Simulating Ovariohysterectomy: What Type of Practice Promotes Short- and Long-Term Skills Retention?

Simulation-based surgical training allows students to learn skills through deliberate practice without the patient risk and stress of operating on a live animal. This study sought to determine the ideal distribution of training sessions to improve short- and long-term retention of the skills necessary to perform a simulated ovariohysterectomy (OVH). Fourth-semester students (n = 102) were enrolled. Students in the weekly instruction group (n = 57) completed 10 hours of training on the OVH simulator, with sessions held at approximately weekly intervals. Students in the monthly instruction group (n = 45) completed the same training with approximately monthly sessions. All students were assessed 1 week (short-term retention test) and 5 months following the last training session (long-term retention test). Students in the weekly instruction group scored higher on their short-term assessment than students in the monthly instruction group (p < .001). However, students' scores in the weekly instruction group underwent a significant decrease between their short- and long-term assessments (p < .001), while the monthly group did not experience a decrease in scores (p < .001). There was no difference in long-term assessment scores between weekly and monthly instruction groups. These findings suggest that if educators are seeking maximal performance at a single time point, scheduling instructional sessions on a weekly basis prior to that time would be superior to monthly sessions, but if educators are concerned with long-term retention of skills, scheduling sessions either on a weekly or monthly basis would accomplish that purpose.

Retention of basic surgical skills in veterinary students.

OBJECTIVE: To quantify veterinary students' retention of surgical skills after a 5-month period without practice. STUDY DESIGN: Prospective longitudinal descriptive study. SAMPLE POPULATION: Convenience sample of second year veterinary students (n = 57). METHODS: Students practiced ovariohysterectomy (OVH) on a model during 4 clinical skills laboratories during spring 2021. Students were assessed performing OVH on their model using a validated 22-item rubric. Students not meeting expectations repeated their assessment 2 weeks later. All students had a 5-month period, including summer break, without skills practice. Students were again assessed performing OVH on their model in the fall. Students' rubric scores and pass rates were compared before and after summer break. RESULTS: Students scored lower on their retention test in fall (median = 43) than at the spring assessment (median = 56, P < .001). No difference was detected between lower and higher performing students. Five students (9%) did not meet expectations on their first assessment; more students (17/57, 30%) failed to meet expectations on their retention test (P = .004). CONCLUSION: Students experienced a decay in the surgical skills required to perform OVH after a 5-month period without practice, regardless of the quality of their initial performance. CLINICAL SIGNIFICANCE: Veterinary educators should emphasize the importance of continual practice to maintain skills and should consider assisting students in regaining skills during review sessions on models to improve surgical skill retention after a prolonged break.

Stiffness of a type II external skeletal fixator and locking compression plate in a fracture gap model.

OBJECTIVE: To compare the stiffness of constructs fixed with a type II external skeletal fixator (ESF) or a 3.5-mm locking compression plate (LCP) in axial compression and bending with a fracture gap model. STUDY DESIGN: Quasi-static four-point bending and axial compression tests. SAMPLE POPULATION: Ten LCP and 10 ESF immobilizing epoxy cylinders with a 40-mm fracture gap. METHODS: Five constructs of each type were tested in nondestructive mediolateral (ML) four-point bending and then rotated and tested in nondestructive craniocaudal (CC) four-point bending. Five additional constructs of each type were tested in nondestructive axial compression. Stiffness was compared between loading modes by construct type and between construct types by loading mode. RESULTS: Type II ESF were stiffer than LCP in ML bending (difference, 1474 N/mm, P < .0001) and in axial compression (difference, 458 N/mm, P = .008) but not in CC bending (P = .1673). Type II ESF were stiffer in ML bending than in CC bending (difference, 999 N/m, P < .0001), while LCP were stiffer in CC bending than in ML bending (difference, 634 N/mm, P < .0001). CONCLUSION: Type II ESF generated stiffer constructs compared with LCP in ML bending and in axial compression without a difference in CC bending. External skeletal fixator and LCP bending stiffness varied by loading direction. CLINICAL SIGNIFICANCE: A type II ESF should be considered in a comminuted fracture requiring increased stability in ML and axial directions.

Long-term Formation of Aggressive Bony Lesions in Dogs with Mid-Diaphyseal Fractures Stabilized with Metallic Plates: Incidence in a Tertiary Referral Hospital Population.

The incidence of complications secondary to fracture stabilization, particularly osteolytic lesions and bony tumor formation, has long been difficult to evaluate. The objective of this study was to describe the long-term incidence of aggressive bony changes developing in dogs with long bone diaphyseal fractures stabilized by metallic bone plates compared to a breed-, sex-, and age-matched control group. The medical records of a tertiary referral center were retrospectively reviewed for dogs that matched each respective criterion. Signalment, history, cause of death (if applicable), and aggressive bony changes at previous fracture sites were recorded. Ninety dogs met the criteria for inclusion in the fracture group and were matched with appropriate control dogs. Four of the dogs in the fracture group developed aggressive bony changes at the site of previous fracture repairs most consistent with osseous neoplasia. One lesion was confirmed with cytology as neoplastic. The population of dogs was mixed with regard to breed and body weight, but all dogs with aggressive bony lesions were male. Incidence of aggressive bony lesion formation in the fracture group was 4 (4.4%) and was 0 (0%) in the control group; three (75%) of the affected dogs in the fracture group included cerclage as a component of their primary fracture stabilizations. Incidence of aggressive bony lesions in the fracture group compared to the control group was determined to be statistically significant (p = 0.0455), as was the incidence of cerclage among dogs affected by aggressive bony lesions compared to the rest of the fracture group (p = 0.0499). Development of aggressive bony lesions is an uncommon complication of fracture fixation. Additional research is needed to further identify and elucidate the long-term effects of metallic implants in dogs.

Surgical stabilization of an occipitoatlantoaxial malformation in an adult dog.

OBJECTIVE: To report surgical planning, technique, and outcome of stabilization surgery in an adult dog with occipitoatlantoaxial malformation (OAAM). STUDY DESIGN: Clinical report. ANIMAL: A 19-month-old, 25.5 kg, male castrated, Shiba Inu. METHODS: Radiographic and magnetic resonance imaging were used to identify and characterize OAAM. Using a ventral approach to the cranial cervical region 2 cortical bone screws were inserted from the axis into the malformed atlas and occiput. RESULTS: Ambulation was conserved postoperatively. Within 4 weeks, neurologic examination was mostly normal except for decreased proprioception in the right pelvic limb. At 9 months, the dog retained an extended neck posture, but had no neurologic abnormalities. CONCLUSION: OAAM should be considered as a differential diagnosis in an adult dog with cervical myelopathy. Surgical fixation with cortical bone screws using a ventral approach can be successful.

Meniscal injury in dogs with cranial cruciate ligament rupture.

Meniscal damage is common in dogs with naturally occurring rupture of the cranial cruciate ligament (CrCL). Appropriate diagnosis and treatment of meniscal injuries is critical to avoid chronic lameness in these patients. Given the frequency, expense, and clinical importance of meniscal injuries, a thorough understanding of the meniscus is important for general practitioners and veterinary surgeons alike. Research over the past 7 years has produced an abundance of new information regarding the importance of meniscal pathology, diagnostic methods, and potential treatment options at the time of CrCL surgery. This manuscript highlights recent advances that can benefit clinical practitioners and summarizes research developments that promise new therapies in the near future.

Incidence of and risk factors for postoperative pneumonia in dogs anesthetized for diagnosis or treatment of intervertebral disk disease.

OBJECTIVE: To determine incidence of and risk factors for postoperative pneumonia in dogs anesthetized for diagnosis or treatment of intervertebral disk disease (IVDD). DESIGN: Retrospective case-control study. ANIMALS: 707 dogs that underwent general anesthesia for the diagnosis or treatment of IVDD between 1992 and 1996 or between 2002 and 2006. PROCEDURES: Postoperative pneumonia was diagnosed if compatible clinical signs (cough or hypoxemia) and radiographic abnormalities (alveolar infiltrates) developed within 48 hours after anesthesia. To identify risk factors for postoperative pneumonia, findings for dogs that developed postoperative pneumonia between 2002 and 2006 were compared with findings for a randomly selected control group of unaffected dogs from the same population. RESULTS: There were no significant differences in age, breed, body weight, sex, location of IVDD, or survival rate between the 2 time periods, but there were significant differences in the use of magnetic resonance imaging, computed tomography, and hemilaminectomy and in the percentage of dogs that developed postoperative pneumonia in the later (4.6%) versus the earlier (0.6%) years. Significant risk factors for postoperative pneumonia included preanesthetic tetraparesis, cervical lesions, undergoing magnetic resonance imaging, undergoing > 1 anesthetic procedure, longer duration of anesthesia, and postanesthetic vomiting or regurgitation. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that at this institution, the incidence of postoperative pneumonia in dogs anesthetized for diagnosis or treatment of IVDD had increased in recent years.

External fixator clamp reuse degrades clamp mechanical performance.

OBJECTIVE: To determine the effects of clamp reuse for the Kirschner-Ehmer (KE); Securos; and the IMEX-SK clamp. STUDY DESIGN: Experimental bench test of mechanical properties. METHODS: Specially designed fixtures were used to mechanically test 18 clamps of each type with respect to 6 mechanical variables: fixator pin slippage, connecting bar slippage, fixator pin rotation, connecting bar rotation, and clockwise and counterclockwise clamp-bolt axis pivot. Each clamp was tested 6 times for each variable at 7.68 Nm of clamp-bolt tightening torque. RESULTS: were compared using repeated measures ANOVA. Results- For the IMEX-SK clamp, a significant degradation in the force required to cause slippage was found for connecting bar slippage and fixator pin rotation; however, this clamp also had a significant increase in the force to initiate slippage for clockwise clamp-bolt axis pivot with reuse. The Securos clamp had significant degradation in connecting bar slippage, connecting bar rotation, and fixator pin rotation whereas the KE clamp had significant degradation in connecting bar slippage only. CONCLUSIONS: All 3 external fixator clamp types degraded in 1 or more movement variables in their ability to resist motion with reuse. The IMEX and Securos clamps were more subject to degradation than the KE clamp and this may have clinical importance for fixator composite rigidity. CLINICAL RELEVANCE: Fracture-reduction stability is related to the ability to resist motion within a clamp. The unpredictable nature of degradation we found cautions against repeated use. Clinicians should consider reuse of external fixator clamps with the knowledge that repeated use degrades clamp mechanical performance.

OP-1 augments glucocorticoid-inhibited fracture healing in a rat fracture model.

Glucocorticoids inhibit bone remodeling and fracture healing. We sought to determine whether osteogenic protein 1 (OP-1) can overcome this inhibition in a closed fracture model in the rat. Time-released prednisolone or placebo pellets were implanted subcutaneously; closed femoral fractures were created 2 weeks later in rats. Fractures received sham, OP-1 and collagen, or collagen-only implants. Femurs were harvested at 3, 10, 21, 28, and 42 days postfracture. Fractures were examined radiographically for amount of hard callus; mechanically for torque and stiffness (also expressed as a percentage of the contralateral intact femur); and histomorphometrically for amount of cartilaginous and noncartilaginous soft callus, hard callus, and total callus. Glucocorticoid administration inhibited fracture healing. The application of a devitalized Type I collagen matrix mitigated the inhibitory effects of prednisolone on fracture healing However, further increases in indices of fracture healing were observed when OP-1 was added to the collagen matrix compared with collagen alone. OP-1 and collagen was more effective than collagen alone.

Mandibular reconstruction after gunshot trauma in a dog by use of recombinant human bone morphogenetic protein-2.

CASE DESCRIPTION: A 6-year-old German Shorthaired Pointer was evaluated for possible reconstruction of a mandibular defect resulting from gunshot trauma. CLINICAL FINDINGS: A 5-cm defect of the right mandibular body was evident. A segment of the mandibular body was removed 9 weeks earlier because of severe contamination and comminution associated with gunshot trauma. Subsequent right-sided mandibular drift resulted in malocclusion in which the left mandibular canine tooth caused trauma to mucosa of the hard palate medial to the left maxillary canine tooth. The right maxillary canine tooth caused trauma to gingiva lingual to the right mandibular canine tooth. TREATMENT AND OUTCOME: The right mandible was stabilized with a 2.0-mm maxillofacial miniplate positioned along the lateral alveolar margin and a 2.4-mm locking mandibular reconstruction plate placed along the ventrolateral mandible. An absorbable compression-resistant matrix containing collagen, hydroxyapatite, and tricalcium phosphate was soaked in recombinant human bone morphogenetic protein-2 (rhBMP-2; 7.2 mL of a 0.5 mg/mL solution for a dose of 3.6 mg) and placed in the defect. By 4 weeks after surgery, an exuberant callus was evident at the site of the defect. By 7 months after surgery, the callus had remodeled, resulting in normal appearance, normal occlusion, and excellent function of the jaw. CLINICAL RELEVANCE: Mandibular defects resulting from gunshot trauma can be treated by removal of contaminated tissue and comminuted bone fragments, followed by staged reconstruction. The combination of rhBMP-2 and compression-resistant matrix was effective in a staged mandibular reconstruction in a dog with a severe traumatic mandibular defect.

Kinetic gait analysis of healthy dogs on two different surfaces.

OBJECTIVE: To determine the effects of 2 different, commonly used surfaces with different coefficients of friction on ground reaction forces in normal dogs. STUDY DESIGN: Prospective, observational, single cross-over study. ANIMALS: Dogs (n=10) with no gait abnormalities. METHODS: Dogs were acclimated to the force plate and 5 valid trials for each dog and each limb were recorded. Velocity and acceleration were tightly controlled. Each dog was tested on both surfaces sequentially in different sequences. Data analysis was done on peak vertical force, peak impulse, breaking and propulsion peak forces and impulses. Three-way repeated measures analysis of variance was used to separately evaluate the effect of floor type on force plate measures in fore and hind limbs, while controlling for side (left versus right) and experimental replicate. P-values<.05 were considered significant. Mean force and 95% confidence interval for the 6 variables analyzed for all limbs on each surface were calculated. RESULTS: There were no significant differences in ground reaction forces between the linoleum and the carpet surface for thoracic or pelvic limbs for all gait variables measured. There were no significant differences between each individual gait trial per dog between the right and left thoracic limbs trials nor differences between the right and left pelvic limb trials. CONCLUSIONS: Normal dogs had no change in their ground reaction forces on linoleum and carpet surfaces. CLINICAL RELEVANCE: Kinetic results from multi-center or comparative trials will not be affected by use of either linoleum or carpet surfaces.

Absolute and relative cell counts for synovial fluid from clinically normal shoulder and stifle joints in cats.

OBJECTIVE: To determine absolute and relative cell counts for synovial fluid from grossly, radiographically, and histologically normal shoulder and stifle joints in healthy cats. DESIGN: Clinical study. ANIMALS: 52 cats scheduled to be euthanatized for unrelated reasons. PROCEDURE: Arthrocentesis of the shoulder and stifle joints was performed bilaterally, and synovial fluid was analyzed for absolute WBC count, WBC morphology, and percentages of neutrophils and mononuclear cells. Joints were examined grossly and radiographically, and synovial membrane specimens were submitted for histologic examination. Synovial fluid samples that were contaminated with blood and samples from joints with any gross, radiographic, or histologic abnormalities were excluded. RESULTS: 82 of the 208 synovial fluid samples were excluded because abnormalities were identified during physical examination; the volume of fluid obtained was insufficient for analysis; there was evidence of blood contamination; or the joint had gross, radiographic, or histologic abnormalities. Median WBC count for the remaining 126 synovial fluid samples was 91 cells/microL (96.4% mononuclear cells and 3.6% neutrophils); WBC count was not significantly different between left and right joint samples or between shoulder and stifle joint samples. Body weight was associated with synovial fluid WBC count, with WBC count increasing as body weight increased. Sixteen of the 52 (30%) cats had radiographic evidence of osteoarthritis involving at least 1 joint. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that synovial fluid can be obtained reliably from shoulder and stifle joints in cats.

Treatment with a combined cystopexy-colopexy for dysuria and rectal prolapse after bilateral perineal herniorrhaphy in a dog.

A 9-year-old castrated male Yorkshire Terrier was evaluated for dysuria and rectal prolapse 2 weeks after bilateral perineal herniorrhaphy. Dysuria was secondary to caudal displacement of the bladder, rather than retroflexion of the bladder. Dysuria and rectal prolapse were associated with disruption of supporting ligaments of the urinary bladder and colon, which may have been caused by tenesmus. Combined cystopexy and colopexy were used successfully to treat the dysuria and rectal prolapse.

Clinical and pathologic analyses of bicipital tenosynovitis in dogs.

OBJECTIVE: To determine the clinical and pathologic findings in dogs with primary bicipital tenosynovitis. ANIMALS: 19 dogs with 20 shoulder joints treated surgically for bicipital tenosynovitis and 8 shoulder joints from 4 clinically normal dogs. PROCEDURE: Histologic abnormalities of tendon sheaths of the biceps brachii in affected dogs were determined by use of comparison with findings in clinically normal dogs. Specimens were graded for inflammation, fibrosis, villous hypertrophy, vascular prominence, and synovial cell proliferation. Histopathologic results were statistically evaluated for relationship with clinical findings and treatment before surgery. RESULTS: Synovial villous hypertrophy and vascular prominence were the most consistent histologic findings in 16 and 14 of 20 affected joints, respectively. Evidence of inflammation was lacking in 6 joints. Ten joints had inflammatory cell infiltration of the tendon sheath. Plasma cells and lymphocytes were the most common infiltrates; however, the type and amount of inflammatory cell infiltrate were variable. Fibrosis of the tendon sheath was seen in 8 joints, and synovial cell proliferation was seen in 11 joints. Other changes included accumulation of hemosiderin, focal calcification, osseous metaplasia, lysis of collagen, and fibrocartilaginous metaplasia. No significant relationship was detected between histopathologic findings and clinical findings or treatment before surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Inflammation was more variable than hypothesized and may not be a consistent pathophysiologic feature of bicipital tenosynovitis. In some dogs, this disease may be the result of a degenerative process rather than an inflammatory process.