G. M. Hayes

Relationship between pharyngeal conformation and otitis media with effusion in Cavalier King Charles spaniels.

Otitis media with effusion (OME) is a common incidental finding in otherwise normal Cavalier King Charles spaniels (CKCS). In this study, measurements made on MRI were used to determine whether there was an association between OME and brachycephalic conformation. The results confirm that association and also demonstrate that, in CKCS, greater thickness of the soft palate and reduced nasopharyngeal aperture are significantly associated with OME. These results suggest that auditory tube dysfunction and OME may represent a previously overlooked consequence of brachycephalic conformation in dogs.

Does the degree of preoperative subluxation or soft tissue tension affect the incidence of postoperative luxation in dogs after total hip replacement

OBJECTIVE To investigate whether preexisting coxofemoral subluxation/luxation predisposes to postoperative total hip replacement (THR) luxation. STUDY DESIGN Case series. ANIMALS Dogs (n=100) that had cemented THR (n=109); 23 normal controls. METHODS A preliminary study was performed to validate our methods of assessing luxation and laxity by comparing dogs with severe hip dysplasia with a control population of normal dogs. For the main study, the records and radiographs of all dogs that had primary THR were reviewed. Measurements taken from preoperative radiographs to quantify hip subluxation/laxity included the Norberg angle, subluxation index, and 2 new measures: acetabular depth ratio (ADR) and dorsal acetabular rim ratio (DARR). Differences between groups that had luxation within 8 weeks and those that did not were investigated. RESULTS Postoperative luxation occurred in 13 dogs (12%) within 8 weeks of surgery. Luxation was significantly associated with various measurements (including Norberg angle, ADR, DARR) thought to reflect degree of subluxation/soft tissue tension. CONCLUSION Luxation after canine THR is a multifactorial problem but preexisting subluxation/soft tissue laxity is a significant risk factor for this complication.Objective: To investigate whether preexisting coxofemoral subluxation/luxation predisposes to postoperative total hip replacement (THR) luxation. Study Design: Case series. Animals: Dogs (n=100) that had cemented THR (n=109); 23 normal controls. Methods: A preliminary study was performed to validate our methods of assessing luxation and laxity by comparing dogs with severe hip dysplasia with a control population of normal dogs. For the main study, the records and radiographs of all dogs that had primary THR were reviewed. Measurements taken from preoperative radiographs to quantify hip subluxation/laxity included the Norberg angle, subluxation index, and 2 new measures: acetabular depth ratio (ADR) and dorsal acetabular rim ratio (DARR). Differences between groups that had luxation within 8 weeks and those that did not were investigated. Results: Postoperative luxation occurred in 13 dogs (12%) within 8 weeks of surgery. Luxation was significantly associated with various measurements (including Norberg angle, ADR, DARR) thought to reflect degree of subluxation/soft tissue tension. Conclusion: Luxation after canine THR is a multifactorial problem but preexisting subluxation/soft tissue laxity is a significant risk factor for this complication.

Risk factors for medial meniscal injury in association with cranial cruciate ligament rupture.

OBJECTIVES To determine the significant risk factors for medial meniscal injury in naturally occurring cranial cruciate ligament rupture and to quantify the risk using multivariate analysis. METHODS A retrospective case control study was performed of dogs that had undergone surgery for cranial cruciate ligament rupture. Data recorded included patient signalment (age, breed and sex), the duration of the lameness, the extent of the cranial cruciate ligament rupture (complete or partial) and the condition of the medial meniscus. Logistic regression was used to analyse the relationship between these variables and tears in the medial meniscus. RESULTS One hundred and sixty-one of 443 stifles (36·3%) in 366 dogs had a medial meniscal tear. The risk of a medial meniscal tear was increased by 12·9 times in association with complete cranial cruciate ligament rupture (OR 12·9; 95% CI 6·8 to 24·2), by approximately 2·6% for each additional week of lameness (OR 1·026; 95% CI 1·009 to 1·043) and by approximately 1·4% for each additional kilogram of bodyweight (OR 1·014; 95% CI 1·000 to 1·028). Golden retrievers and Rottweilers were at increased risk and West Highland white terriers were at reduced risk of medial meniscal tears compared with Labrador retrievers. CLINICAL SIGNIFICANCE To minimise the risk of medial meniscal tears, surgical stabilisation should not be unnecessarily delayed.

Use of the Cumulative Summation Technique to Quantitatively Assess a Surgical Learning Curve: Canine Total Hip Replacement

Objective: To quantitatively assess a surgical “learning curve” using the cumulative summation (CUSUM) score technique. Study Design: Application of a CUSUM technique to a consecutive series of surgical cases. Animals: Consecutive primary cemented total hip replacement (THR; n=116) in 106 dogs. Methods: Records of all dogs that had primary canine THR were reviewed. Data retrieved included date of surgery, postoperative complications, and duration of follow-up. The 12-week outcome was analyzed graphically and with a CUSUM technique. Results: One hundred and one (87%) procedures were “successful” and 15 (13%) developed major complications within 12 weeks (failures). The CUSUM chart clearly demonstrated an initial “learning curve” of ∼44 THR. Conclusion: The CUSUM technique can be used to demonstrate the learning curve for canine THR surgery.

Long bone fracture as a complication following external skeletal fixation: 11 cases.

OBJECTIVES To report on a series of dogs and cats with long bone fractures that occurred as a direct consequence of linear external skeletal fixation (ESF) application. METHODS Retrospective study. Data from the medical records and radiographs of canine (n = 4) and feline (n = 7) cases were collected from three referral and three first opinion practices in the UK (1999 to 2011). RESULTS Long bone fractures occurred following the application of linear ESF either while the ESF was in situ or after removal. All fractures occurred through either a pin tract or an empty drill hole. Pins associated with ESF-related fracture tended to be in the higher end of the recommended size range. The majority of cases had additional complicating factors such as multiple injuries, revision surgery, poor owner compliance with postoperative exercise restriction and the presence of empty drill holes. CLINICAL SIGNIFICANCE In cases with features that could complicate outcome, careful attention should be paid to recommendations for ESF application. Leaving empty drill holes is suboptimal. The retrospective nature of the study, low numbers of, and diversity amongst, cases should be taken into consideration when interpreting the results from this study.

Surgical treatment of dorsal hemivertebrae associated with kyphosis by spinal segmental stabilisation, with or without decompression

This retrospective case series examined the effectiveness of spinal segmental stabilisation, with or without decompression, in nine dogs with neurological deficits associated with dorsal hemivertebrae. Data on signalment, preoperative neurological status, imaging findings, surgical techniques and outcome were evaluated. All cases occurred in young or adult, small-breed dogs with neurological signs ranging from progressive moderate pelvic limb ataxia to non-ambulatory paraparesis. Six dogs also showed urinary and faecal incontinence. In each dog, one or more dorsal thoracic hemivertebra(e) were detected by radiography and MRI. In all dogs, hemivertebra(e) were associated with kyphosis and reduced vertebral canal diameter. All dogs were surgically managed with spinal segmental stabilisation, using Steinmann pins and orthopaedic wires and/or sutures attached to the spinous processes. Three dogs also underwent additional decompressive surgery. Post-operative follow-up ranged from 1.5 to 5.5 years. Immediate or delayed post-operative complications occurred in three dogs, including implant migration or loosening. Eight dogs showed long-term gait improvement, with resolution of incontinence if previously present. At 2-6 years post-surgery, four dogs were neurologically normal, three had mild residual ataxia, one had moderate ambulatory paraparesis, and one dog relapsed 3.5 years after surgery, resulting in severe paraparesis. Spinal segmental stabilisation techniques, with or without decompression, can result in satisfactory outcomes in small dogs with hemivertebrae and mild to moderate neurological signs. Further adaptations might be required to avoid implant loosening and allow continued growth in immature dogs.

Distribution and persistence of topical clotrimazole after sinus infusion in normal canine cadavers.

OBJECTIVES To determine the in vitro persistence of clotrimazole 1% cream in the canine frontal sinus and to evaluate the distribution of clotrimazole solution over the sino-nasal mucosa using a previously described surgical treatment protocol for canine nasal aspergillosis. METHODS Two canine skulls were used to monitor the persistence of clotrimazole cream in the lateral frontal sinus at 37°C. The distribution of irrigation solution around the frontal sinus compartments and nasal cavity was determined using six canine cadaver heads by trephining either the lateral or both the lateral and rostral compartments of the frontal sinus. Stain was added to the sinus irrigation solution before visually inspecting the sagittally sectioned heads. RESULTS Clotrimazole cream persisted in the frontal sinus for at least 96 hours. The nasal cavity mucosa was completely stained in 8 of 12 sides and almost completely stained in the remaining 4 of 12 sides. Flushing irrigation solution through the lateral compartment of the frontal sinus resulted in inadequate staining of the rostral compartment but medicating both the lateral and rostral compartments resulted in complete coating of all frontal sinus mucosa in eight of eight sides. CLINICAL SIGNIFICANCE Clotrimazole cream has the potential to be retained in the frontal sinus for several days and is distributed effectively in normal canine cadavers. Medicating both the rostral and lateral compartments of the frontal sinus may be indicated in some clinical cases.

Salter-Harris type III fractures of the distal humerus in two dogs

Salter-Harris type III fractures of the distal humerus in a four-month-old male Labrador Retriever and a male crossbreed dog (estimated to be 3.5-months-old) are reported. Both fractures were treated with open reduction and interfragmentary compression by lag screw fixation. Both fractures healed and full limb use was regained at four weeks postoperatively. The occurrence of this unusual fracture type may be related to the physeal closure pattern of the distal humeral physis, and a different mechanism of injury compared to the more common Salter-Harris type IV fracture seen in this region.

Comparison of Veterinary Student Ability to Learn 1-Handed and 2-Handed Techniques for Surgical Knot Tying.

OBJECTIVE To determine which type of surgical hand-tie trainee surgeons learn most readily in a laboratory setting, using a combination of audiovisual demonstration and one-on-one teaching. STUDY DESIGN Randomized controlled learning trial. SAMPLE POPULATION Year 4 veterinary students in their 1st year of clinical training (n = 58). METHODS Veterinary students entering clinical rotations were randomly allocated to 2 learning groups: 1-handed (28 students) or 2-handed (30 students) surgical ties. Knot tying technique was taught followed by three 15-minute practice sessions with student progress recorded by filming each student tying a square knot (2 throws). All 3 knot tying attempts were scored for technique and knot formation. Data on potential confounding factors between groups, including age and gender, were recorded. RESULTS There were no significant differences between group scores for each attempt (1st attempt P = .5; 2nd P = .2; 3rd P = .19). Initially, scores indicated more rapid learning in the 1-handed group but fewer individuals achieved a perfect technique and knot after 60 minutes of learning (29/30 for 2-handed; 24/28 for 1-handed group). The 1-handed group was the most error-prone (after 45 minutes P < .01; after 60 min P < .01). CONCLUSIONS Over 95% of students in the 2-handed group performed the technique and knot perfectly after 60 minutes learning time; were significantly less error-prone and fewer students continued to make corrected errors after 60 minutes. This evidence indicates that the 2-handed technique allows students to achieve success in a manageable teaching time.

Use of the cumulative summation technique to quantitatively assess a surgical learning curve

Objective: To quantitatively assess a surgical “learning curve” using the cumulative summation (CUSUM) score technique. Study Design: Application of a CUSUM technique to a consecutive series of surgical cases. Animals: Consecutive primary cemented total hip replacement (THR; n=116) in 106 dogs. Methods: Records of all dogs that had primary canine THR were reviewed. Data retrieved included date of surgery, postoperative complications, and duration of follow-up. The 12-week outcome was analyzed graphically and with a CUSUM technique. Results: One hundred and one (87%) procedures were “successful” and 15 (13%) developed major complications within 12 weeks (failures). The CUSUM chart clearly demonstrated an initial “learning curve” of ∼44 THR. Conclusion: The CUSUM technique can be used to demonstrate the learning curve for canine THR surgery.