Successful total hip arthroplasty in a miniature horse.

OBJECTIVE: To describe the surgical treatment, postoperative management, and outcome of a miniature horse undergoing total hip arthroplasty (THA). STUDY DESIGN: Case report. ANIMALS: A 4-year-old miniature horse stallion weighing 85 kg. METHODS: The horse presented with left coxofemoral luxation of ~6 weeks duration. Computed tomography confirmed craniodorsal luxation with marked degenerative changes to the femoral head. The horse underwent THA using cementless press fit implants, including an interlocking lateral bolt for the femoral stem. RESULTS: The horse recovered well from anesthesia but suffered a coma-like episode after returning to a stable. Following treatment of presumed hypovolemia, the horse regained normal mentation and was discharged 24 days after surgery. At reassessment 12 weeks postoperatively, the horse was 2/10 left hind limb lameness at trot with good healing of the surgery site. Five months postoperatively mild (1/10) lameness remained at trot but the horse was able to canter normally on both reins. The horse has since been managed normally with no veterinary treatment required for 32 months postoperatively. CONCLUSION: Total hip arthroplasty is possible in miniature horses weighing up to 85 kg and can result in a good long-term outcome.

Outcomes and complications reported from a multiuser canine hip replacement registry over a 10-year period.

OBJECTIVE: To report outcomes and complications associated with total hip replacements (THR) using a multiuser canine hip registry (CHR) and owner-administered questionnaire. STUDY DESIGN: Prospective longitudinal clinical study. ANIMALS: Dogs (n = 1852). METHODS: Total hip replacement cases submitted to a CHR were reviewed. An online questionnaire including an adapted "Liverpool Osteoarthritis in Dogs" (LOAD) score was e-mailed to owners. Data were analyzed to determine associations between clinical variables and the agreement by veterinary surgeons and owners for complications. RESULTS: A group of 1329 (72%) dogs had unilateral THRs and another group of 523 (28%) dogs had bilateral THRs, resulting in 2375 THRs. Indications included hip dysplasia and osteoarthritis (n = 2028/2375, 85%). Implants were manufactured by Kyon (n = 1087, 46%), BioMedtrix CFX (n = 514, 22%), BioMedtrix hybrid (n = 264, 11%), BioMedtrix BFX (n = 221, 9%), and Helica (n = 107, 4.5%). Median veterinary surgeon and owner follow up were 1328 and 900 days respectively. Postoperative LOAD scores (21 ± 9) reported by 461 owners improved compared to preoperative scores (11 ± 9) (P < .001). Veterinary surgeons reported complications in 201/2375 (8.5%) THRs and owners in 107/461 (23%) THRs, with moderate agreement (weighted kappa = 0.44). No associations were identified between complications and weight, age, sex, or breed. BioMedtrix BFX and Helica implants were associated with increased complications (P = .031) when used for revisions of femoral head and neck excisions. CONCLUSION: Excellent outcomes, including improved canine mobility, were reported after THRs. Complications were underreported by veterinary surgeons compared to owners in this first multiuser CHR. CLINICAL SIGNIFICANCE: Canine THRs are safe, effective procedures but THR implants should be carefully selected when revising femoral head and neck excisions.

Peak Vertical Force and Vertical Impulse in Dogs With Cranial Cruciate Ligament Rupture and Meniscal Injury.

OBJECTIVE: To compare the peak vertical force (PVF) and vertical impulse (VI) in dogs with naturally occurring cranial cruciate ligament (CCL) disease with or without concurrent meniscal injury. STUDY DESIGN: Prospective case series. STUDY POPULATION: Client-owned dogs with naturally occurring CCL disease. METHODS: Dogs with hind limb lameness because of CCL disease that required surgery underwent force plate gait analysis. Force plate analysis was performed at a walking gait (speed 1-1.3 m/s; acceleration ± 0.5 m/s(2)) and data were analyzed using commercial proprietary software. Meniscal injury was diagnosed either by mini-arthrotomy or arthroscopy. The primary outcome was PVF and the secondary outcome was VI. Comparisons were made between dogs with or without meniscal injury, and dogs with partial or complete CCL rupture. RESULTS: Forty dogs were included. Meniscal injury was present in 18/40 dogs (45%). PVF (P = .003) and VI (P = .01) were significantly lower in dogs with meniscal injury than in dogs without meniscal injury. CONCLUSION: Dogs with CCL disease and medial meniscal injury had significantly reduced PVF and VI.

Acid-base and electrolyte balance following administration of three crystalloid solutions in dogs undergoing elective orthopaedic surgery.

OBJECTIVE: To compare acid-base balance and incidence of hyperchloraemic metabolic acidosis following administration of three crystalloid solutions to dogs undergoing anaesthesia for orthopaedic surgery. STUDY DESIGN: Prospective, randomised, clinical study. ANIMALS: Sixty dogs. METHODS: During a non-standardised anaesthetic, 0.9% saline (S), Hartmann's solution (H) or a polyionic glucose-free maintenance solution (M) was administered IV at 10 mL kg(-1)  hour(-1) . Venous blood pH, PCO2 , PCV, total protein, urea, sodium, potassium and chloride concentrations were measured at induction of anaesthesia (T0) and after 2 hours of fluid therapy (T2). Base excess (BE), bicarbonate, corrected chloride concentration (corrCl), osmolality, change in plasma volume (PV) and strong ion gap (SIG) were calculated. Changes in variables within groups (1-sample Student's t-test/Wilcoxon signed rank test) and between groups (1-way anova/Kruskal-Wallis) were assessed. Data are presented as median (interquartile range). Significance was set at p < 0.05. RESULTS: No significant differences existed between groups for pH, PCO2 , PCV, total protein, urea, potassium, corrCl, PV and SIG. Potassium significantly increased in all groups. Significant differences existed between groups S and M for BE, sodium, chloride, bicarbonate and osmolality, and between groups H and M for sodium and osmolality. Chloride concentration significantly changed from 116 (114-117) to 117 (116-119) mmol L(-1) in group S, 116 (115-118) to 115 (113-117) mmol L(-1) in group H and 116 (115-118) to 114 (113-118)  mmol L(-1) in group M. In groups H and M, sodium and osmolality decreased, and BE and bicarbonate concentration increased significantly. Plasma volume increased by 28 (14-44)%, 25 (5-40)% and 24 (13-33)% in groups S, H and M, respectively. CONCLUSION AND CLINICAL RELEVANCE: Hyperchloraemic metabolic acidosis did not develop after intraoperative 0.9% saline, Hartmann's solution or maintenance solution at 10 mL kg(-1)  hour(-1) for 2 hours in dogs undergoing elective orthopaedic surgery. Bicarbonate and BE increased after Hartmann's and maintenance solutions. Increases in potassium concentration were unexplained.

CT attenuation of the medial coronoid process is reduced in dogs with medial coronoid disease but independent of arthroscopic disease severity.

OBJECTIVE: To compare the attenuation of the medial coronoid process (MCP) in dogs with and without arthroscopically confirmed evidence of medial coronoid disease (MCD). ANIMALS: The database at our institution was searched for cases with thoracic limb lameness, diagnosed with MCD by arthroscopic examination that had CT as part of their investigation and compared with a control group of elbow joints from cadavers euthanized for reasons unrelated to MCD. A total of 84 elbow joints were included that met these criteria. PROCEDURES: Following CT, a standardized measurement of the MCP was obtained from apex to base and the mean attenuation, SD, and total area were recorded. A comparative measurement was obtained from the proximal radial cortex at the level of the nutrient foramen. Elbow joint arthroscopy was carried out using standard portals, and the modified Outerbridge score was (MOS) used to score elbow joint cartilage. Descriptive and inferential statistics were carried out using MLwiN and R. RESULTS: Attenuation of the MCP was reduced in dogs with MCD compared with those with no MCD (P < .002). No significant differences were observed in the attenuation between categories of severity (MOS). There was good inter- and intraobserver agreement between measurements (intraclass correlation coefficient = 0.89 and 0.95, respectively). CLINICAL RELEVANCE: MCP attenuation is reduced in dogs with MCD compared with dogs with no evidence of MCD. This finding may be a useful tool for early detection of MCD, but there is no relationship with arthroscopic lesion severity.

Elbow Arthrodesis Using a Medially Positioned Plate in 6 Dogs.

OBJECTIVE: The aim of this study was to report the surgical technique, associated complications and clinical outcome of elbow arthrodesis using a medially positioned plate. STUDY DESIGN: This was a retrospective case series. RESULTS: Six cases met the inclusion criteria. In all cases, the elbow was approached medially without the requirement for ulnar osteotomy. A non-locking 2.7/3.5- mm pre-contoured elbow arthrodesis plate was applied in 5/6 cases and a 2.0-mm String of Pearls plate applied in one case. The mean angle of arthrodesis was 118° (range: 113-130°). One major intraoperative complication occurred. Three minor and 3 major postoperative complications occurred. Postoperative imaging was available for 5/6 cases. Complete arthrodesis was confirmed by imaging in 4/5 cases, partial progression of arthrodesis was documented in 1/5 cases and no further images were deemed necessary. Postoperative Liverpool Osteoarthritis in Dogs score was available for two cases with scores of 20/52 and 10/52, respectively. Subjective outcomes in the remaining three cases were rated as acceptable more than 1 year postoperatively. CONCLUSION: Positioning the plate medially for elbow arthrodesis simplified the surgical approach, could be performed with a pre-contoured plate and allowed successful revision of an arthrodesis previously stabilized with a caudally positioned plate. The cases in this series had acceptable outcomes despite a high risk of complications.

Complications Following Surgical Correction of Medial Patellar Luxation in Small-to-Medium-Size Dogs.

OBJECTIVE: The main aim of this study was to describe complications in dogs weighing < 20 kg treated for medial patellar luxation and to determine risk factors associated with these complications. MATERIALS AND METHODS: Medical records were reviewed and cases were grouped based on four techniques of stabilization for the tibial tuberosity transposition (TTT). Variables including animal signalment, clinical presentation, TTT technique, other concurrent surgical techniques and associated complications were investigated. Multiple logistic regression was used to determine the association of the same variables with specific complications such as tibial tuberosity fractures or avulsions, patellar reluxation and implant-related complications. RESULTS: Of the 100 procedures performed, 37 suffered a complication. There were no significant differences in the overall complication rate between TTT stabilization techniques. Preservation of the tibial tuberosity distal cortical attachment was associated with a reduced risk of implant-related complications, whereas adding a medial release to the surgical techniques was associated with an increased risk of medial patellar reluxation. The type of trochleoplasty performed did not affect the complication rate. CONCLUSIONS: In the current study, a high rate of complications was found in dogs < 20 kg undergoing medial patellar luxation surgery. Performing a medial release and preserving the distal cortical attachment of the tibial tuberosity were the only variables associated respectively with an increase and a reduction in the risk of postsurgical complications.

A Comparison of Owner-Assessed Long-Term Outcome of Arthroscopic Intervention versus Conservative Managemento f Dogs with Medial Coronoid Process Disease.

OBJECTIVES: The purpose of this study was to compare the long-term outcome of dogs with medial coronoid process disease (MCPD) treated with arthroscopic intervention versus conservative management. MATERIALS AND METHODS: Medical records of dogs with MCPD treated by arthroscopic intervention or conservative management over an 8-year period were retrospectively reviewed. Long-term outcome (>12 months) was assessed via owner questionnaire including Liverpool Osteoarthritis in Dogs (LOAD) scores and Canine Brief Pain Inventory scores. RESULTS: Data from 67 clinically affected elbow joints (67 dogs) diagnosed with MCPD on computed tomography were included. Forty-four dogs underwent arthroscopic intervention and 23 dogs were treated with conservative management. The median LOAD and Pain Severity Score (PSS) for dogs in the arthroscopic intervention group compared with the conservatively managed group were not significantly different (p = 0.066 and p = 0.10, respectively). The median Pain Interference Score (PIS) was significantly higher in the arthroscopic intervention group versus the conservative management group (p = 0.028). There was no significant difference after controlling for age. For LOAD, PSS and PIS, older age at diagnosis was all significantly associated with higher scores (p = 0.048, p = 0.026 and p = 0.046, respectively) and older age at time of questionnaire completion showed a stronger association with the scores (p ≤0.001 for all). CLINICAL SIGNIFICANCE: Arthroscopic intervention showed no long-term benefit over conservative management for dogs with MCPD.

Evaluation of variables influencing success and complication rates in canine total hip replacement: results from the British Veterinary Orthopaedic Association Canine Hip Registry (collation of data: 2010-2012).

The objective of this study was to assess the variables associated with complications of total hip replacement (THR) and report owner-assessed outcomes. Entries into the British Veterinary Orthopaedic Association-Canine Hip Registry (BVOA-CHR) between September 2011 and December 2012 were reviewed separately and in conjunction with previous data (January 2010-August 2011). An outcomes assessment questionnaire was used to collect data from owners. Incidences of surgeon-reported and owner-reported complications were 8.2 per cent and 4.3 per cent, respectively. THR using the BioMedtrix BFX cup/stem prosthesis had a greater incidence of complications compared with THR using the BioMedtrix CFX cup/stem prosthesis (P=0.002); complications were 4.48 times more likely when using the BioMedtrix BFX cup/stem prosthesis versus the BioMedtrix CFX cup/stem prosthesis. THR using the BioMedtrix BFX cup/stem prosthesis had a higher incidence of complications compared with THR using a hybrid prosthesis (BioMedtrix BFX cup/CFX stem, BioMedtrix CFX cup/BFX stem) (P=0.046); complications were 2.85 times more likely when using the BioMedtrix BFX cup/stem prosthesis versus a hybrid prosthesis. In 95 per cent of cases, owner satisfaction with the outcome of THR was 'very good' or 'good'. Complication rates from the BVOA-CHR are similar to previous studies. The data suggest that prosthesis type is associated with complication rate, with BioMedtrix BFX (circa 2012) having a high short-term complication rate.