Humeral Condylar Fractures in French Bulldogs-Inciting Cause and Factors Influencing Complications of Internal Fixation in 136 Dogs.

OBJECTIVE: To report the inciting cause and configuration of humeral condylar fractures in French Bulldogs, and to identify risk factors for complications associated with their surgical stabilization, as well as their occurrence. STUDY DESIGN: Retrospective multicenter clinical cohort study. ANIMALS: French bulldogs (n = 136) with humeral condylar fracture. METHODS: Records from eight United Kingdom referral centers were reviewed for French bulldogs that underwent surgery for humeral condylar fracture between January 2017 and January 2021. RESULTS: Lateral fractures of the humeral condyle represented two-thirds of condylar fractures in this study (95 elbows; 69.8%); medial fractures of the humeral condyle and intracondylar Y or T fractures affected 22 (16.2%) and 19 (14%), respectively. A fall was the inciting cause for 60 elbows (45.6%), with stairs implicated in 27 (20.45%) elbows. Skeletal immaturity was significantly correlated with fracture. Complications affected 30 out of 132 dogs (136 elbows) (22%), of which 10 (33%) were major, and 20 (66%) were minor. Fixation method did not significantly impact complication rate for medial or lateral fractures of the humeral condyle (p = 0.87). Comminution increased the risk of complication for all humeral condylar fracture types (p = 0.02). CLINICAL RELEVANCE: Fixation method was not found to significantly impact the complication rate of surgically managed fractures of the humeral condyle in French bulldogs. Stair use, falling from low heights, and skeletal immaturity were common inciting reasons for humeral condylar fractures.

Long-Term Outcome and Complications after Transcondylar Screw Placement for Canine Humeral Intracondylar Fissure.

OBJECTIVE: The aim of this study was to report postoperative complications and long-term outcomes following transcondylar screw placement for humeral intracondylar fissure (HIF). STUDY DESIGN: It was a retrospective single-centre case series. Medical records (2018-2022) were reviewed for dogs with HIF treated with transcondylar screw placement. Data collected included signalment, concurrent orthopaedic disease, partial or complete HIF, surgeon, surgical approach, surgical technique and implant type, transcondylar screw angulation, postoperative complications and outcomes. Long-term outcome was assessed with owner questionnaire, orthopaedic examination and follow-up radiography. Statistical analysis was performed to identify risk factors predisposing to a complication or a poor outcome. RESULTS: Forty-seven dogs (57 elbows) met the inclusion criteria; long-term follow-up was available in 41 dogs (50 elbows). Minor and major medical complications were noted in seven and three elbows respectively. The total complication rate was 17.5%. Increasing age was significantly associated with a reduced risk of postoperative complications (p = 0.0051). No other risk factors were identified. A postoperative complication was not associated with a less than full outcome (p = 0.5698). CONCLUSION: Transcondylar screw placement for HIF is associated with a low complication rate and good outcome.

Farm management and husbandry practices associated with spontaneous humeral fractures in New Zealand dairy heifers.

AIMS: To use a farm-based survey to identify characteristics of the New Zealand dairy system associated with the risk of spontaneous humeral fracture in dairy heifers. METHODS: A questionnaire was designed and made available in print and online to collect information from dairy farmers and/or veterinarians, across New Zealand, about the management and nutrition of cows from birth to first lactation. Data were collected from July 2019 to March 2020 from farms that either had recorded (case farms) or not recorded (control farms) cases of humeral fractures in dairy heifers. RESULTS: A total of 68 completed questionnaires were returned, with 35 responses from case farms and 33 responses from control farms. Twenty-six responses (38%) were from the South Island (13 case farms and 13 control farms) and 38 responses (56%) were from the North Island (20 case farms and 18 control farms). For four questionnaires (6%) farm location was not given. Adjusting for the effect of age when calves accessed pasture, case farms had increased odds of having Holstein-Friesian Jersey crossbreed cows as the predominant breed (OR = 9.7; 95% CI = 3.1-36.0; p < 0.001). Adjusting for the effect of breed, allowing calves access to pasture a week later decreased the odds of being a case farm (OR = 0.68; 95% CI = 0.47-0.90; p = 0.006). CONCLUSIONS: Cows being Holstein-Friesian Jersey crossbreed was identified as a possible risk factor associated with spontaneous humeral fracture in dairy heifers in New Zealand. Given the small sample size, the likely multifactorial aetiology for humeral fractures, and the non-randomised survey, this risk factor, and the possible association between age at turn out and herd production with humeral fractures, all require further investigation.

Adjunctive fixation of the humeral epicondyle in a lateral condylar fracture model: Ex vivo comparison of pins and plates with a novel composite (AdhFix).

OBJECTIVE: To compare the biomechanical properties of using a novel composite construct (AdhFix) to an interfragmentary Kirschner wire or a reconstruction plate as adjunctive epicondylar stabilization in simulated lateral unicondylar humeral fractures. STUDY DESIGN: Cadaveric biomechanical assessment. SAMPLE POPULATION: Paired humeri harvested from skeletally mature dogs (14-41 kg), nine cadavers per group. METHODS: Simulated lateral unicondylar humeral fractures were stabilized with a transcondylar 4.5 mm cortical screw placed in lag fashion. Adjunct fixations consisting of a novel composite incorporating 2.7 mm cortical screws on one side, and either a 2.7 mm reconstruction plate or a 1.6 mm Kirschner wire on the contralateral side, were tested within paired humeri. Repaired humeri were axially loaded to failure and construct stiffness, yield load, and ultimate load were obtained from the load-deformation curves. RESULTS: In pairwise comparison, yield load was significantly higher for AdhFix group compared to the pin group, p = .016. No statistical significance was seen in the comparison between AdhFix group and the plate group, p = .25. CONCLUSION: Adhfix was mechanically superior to K-wires, and comparable to plate fixation, for adjunctive fixation in a lateral humeral condylar model. Our results support further investigation of the novel composite for adjunct fracture fixation in lateral humeral condylar fractures. CLINICAL SIGNIFICANCE: The novel composite tested may be a viable alternative for adjunct fixation of humeral condylar fractures, a technique that circumvents plate contouring.

Presumed concurrent medial coronoid process fracture is a frequent radiographic finding in dogs and cats with humeral condylar fractures.

OBJECTIVE: To report the prevalence of presumed concurrent medial coronoid process fractures in a series of cases of humeral condylar fractures and evaluate factors influencing the presence of a suspected fracture of the medial coronoid process. ANIMALS: 48 dogs and 7 cats, with a total of 57 humeral fractures. METHODS: Medical records of dogs and cats diagnosed with a humeral condylar fracture with radiographs were reviewed between October 2013 and March 2022. Species, sex, neutered status, age, weight, and the nature of the trauma were noted. Radiographs were assessed for the configuration of humeral condylar fracture, the presence of a suspected fractured medial coronoid process (MCP), number of MCP fragments, nature of fracture, degree of radioulnar incongruity, soft tissue swelling, and elbow luxation/subluxation. RESULTS: A presumed fracture of the MCP was seen in 26 of 57 cases. Comminution of the condylar fracture was the only parameter that had a positive effect on the presence of a possible fractured MCP. Body weight was significantly associated with size of the suspected fractured MCP. The presence of this fracture was not associated with the type of humeral condylar fracture. The size of the presumed fractured MCP fragment was positively correlated with body weight. CLINICAL RELEVANCE: There was a high prevalence of presumed fractured MCPs in dogs with humeral condylar fractures (almost 50%) and even more so in animals with comminuted fractures. The consequences of suspected fractured MCP associated with humeral condylar fractures and whether dogs and cats would benefit from removal of the fragment remain unknown.

Surgical repair of Salter-Harris type II fracture of the distal humerus: short and long-term outcomes in a case series of three dogs and one cat.

CASE HISTORIES: Three dogs and one cat sustained forelimb trauma and were presented to a university veterinary clinic (Liège, Belgium) and a private veterinary hospital (Beacouzé, France). All four animals were referred for surgery. CLINICAL FINDINGS: Two dogs and the cat were ambulatory on admission but unable to bear weight on the affected limb. One dog was non-ambulatory and lacked voluntary movement and sensation in one forelimb. Salter-Harris type II fractures of the distal humerus were diagnosed by radiography in all cases; avulsion of the brachial plexus and pelvic fractures were also present in the non-ambulatory dog. TREATMENT AND OUTCOME: All Salter-Harris type II fractures were stabilised by open reduction and internal fixation with cross pins. One minor complication (seroma) and three major complications (implant migration) developed after surgery. The pins were completely removed in one case and partially removed in two cases to resolve these complications. At the final follow-up examination (12-31 months after surgery), owners reported no lameness in three of the four cases and grade 2/5 left forelimb lameness in one case. CLINICAL RELEVANCE: This type of fracture is rarely described in the literature; however, it should be included in the differential diagnoses of traumatic humeral fractures in growing dogs and cats. In this case series, we achieved fair-to-excellent short-term and long-term outcomes after osteosynthesis of Salter-Harris type II fractures by cross pinning.

Humeral intracondylar fissures and intracondylar sclerosis are common CT findings in the limb contralateral to a humeral condylar fracture in French bulldogs and spaniel breeds.

French bulldogs (FBD) are reported to be at an increased risk of developing humeral condylar fractures (HCF). Spaniel breeds have been reported to be at increased risk of HCF due to a high prevalence of humeral intracondylar fissures (HIF), which can predispose to fracture. The aims of this retrospective, single center, observational study were twofold. First, to compare the signalment, fracture configuration, and etiology of populations of FBD and spaniel breeds presenting with HCF at a single hospital. Second, to evaluate the computed tomographic (CT) findings of the contralateral elbow joints of FBD and spaniel breeds presenting with HCF for concomitant pathology. FBDs were overrepresented for HCF, most commonly presenting when skeletally immature, with a median age of 3.7 months. Fractures of the lateral condyle were the most common configuration for both breed groups. Sclerosis at the fracture site was identified in 62% of FBD and 95% of spaniels undergoing CT scans. Humeral intracondylar fissures and intracondylar sclerosis were commonly observed in the contralateral elbows of FBD (44% and 50%, respectively) and spaniel breeds (58% and 95%, respectively). Medial coronoid pathology, elbow incongruency, and periarticular osteophytes were not identified in the contralateral elbows of FBD but were identified in 29%, 4%, and 20% of spaniels, respectively. The high prevalence of HIF in the FBD group may be a predisposing factor for HCF in this breed.

Biomechanical Comparison of Cortical Lag Screws and Cortical Position Screws for Their Generation of Interfragmentary Compression and Area of Compression in Simulated Lateral Humeral Condylar Fractures.

OBJECTIVE: The aim of this study was to compare the interfragmentary compressive force and area of compression generated by cortical screws inserted as either a lag screw or position screw in simulated lateral humeral condylar fractures. STUDY DESIGN: Ex vivo biomechanical study. MATERIALS AND METHODS: Thirteen pairs of cadaveric humeri from skeletally mature Merinos with simulated lateral humeral condylar fractures were used. Pressure sensitive film was inserted into the interfragmentary interface prior to fracture reduction with fragment forceps. A cortical screw was inserted as a lag screw or a position screw and tightened to 1.8Nm. Interfragmentary compression and area of compression were quantified and compared between the two treatments groups at three time points. RESULTS: After fracture reduction using fragment forceps (Time point 1: T1), there was no significant difference in interfragmentary compression and area of compression between the two treatments. A combination of fragment forceps and a cortical screw inserted as a lag screw (Time point 2: T2) produced significantly greater interfragmentary compression and area of compression compared with the same screw inserted as a positional screw. After removal of the fragment forceps, leaving only the cortical screw (Time point 3: T3), both the interfragmentary compression and area of compression remain significantly greater in the lag screw group. CONCLUSION: Lag screws generate a greater force of compression and area of compression compared with position screws in this mature ovine humeral condylar fracture model.

Biochemical profile of heifers with spontaneous humeral fractures suggest that protein-energy malnutrition could be an important factor in the pathology of this disease.

CASE HISTORY: Serum and liver samples from 35, 2-year-old dairy heifers that had fractured one or both humeri post-calving between July and December 2019 were submitted to a diagnostic laboratory for analysis. Serum samples were analysed for albumin, ß-hydroxybutyrate (BHB), creatinine, Ca, Mg, phosphate, non-esterified fatty acids (NEFA), and serum Cu concentration. Liver samples were analysed for liver Cu concentration. Data were compared to published reference intervals. Data values for heifers that prior to fracture had grazed fodder beet were also compared to values for those that had grazed pasture. CLINICAL FINDINGS: Sixty-nine percent of heifers with humeral fracture had serum creatinine concentrations below the lower value of the reference range (55-130 µmol/L). In 3/32 (9%) heifers, serum NEFA concentrations were increased above the reference value indicating body fat mobilisation (≥1.2 mmol/L for peri-partum cows) and in 20/35 (57%) heifers BHB serum concentrations were above the reference value indicating subclinical ketosis (≥1.1 mmol/L for peri-partum cows). In 24/35 (69%) heifers, liver Cu concentration was low (≤ 44 µmol/kg) or marginal (45-94 µmol/kg). The concentration of Cu in serum was low (≤ 4.5 µmol/L) in 2/33 (6%) heifers and marginal (4.6-7.9 µmol/L) in 5/33 (15%) heifers. There was moderate positive correlation between the logged concentrations of Cu in paired liver and serum samples, r(31) = 0.43; (95% CI = 0.1-0.79; p = 0.014). One heifer had a serum phosphate concentration below the lower limit of the reference range (< 1.10 mmol/L). For all heifers, the concentrations of albumin, Ca, and Mg in serum were within the reference intervals (23-38 g/L, 2.00-2.60 mmol/L, and 0.49-1.15 mmol/L respectively). Over winter, 15/35 (43%) heifers grazed predominantly pasture, 14/35 (40%) grazed fodder beet and 6/35 (17%) had a mixed diet. CLINICAL RELEVANCE: In some of these heifers with humeral fractures, there was evidence for protein and/or energy malnutrition in the form of elevated NEFA and BHB concentrations and low creatinine concentrations in serum. Liver Cu concentrations were also reduced in most affected heifers. However, the absence of a control group means it is not possible to determine if these are risk factors for fracture or features common to all periparturient heifers. Clinical trials and molecular studies are needed to determine the true contribution of Cu and protein-energy metabolism to the pathogenesis of spontaneous humeral fractures in dairy heifers. ABBREVIATIONS: BHB: ß-hydroxybutyrate; NEFA: Non-esterified fatty acids.

Management of Feline Femoral, Tibial and Humeral Fractures Using a 3.5 mm Titanium Interlocking Nail.

OBJECTIVE: Our objectives were to report complications associated with stabilization of long-bone fractures in cats using a 3.5-mm titanium interlocking nail and to examine the influences of signalment, fracture type and fixation evaluations on the occurrence of complications. STUDY DESIGN: Retrospective clinical study. MATERIAL AND METHODS: Medical and radiographic records of cats with long-bone fractures treated with an interlocking nail were reviewed. Data included age, sex, weight, cause of the fracture, fractured bone(s) and fracture type. Complications were classified as minor and major complications. Fisher's exact tests and logistic regression analysis were used to test whether certain variables of signalment and interlocking nail configuration had an effect on the occurrence of complications. RESULTS: Sixty-seven fractures of 67 cats were examined in this study. Forty-eight femora, sixteen tibiae and three humeri were included. Complications occurred in 11/67 fractures. Major complications occurred in 8/67 fractures and included screw breakage (n = 3), nail breakage (n = 2), nail bending (n = 1), screw loosening (n = 1), non-union (n = 1). Statistical analysis showed a significant difference between fracture types and the occurrence of major complications (p = 0.02). CONCLUSION: In conclusion, use of this commercially available standard 3.5-mm titanium interlocking nail for stabilization of comminuted and oblique humeral, femoral and tibial fractures in cats is feasible.

Humeral condylar fractures and fissures in the French bulldog.

OBJECTIVE: To report the configuration, risk factors, fixation methods and complication rates after repair of humeral condylar fractures (HCF) in French bulldogs, and report the presence of humeral intracondylar fissures (HIF) in this population as a possible predisposing factor. STUDY DESIGN: Retrospective clinical cohort study. SAMPLE POPULATION: Forty-four elbows. METHODS: The medical records of dogs referred between January 2012 and December 2021 were searched for French bulldogs presenting with HCF. Signalment, fracture configuration, stabilization method and complication occurrence were obtained. Postoperative radiographs were assessed for implant positioning, and computed tomography (CT) scans were assessed for the presence and size of HIF in the contralateral elbow. RESULTS: Lateral humeral condylar fractures represented 28/44 (63.6%) of HCF in French bulldogs. Repair with a transcondylar screw (TCS) and Kirschner-wire(s) (K-wire) were 7.62 times more likely to result in a major complication (95% CI: 1.43, 21.89; p = .01) compared to other methods. All incidences (7/7) of TCS migration were within the TCS + K-wire group. A HIF was identified in 18/31 (58.1%) dogs. Older animals were not significantly less likely to have a HIF than younger animals (p = .129). CONCLUSIONS: Fracture stabilization with a TCS and K-wire(s) was associated with an increased risk of major complications and migration of the TCS. A HIF was present in the contralateral elbow of over half of the French bulldogs where CT was available. CLINICAL SIGNIFICANCE: A HIF may be a predisposing factor of HCF in French bulldogs. Alternative methods of stabilization to a TCS and K-wire(s) should be used to reduce complication risk.

Osteoporosis is the cause of spontaneous humeral fracture in dairy cows from New Zealand.

Outbreaks of humeral fractures in dairy cows have been reported in New Zealand for several years. Gross, histologic, and histomorphometric findings in the humerus from primiparous cows with spontaneous humeral fracture were compared to age-matched control cows. Affected cows had a complete nonarticular spiral fracture of the humerus. Histologically affected humeri had a thicker growth plate with abnormal architecture, thinner cortex with increased abnormal resorption, increased resorption in the distal humerus, decreased trabecular density, abnormal trabecular architecture, presence of growth arrest lines and woven bone formation. Histomorphometry showed reduction in bone volume, trabecular perimeter, and trabecular width. Cows grazed on fodder beet had thicker growth plates with an abnormal appearance compared with cows grazed on pasture, and cows with low/marginal liver copper concentration had more resorption cavities in the distal humerus and thinner cortical bone compared with cows with adequate liver copper concentration. Decreased trabecular density (OR = 249.5), abnormal cortical resorption (OR = 54.2), presence of woven bone formation in the proximal metaphysis (OR = 37.2), and the number of resorption cavities in the distal humerus were significantly associated with a high probability of fracture. Ribs had enlargement of the costochondral junction with fractures in different stages of healing. Histology of the ribs revealed abnormal growth plate appearance, presence of fracture lines, callus tissue, fibrosis, and microfractures. Cows with humeral fracture have osteoporosis due to decreased bone formation and increased bone resorption, likely associated with inadequate feed quality and perhaps copper deficiency leading to a reduction in bone strength and fracture.

Design and topographic evaluation of a canine humeral anatomic plating system (CHAPS) for humeral condylar fracture repair in spaniels.

OBJECTIVE: To design a precontoured plating system for humeral condylar fracture repair in spaniels with humeral intracondylar fissure (HIF) and quantify accuracy of fit of the system on 3D printed bone models. STUDY DESIGN: Experimental on 3D printed models. METHODS: The plating system was based on morphometric data obtained from CT. Plates were applied to models and impression material was measured under the plates at points of interest to define plate bone gap (PBG). Data on locking screw interference on plate application were also obtained. RESULTS: Eleven elbows models were plated. Statistical analysis to assess for any difference in PBG measurements between left and right humuri revealed two loci (3 and 17) under the lateral plate and two loci (3 and 17) under the medial plate. On cumulate portion analysis, 67% of lateral plate loci and 80% of medial plate loci had a PBG of ≤2 mm respectively. An incidence of 2.1% (3/143) screw interference occurred. CONCLUSION: Design of a contoured plating system for application to humeral models from spaniels with HIF and its application with objective measurement of PBG is described. The majority of the loci measured under both lateral and medial plates had a BPG of ≤2 mm and the incidence of locking screw interference on plate application was low. CLINICAL SIGNIFICANCE: This novel system may have application for the stabilization of humeral condylar fractures in spaniels avoiding the need for plate contouring and minimizing the incidence of locking screw interference.

Humeral unicondylar fractures in immature dogs treated using a bone screw and Kirschner wire.

BACKGROUND: To investigate the incidence of implant-related complications when humeral unicondylar fractures in immature dogs are stabilised with a transcondylar bone screw and epicondylar Kirschner wire (K-wire)/pin. METHODS: Records of cases treated by the author in this clinic over a 10-year period were screened for those involving humeral condylar fractures. These were then reduced to include those patients who were less than 7 months of age with unicondylar fractures and follow-up radiographs. RESULTS: Thirty fractures in 29 dogs met the inclusion criteria. All of these had been stabilised with a transcondylar bone screw and epicondylar K-wire. Fracture healing was documented in all dogs. Surgical site infection was not recorded. Implant-related major complications were reported in four (13%) dogs and successfully treated by either implant removal or replacement. Short-term outcome was judged as excellent in 23 out of 30 and good in seven out of 30 of these fractures. CONCLUSION: The use of a transcondylar bone screw in combination with an epicondylar K-wire is an appropriate fixation method for humeral unicondylar fractures seen in puppies less than 7 months of age.

Retrospective evaluation of surgical technique, complications and long-term outcome of lateral and medial humeral condylar fractures in 80 dogs.

CASE HISTORY: Medical records from a single veterinary teaching hospital in Giessen, Germany were retrospectively reviewed for dogs presenting with medial or lateral humeral condylar fractures (HCF) between 2007 and 2019. Data regarding surgical technique and complications were collected from the medical records. These were supplemented through information obtained from telephone interviews with referral veterinarians and from an owner questionnaire completed ≥12 months after surgical repair, which also provided data regarding the outcome. CLINICAL FINDINGS: Eighty dogs with 85 HCF were identified: 13 (15.3%) HCF were medial (bilateral in two dogs) and 72 (84.7%) were lateral (bilateral in three dogs). French Bulldogs (n = 19/80; 23.8%) were most commonly affected. Patients were predominantly skeletally immature and light-weight, with a median age at the time of presentation of 3 (min 2, max 118) months and with a median body weight of 6.4 (min 1, max 46) kg. There were 38 female (47.5%) and 42 male (52.5%) dogs. Fractures developed most frequently secondary to minor trauma (67/77; 87.0%). Dogs were presented in 35/84 (41.7%) cases more than 24 hours after fracture occurrence. TREATMENT AND OUTCOME: Surgical treatment was performed in 80/85 (94.1%) HCF. An open reduction and internal fixation approach was chosen in all cases. A transcondylar screw (TS) combined with a supracondylar (SC) K-wire (67/80; 83.8%) was the most frequently used fixation technique. Considering all fracture fixation methods, complications (26/80; 32.5%) were classed as minor in 10 (12.5%), major in 14 (17.5%) and catastrophic in two (2.5%) of the 80 surgically treated HCF. Long-term outcome was excellent in 68.6% (24/35 HCF) and very good in 22.9% (8/35 HCF) of the cases for which follow-up information was obtained. Additionally, owner information revealed that 85.7% of dogs (30/35 HCF) were free of lameness in the long-term. CLINICAL RELEVANCE: This case series demonstrates that surgical repair of lateral and medial HCF with a TS and SC K-wire is a viable option to consider in skeletally immature and light-weight patients. Complications occur frequently after surgical fixation of HCF, but owners can expect a very good to excellent long-term outcome in the majority of cases.

A Prevalence Study of Canine Humeral Condylar Fractures Over a Ten-Year Period at an Academic Teaching Hospital.

OBJECTIVE: The aim of this study was to investigate the prevalence, breed predisposition and fracture conformation of humeral condylar fractures (HCF) over a 10-year period. Results were compared with published studies emanating from the United Kingdom exploring effect of breed on HCF. METHODS: Data for all canine admissions to the Veterinary Teaching Hospital at Kansas State University were extracted for the period January 2010 to October 2020. Humeral fractures were recorded and further subclassified as medial, lateral and 'T'/'Y' condylar fractures. The associations between HCF and subtypes with breed were assessed using univariate logistic regression with a comparison group. Multivariable logistic regression was used to evaluate the effect of breed while accounting for dog age, sex and neuter status. RESULTS: Of the 44,952 canine patients seen during the study period, period prevalence (95% confidence interval [CI] for HCF was 0.26% [0.22, 0.31]). After adjustment for age and neuter status, French Bulldogs were 49 times more likely to be diagnosed with a HCF compared with the comparison breed group (odds ratio [OR], 49.0; 95% CI, 26.9-89.3). After adjustment for age and neuter status, Cocker Spaniels (OR, 42.8; 95% CI, 16.8-108.6), Boston Terriers (OR, 22.9; 95% CI, 11.0-47.9) and Brittany Spaniels (OR, 21.5; 95% CI, 7.3-63.1) had the next highest increase in HCF compared with the comparison group. CONCLUSION: Based on a study population from the United States, French Bulldogs were 49 times more likely to be diagnosed with a HCF compared with the comparison breed group.

Risk Factors and Prognosis for Humeral Fractures in Birds of Prey: A Retrospective Study of 461 Cases from 2000 to 2015.

The objectives of this retrospective study were 1) to characterize humeral fractures in raptors at a rehabilitation program, 2) to determine risk factors for closed and compound humeral fractures in the raptors, and 3) to investigate prognostic factors for humeral fractures in raptors. Of the 6017 birds of prey admitted over 15 years to the Université de Montréal raptor rehabilitation program, 461 birds presented with a humeral fracture. The highest occurrences of humeral fractures were documented in short-eared owls (33%; Asio flammeus), Northern hawk-owls (24%; Surnia ulula), long-eared owls (20%; Asio otus), and Northern harriers (19%; Circus hudsonius). Humeral fractures were more common in males, and species from the intermediate weight group (300 g to 1 kg) were more likely to have compound humeral fractures than birds from the lower and higher weight groups. Humeral fractures of the middle and distal third of the bone were diagnosed as compound more often than fractures of the proximal third. A correlation between the occurrences of humeral fractures and the relative average width of the humerus for each species was observed and suggests that species with slender humeri have an increased likelihood of compound humeral fractures. Following the triage criteria used at this rehabilitation program, surgical (119 birds) or nonsurgical (77 birds) treatments were attempted. Release rate for birds without concomitant conditions in which a treatment was attempted was 39.3% (59/150) and did not significantly differ between closed and compound fractures, which suggests that the triage criteria used for compound fractures in this program were adequate. Our findings emphasize that raptors should not be systematically euthanatized when presented with compound humeral fractures to a rehabilitation facility.

Biomechanical analysis of 3 fixation techniques in rabbit radius and humerus bones.

The objective of this study was to compare the strength and stiffness of various fixation methods applied to the long bones of the rabbit forelimb. Twenty rabbit radius/ulna and 20 rabbit humeri were randomly assigned to 1 of 4 groups. Control bones remained intact, whereas all others were osteotomized to create fracture models that were fixated with locking plate and locking screws (LP), veterinary cuttable plate (VCP) with cortical screws, or external skeletal fixator constructs (ESF), and tested in 4-point bending until failure. Load/deformation curves were generated for each sample and used to calculate stiffness (slope of the curve) and strength (load to failure). Intact controls had greater strength and stiffness than any fixation techniques in the rabbit radius/ulna and humeri samples. Locking plate and VCP constructs had greater stiffness than ESF when applied to the radius, whereas locking plate constructs were stronger than VCP or ESF when applied to the humerus. Overall, the LP construct had characteristics most closely resembling those of the intact control regarding strength in the humerus. Therefore, fracture fixation with a LP would provide the greatest strength in humeral fracture repairs in the rabbit.

Analyse biomécanique de trois techniques de fixation du radius et de l'humérus de lapin. L'objectif de cette étude était de comparer la résistance et la rigidité de différentes méthodes de fixation appliquées aux os longs du membre antérieur du lapin. Vingt radius/cubitus de lapin et 20 humérus de lapin ont été assignés au hasard à un des quatre groupes. Les os témoins sont restés intacts, tandis que tous les autres ont été ostéotomisés pour créer des modèles de fracture qui ont été fixés avec une plaque de verrouillage et des vis de verrouillage (LP), une plaque vétérinaire découpable (VCP) avec des vis corticales ou des constructions de fixateur squelettique externe (ESF), et testés dans une flexion en quatre points jusqu'à la rupture. Des courbes de charge/déformation ont été générées pour chaque échantillon et utilisées pour calculer la rigidité (pente de la courbe) et la résistance (charge à la rupture). Les témoins intacts avaient une résistance et une rigidité supérieures à toutes les techniques de fixation dans les échantillons de radius/cubitus et d'humérus de lapin. Les constructions à plaque de verrouillage et VCP avaient une plus grande rigidité que l'ESF lorsqu'elles étaient appliquées au radius, tandis que les constructions à plaque de verrouillage étaient plus solides que VCP ou ESF lorsqu'elles étaient appliquées à l'humérus. Dans l'ensemble, la construction LP avait des caractéristiques ressemblant le plus à celles du témoin intact en ce qui concerne la force de l'humérus. Par conséquent, la fixation des fractures avec un LP fournirait la plus grande résistance dans les réparations des fractures humérales chez le lapin.(Traduit par Dr Serge Messier).