Joints Of Horses Research Articles

Comparison of the effects of triamcinolone acetonide or platelet-rich plasma on expression of extracellular matrix-related genes in equine healthy chondrocytes in vitro

ABSTRACT: In healthy cartilage, chondrocytes maintain an expression of collagens and proteoglycans and are sensitive to growth factors and cytokines that either enhance or reduce type II collagen synthesis. In osteoarthritis, pro-inflammatory cytokines, such as IL-6, induce overexpression of metalloproteinases (MMP) and decreasing synthesis of aggrecan. Use of chondroprotectors agents, such as Platelet-Rich Plasma (PRP) and triamcinolone (TA) are alternatives to reduce the progression of joint damage. In this study, we used chondrocytes extracted from metacarpophalangeal joints of healthy horses as the experimental model. Cells were treated in vitro with PRP or TA. No differences were observed between these treatments in comparison to the control group when the expressions of MMP9, MMP13, IL-6 and ACAN genes were evaluated (P<0.05). With these results, we can suggest that the treatments were not deleterious to equine cultured chondrocyte, once they did not stimulate MMPs and IL-6 synthesis or caused changes in ACAN.

Galectins-1 and-3 Increase in Equine Post-traumatic Osteoarthritis.

Galectins are potent regulators of cell adhesion, growth and apoptosis in diverse cell types, including chondrocytes and synovial fibroblasts. Elevations in synovial fluid galectin-3 have been observed in rheumatoid arthritis, juvenile idiopathic arthritis and experimental inflammatory arthritis in animal models, whereas galectin-1 is thought to be protective. Less is known about galectins-1 and-3 in osteoarthritis (OA). Therefore, the purpose of this study was: (1) to determine whether galectin-1 and-3 synovial fluid concentrations and synovial membrane and cartilage histochemical staining were altered following osteochondral injury in an experimental equine osteoarthritis (OA) model and (2) to measure galectin-1 and-3 mRNA expression and synovial fluid concentrations in naturally occurring equine carpal OA. Synovial fluid galectin-1 and-3 concentrations were quantified using custom ELISAs in two research horse cohorts undergoing experimental OA induction (n = 5 and 4) and in a cohort of horses with naturally occurring carpal OA (n = 57). Galectin mRNA expression in synovial membrane and cartilage tissue obtained from carpal joints of horses with naturally occurring OA was measured using RT-qPCR, and galectin immunostaining was assessed in synovial membrane and osteochondral tissues in the experimental model (n = 5). Synovial fluid galectin-1 and-3 concentrations increased following experimental carpal osteochondral fragmentation. Cartilage galectin-1 mRNA expression increased with OA severity in naturally occurring disease. The superficial zone of healthy articular cartilage stained intensely for galectin-3 in sham-operated joints, whereas galectin-1 staining was nearly absent. Chondrocyte galectin-1 and-3 immunoreactivity increased following cartilage injury, particularly in galectin-1 positive chondrones. Galectins-1 and-3 are present in healthy equine synovial fluid and increase following post-traumatic OA. Healthy superficial zone chondrocytes express galectin-3, whereas galectin-1 chondrocyte staining is limited predominantly to chondrones and injured cartilage. Further work is needed to clarify the functions of galectins-1 and-3 in healthy and OA joints.

Objective Evaluation of the Response to Perineural Analgesia of the Deep Branch of the Lateral Plantar Nerve and Intraarticular Analgesia of the Tarsometatarsal Joint in Horses With Suspected Proximal Metatarsal Pain Using Body-Mounted Inertial Sensors

Perineural analgesia of the deep branch of the lateral plantar nerve (DBLPN block) and intraarticular analgesia of the tarsometatarsal joint (TMT block) are commonly used to differentiate pain originating from the distal tarsal and the proximal metatarsal areas in horses. However, both analgesic techniques have recently been subjected to close scrutiny, with questions raised as to their efficacy. The purpose of this study is to undertake an objective assessment of the effect of both diagnostic analgesia techniques on hindlimb lameness using a body-mounted inertial sensor system (Lameness Locator; Equinosis LLC, Columbia, MO). Horses with chronic hindlimb lameness were instrumented with inertial sensors measuring vertical pelvic asymmetry in millimeters and underwent a routine lameness examination including diagnostic analgesia. Twenty-seven horses showing an improvement in lameness after the DBLPN block were selected for the study. These horses underwent the TMT block on the following day. The change in vertical pelvic asymmetry after the DBLPN block was compared to the change following the TMT block. Of 27 horses, 17 showed improvement after the DBLPN block but not after the TMT block (group 1). The other 10 horses showed improvement in lameness after both analgesic techniques (group 2). The DBLPN block and the TMT block desensitized different structures in more than half of the horses. However, the possibility that both analgesic techniques can desensitize the same structures due to either the diffusion of the anesthetic agent or of an inadvertent injection still remains.

Gene Therapy for Osteoarthritis: Pharmacokinetics of Intra-Articular Self-Complementary Adeno-Associated Virus Interleukin-1 Receptor Antagonist Delivery in an Equine Model.

Toward the treatment of osteoarthritis (OA), the authors have been investigating self-complementary adeno-associated virus (scAAV) for intra-articular delivery of therapeutic gene products. As OA frequently affects weight-bearing joints, pharmacokinetic studies of scAAV gene delivery were performed in the joints of the equine forelimb to identify parameters relevant to clinical translation in humans. Using interleukin-1 receptor antagonist (IL-1Ra) as a secreted therapeutic reporter, scAAV vector plasmids containing codon-optimized cDNA for equine IL-1Ra (eqIL-1Ra) were generated, which produced eqIL-1Ra at levels 30- to 50-fold higher than the native sequence. The most efficient cDNA was packaged in AAV2.5 capsid, and following characterization in vitro, the virus was injected into the carpal and metacarpophalangeal joints of horses over a 100-fold dose range. A putative ceiling dose of 5 × 1012 viral genomes was identified that elevated the steady-state eqIL-1Ra in the synovial fluids of injected joints by >40-fold over endogenous levels and was sustained for at least 6 months. No adverse effects were seen, and eqIL-1Ra in serum and urine remained at background levels throughout. Using the 5 × 1012 viral genome dose of scAAV, and green fluorescent protein as a cytologic marker, the local and systemic distribution of vector and transduced cells following intra-articular injection scAAV.GFP were compared in healthy equine joints and in those with late-stage, naturally occurring OA. In both cases, 99.7% of the vector remained within the injected joint. Strikingly, the pathologies characteristic of OA (synovitis, osteophyte formation, and cartilage erosion) were associated with a substantial increase in transgenic expression relative to tissues in healthy joints. This was most notable in regions of articular cartilage with visible damage, where foci of brilliantly fluorescent chondrocytes were observed. Overall, these data suggest that AAV-mediated gene transfer can provide relatively safe, sustained protein drug delivery to joints of human proportions.

Subchondral bone cyst surgical treatment using the application of stem progenitor cells combined with alginate hydrogel in small joints in horses.

One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We have observed at the in vitro level, that this hydrogel complex induces osteogenic and chondrogenic differentiation potential through the upregulation of bone morphogenetic protein, osteopontin, collagen type I and aggrecan mRNA levels. Moreover, we detected the creation of a 3D extracellular matrix (EM). To investigate the complex in vivo, we chose 8 horses of varying age suffering from SBC, which resulted in lameness, to undergo experimental surgery. We documented the horses' clinical appearance, lameness and radiographic appearance, to determine that there was clinical improvement in 87.75% of the patients (n=7, out of 8 horses) 6 months postoperatively and 100% (n=8, out of 8 horses) a year after surgery. These results are promising for the potential of this procedure to become the standard in SBC treatment.

Use of a 3-Telsa magnet to perform delayed gadolinium-enhanced magnetic resonance imaging of the distal interphalangeal joint of horses with and without naturally occurring osteoarthritis.

OBJECTIVE To characterize delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) features of healthy hyaline cartilage of the distal interphalangeal joint (DIPJ) of horses, to determine whether dGEMRIC can be used to differentiate various stages of naturally occurring osteoarthritis of the DIPJ, and to correlate relaxation times determined by dGEMRIC with the glycosaminoglycan concentration, water content, and macroscopic and histologic findings of hyaline cartilage of DIPJs with and without osteoarthritis. SAMPLE 1 cadaveric forelimb DIPJ from each of 12 adult warmblood horses. PROCEDURES T1-weighted cartilage relaxation times were obtained for predetermined sites of the DIPJ before (T1preGd) and after (T1postGd) intra-articular gadolinium administration. Corresponding cartilage sites underwent macroscopic, histologic, and immunohistochemical evaluation, and cartilage glycosaminoglycan concentration and water content were determined. Median T1preGd and T1postGd were correlated with macroscopic, histologic, and biochemical data. Mixed generalized linear models were created to evaluate the effects of cartilage site, articular surface, and macroscopic and histologic scores on relaxation times. RESULTS 122 cartilage specimens were analyzed. Median T1postGd was lower than the median T1preGd for normal and diseased cartilage. Both T1preGd and T1postGd were correlated with macroscopic and histologic scores, whereby T1preGd increased and T1postGd decreased as osteoarthritis progressed. There was topographic variation of T1preGd and T1postGd within the DIPJ. Cartilage glycosaminoglycan concentration and water content were significantly correlated with T1preGd and macroscopic and histologic scores but were not correlated with T1postGd. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dGEMRIC relaxation times varied for DIPJs with various degrees of osteoarthritis. These findings may help facilitate early detection of osteoarthritis.

Time required to achieve maximum concentration of amikacin in synovial fluid of the distal interphalangeal joint after intravenous regional limb perfusion in horses.

OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial fluid was collected from the DIP joint 5, 10, 15, 20, 25, and 30 minutes after IVRLP; the tourniquet was removed after the 20-minute sample was collected. Blood samples were collected from the jugular vein 5, 10, 15, 19, 21, 25, and 30 minutes after IVRLP. Amikacin was quantified with a fluorescence polarization immunoassay. Median Cmax of amikacin and Tmax in the DIP joint were determined. RESULTS 2 horses were excluded because an insufficient volume of synovial fluid was collected. Median Cmax for the DIP joint was 600 μg/mL (range, 37 to 2,420 μg/mL). Median Tmax for the DIP joint was 15 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Tmax of amikacin was 15 minutes after IVRLP in horses and Cmax did not increase > 15 minutes after IVRLP despite maintenance of the tourniquet. Application of a tourniquet for 15 minutes should be sufficient for completion of IVRLP when attempting to achieve an adequate concentration of amikacin in the synovial fluid of the DIP joint.

Erratum: Didatic approach of ultrasonographic examination for evaluation of the carpal joint in horses

Erratum: Didatic approach of ultrasonographic examination for evaluation of the carpal joint in horses

Didatic approach of ultrasonographic examination for evaluation of the carpal joint in horses

ABSTRACT: The carpus is a complex articulation, which is often involved in injuries in equine athletes. The objective of this study was to suggest a didactic approach for ultrasonography training for the examination of the carpal joint in horses. Ultrasonograhy examination was performed in a healthy 14-year-old horse. The images were compared with those of a dissected anatomic specimen of the carpal region of a senior horse and with those reported in the literature. Identifiable structures were as follows: (dorsal) tendon of the muscle extensor carpi radialis, tendon of the muscle extensor carpi obliquus, tendon of the muscle commom digital extensor, dorsal synovial outpouchings, joint capsule and fat cushion, (lateral) tendon of the muscle lateral digital extensor, lateral collateral ligament (deep and superficial components), (medial) medial collateral ligament (deep and superficial components) and (palmar) palmar intercarpal ligament, carpal sheath, carpal tunnel, superficial digital flexor tendon, proximal origin of the deep digital flexor tendon, and palmar carpal ligament. Prior knowledge of the anatomy in combination with the study of anatomical specimens is essential for recognizing musculoskeletal structures during ultrasound examination, contributing to the training and learning processes.

Response of three digital anesthetic technics in horses with forelimb hoof lameness

ABSTRACT The presented study aimed to assess objectively the response of distal interphalangeal joint (DIJ), navicular bursa (NB) and deep digital flexor tendon sheath (DDFTS) anesthesia in horses with forelimb hoof lameness; and evaluate if the presence of radiographic abnormalities on navicular bone could interfere on blocks’ results. Fifteen horses with lameness improvement above 70% after palmar digital nerve (PDN) block were selected for this study. Blocks were assessed separately on five consecutive trials at seven different time-points. The fifth trial was performed to evaluate the influence of exercise on preexisting lameness. Most of horses (73.33%) presented pain related to the podotrochlear apparatus based on clinical and lameness exam and blocks’ responses. NB and DIJ anesthesia differed on the frequency of horses with lameness improvement above 70% only at 10min (p=0.03), and both differed from DDFTS block until 30’(p<0.05). The blocks’ response was variable along the time and the highest means for NB, DIJ and DDFTS were observed at 5-10 minutes (’), 15-20’ and 10-15’ respectively.Exercise had low interference on lameness intensity since no improvement above 50% was observed and an increase on lameness intensity over time was identified in seven horses. Variable grades of navicular bone radiographic lesions were observed in 14 horses, although these lesions had no interference on blocks’ response (p>0.05). The NB and DIJ blocks had similar responses and both were superior to DDFTS anesthesia, coincident with a major prevalence of podotroclear apparatus abnormalities in this equine population.

Cartilage oligomeric matrix protein neoepitope in the synovial fluid of horses with acute lameness: A new biomarker for the early stages of osteoarthritis.

SummaryBackgroundClinical tools to diagnose the early changes of osteoarthritis (OA) that occur in the articular cartilage are lacking.ObjectivesWe sought to identify and quantify a novel cartilage oligomeric matrix protein (COMP) neoepitope in the synovial fluid from the joints of healthy horses and those with different stages of OA.Study design In vitro quantitative proteomics and assay development with application in synovial fluids samples obtained from biobanks of well‐characterised horses.MethodsArticular cartilage explants were incubated with or without interleukin‐1β for 25 days. Media were analysed via quantitative proteomics. Synovial fluid was obtained from either normal joints (n = 15) or joints causing lameness (n = 17) or with structural OA lesions (n = 7) and analysed for concentrations of the COMP neoepitope using a custom‐developed inhibition enzyme‐linked immunosorbent assay (ELISA). Explants were immunostained with polyclonal antibodies against COMP and the COMP neoepitopes.ResultsSemitryptic COMP peptides were identified and quantified in cell culture media from cartilage explants. A rabbit polyclonal antibody was raised against the neoepitope of the N‐terminal portion of one COMP fragment (sequence SGPTHEGVC). An inhibition ELISA was developed to quantify the COMP neoepitope in synovial fluid. The mean concentration of the COMP neoepitope significantly increased in the synovial fluid from the joints responsible for acute lameness compared with normal joints and the joints of chronically lame horses and in joints with chronic structural OA. Immunolabelling for the COMP neoepitope revealed a pericellular staining in the interleukin‐1β‐stimulated explants.Main limitationsThe ELISA is based on polyclonal antisera rather than a monoclonal antibody.ConclusionsThe increase in the COMP neoepitope in the synovial fluid from horses with acute lameness suggests that this neoepitope has the potential to be a unique candidate biomarker for the early molecular changes in articular cartilage associated with OA.

Ultrasound-guided approach to the cervical articular process joints in horses: a validation of the technique in cadavers.

To compare accuracy of the ultrasound-guided craniodorsal (CrD) approach with the dorsal (D) approach to the cervical articular process joints, and to evaluate the effect of the transducer, needle gauge, and operator experience. Cervical articular process joints from 14 cadaveric neck specimens were injected using either a D or CrD approach, a linear (13 MHx) or microconvex transducer (10 MHz), and an 18 or 20 gauge needle, by an experienced or inexperienced operator. Injectate consisted of an iodinated contrast material solution. Time taken for injection, number of redirects, and retrieval of synovial fluid were recorded. Accuracy was assessed using a scoring system for contrast seen on computed tomography (CT). The successful performance of intra-articular injections of contrast detected by CT using the D (61/68) and CrD (57/64) approaches was comparable. No significant effect of approach, transducer or needle gauge was observed on injection accuracy, time taken to perform injection, or number of redirects. The 18 gauge needle had a positive correlation with retrieval of synovial fluid. A positive learning curve was observed for the inexperienced operator. Both approaches to the cervical articular process joints were highly accurate. Ultrasound-guided injection of the cervical articular process joints is an easily-learnt technique for an inexperienced veterinarian. Either approach may be employed in the field with a high level of accuracy, using widely available equipment.

Efficacy of intravenous administration of hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses.

OBJECTIVE To evaluate the efficacy of IV administration of a product containing hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses. ANIMALS 32 healthy 2- to 5-year-old horses. PROCEDURES The study involved 2 portions. To evaluate prophylactic efficacy of the test product, horses received 5 mL of the product (n = 8) or saline (0.9% NaCl) solution (8; placebo) IV every fifth day, starting on day 0 (when osteoarthritis was induced in the middle carpal joint of 1 forelimb) and ending on day 70. To evaluate treatment efficacy, horses received either the product or placebo (n = 8/treatment) on days 16, 23, 30, 37, and 44 after osteoarthritis induction. Clinical, diagnostic imaging, synovial fluid, gross anatomic, and histologic evaluations and other tests were performed. Results of each study portion were compared between treatment groups. RESULTS Limb flexion and radiographic findings were significantly worse for horses that received the test product in the prophylactic efficacy portion than for placebo-treated horses or product-treated horses in the treatment efficacy portion. In the prophylactic efficacy portion, significantly less articular cartilage erosion was identified in product-treated versus placebo-treated horses. In the treatment efficacy portion, joints of product-treated horses had a greater degree of bone edema identified via MRI than did joints of placebo-treated horses but fewer microscopic articular cartilage abnormalities. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that caution should be used when administering the evaluated product IV to horses, particularly when administering it prophylactically, as it may have no benefit or may even cause harm.

In vitro biomechanical evaluation of four surgical techniques for fusion of equine centrodistal and tarsometatarsal joints.

OBJECTIVE To evaluate the biomechanical properties of 4 methods for fusion of the centrodistal and tarsometatarsal joints in horses and compare them among each other and with control tarsi. SAMPLE 24 sets of paired tarsi without substantial signs of osteoarthritis harvested from equine cadavers. PROCEDURES Test constructs (n = 6/type) were prepared from 1 tarsus from each pair to represent surgical drilling; 2 medially to laterally placed kerf-cut cylinders (MLKCs); a single large, dorsally applied kerf-cut cylinder (DKC); and a dorsomedially applied locking compression plate (DMLCP). Constructs and their contralateral control tarsi were evaluated in 4-point bending in the dorsoplantar, lateromedial, and mediolateral directions; internal and external rotation; and axial compression. Bending, torsional, and axial stiffness values were calculated. RESULTS Mean stiffness values were consistently lower for surgical drilling constructs than for contralateral control tarsi. Over all biomechanical testing, surgical drilling significantly reduced joint stability. The MLKC constructs had superior biomechanical properties to those of control tarsi for 4-point bending but inferior properties for external and internal rotation. The DMLCP and DKC constructs were superior to control tarsi in dorsoplantar, rotational, and axial compression directions only; DMLCP constructs had no superior stiffness in lateromedial or mediolateral directions. Only the DKC constructs had greater stiffness in the mediolateral direction than did control tarsi. Over all biomechanical testing, DMLCP and DKC constructs were superior to the other constructs. CONCLUSIONS AND CLINICAL RELEVANCE These biomechanical results suggested that a surgical drilling approach to joint fusion may reduce tarsal stability in horses without clinical osteoarthritis, compared with stability with no intervention, whereas the DMLCP and DKC approaches may significantly enhance stability.

Osteochondrosis dissecans of the fetlock joint – diagnosis, management and prognosis

Osteochondral ‘chip’ fragments of the fetlock joint of horses is a common presentation. The aim of the article is to explore the diagnosis, case management and the process of the different fragments of the fetlock joint.

Effects of regional limb perfusion volume on concentrations of amikacin sulfate in synovial and interstitial fluid samples from anesthetized horses.

OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin concentrations in synovial and interstitial fluid of horses. ANIMALS 8 healthy adult horses. PROCEDURES Each forelimb was randomly assigned to receive IVRLP with 4 mL of amikacin sulfate solution (250 mg/mL) plus 56 mL (total volume, 60 mL) or 6 mL (total volume, 10 mL) of lactated Ringer solution. Horses were anesthetized, and baseline synovial and interstitial fluid samples were collected. A tourniquet was placed, and the assigned treatment was administered via the lateral palmar digital vein. Venous blood pressure in the distal portion of the limb was recorded. Additional synovial fluid samples were collected 30 minutes (just before tourniquet removal) and 24 hours after IVRLP began; additional interstitial fluid samples were collected 6 and 24 hours after IVRLP began. RESULTS 30 minutes after IVRLP began, mean amikacin concentration in synovial fluid was significantly greater for the large-volume (459 μg/mL) versus small-volume (70 μg/mL) treatment. Six hours after IVRLP, mean concentration in interstitial fluid was greater for the large-volume (723 μg/mL) versus small-volume (21 μg/mL) treatment. Peak venous blood pressure after large-volume IVRLP was significantly higher than after small-volume IVRLP, with no difference between treatments in time required for pressure to return to baseline. CONCLUSIONS AND CLINICAL RELEVANCE Study findings suggested that large-volume IVRLP would deliver more amikacin to metacarpophalangeal joints of horses than would small-volume IVRLP, without a clinically relevant effect on local venous blood pressure, potentially increasing treatment efficacy.

Evaluation of intra-articular injection of autologous platelet lysate (PL) in horses with osteoarthritis of the distal interphalangeal joint

ABSTRACTBackground: Regenerative medicine has become one of the most promising therapies of equine osteoarthritis. Platelet lysate (PL) is rich in bioactive proteins and growth factors that play a crucial role in tissue healing.Objective: To evaluate the efficacy of intra-articularly injected autologous PL in equine athletes with naturally occurring osteoarthritis.Animals and methods: Fifteen warmblood geldings aged 8–19 years with osteoarthritis of the distal interphalangeal joint were included in this study. They were randomly divided into two groups; 10 horses received intra-articular injections of PL and 5 of normal saline (controls). Before treatment, platelet-derived growth factor (PDGF) levels in basal plasma and prepared PL were estimated. Each joint was injected twice within a three-week period. Lameness was evaluated using the American Association of Equine Practitioners grading system, before treatment and 10 days after each intra-articular injection. Horses were examined fortnightly for one year. Radiographic examination was performed six months post-treatment. The generalized estimating equation test was used for statistical analysis.Results: Acceptable levels of PDGF were detected in PLs (mean ± SD: 258.0 ± 52.3 pg/ml). The majority of horses (9/10) responded positively to PL treatment presenting lower lameness grades (p < 0.0005) compared to controls 10 days after the second injection, and returned to normal athletic activity. Radiographs revealed no changes in osteoarthritis lesions six months after treatment. One year post-injections, however, all horses relapsed to their initial degree of lameness.Conclusion: Intra-articularly injected autologous PL is an efficient method for temporarily managing osteoarthritis of the distal interphalangeal joint in athletic horses.

Radiographic evaluation of the width of the femorotibial joint space in horses.

To measure the minimal joint space width (mJSW) in caudocranial radiographic views of orthopedically normal femorotibial joints of horses, to compare the accuracy of measurements with those of a software program designed for humans, and to identify the ideal caudocranial radiographic projection angle for mJSW measurement. ANIMALS 12 healthy mares (22 femorotibial joints) and 3 equine cadavers (6 stifle joints). Caudocranial views of femorotibial joints were acquired in the proximodistal plane at 5°, 10°, and 15° (caudo-5°-proximal-craniodistal oblique, 10°, and 15°) and lateromedial plane (caudo-10°-proximo-5°-lateral-craniodistomedial oblique and caudo-10°-proximo-5°-medial-craniodistolateral oblique). The mJSWs of medial and lateral femorotibial joint compartments were measured manually by 2 evaluators and automatically by a digital analysis software program. Interevaluator reproducibility was assessed. Post hoc tests were used to identify the projection angle that provided the largest measurements. Validation of mJSW measurements was performed by evaluation of 6 stifle joints ex vivo. Excellent agreement was achieved between the 2 evaluators and between the veterinary radiologist and the analysis software for the medial and lateral compartments of femorotibial joints. Angle of caudocranial view in the proximodistal but not lateromedial plane had a significant effect on the medial compartment mJSW measurements. Mean mJSW for the medial compartment was significantly higher for the caudoproximal-craniodistal oblique projection made at 10° from the horizontal than for other angles. Angle had no significant effect on mean mJSW for the lateral compartment. Agreement between automated measurements of mJSW in the medial compartment and thickness of nonmineralized cartilage in histologic preparations of associated tissues was excellent. Measurements of mJSW in the medial compartment of femorotibial joints, the most common site of osteoarthritis in horses, were reproducible and optimal with a caudoproximal-craniodistal oblique radiographic projection made at 10° from the horizontal.

Comparison of Arthroscopic Lavage and Needle Lavage Techniques, and Lavage Volume on the Recovery of Colored Microspheres From the Tarsocrural Joints of Cadaver Horses.

To quantify recovery of colored microspheres from normal cadaver tarsocrural joints using arthroscopic or needle lavage with 1-5 L of fluid. Ex vivo experimental study. Adult Quarter Horse cadavers (n = 8). After euthanasia, 1.5 × 10(6) colored microspheres were injected into each tarsocrural joint. Each joint was randomly assigned to receive lavage (5 L 0.9% NaCl) with an arthroscope (dorsomedial arthroscope and dorsolateral egress cannula) or three 14 g needles (dorsomedial ingress, dorsolateral, and plantarolateral egress). Egress fluid from each liter was collected separately over time and the number of microspheres present in each recovered liter determined by spectrophotometry. A significant interaction was present between treatment group and liter of fluid (P < .01). The number of microspheres recovered in the first liter of lavage fluid was significantly higher in the needle lavage group than in the arthroscopic lavage group (P < .01). For both groups, the number of microspheres recovered in the first liter of lavage fluid represented a majority of the total microspheres collected and was significantly different from each subsequent liter collected (P < .01). The number of microspheres recovered did not differ between liters 2, 3, 4, and 5 within or between treatment groups. In this model, tarsocrural lavage with three 14 g needles was more effective at removing colored microspheres from the joint than arthroscopic lavage, suggesting that the number or placement of portals present may be more important than portal size and flow rate. No difference in microsphere recovery was seen with lavage volumes >1 L.

An Alternative, Direct Approach for Arthroscopic Removal of Osteochondral Fragments in the Dorsal Pouch of the Proximal Intertarsal Joint of Horses.

To describe an alternative technique and resulting outcomes for arthroscopic removal of osteochondral (OC) fragments from the proximal intertarsal joint (PIJ) using a direct approach without resection of the membrane between the tarsocrural joint (TCJ) and the PIJ. Retrospective case series. Client owned horses (n = 11) with Category 1 OC fragments in the PIJ. Arthroscopic examination of the dorsal pouch of the TCJ was performed with horses positioned in dorsal recumbency using routine portals. A hook probe placed through one of the standard portals was used to lift the edge of the communication between TCJ and PIJ to help pass the arthroscope into the PIJ from the opposite standard portal. A third direct portal into the PIJ was created under arthroscopic visualization, and loose OC fragments (Category 1) were removed using the direct portal. Medical records, race records, and owner surveys were reviewed for case details and outcome. The described technique allowed removal of all fragments in all 11 cases. No complications associated with the procedure were observed. Of the 9 horses with long term follow-up available, 7 were used as intended (4/4 riding horses, 3/5 racehorses). Two horses did not enter an athletic career because of reasons unrelated to fragment removal. A direct approach for arthroscopic removal of OC fragments of the PIJ using a third portal into this joint, without resection of the membrane between the TCJ and PIJ is a good alternative for removal of fragments at this site.