Effects of cyclooxygenase and soluble epoxide hydrolase inhibitors on apoptosis of cultured primary equine chondrocytes.

BACKGROUND: Apoptosis is an important mechanism underlying chondrocyte loss in osteoarthritis that could be affected by modulation of lipid signaling via inhibition of cyclooxygenases (COX) and soluble epoxide hydrolase (sEH). OBJECTIVE: To determine the impact of inhibiting COX and sEH alone or in combination on apoptosis of equine chondrocytes. METHODS: Cultured primary equine chondrocytes were subjected to serum deprivation or incubation with 1 µg/ml tunicamycin for 24 h to induce apoptosis via caspase activation and endoplasmic reticulum (ER) stress, respectively. Cells were treated with the non-selective COX inhibitor phenylbutazone, the COX-2 selective inhibitor firocoxib and the sEH inhibitor t-TUCB alone or in combination. The inhibitors were used at half-maximal (IC50), 80% of maximal (IC80) and 10-fold the 80% inhibitory concentration (10xIC80) for the equine enzymes. Apoptosis was quantified via ELISA technique. Data were analyzed with unpaired two-tailed t-test or one-way ANOVA followed by Bonferroni's post-hoc while correcting for multiple comparisons via statistical hypothesis testing. P < 0.05 was considered significant. RESULTS: In the caspase model, 10xIC80t-TUCB significantly decreased whereas 10xIC80 phenylbutazone significantly enhanced apoptosis. Apoptosis enhancement by phenylbutazone was significantly attenuated by concurrent 10xIC80t-TUCB. The remaining treatments and concentrations had no effect on apoptosis development. In the ER stress model, IC50 and IC80 phenylbutazone and firocoxib significantly enhanced apoptosis, which was fully prevented by concurrent 10xIC80t-TUCB. MAIN LIMITATIONS: In vitro findings that will need to be verified in vivo. CONCLUSIONS: Chondrocyte apoptosis caused by ER stress can be enhanced by COX inhibition but prevented by concurrent inhibition of sEH.

The association between collagen and bone biomarkers and radiographic osteoarthritis in the distal tarsal joints of horses.

BACKGROUND: Osteoarthritis (OA) of the distal intertarsal (DIT) and tarsometatarsal (TMT) joints occurs commonly. Synovial fluid (SF) biomarkers of collagen and bone turnover have potential clinical value. OBJECTIVES: To measure SF biomarker concentrations from DIT and TMT joints in adult horses and determine if they correlate with radiographic OA severity and are higher in joints with radiographic OA compared to controls. STUDY DESIGN: Cross-sectional. METHODS: Radiographic OA of DIT and TMT joints was evaluated from adult horses (5-35 years old). Overall radiographic scores divided horses into those with mild or moderate radiographic OA (16 joints from 9 horses) or controls (13 joints from 9 horses). Direct biomarkers of OA (Carboxypropeptide of type II collagen = CPII, carboxy-neoepitope of type II collagen exposed after collagenase-cleavage = C2C, Bone alkaline phosphatase = BAP and Chondroitin sulfate epitope = CS846) were measured via ELISA and CPII/C2C was calculated. Biomarkers were correlated with radiographic findings and concentrations from those with radiographic OA to control joints and were compared. RESULTS: Concentrations of CPII (R = 0.84, P<0.001), C2C (R = 0.69, P<0.001) and BAP (R = 0.41, P = 0.03) as well as CPII/C2C (R = 0.69, P<0.001) values positively correlated with overall radiographic scores. Adjusted means ± s.d., after controlling for age, for CPII (P<0.001), C2C (P<0.001), CPII/C2C (P = 0.004) and BAP (P = 0.05) were significantly higher in DIT and TMT joints with radiographic OA (CPII: 2174.45 ± 1064.01; C2C: 233.52 ± 51.187; CPII/C2C: 9.01 ± 4.09; BAP: 21.98 ± 15.34) compared to controls (CPII: 594.53 ± 463.05; C2C: 153.12 ± 48.95; CPII/C2C: 3.96 ± 2.38; BAP: 12.76 ± 3.61). CPII (P<0.001), C2C (P = 0.001) and CPII/C2C (P = 0.001) were significantly higher with moderate radiographic OA (CPII: 2444.61 ± 772.78; C2C: 248.90 ± 44.94; CPII/C2C: 9.47 ± 2.97) compared to controls (CPII: 658.38 ± 417.36; C2C: 156.49 ± 47.61; CPII/C2C: 4.15 ± 2.04), with CPII also showing significantly higher concentrations (P = 0.04) with mild radiographic OA compared (1515.00 ± 584.95) to controls (658.38 ± 417.36). There were no differences in CS846 concentrations between radiographic OA and control joints. Age positively correlated with CPII (R = 0.48, P = 0.01) and C2C (R = 0.44, P = 0.02) concentrations. MAIN LIMITATIONS: Radiographic OA was assessed, not clinical lameness. Controls were not age-matched to those with spontaneous radiographic OA. CONCLUSIONS: There is an association between collagen (CPII, C2C and CPII/C2C) and bone (BAP) biomarkers and radiographic OA in the distal tarsal joints of horses.

Circumferential hoof clamp method of lameness induction in the horse.

A circumferential hoof clamp method to induce controlled and reversible lameness in the forelimbs of eight horses was assessed. Peak vertical forces and vertical impulses were recorded using a force plate to verify induced lameness. Video recordings were used by blinded observers to determine subjective lameness using a 0-5 scale and any residual lameness following clamp loosening. Tightening of clamps resulted in consistent, visible lameness in the selected limbs in all horses. Lameness was confirmed by significant decreases from baseline in the peak vertical force (P <0.01). Lameness was also confirmed subjectively by elevated median scores (0 at baseline and 2 during lameness). Lameness was not immediately reversible after clamp loosening (median score 1.5), but horses were not obviously lame after clamp removal and were no different from initial baseline (median score 0.5) approximately 3 days later.

Posture and movement characteristics of forward and backward walking in horses with shivering and acquired bilateral stringhalt.

REASONS FOR PERFORMING STUDY: To investigate and further characterise posture and movement characteristics during forward and backward walking in horses with shivering and acquired, bilateral stringhalt. OBJECTIVES: To characterise the movement of horses with shivering (also known as shivers) in comparison with control horses and horses with acquired bilateral stringhalt. STUDY DESIGN: Qualitative video analysis of gait in horses. METHODS: Owners' and authors' videos of horses with shivering or stringhalt and control horses walking forwards and backwards and manually lifting their limbs were examined subjectively to characterise hyperflexion, hyperextension and postural abnormalities of the hindlimbs. The pattern and timing of vertical displacement of a hindlimb over one stride unit was evaluated among control, shivering and stringhalt cases. RESULTS: Gait patterns of shivering cases were characterised as follows: shivering-hyperextension (-HE, n = 13), in which horses subjectively showed hyperextension when backing and lifting the limb; shivering-hyperflexion (-HF, n = 27), in which horses showed hindlimb hyperflexion and abduction during backward walking; and shivering-forward hyperflexion (-FHF, n = 4), which resembled shivering-HF but included intermittent hyperflexion and abduction with forward walking. Horses with shivering-HF, shivering-FHF and stringhalt (n = 7) had a prolonged swing phase duration compared with control horses and horses with shivering-HE during backward walking. With the swing phase of forward walking, horses with stringhalt had a rapid ascent to adducted hyperflexion of the hindlimb, compared with a rapid descent of the hindlimb after abducted hyperflexion in horses with shivering-FHF. CONCLUSIONS: Shivering affects backward walking, with either HE or HF of hindlimbs, and can gradually progress to involve intermittent abducted hyperflexion during forward walking. Shivering-HF and shivering-FHF can look remarkably similar to acquired bilateral stringhalt during backward walking; however, stringhalt can be distinguished from shivering-HF by hyperflexion during forward walking and from shivering-FHF by an acute onset of a more consistent, rapidly ascending, hyperflexed, adducted hindlimb gait at a walk.

Vascular perfusion of the dorsal and palmar condyles of the equine third metacarpal bone.

REASONS FOR PERFORMING STUDY: Palmar osteochondral disease (POD) is an overload arthrosis that commonly affects fetlock joints of racing Thoroughbreds (TB) but the aetiopathogenesis of the disease has not been well defined. OBJECTIVES: The aim of this study was to compare India ink perfusion in the dorsal and palmar condyles of the third metacarpal bone (McIII) in both passively flexed and maximally extended fetlock joints from paired equine cadaver limbs. STUDY DESIGN: Descriptive cadaver study comparing perfusion of condyles of McIII in paired cadaver limbs in flexion (control group) and maximal extension (intervention group). METHODS: Pairs of forelimbs were acquired from 5 TB horses subjected to euthanasia for reasons unrelated to lameness. Limb pairs were perfused intra-arterially with India ink and then randomly assigned to passive flexion or maximal extension of the fetlock joint. Limbs were sectioned sagittally in 3 mm sections through the fetlock and 12 sections per limb processed using a modified tissue-clearing technique. Sections were subsequently digitally imaged and bone perfusion evaluated with image analysis software. RESULTS: Greater perfusion of the dorsal condyle than of palmar condyle was observed in 78% of sections from limbs in passive flexion and 92% of maximally extended sections. Perfusion to the palmar aspect of the condyle was significantly decreased (P < 0.0001) when the limbs were placed in maximal extension compared to passive flexion. CONCLUSIONS: The palmar condyle of McIII had less perfusion than the dorsal condyle when the fetlock joint was in passive flexion and this difference was exacerbated by maximal extension. Based on the anatomical location of POD lesions, perfusion differences between the dorsal and palmar condyles of McIII may be associated with development of these lesions.

Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury.

OBJECTIVE: Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). METHODS: An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) were graded. At week 16, synovium and cartilage biopsies were taken arthroscopically from OC injured and sham joints for histologic evaluation and the OC fragment was removed. RESULTS: OC fragments were successfully created and horses were free of clinical lameness after fragment removal. Forelimb gait asymmetry was observed at week 2 (P = 0.0012), while joint circumference (P < 0.0001) and effusion scores (P < 0.0001) were increased in injured limbs compared to baseline from weeks 2 to 16. Positive flexion response of injured limbs was noted at multiple time points. Capsular enthesophytes were seen radiographically in injured limbs. Articular cartilage damage was demonstrated arthroscopically as mild wear-lines and histologically as superficial zone chondrocyte death accompanied by mild proliferation. Synovial hyperemia and fibrosis were present at the site of OC injury. CONCLUSION: Acute OC injury to the MCP joint resulted in clinical, imaging, and histologic changes in cartilage and synovium characteristic of early PTOA. This model will be useful for defining biomarkers of early osteoarthritis and for monitoring response to therapy and surgery.

Steroid diffusion into the navicular bursa occurs in horses affected by palmar foot pain.

Palmar foot pain is frequently treated by steroid injections into the distal interphalangeal joint (DIPJ) in the anticipation that the steroid will diffuse to the navicular bursa and palmar foot structures. The object of this study was to determine if triamcinolone acetonide (TA) would in fact be able to locally diffuse from the DIPJ into the navicular bursa in horses affected by palmar foot pain. Both forelimb DIPJs (nine horses) were injected with 10 mg of TA. Navicular bursa fluid samples, both forelimb and one hind limb (systemic control), were analysed for TA with high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) six hours later. Foot radiographs were graded (0-4) on severity of changes. Forelimb navicular bursa TA concentrations (mean±sd log(10), 3.20±0.56) were significantly higher than systemic control concentrations (mean±sd log(10), 1.89±0.3) (P<0.0001). Horses with a radiographic grade of >2 were four times as likely to have TA log(10) concentrations less than 3.2 (158.49 ng/ml). TA locally diffused from the DIPJ into the navicular bursa in horses affected by palmar foot pain; TA concentrations decreased as radiographic severity increased.

Urinary CTX-II concentrations are elevated and associated with knee pain and function in subjects with ACL reconstruction.

OBJECTIVE: Post-traumatic knee osteoarthritis (OA) is prevalent after anterior cruciate ligament reconstruction (ACLR). Biomarkers that identify individuals likely to develop OA, especially symptomatic OA, can help target preventative and therapeutic strategies. This study examined the magnitude and change over time in urinary CTX-II (uCTX-II) concentrations shortly after ACL reconstruction, and, secondarily, the associations with knee pain and function. DESIGN: Subjects were 28 patients with ACLR and 28 age- and sex-matched controls (CNTRL). Testing was conducted at four time points spaced 4 weeks apart (4, 8, 12 and 16 weeks post-operative in ACLR). Measures included demographics, urine samples, Numeric Pain Rating Scale (NPRS) and International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). uCTX-II concentrations were determined with competitive enzyme-linked immunosorbent assay (ELISA). uCTX-II concentrations at each time point in ACLR were compared to the mean concentration over time in CNTRL, with and without adjustment for body mass index (BMI). Changes over time in each measure and correlations between the slopes of change were examined. RESULTS: uCTX-II concentrations were significantly higher in ACLR than CNTRL through 16 weeks post-operative when adjusted for BMI. In ACLR, uCTX-II concentrations significantly decreased over time, and the slope was associated with NPRS (r = 0.406, P = 0.039) and IKDC-SKF (r = -0.402, P = 0.034) slopes. CONCLUSION: uCTX-II concentrations shortly after ACLR were elevated compared to CNTRL and declined over time. Decreasing uCTX-II concentrations were associated with decreasing knee pain and improving function. uCTX-II may have a role as a prognostic marker following ACLR and warrants further investigation.

Osteochondral injury increases type II collagen degradation products (C2C) in synovial fluid of Thoroughbred racehorses.

OBJECTIVES: To investigate the effects of exercise and osteochondral (OC) injury on type II collagen degradation products (collagenase cleavage neoepitope commercially known as C2C) in synovial fluid (SF) from Thoroughbred (TB) racehorses and to compare these results with radiographic and arthroscopic scores of severity of joint injury. METHODS: Metacarpophalangeal/metatarsophalangeal (MCP/MTP) and carpal SF was obtained from (1) 20 normal rested horses, (2) the same horses after 5 to 6 months of race training, and (3) 27 horses with OC injury from racing. For group 3, radiographic and arthroscopic scores were determined. Concentrations of SF C2C were determined by ELISA. RESULTS: SF C2C concentrations in OC injured carpal and MCP/MTP joints were significantly different than rested and exercised joints (P<0.01). However, carpal and MCP/MTP SF C2C concentrations were not significantly different between rested and exercised groups. Arthroscopic scores were significantly higher for OC injured carpal than OC injured MCP/MTP joints (P=0.002). OC injured SF C2C concentrations were positively correlated with radiographic and arthroscopic scores. Arthroscopic scores were positively correlated with radiographic scores. SF C2C concentrations >or= 64 pmol/mL for MCP/MTP joints and >or= 75 pmol/mL for carpal joints discriminated OC injured joints from rested or exercised joints. CONCLUSION: OC injury caused a significant increase in SF C2C concentrations in carpal and MCP/MTP joints compared to rested and exercised horses. SF C2C concentrations were correlated to severity of joint injury. Based on these findings, SF C2C analysis may be useful for evaluation of joint injury.

Joint dependent concentrations of bone alkaline phosphatase in serum and synovial fluids of horses with osteochondral injury: an analytical and clinical validation.

OBJECTIVES: Validate use of a commercially available immunoassay for measurement of bone alkaline phosphatase (BAP) in equine serum and synovial fluid (SF), and investigate the effects of osteochondral (OC) injury in horses on BAP concentrations in serum and SF. METHODS: SF was collected from 37 joints of 34 Thoroughbred (TB) racehorses undergoing arthroscopic surgery for the removal of OC fragments from either the carpal joints (n=18) or the metacarpo-/metatarsophalangeal (MP) joints (n=19). SF was also obtained from 52 joints of 16 normal TB horses, collected bilaterally from carpal joints of 10 horses (n=40), and MP joints of six horses (n=12). Blood was obtained from all 50 horses. A commercially available immunoassay was validated and subsequently used to determine equine serum and SF BAP concentrations. Correlations to radiographic and arthroscopic scores were assessed. RESULTS: BAP concentrations were significantly lower in serum from horses with OC injury in their carpal or MP joints than in serum from normal horses. SF BAP concentrations in normal and OC injured carpal joints were significantly higher than MP joints. BAP concentrations were significantly higher in SF from OC injured carpal joints than normal. BAP concentrations were affected by joint sampled, with age having a significant interaction. Concentrations of BAP in the serum (<30U/L), SF (>22U/L) and a ratio of SF to serum > or = 0.5 were predictive of OC injury. Radiographic and arthroscopic scores significantly correlated with serum BAP concentrations, and SF:serum BAP correlated with arthroscopic scores. CONCLUSIONS: Determination of serum and SF BAP concentrations may be beneficial in the investigation of early joint injury. Joint and injury dependent differences in BAP concentrations allowed the estimation of predictive value for identifying OC injury.

A simplified method of determining synovial fluid chondroitin sulfate chain length.

OBJECTIVE: To determine whether dimethylmethylene blue (DMMB) analysis, when combined with agarose gel filtration chromatography (Superose 6), can be performed instead of fluorophore-assisted carbohydrate electrophoresis (FACE) to determine chondroitin sulfate (CS) chain length in synovial fluid (SF). METHODS: SF was obtained from (1) normal horses after 8 weeks of rest, (2) the same horses after 9 months of treadmill training, and (3) horses with osteochondral (OC) injury from racing. SF CS concentrations and chain lengths were determined by gel chromatography and DMMB analysis and compared with previous results determined by FACE analysis on the same samples. RESULTS: DMMB analysis showed that SF CS peak chain length in the OC injury group increased significantly (18.7 kDa) when compared to rested and exercised normal horses (15.6 kDa). The assay had a positive predictive value of 71% and a negative predictive value of 75% for discriminating between normal and injured joints. CONCLUSIONS: We report a simple and inexpensive DMMB analysis of SF CS chain length, which, when coupled with Superose 6 chromatography, discriminates between normal and post-injury joints. Similar to our previous FACE analysis results [Brown MP, Trumble TN, Plaas AHK, Sandy JD, Romano M, Hernandez J, et-al. Exercise and injury increase chondroitin sulfate chain length and decrease hyaluronan chain length in synovial fluid. Osteoarthritis Cartilage 2007;15], our DMMB results show an increase in the chain length of the CS in the SF of injured joints.

Exercise and injury increase chondroitin sulfate chain length and decrease hyaluronan chain length in synovial fluid.

OBJECTIVES: (1) To investigate the effects of exercise and osteochondral (OC) injury on synovial fluid (SF) chondroitin sulfate (CS) and hyaluronan (HA) concentration and chain length, (2) to compare SF and cartilage CS data from joints with OC fragmentation, and (3) to compare SF CS and HA profiles with those seen in serum from the same horses. METHODS: Serum and SF were obtained from (1) normal horses after 8 weeks rest, (2) the same horses after 9 months treadmill training, and (3) horses with OC injury from racing. Articular cartilage was also collected from group 3 horses. Concentrations and chain lengths of CS and HA were determined by gel chromatography and fluorophore-assisted carbohydrate electrophoresis. RESULTS: SF CS peak chain length in the OC injury group increased significantly (18.7kDa) when compared to rested horses (11.6kDa), with exercise producing an intermediate chain length (15.6kDa). Cartilage and serum from the OC injury group had the abnormally long CS chains seen in SF from these horses. Total SF HA was significantly lower in the OC injury group compared to the rested group. Both the OC injury group and the exercised group had significant decreases in SF HA chain length compared to the rested group. CONCLUSIONS: Chain length of SF CS was increased by exercise and OC injury. Exercise resulted in a modest increase, whereas OC injury caused a marked increase. In contrast to CS, SF HA chain length was decreased by OC injury, and to a lesser extent by exercise. Chain length analysis of SF CS and HA may provide a useful tool for evaluation of joint health.

Synovial fluid gelatinase concentrations and matrix metalloproteinase and cytokine expression in naturally occurring joint disease in horses.

OBJECTIVES: To determine concentrations of matrix metalloproteinase (MMP)-2 and -9 in synovial fluid; and mRNA expression of MMP-1, -13, and -3; interleukin[IL]-1alpha and beta; and tumor necrosis factor (TNF)-alpha in synovial membrane and articular cartilage from horses with naturally occurring joint disease. SAMPLE POPULATION: Synovial fluid (n = 76), synovial membrane (59), and articular cartilage (45) from 5 clinically normal horses and 55 horses with joint disease categorized as traumatic (acute [AT] or chronic [CT]), osteochondritis dissecans (OCD), or septic (S). PROCEDURE: Synovial fluid gelatinase concentrations were analyzed, using zymography. Synovial membrane and articular cartilage mRNA expression for MMP-1, -3, and -13, IL-1alpha and beta, TNF-alpha, type-II collagen, and aggrecan were analyzed, using quantitative reverse transcriptase-polymerase chain reaction. RESULTS: Synovial fluid pro-MMP-2 concentration was significantly higher in diseased joints than normal joints. Septic joints had significantly higher concentrations of pro and active MMP-9. Stromelysin-1 was expressed in > or = 80% of synovial membrane and articular cartilage samples and was strongly influenced by age. Collagenases were rarely expressed, with MMP-13 expressed only in diseased joints. Interleukin-1beta expression was significantly higher in all OCD samples and was influenced by age. Tumor necrosis factor-alpha expression was significantly higher in cartilage from joints with AT and OCD. There was no correlation between MMP or cytokines and type-II collagen or aggrecan expression. CONCLUSIONS AND CLINICAL RELEVANCE: Matrix metalloproteinase-2 and -3 are abundant in naturally occurring joint disease and normal joints. Interleukin-1beta and TNF-alpha may be important in the pathogenesis of OCD. Age affects MMP and IL-1beta concentrations.

The application of technetium-99m hexamethylpropyleneamine oxime (99mTc-HMPAO) labeled white blood cells for the diagnosis of right dorsal ulcerative colitis in two horses.

The application of 99mTc-HMPAO labeled white blood cells to support the diagnosis of right dorsal ulcerative colitis was studied in two horses with a history and clinical signs consistent with phenylbutazone toxicity. These images were compared to a reference horse unaffected by right dorsal ulcerative colitis. Blood was collected aseptically in heparinized syringes from the patients for in vitro white blood cell (WBC) radiolabeling. The buffy coat was separated out and radiolabeled with 99mTc-HMPAO. The radiolabeled blood was re-injected i.v. and four images of the right and left side of the patient's abdomen were acquired at 4 hours and 20 hours post-injection. Results of the nuclear study revealed no abnormal findings in the abdomen at the four-hour post-injection images in any horse. Images obtained 20 hours post-injection revealed a linear uptake of radiolabeled WBCs in the right cranioventral abdomen in the region of the right dorsal colon in both horses with right dorsal ulcerative colitis. The reference horse had no radiopharmaceutical uptake in this region. This nuclear imaging study was a rapid, non-invasive method to identify right dorsal colon inflammation. These findings not only supported the diagnosis of right dorsal ulcerative colitis, but also facilitated appropriate medical management of each horse.

Laparoscopic intra-abdominal ligation of the testicular artery following castration in a horse.

A 364-kg (800-lb) 1-year-old mixed-breed horse was admitted for treatment of uncontrolled bleeding after castration. Multiple attempts to ligate the testicular artery through the scrotal incisions prior to referral had been unsuccessful. Because of the owner's concerns about cost, an attempt was made to control the bleeding by applying pressure to the inguinal region and administering formalin IV. However, hemorrhage continued. A decision was made to use laparoscopy to ligate the testicular artery. The horse was anesthetized and positioned in dorsal recumbency, and a routine ventral laparoscopic approach was used. The horse recovered without further complications. Laparoscopy should be considered for ligation of the testicular artery in horses with uncontrolled bleeding after castration.

Standing male equine urogenital endoscopic surgery.

Standing laparoscopy in the horse was used initially as a diagnostic tool to assist in the diagnosis of a cryptorchid testicle. Now, this technique is also used for treatment of cryptorchid testicles. The focus of this article is the standing laparoscopic cryptorchidectomy, the most common laparoscopic procedure performed on the male equine urogenital tract. Advantages, disadvantages, instrumentation, and general procedure are discussed.

Laparoscopic ovariectomy in two standing llamas.

Laparoscopic ovariectomy was performed in 2 llamas that were sedated but remained standing, avoiding possible complications associated with general anesthesia. All incisions were made in the left paralumbar fossa. The only intraoperative complications encountered were difficulty in maneuvering the laparoscope ventral to the uterine body in 1 llama because of distension of the urinary bladder, and a tendency to lean on the sidebar of the stocks in the other llama. The only postoperative complication was subcutaneous emphysema, which could be minimized by suctioning excess CO2 from the abdomen at completion of surgery. Laparoscopic ovariectomy was successful in these llamas and allowed direct examination and manipulation of the ovaries even though llamas were standing during surgery.

Epiglottic augmentation for treatment of dorsal displacement of the soft palate in racehorses: 59 cases (1985-1994).

OBJECTIVE: To determine whether epiglottic augmentation, in conjunction with more traditional surgical methods, would be useful in the treatment of dorsal displacement of the soft palate in racehorses. DESIGN: Retrospective study. ANIMALS: 40 Thoroughbred and 19 Standardbred racehorses. PROCEDURE: Polytetrafluoroethylene paste was injected submucosally on the lingual epiglottic surface of each horse. In addition, sternothyrohyoideus myectomy or sternothyroideus tenectomy and staphylectomy were performed in most horses. RESULTS: Racing performance was improved after surgery in 29 of 40 (73%) Thoroughbreds and 10 of 19 (53%) Standardbreds. Twenty-nine (49%) horses won > or = 1 race after surgery. CLINICAL IMPLICATIONS: Results suggest that epiglottic augmentation, in conjunction with other surgical methods, may be an effective method of treating horses with poor racing performance attributable to dorsal displacement of the soft palate.

Clinical relevance of the microvasculature of the equine proximal sesamoid bone.

The blood supply to the proximal sesamoid bone of the equine forelimb was examined in 18 cadaver limbs from adult horses, using x-ray computed tomography and a tissue-clearing (Spalteholz) technique. Results of the study indicated that the proximal sesamoid bones were supplied by multiple branches of the medial and lateral palmar digital arteries, which entered the proximal half of the bones on their non-articular, abaxial surface. After entering the bone, the vessels traverse dorsally, axially, and distally, arborizing into several smaller branches that appear to supply the entire bone. The major branches of these vessels reside in bony canals, the orientation and distribution of which parallel the radiographic lucencies seen in horses with sesamoiditis and correspond to the configuration of apical fracture patterns.

Consideration of anatomic and radiographic features of the caudal pouches of the femorotibial joints of horses for the purpose of arthroscopy.

Development of an arthroscopic approach to the caudal pouches of the equine stifle has been necessary because cranial approaches do not allow access to articular lesions in the caudal aspect of the joint. Therefore, the anatomy of the caudal region was examined in 52 cadaver limbs by use of gross dissection (29), x-ray-computed tomography (6), fluoroscopy (8), or arthroscopy (9). Additionally, using arthroscopic techniques developed in equine cadaver limbs, 3 stifles from 2 anesthetized horses were arthroscopically explored. Fluoroscopy was used to verify needle placement for joint injection and filling patterns of each femorotibial joint. The medial femorotibial joint sac (n = 4) held a mean +/- SD 41.67 +/- 5.77 ml of injection fluid, and the lateral femorotibial joint sac (n = 4) held a mean 61.67 +/- 2.89 ml of injection fluid. Vital structures that inadvertently could be damaged during arthroscopy of the caudal pouches of the stifle included the peroneal nerve (located approx 7 cm caudal to the lateral collateral ligament), the popliteal artery and vein (situated directly between the medial and lateral femoral condyles), and the lateral femoral condyle (most often traumatized during arthroscopy). The tendon of the popliteus muscle, which is contiguous with the joint capsule of the caudal pouch of the lateral femorotibial joint, made arthroscopic exploration of this pouch particularly difficult.