joint disease (DJD; 10), and large dogs with trauma (10) were studied in addition to 6 femoral heads harvested from 6 small immature and healthy dogs euthanatized for reasons unrelated to this study. Densitometric measurements of femoral heads, urine NTx excretion, and serum NTx concentration were compared between groups. RESULTS: Avascular necrosis resulted in a decrease in bone mineral density (BMD) (0.18 ± 0.01 g/cm(2;) P < .01) of the femoral head and elevation of serum NTx (159.3 ± 59.4 nM; P = .03) compared to small dog controls (0.28 ± 0.02 g/cm(2) ; 18.7 ± 1.83 nM, respectively), but did not seem to affect urine NTx. DJD in large dogs did not seem to affect any of the densitometric parameters evaluated. BMD (P = .03) and serum NTx (P = .04) were lower in small compared to large dogs. Serum NTx and densitometric measurements correlate inversely with each other (P = .001) but neither test correlated with urine NTx (P = .8-.9). CONCLUSION: Serum NTx levels vary with dog size but seem to correlate better with BMD better than urine NTx excretion in dogs with nonneoplastic bone resorption.