Assessment of Outcome of Arthroscopic Subtotal Coronoidectomy in Treating Medial Coronoid Disease and Effect of Concurrent Autologous Conditioned Plasma in Dogs Using Force Plate Analysis.

OBJECTIVE: The aim of this study was to assess the outcome of arthroscopic subtotal coronoidectomy in treating medial coronoid disease and the effect of concurrent autologous conditioned plasma (ACP) in dogs using force plate analysis. STUDY DESIGN: This study included 16 dogs with unilateral medial coronoid disease based on computed tomographic imaging. Treatment consisted of an arthroscopic subtotal coronoidectomy. As concurrent therapy, eight dogs received ACP at the end of the arthroscopy and eight dogs a placebo. Force plate analysis, including vertical forces, braking and propulsive forces, corresponding impulses and symmetry indices, was performed prior to arthroscopy and at 4, 12 and 26 weeks postoperatively. RESULTS: After an initial reduction of all force plate analysis parameters, vertical and propulsive parameters gradually improved to the level of healthy dogs at 26 weeks postoperatively. In contrast, braking parameters did not reach normal values at 26 weeks, demonstrating ongoing loss of elbow joint function. The ACP and placebo group did not show any significant difference in force plate analysis parameters during the 26 weeks study period. CONCLUSION: Arthroscopic subtotal coronoidectomy did not result in complete normalization of ground reaction forces, impulses and symmetry indices. Concurrent treatment with ACP, immediately after arthroscopy, did not improve outcome. Our results show that outcome of arthroscopic subtotal coronoidectomy in treating medial coronoid disease is less favourable than previously reported.

Review of minimally invasive surgical procedures for assessment and treatment of medial coronoid process disease.

OBJECTIVE: To summarize the current peer-reviewed publications on minimally invasive surgery (MIS) for medial coronoid process disease (MCPD) in dogs. STUDY DESIGN: Invited review. METHODS: Pubmed, CAB Abstracts and Scopus databases were utilized for literature review (1990-2023). RESULTS: More than 60 papers have been published that involve MIS evaluation or treatment of MCPD. Six prospective trials incorporated quantitative gait analysis evaluating outcome following MCPD debridement, of which three included a control group. Whilst case numbers were limited, all studies employing a control group failed to demonstrate superiority of surgery over nonsurgical management. Of three studies employing gait analysis and no control group, all documented some improvement in function compared to pretreatment lameness. Multiple studies document progression of osteoarthritis in dogs following MCPD debridement although this may not be synonymous with worsened function. Subtotal coronoid osteotomy (SCO) is described as an alternative to MCP fragment removal, although the long-term biomechanical consequences are currently unclear and quantitative data on the efficacy of this treatment in isolation for MCPD is awaited. CONCLUSION: Arthroscopy of the canine elbow joint is a safe means by which to evaluate MCP pathology. Quantitative longitudinal analysis of outcome following minimally invasive surgery for MCPD is required. Correlation with clearly defined subclassification inclusion criteria such as age, incongruity and the precise arthroscopic findings in each case are required to more accurately differentiate any superiority of surgery over nonsurgical management for this disease.

Computed tomographic assessment of the completeness of arthroscopic subtotal coronoidectomy in dogs with medial coronoid disease.

BACKGROUND: Until recent years, arthroscopic subtotal coronoidectomy has been the universally accepted treatment for medial coronoid disease but has variable clinical outcomes. The aim of this study was to evaluate the completeness of arthroscopic medial coronoid debridement and to detect the most vulnerable location of failure. METHODS: Eighty-three dogs with a diagnosis of medial coronoid disease were included in the study. Arthroscopic debridement was performed in 92 elbow joints, and the completeness of removal was assessed by postoperative computed tomography scans. RESULTS: Pathological changes were confined to the coronoid apex in 92/92 (100%) of cases and combined with radial incisure lesions in 39/92 (42%). Apical lesions were completely removed in 66/92 (72%) of cases and radial incisure lesions in 2/39 (5%). Bony remnants were detected at the apex (46%) and base (24%) of the medial coronoid process, free within the elbow joint (9%), and/or within the instrument port (84%). Fissures were positively associated with the occurrence of bony remnants (p = 0.038) and a 37% higher probability of incomplete removal of radial incisure lesions (p = 0.001). CONCLUSION: In this study, incomplete removal was more likely to occur in the presence of radial incisure lesions. Thorough assessment of this region during arthroscopy is strongly recommended.

Retrospective assessment of perioperative antimicrobial use for elective arthroscopy in horses.

OBJECTIVE: To describe perioperative antimicrobial use in horses undergoing elective arthroscopy. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Horses that underwent elective arthroscopy at one institution between July 2016 and May 2018, excluding those with a suspected infectious orthopedic disease or with a comorbidity that may have impacted prophylactic antimicrobial use decisions. METHODS: Medical records were reviewed to evaluate preoperative, intraoperative, and postoperative antimicrobial drug selection, dose, and timing. Associations between body weight and underdosing were evaluated by using analysis of variance, χ2 test was used for categorical comparisons, and least squares fit was used to evaluate factors associated with duration of postoperative antimicrobials. RESULTS: Among 150 horses, 149 (99.3%) received systemic preoperative antimicrobials. Only 53 (40.2%) horses were administered doses within 60 minutes of surgical incision. First incision was performed more than two half-lives after administration of sodium penicillin in 46 of 131 (35.1%) horses but in only 1 of 106 (0.8%) horses that received trimethoprim-sulfadoxine. Body weight was associated with underdosing for penicillin (P = .0075) and trimethoprim-sulfadoxine (P = .002) but not gentamicin (P = .92). Twenty-six (17%) horses received one postoperative antimicrobial dose, while antimicrobials were continued in hospital for a mean of 22.3 ± 4.4 hours after surgery in the other 123 horses. Among the 149 discharged horses, 115 (77.2%) were prescribed antimicrobials after discharge (range, 3-10 days; median, 3 days, interquartile range, 0 days). CONCLUSION: Deviations from common recommendations were apparent and provide evidence for the requirement to develop interventions to optimize perioperative prophylaxis. CLINICAL SIGNIFICANCE: Perioperative antimicrobial use practices should be regularly assessed to provide a benchmark and identify areas for intervention.

Long-term arthroscopic assessment of intra-articular allografts for treatment of spontaneous cranial cruciate ligament rupture in the dog.

OBJECTIVE: To assess the 12-month survival of intra-articular, decellularized allografts for the treatment of cranial cruciate ligament disease (CCLD) in dogs. STUDY DESIGN: Prospective case series. ANIMALS: Twenty client-owned dogs with spontaneous CCL rupture. METHODS: Affected stifles were treated solely by implantation of an intra-articular, decellularized, deep digital flexor tendon allograft. Functional outcome was evaluated at baseline and at 6 and 12 months after surgery with the Liverpool Osteoarthritis for Dogs questionnaire and force platform gait analysis. At 12 months after surgery, dogs underwent arthroscopy to visually assess the allografts. RESULTS: Scores on owner questionnaires (improved 62.5%; P = .005) and ground reaction forces (improved 34.4%; P = .017) were improved in all dogs 12 months after surgery. Dogs with an intact graft (IG) were more likely to have a successful outcome compared with dogs with a torn graft (P = .011). According to arthroscopy, 45% of grafts seemed to survive at 12 months after surgery. CONCLUSION: About half of intra-articular allografts survived 12 months after implantation in CCL-deficient stifles. Dogs with IG had successful outcomes at 12 months after surgery according to assessment by force platform gait analysis. CLINICAL SIGNIFICANCE: These results preclude immediate clinical application but provide evidence to justify further investigation of intra-articular grafts as a repair option for CLLD.

Teaching and proficiency assessment for arthroscopy in veterinary surgery: A 2017 survey of diplomates and residents of the American and European College of Veterinary Surgeons.

OBJECTIVE: To determine current methods of arthroscopic skills training and proficiency assessment, identify skills considered fundamental to arthroscopy, and evaluate desire for a formal training and assessment program. STUDY DESIGN: Anonymized electronic survey. SAMPLE POPULATION: Diplomates and residents of the American College of Veterinary Surgeons (ACVS) and European College of Veterinary Surgeons (ECVS). METHODS: An electronic survey was distributed in commercial software (Qualtrics, Provo, Utah). Questions were divided into 4 categories: (1) demographics, (2) arthroscopy experience, (3) teaching, and (4) proficiency assessment. Descriptive statistical analysis was performed. Comparisons between groups were performed by using χ2 , t tests, and 1-way ANOVA (P ≤ .05). RESULTS: In total, 429 diplomates and 149 residents responded (response rate 28%). Overall, 80% of respondents trained using clinical cases. Barriers to simulator training included cadaver/simulator availability and time. Skills deemed most fundamental included anatomic knowledge, precise portal placement, triangulation, and image orientation. Overall, 90% of respondents supported a formal training program with requirement to demonstrate proficiency; 80% believed this should be part of standard ACVS/ECVS residency training. CONCLUSION: Arthroscopic skills are taught by using clinical cases, with subjective proficiency assessment. Fundamental skills are those that may be taught using simulators. There is enthusiasm for formal arthroscopic skills training and assessment. CLINICAL SIGNIFICANCE: Improved acquisition and assessment of fundamental arthroscopic skills is indicated. A validated methodology for formal training using simulators, minimizing morbidity, and facilitating objective evaluation is warranted. This is the first phase of a project to develop and validate a simulator program.

Assessment of a novel equine tarsocrural experimental joint disease model using recombinant interleukin-1ß and arthroscopic articular sampling of the medial malleolus of the tibia on the standing sedated horse.

Joint disease and osteoarthritis are common problems in the horse and numerous experimental studies have been developed to determine the safety and efficacy of new therapies. Synovitis, a critical component of joint disease, has been experimentally induced using recombinant interleukin-1 beta (reIL-1ß) to investigate new joint therapies in a controlled environment, although the use of reIL-1ß has not been reported in the equine tarsocrural joint. A common consequence of performing controlled experiments is that articular tissue collection typically requires general anesthesia or euthanasia. This report describes a minimally invasive surgical biopsy technique to harvest joint tissues from the tarsocrural joint in standing horses. The aims of the study were to assess subjective and objective pain parameters following reIL-1ß induced synovitis in the tarsocrural joint and to describe the surgical technique including the location and quantity of tissues obtained with this method. Experimental synovitis was induced using reIL-1ß in one equine tarsocrural joint of each horse using a randomised controlled design. The minimally invasive surgical technique provided sufficient amounts of articular cartilage from the medial malleolus of the tibia and synovium to perform viability, biochemical and histological assessments without necessitating general anesthesia. The minimally invasive technique also allowed for lameness assessment that could have been influenced by more invasive methods of tissue collection. No incisional or lameness complications were detected after use. The synovitis model and surgical technique provided ample tissue for laboratory evaluation and avoided general anesthesia or sacrifice of the horse.

Systematic review of the prevalence, risk factors, diagnosis and management of meniscal injury in dogs: Part 2.

OBJECTIVE: To systematically evaluate the evidence reporting the diagnosis and management of meniscal injury in dogs with cranial cruciate ligament failure. STUDY DESIGN: Systematic literature review. MATERIALS AND METHODS: Research questions relating to the accuracy of diagnostic techniques for meniscal injury and the effects of meniscal treatment were defined. An electronic database search of PubMed and CAB Abstracts was performed during March 2015. Data were extracted for study participants, design, intervention, outcome measures and results. Studies were evaluated using a validated instrument for assessing methodological quality and assigned a Quality Index score. A level of evidence was then assigned to each study. RESULTS: Eighty-nine studies were identified. The median Quality Index score was 14 out of a possible 26. Twenty-seven studies were prospective case series, 31 retrospective case series, 16 animal research and 15 cadaveric studies. There were no class I or class II studies, 27 class III and 62 class IV studies. CONCLUSIONS: Despite a large number of publications the quality of evidence was generally low. No one study or combination of studies provided high quality evidence to support one diagnostic or surgical intervention over another for meniscal injuries in dogs with cranial cruciate ligament failure.

Assessment of medial coronoid disease in 180 canine lame elbow joints: a sensitivity and specificity comparison of radiographic, computed tomographic and arthroscopic findings.

BACKGROUND: Diagnostic imaging is essential to assess the lame patient; lesions of the elbow joint have traditionally been evaluated radiographically, however computed tomography (CT) has been suggested as a useful technique to diagnose various elbow pathologies. The primary objective of this study was to determine the sensitivity and specificity of CT to assess medial coronoid disease (MCD), using arthroscopy as gold standard. The secondary objective was to ascertain the radiographic sensitivity and specificity for MCD compared with CT. METHODS: For this study 180 elbow joints were assessed, of which 141 had been examined with radiography, CT and arthroscopy; and 39 joints, had radiographic and CT assessment. Sensitivity and specificity were calculated for CT and radiographic findings using available statistical software. RESULTS: Sensitivity and specificity of CT using arthroscopy as gold standard resulted in high values for sensitivity (100 %) and specificity (93 %) for the assessment of MCD. For the radiographic evaluation, a sensitivity of 98 % and specificity of 64 - 69 % using CT as the technique of reference, were found. DISCUSSION: These results suggest that in case of doubt during radiographic assessment, CT could be used as a non-invasive technique to assess the presence of MCD. CONCLUSION: Based on the high sensitivity and specificity obtained in this study it has been considered that CT, rather than arthroscopy, is the preferred noninvasive technique to assess MCD lesions of the canine elbow joint.

Arthroscopic assessment of osteochondrosis of the medial humeral condyle treated with debridement and sliding humeral osteotomy.

OBJECTIVE: To document the progression of disease after an unloading procedure when combined with arthroscopic debridement to treat osteochondrosis (OC) lesions affecting the medial humeral condyle in juvenile dogs without medial compartment disease. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs with medial humeral condyle OC (n = 6). METHODS: Dogs with medial humeral condyle OC (9 elbows) were treated by arthroscopic debridement of the OC lesion and sliding humeral osteotomy (SHO). Outcomes were assessed by radiography (n = 9), 2nd-look arthroscopy (9) and clinical examination including lameness assessment (9) at 18-28 months after surgery. RESULTS: Seven elbows had marked progression of pathology affecting the medial compartment, 5 elbows developed subsequent fragmentation of the medial coronoid process of the ulna [FMCP], 2 elbows had fibrocartilaginous infill of the humeral defect without development of coronoid pathology. CONCLUSION: This limited case series suggests that medial compartment disease develops despite unloading of the medial compartment using a distal diaphyseal SHO in juvenile dogs with OC.

Arthroscopic biceps ulnar release procedure (BURP): technique description and in vitro assessment of the association of visual control and surgeon experience to regional damage and tenotomy completeness.

OBJECTIVES: (1) Describe arthroscopic BURP surgical technique, (2) assess association of visual control and surgeon experience to tenotomy completeness and regional iatrogenic tissue damage. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: Canine cadavers weighing >20 kg (n = 16; 32 elbows). METHODS: Phase 1 = dissection/anatomic description/procedural refinement (n = 6). Phase 2 = technique description (n = 6). Phase 3 = association of surgeon experience and procedural visual control to tenotomy completion and regional iatrogenic damage (n = 20). Elbows were randomly assigned via coin toss to an experienced- or inexperienced-arthroscopist. Using conventional medial portals, surgeons sought to identify the medial collateral ligament (MCL) and ulnar insertion of the biceps tendon (uBT) before attempting complete tenotomy. Upon procedural completion, surgeons assigned a standardized "visual control score" (VCS) describing viewing that governed procedure and predicted % uBT release, MCL, and median nerve damage. Post-procedural dissection determined actual tenotomy completion and iatrogenic tissue damage. RESULTS: Complete BURP was achieved in 16 of 19 elbows. VCS was associated with tenotomy completeness (P < .01). "Blind" BURP was incomplete in both elbows in which it was attempted. Perception of complete BURP was associated with complete release (P < .01). MCL damage occurred in 10% of elbows. Surgeon experience did not influence VCS, regional damage, or BURP completeness. CONCLUSION: In canine cadavers, arthroscopic BURP can be consistently performed using conventional arthroscopic instruments and portals by both experienced and inexperienced arthroscopists when visual control guides the tenotomy into the distal aspect of the tendon.

Arthroscopic assessment for patellar injuries and novel suture repair of patellar fracture in a cat.

A 4 yr old spayed female domestic shorthair was evaluated for an acute, nonweight-bearing, left hind limb lameness. Following 2 wk of conservative management without clinical improvement, the patient was referred for further examination. The stifle was palpably enlarged with suspected periarticular fibrosis. Radiographs showed a lateral longitudinal patellar fracture as well as a medial patellar luxation. Arthroscopic examination of the stifle and repair of the patellar fracture and luxation were performed with an excellent clinical outcome. Nine weeks postoperatively, the owners reported that the cat was using the leg normally inside, and re-examination revealed no pain or crepitus with manipulation of the limb. To the authors' knowledge, this is the first reported use of arthroscopy as a diagnostic tool and of suture reduction for fracture repair in the management of feline patellar injury.

Comparison of five radiographic views for assessment of the medial aspect of the humeral condyle in dogs with osteochondritis dissecans.

OBJECTIVE: To compare 5 radiographic views for the detection of osteochondritis dissecans (OCD) in dogs with signs of elbow joint pain. ANIMALS: 53 dogs (100 elbow joints) with forelimb lameness and signs of elbow joint pain. PROCEDURES: Mediolateral (ML), flexed ML, craniocaudal (CC), craniolateral-caudomedial oblique (Cr15L-CdMO), and distomedial-proximolateral oblique (Di35M-PrLO) radiographic views of the 100 elbow joints were obtained. Four examiners graded radiographs with regard to elbow joint OCD. Joints were assessed by use of arthroscopy. Receiver operating characteristic (ROC) curves, kappa measure of agreement, and Fisher exact tests for association between median diagnostic value and actual status were computed. RESULTS: 47 joints had an abnormal medial aspect of the humeral condyle (MAHC), and among them, 11 had OCD. The presence of fractures of the medial coronoid process was significantly and positively correlated with the presence of abnormalities of the MAHC (r = 0.40), but was negatively correlated with the presence of OCD (r = -0.32). At 95% specificity, median sensitivities to detect OCD were 57% for Cr15L-CdMO, 56% for CC, 10% for flexed ML, 7% for ML, and 4% for Di35M-PrLO views. The areas under the ROC curves were significantly larger for the Cr15L-CdMO and CC views than for the ML, flexed ML, and Di35M-PrLO views for the detection of OCD. Only the Cr15L-CdMO and CC views allowed accurate detection of OCD. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with signs of elbow joint pain, the Cr15L-CdMO view is excellent and the CC view was good for detection of OCD.

A novel pin distraction device for arthroscopic assessment of the medial meniscus in dogs.

OBJECTIVE: To describe an extra-articular joint distractor for meniscal examination and treatment during canine stifle arthroscopy. STUDY DESIGN: Case series. ANIMALS: Dogs >or=20 kg with suspected cranial cruciate ligament (CrCL) deficiency. METHODS: A custom designed linear side bar was constructed to allow invasive pin distraction of the stifle joint. Its design efficacy for distraction of the medial joint compartment, observation and probing of the medial meniscus, and value during meniscal surgery was evaluated by clinical use. RESULTS: Application of the stifle distractor medial to the stifle joint using 2 negative threaded pins was easily performed percutaneously without the need of power equipment; however, unintended intra-articular placement of 1 threaded pin occurred in 2 stifles, without appreciable consequence to joint function. Observation as well as thorough probing of the caudal horn of the medial meniscus, even in the presence of a prominent remnant of the CrCL or severe periarticular fibrosis, was possible. Partial meniscectomy was effectively performed as needed without apparent damage to the associated articular surfaces. CONCLUSIONS: Distraction and translation of the medial compartment of the stifle joint using invasive pin distraction allowed observation and palpation of the caudal horn of the medial meniscus so that assessment and treatment were readily accomplished without apparent morbidity. CLINICAL RELEVANCE: With careful attention to accurate pin placement, invasive pin distraction of the medial compartment of the canine stifle joint may improve arthroscopic evaluation and treatment of meniscal pathology.

Accuracy of diagnostic arthroscopy for the assessment of cartilage damage in the equine metacarpophalangeal joint.

REASONS FOR PERFORMING STUDY: There are many noninvasive diagnostic methods used for evaluating chronic progressive joint disease, but each has severe limitations in the detection of early articular cartilage damage. OBJECTIVES: To evaluate the accuracy of arthroscopy as a diagnostic method for the assessment of the severity of cartilage surface damage on the proximal articular margin of the equine first phalanx (P1). HYPOTHESIS: That arthroscopic assessment of the visible cartilage provides 1) a good indication of the integrity of the cartilage surface and 2) a good estimation of the status of the cartilage surface of the entire articular area of P1. METHODS: Arthroscopic examination of the dorsal pouch of the metacarpophalangeal joint was performed in the left front limbs of 74 slaughter horses (age 5 months to 23 years). The appearance of the visible cartilage of P1 was scored by 2 independent arthroscopists, using the SFA arthroscopic grading system. The joints were dissected after completion of the arthroscopic procedure. The cartilage degeneration index (CDIP1) was determined and used as a quantitative measure for the overall degree of cartilage surface deterioration on the articular area of P1. Further, CDI values were determined for the dorsal articular margin of P1 (CDIdam), i.e. the area that can be visualised with arthroscopy. The CDIdam values were classified into 3 groups (CDIdam<25%, minor lesions; 25%45%, severe lesions). Differences between the 2 arthroscopists were evaluated statistically in a nonparametric test and Pearson correlation coefficients (r) with matching P values were determined for the correlations between SFA and CDIdam and between CDIP1 and CDIdam. The level of significance was set at P<0.05. RESULTS: Differences between SFA scores of the 2 arthroscopists were not significant (P = 0.22). In the group of joints with minor cartilage changes, there was no correlation between SFA and CDIdam (r = 0.12; P = 0.71), but there was a significant correlation between CDIP1 and CDIdam (r = 0.95; P<0.01). In the group with moderate cartilage damage, there was an increase in correlation between SFA and CDIdam (r = 0.27; P = 0.09) and a decrease in the correlation between CDIP1 and CDIdam (r = 0.48; P<0.01). In the group with severe cartilage changes, there was a significant correlation between SFA and CDIdam (r = 058; P<0.01), but no significant correlation between CDIP1 and CDIdam (r = 0.43; P = 0.06). CONCLUSIONS: Arthroscopic assessment of cartilage lesions on the proximal articular surface of P1 in joints with minor cartilage damage leads to an underestimation of the actual damage because proteoglycan depletion and light cartilage fibrillation cannot be detected arthroscopically. In cases with mild cartilage damage, the status of the cartilage surface of the visible area of P1 is a good representation of the status of the entire articular surface. In cases with severe cartilage lesions, there is an overestimation of real damage. In such joints, the arthroscopic scoring system provides reliable information, but the visible area is not representative of the entire articular surface. POTENTIAL RELEVANCE: From a practical viewpoint, it can be stated that the arthroscopic grading of visible lesions on the equine P1 gives the best impression of overall cartilage damage in joints with moderately severe cartilage lesions. It should be realised, however, that this is the result of an underestimation due to the shortcomings of the grading system, which is neutralised by an overestimation due to the fact that the severity of lesions on the visible area of P1 is not representative for the entire articular surface.

Preliminary evaluation of a behaviour-based system for assessment of post-operative pain in horses following arthroscopic surgery.

OBJECTIVE: To develop a method for objective assessment of equine post-operative pain. STUDY DESIGN: Prospective nonblinded clinical study. ANIMALS: Twelve adult horses: Group 1 (G1, n = 6), admitted for arthroscopy (under general anaesthesia, with multimodal analgesia); Group 2 (G2, n = 6), 'pain free' controls. MATERIALS AND METHODS: Horses were filmed continuously (CVI, time-lapse video recorder) over 72 hours, from 24 hours pre-surgery (PS) to 48 hours post-recovery (PR) (G1), and over 24 hours (G2). Activity budgets were determined from 24 to 0 hours PS, 0-24 and 24-48 hours PR (G1) and for 24 hours (G2). Using direct observation (DO), active behaviours and postures were recorded at set time points PS and PR (G1) and at two time points (morning/evening) (G2). Heart rate (HR) and respiration rate (RR) were recorded simultaneously. Statistical analysis investigated within-group and between-group time-related changes in behaviour, HR and RR. RESULTS: There was no difference in HR or RR between G1 and G2 at any time point. Anaesthetic 'hangover' and hunger-related activity modulated behaviour from 0 to 6 hours PR, when abnormal postures and locomotion occurred in all G1 horses, but no G2 horses. Compared with G1 (0-24 hours PR), G2 spent more time eating (t = -3.34, p < 0.01), more time at the front of the stable (t = -2.42, p < 0.05), and less time exhibiting 'abnormal' behaviour (U = 56, p < 0.01). Comparing PS and PR behaviour, G1 spent less time exploring from 24 to 48 hours PR (t = 3.49, p < 0.05), less time in sternal recumbency (t = -3.8, p < 0.05) and less time moving (t = 3.19, p < 0.05). Horses tended (p < 0.07) to spend less time positioned in the front of the stable PR (less from 24 to 48 hours PR than from 0 to 24 hours PR). Comparing PR (evening) behaviour, G2 spent more time with head above withers (U = 21.5, p < 0.01), and ears forwards (U = 22, p < 0.01). G1 showed time-related changes (all p < 0.05) in time with lower lip tense (S = 15.8), eating (S = 17.08) and with head positioned above withers (S = 18.04). No differences in event behaviours were observed between G1 and G2. Within G1, only olfactory behaviour varied significantly with time (S = 14.52, p < 0.05). CONCLUSIONS: Changes in equine behaviour suggestive of post-operative discomfort were identified using both DO and CVI. Analysis of activity budgets may be a more sensitive method of identifying behavioural changes indicative of equine discomfort than repeated DO of specific events and postures.

Qualitative and quantitative documentation of the racing performance of 461 Thoroughbred racehorses after arthroscopic removal of dorsoproximal first phalanx osteochondral fractures (1986-1995).

The purpose of this study was to examine the longevity of postoperative careers and quality of performance of 461 Thoroughbred racehorses after arthroscopic removal of dorsoproximal first phalanx (P1) osteochondral fractures. Six hundred and 59 dorsoproximal P1 chip fractures were removed arthroscopically from 574 joints in 461 horses presented for lameness or decreased performance attributed to the chip fractures. Radiological and arthroscopic examination revealed an average of 1.43 fragment sites/horse, 1.15 fragment sites/joint and 1.25 affected joints/horse. Eighty-nine percent of the horses (411/461) raced after surgery and 82% (377/461) did so at the same or higher class. Fifty horses did not race after surgery. Sixty-eight percent of the horses raced in a Stake or Allowance race postoperatively. Data, previously undocumented, establishes that the quantity and quality of performance is not diminished after arthroscopic treatment of dorsoproximal P1 fragmentation. Surgical removal of chip fractures is a means of preserving the economic value of an injured Thoroughbred, allowing a rapid and successful return to racing at the previous level of racing performance.

Apical fracture of the proximal sesamoid bone in standardbred horses: 43 cases (1990-1996).

OBJECTIVE: To determine whether fracture fragment dimensions, suspensory ligament damage, and racing status at the time of injury were associated with outcome in Standardbred horses with apical fracture of the proximal sesamoid bone. DESIGN: Retrospective study. ANIMALS: 43 Standardbred racehorses. PROCEDURE: Medical records, racing records, and radiographs were reviewed, and ultrasonographic findings were scored. Measurements of the fractured portion of the proximal sesamoid bone were made. RESULTS: Seventy-four percent (32/43) of horses were pacers, and 26% (11/43) were trotters. Statistical differences between trotters and pacers regarding ability to start, number of starts, or amount of money earned after injury were not detected. Females earned significantly more money per start after injury than males. Eighty-six percent (37/43) of fractures involved hind limbs and 14% (6/43) involved forelimbs. Horses with forelimb injuries earned less money per start. Severity of suspensory ligament damage did not affect postinjury racing performance. A higher proportion of horses that had raced before injury returned to racing after surgery than horses that had not raced before injury, although a significant difference between these groups was not detected. Eighty-eight percent of horses that raced before injury raced after injury. Fifty-six percent of horses that did not race before injury raced after injury. Fracture fragment dimensions did not affect outcome. CLINICAL IMPLICATIONS: Dimensions of the apical fracture fragment of the proximal sesamoid bone in Standardbred horses and degree of suspensory ligament damage did not affect outcome. Prognosis for return to racing soundness is good in horses that had raced before injury and fair in horses that had not raced before injury.

Preliminary investigations of pain and analgesia assessment in horses administered phenylbutazone or placebo after arthroscopic surgery.

Twenty-five horses undergoing arthroscopic surgery were studied to develop a scheme for assessing pain in horses while investigating the effects of phenylbutazone (PBZ) analgesia. Fifteen of the 25 horses received PBZ 4 mg/kg intravenously (IV) before surgery and 2 mg/kg (IV) every 12 hours thereafter until 60 hours; the remaining 10 (placebo group) were given a corresponding volume of saline. In both groups, venous blood samples were collected for catecholamine, beta-endorphin, and cortisol assays before premedication and up to 72 hours after surgery. Postoperative pain was evaluated by measuring predefined behavioral and physiological variables. A total postoperative pain severity index (TPPSI) was calculated using all variables. There were no differences between PBZ and placebo groups in plasma beta-endorphin or catecholamine concentrations, but the TPPSI was higher in the placebo group than in the PBZ group, suggesting that perioperative treatment with PBZ has some analgesic benefit. This study shows the difficulties associated with pain assessment in horses.