Joints Of Dogs Research Articles

In vitro biomechanical study of rotational stabilizers of the canine elbow joint.

To develop a model for measuring rotary stability of the canine elbow joint and to evaluate the relative contribution of the anconeal process (AN), lateral collateral ligament (LCL), and medial collateral ligament (MCL). 18 forelimbs from 12 canine cadavers. Forelimbs were allocated to 3 experimental groups (6 forelimbs/group). Each intact forelimb was placed in extension at an angle of 135 degrees and cycled 50 times from -16 degrees (pronation) to +28 degrees (supination) in a continuous manner at 2.0 Hz. Cycling was repeated following sectioning of the structure of interest (group 1, AN; group 2, LCL; and group 3, MCL). Torque at -12 degrees (pronation) and +18 degrees (supination) was measured for each intact and experimentally sectioned limb. A Student t test was performed to compare torque values obtained from intact verses experimentally sectioned limbs and for comparison with established criteria for differentiation of primary (> or = 33%), secondary (10 to 33%), and tertiary rotational stabilizers (< 10%). In pronation, the AN was the only primary stabilizer (65%). For supination, the LCL was a primary stabilizer (48%), AN was a secondary stabilizer (24%), and MCL was a tertiary stabilizer (7%). With the elbow joint in extension at an angle of 135 degrees, the AN is a primary rotational stabilizer in pronation, and the LCL is a primary stabilizer in supination. Disruption of the AN or LCL may affect rotary range of motion or compromise stability of the elbow joint in dogs.

Computed tomography of the elbow joint in clinically normal dogs.

To use computed tomography (CT) to provide a detailed description of elbow joint structures in clinically normal dogs. 6 clinically normal adult mixed-breed dogs weighing 24 to 37 kg and one 12-month-old Labrador Retriever weighing 27 kg. To perform CT of both elbow regions, dogs were anesthetized and placed in lateral recumbency. One- and 2-mm contiguous slices were obtained by use of a third generation computed tomographic scanner. Good resolution and anatomic detail were acquired from the computed tomographic images by use of a bone (window width, 3,500 Hounsfield units; window level, 500 Hounsfield units) and soft-tissue setting (window width, 400 Hounsfield units; window level, 66 Hounsfield units). After euthanasia, the forelimbs from the Labrador Retriever were removed and frozen in water at -18 degrees C. Elbow joints were sectioned into approximately 1-mm-thick slab sections by use of an electric planer. Anatomic sections were photographed and compared with the corresponding computed tomographic images. Computed tomographic reconstructions of the elbow joint were created in sagittal and dorsal planes. Structures on the computed tomographic images were matched with structures in the corresponding anatomic sections. The entire humeroradioulnar joint surface could be evaluated on the reconstructed images in the sagittal and dorsal plane. Computed tomographic images provide full anatomic detail of the bony structures of the elbow joint in dogs. Muscles, large blood vessels, and nerves can also be evaluated. These results could be used as a basis for evaluation of computed tomographic images of the forelimbs of dogs with elbow joint injuries.

Use of the distomedial-proximolateral oblique radiographic view of the elbow joint for examination of the medial coronoid process in dogs.

To describe and evaluate a new radiographic view of the elbow joint in dogs that would potentially enhance observation of the medial coronoid process (MCP). 20 cadaver limbs from 10 dogs and clinical examination of 100 elbow joints of 53 dogs. Twenty elbow joints from 10 cadavers were imaged by use of mediolateral, flexed mediolateral, craniocaudal, craniolateral-caudomedial oblique (Cr15L-CdMO), and distomedial-proximolateral oblique (Di35M-PrLO) radiographic views before and after placement of 3 lead pellets placed on the cranial, medial, and craniodistal aspect of the MCP. Three examiners independently reviewed these radiographs. One hundred elbow joints of 53 dogs with forelimb lameness and signs of pain elicited on palpation of the elbow joint were examined. These joints were radiographed and treated by use of arthroscopy. Three examiners independently graded the radiographs. The MCP was identified on all Di35M-PrLO views made during the anatomic study. The Di35M-PrLO view had the largest area under the receiving operating characteristic (ROC) curve for detection of abnormalities of the MCP. Fractured and nonfractured MCP could only be significantly differentiated on Di35M-PrLO and mediolateral views. The Di35M-PrLO view had a higher agreement between examiners than other radiographic views for detection of fractures of the MCP. The Di35M-PrLO view enhances the identification of anomalies and fragmentation of the MCP in dogs, compared with other radiographic views. The Di35M-PrLO view may be of benefit for early screening of dogs potentially affected with elbow dysplasia.

Biomechanical properties of braided polyester tapes intended for use as intra-articular cranial cruciate ligament prostheses in dogs.

To determine the in vitro structural and material properties of braided, multifilament, nonabsorbable polyester tapes, used for intra-articular stabilization of cranial cruciate ligament- (CCL-) deficient stifle joints in dogs, and compare those with properties of multifilament polyamide tapes. 30 polyester tapes (width, 4 mm), 10 polyester tapes (width, 7 mm), and 30 polyamide tapes (width, 4 mm) were tested to failure. Cyclic loading experiments were also performed, using 3 polyester tapes of each width. Tapes were mounted in a tensile tester as single loops, simulating intra-operative conditions, and elongated to failure at 1,000 mm/min. Additionally, the behavior of polyester tapes was tested at different elongation rates. In a second series of experiments, biomechanical variables of the polyester tapes were measured after 25 sets of 2,000 cycles between physiologic force limits. Mean (+/- SD) ultimate loads of the 4-mm wide polyamide tapes, 4-mm wide polyester tapes, and 7-mm wide polyester tapes were 266.48 +/- 13.19 301.78 +/- 16.92, and 726.40 +/- 37.74 N, respectively. Corresponding stiffnesses were 15.57 +/- 0.49, 21.63 +/- 2.19, and 34.85 +/- 2.66 N/mm, respectively. Failure properties of polyester tapes were affected by previous cyclic loading. Polyester tapes of 4- or 7-mm widths should be able to resist forces resulting from weight bearing in dogs, suggesting that these tapes will be effective for stabilization of the stifle joint in dogs with a ruptured CCL.

Functional outcome of transplanted knee joints in dogs.

Total knee joint transplantation has been performed in animal models and humans. This study investigates the impact of this operation on knee joint function in a dog model. Therefore, replantation was compared to transplantation during a 6-month follow-up period in four dogs in each group. The peak vertical ground reaction force normalized in all legs undergoing replantation and in two of four after transplantation. A third transplant recipient reduced loading from the 4th month due to a local complication, and the fourth succumbed to sepsis 3 months postoperatively. A weight-bearing index (WBI), defined as loading of the grafted divided by loading of both hind-limbs decreased from 0.48 +/- 0.08 preoperatively to 0.13 +/- 0.10 by 1 month after replantation and from 0.53 +/- 0.07 to 0 after transplantation. After 6 months, weight-bearing of all replant recipients was restored, but reduced in two transplant recipients with graft function. Full recovery after replantation, but impaired function after transplantation, was also reflected in the histological results: normal histological pictures of blood vessels, cartilage, bone and soft tissues were found in all replant recipients, but infiltrative vasculopathy indicating chronic rejection was found in the transplanted joints. The results of this animal study confirm that the procedure can lead to satisfactory functional results but also emphasize the need for perfect control of immunosuppression.

Evaluation of a method for experimental induction of osteoarthritis of the hip joints in dogs.

To evaluate a method for experimental induction of osteoarthritis in the hip joints of dogs. 12 mixed-breed dogs. A unilateral triple pelvic osteotomy was performed. In 6 dogs, the iliac osteotomy was repaired with 45 degrees of internal rotation, reducing coverage of the femoral head by the acetabulum. In the other 6 dogs, the fragments were repaired in anatomic alignment. Radiography, force plate evaluations, and subjective lameness evaluations were performed before and after surgery. Dogs were euthanatized 7 months after surgery, and samples of cartilage and joint capsule were examined histologically. Subjective lameness scores, radiographic appearance of the hip joints, and Norberg angles were not significantly different between groups; however, force plate evaluations did reveal significant differences in vertical ground reaction forces. Femoral head coverage was significantly decreased with rotation of the acetabulum. Mild inflammatory changes were discernible in the joint capsule and articular cartilage of some dogs in both groups. Results suggest that 45 degrees internal rotation of the acetabulum does not consistently induce biologically important osteoarthritic changes in the hip joints of dogs.

Measuring Craniocaudal Instability in Stifle Joints of Dogs Using Stress Radiographs

Zatloukal J . , Neaas, A. , Dvofiak, M: Measuring Craniocaudal Instability in Stifle Joints of Dogs Using Stress Radiographs. Acta Vet. Brno 2000, 69: 311-317. Craniocaudal stifle joint laxity in dogs affected by various stifle disorders was determined using mediolateral X-ray projections of the stifle joint in neutral and tibial compression stress position. In all, 129 stifle joints of 80 dogs were included in the study. Patients were classified into following groups characterised by: 1) total cranial cruciate ligament (CCL) rupture, 2) total CCL rupture and medial meniscus lesion, 3) partial CCL rupture, 4) partial CCL rupture and medial meniscus lesion, 5) clinically evident CCL rupture only, 6) normal stifle joints, 7) normal stifle joint on the contralateral joint to the one affected by the CCL rupture, 8) radiographically abnormal and clinically stable stifle contralateral to the joint affected by the CCL rupture, and 9) other stifle disorders. Index of laxity (IL) of the stifle joint giving the extent of cranial tibial displacement relative to the femur in the stress tibial compression projection expressed as percents of the femur width was computed. Stifle joints with IL values over 25 can be supposed to be affected by CCL rupture, whereas joints with the IL value less than 15 can be considered to have an intact cranial cruciate ligament. There were significantly higher IL values in stifle joints with clinically or by arthrotomy diagnosed CCL rupture as compared to the group of healthy joints (Wilcoxon’s test; p < 0.01 and p < 0.05, respectively in these ones with partial CCL rupture and medial meniscus damage). Contrary to published data, we found considerably higher IL values in stifle joints with total CCL rupture as compared to those ones with partial rupture (p < 0.01). Significant differences in the index of laxity value were not found in stifles with other disorder than the CCL rupture as compared to the group of healthy joints. Measurement of the index of laxity is an undemanding and noninvasive technique supplementing the clinical examination and could serve as an early diagnostic method for the CCL injury. Index of laxity, stifle joint, cranial cruciate ligament, rupture, tibial compression test Disorders of the stifle joint in dogs are relatively frequent (Johnson et al. 1994). Craniocaudal instability of the stifle joint is mainly associated with the cranial cruciate ligament rupture (CCL). This instability is diagnosed clinically by the cranial drawer sign and tibial compression test and is mainly pathognomonic for the CCL rupture (Arnoczky 1993). It is more difficult to diagnose cases of chronic stifle joint affection with periarticular fibrosis or partial CCL rupture, when even in sedation of the patient, the clinically detectable instability is small or non-conclusive (Tarvin and Arnoczky 1981, Scavel l i et al. 1990, Strom 1990, de Rooster and van Bree 1999a). The diagnosis of the CCL rupture in these cases is based on ruling out other causes of lameness due to the stifle joint disorder. It may be necessary to directly evaluate the integrity of the cranial cruciate ligament using arthroscopy or arthrotomy (Mil ler and Presnel l 1985). Radiographic examination of the stifle joint in neutral projections shows in cases of CCL rupture only nonspecific changes such as arthrosis and effusion in the stifle joint. It is only in exceptional ACTA VET. BRNO 2000, 69: 311–317 Address for correspondence: MVDr. Josef Zatloukal Department of Diagnostic Imaging, Small Animal Clinic University of Veterinary and Pharmaceutical Sciences Palackeho 1-3, 612 42 Brno, Czech Republic, Phone: +420 602 51 14 28 Fax: +420 5 4156 2344 E-mail: zatloukalj@vfu.cz http://www.vfu.cz/acta-vet/actavet.htm

Idiopathic erosive polyarthritis in six dogs (description of the disease and treatment with bilateral pancarpal arthrodesis)

SummarySix dogs with severe, deforming, idiopathic erosive polyarthritis (IEP) were treated with bilateral pancarpal arthrodesis using bone-plate stabilization. This type of arthropathy resembles those classified previously as canine rheumatoid arthritis and results in a progressive erosion of articular cartilage and instability of multiple joints, most notably the carpi, tarsi and digits. Arthrodesis was successful in all of the cases and resulted in a significant improvement in ambulation in all six dogs, even in the presence of continued compromise of phalangeal and tarsal joints.Idiopathic erosive polyarthritis (IEP) is a disease of unknown pathogenesis that affects multiple joints of dogs, usually of the distal limbs, and causes a symmetrical, progressive lameness. Six dogs affected with IEP were treated with bilateral pancarpal arthrodesis, resulting in improved ambulatory ability and an adequate quality of life.

Comparison of measurements of dorsolateral subluxation of the femoral head and maximal passive laxity for evaluation of the coxofemoral joint in dogs

Abstract Objective To determine whether dorsolateral subluxation (DLS) of the femoral head reflects osseous conformation of the coxofemoral (hip) joint and represents a property distinct from maximum passive laxity of the hip joint in dogs. Animals 14 Labrador Retrievers, 16 Greyhounds, 58 Greyhound-Labrador Retriever mixed-breed dogs, and 1 Rottweiler. Procedures DLS of the femoral head (DLS score) and passive laxity of the hip joint (distraction index) were determined radiographically in 3 groups of dogs: not treated (167 joints of 84 dogs); before and after injecting 2 ml of hyaluronan into 25 hip joints of 13 dogs; and before and after unilateral triple pelvic osteotomy in 5 dogs. Results of the 2 methods were compared for each group. Results In untreated dogs, the correlation coefficient (r) of DLS score versus distraction index was −0.73 and −0.69 for 84 left and 83 right hip joints, respectively. Mean coefficient of determination (r2) for both hips was 0.5. Mean DLS score did not differ before and after intra-articular injection of hyaluronan into either hip joint, whereas mean distraction index increased significantly after intra-articular injection. Unilateral triple pelvic osteotomy resulted in a significant increase in DLS score, compared with values obtained before surgery. However, distraction index before and after surgery did not differ significantly. Conclusions and Clinical Relevance The DLS test assesses the congruity of the acetabulum and the femoral head in a canine hip joint and thus represents a characteristic distinct from maximum passive laxity. The DLS score and the distraction index evaluate different components of hip joint stability. (Am J Vet Res 1999;60:1571–1576)

Radiographic measurement of craniocaudal instability in stifle joints of clinically normal dogs and dogs with injury of a cranial cruciate ligament

Abstract Objective To determine craniocaudal laxity of the stifle joint of dogs when joints were positioned in tibial compression or neutral position. Sample Population 19 normal stifle joints in 10 clinically normal dogs, 29 stifle joints with varying injury to the cranial cruciate ligament (10 complete ruptures alone, 10 complete ruptures with concomitant damage to the medial meniscus, 6 partial ruptures alone, and 3 partial ruptures with concomitant meniscal tearing), and 19 unaffected contralateral stifle joints in those 29 dogs. Procedure Relative displacement of bony landmarks was measured on paired lateral radiographs (neutral and tibial compression positions). Two measuring techniques were customized for use in dogs. Results The first technique failed to distinguish results in normal stifle joints from those in stifle joints with partial deficiency of cranial cruciate ligaments. Significant differences were found for joints with complete rupture, compared with stifle joints in clinically normal dogs. The second technique detected differences between normal stifle joints and injured joints with partial or complete rupture of the cranial cruciate ligament. Significant differences were not detected between joints with partial versus complete rupture. Adjusting data to account for size of dog did not improve results. Conclusions and Clinical Relevance A wide range in measurements of laxity was found for stifle joints with intact cranial cruciate ligaments. Differences in degree of damage to the ligament and medial meniscus cannot be deduced from the amount of relative displacement measured on radiographs. Pathologic changes to the cranial cruciate ligament will not necessarily induce detectable changes in laxity of stifle joints in dogs. (Am J Vet Res 1999;60:1567–1570)

Canine rheumatoid arthritis and inflammatory cytokines

Bioassays were developed to detect canine pro-inflammatory cytokines. These enabled characterisation of these cytokines and their isoforms and provided means for their assay in the joints of dogs with different naturally occurring arthropathies. Canine IL-1 was detected by its induction of proliferation of D10(N4)M cell line, whilst IL-6 had a proliferative effect on B9 cell line. TNFα had a cytotoxic effect on WEHI 164 (13) cells. Partial purification of the cytokines was achieved by FPLC ion-exchange chromatography and two isoforms of IL-1 were shown, possibly corresponding to IL-1α and IL-1β. TNFα only appeared as one isoform whereas IL-6 showed at least five isoforms, possibly corresponding to the other molecules in the IL-6 family, such as IL-11 and oncostatin M. Analysis of synovial fluids from dogs with osteoarthritis (OA) and rheumatoid arthritis (RA) showed that IL-1 and TNFα bioactivity was not readily detectable at increased levels in diseased joints but that IL-6 was significantly increased in both diseases. It is now important to determine the role of IL-6 in OA and RA in the dog, particularly in the induction of proteolytic enzymes which lead to cartilage loss.

Efficacy of etodolac for the treatment of osteoarthritis of the hip joints in dogs

Objective To assess the efficacy of etodolac in improving hind limb function in dogs with osteoarthritis of the hip joint. Design Prospective study. Animals 100 client-owned dogs with clinical signs of osteoarthritis of the hip joint. Procedure Baseline ground reaction forces and subjective assessment scores were collected twice at a 7- to 10-day interval. After meeting entrance criteria, dogs were randomly assigned to the following 3 treatment groups: control group (0 mg of etodolac), low-dosage group (135 mg of etodolac), or high-dosage group (450 mg of etodolac). Dogs were treated once daily for 8 days, and gait analysis was repeated on day 8. Results On day 8 of treatment, vertical impulse and vertical peak force values for low- and high-dosage groups were significantly greater than baseline values within each group. On day 8, vertical impulse values from the high-dosage group were significantly greater than values from the low-dosage group. Vertical peak forces for the low- and high-dosage groups were significantly greater at 8 days than that of the control group. Analysis of the effect of evaluation center (site) on treatment outcome did not reveal a significant effect. Clinical Implications Etodolac administration for 8 days improved ground reaction forces in dogs with osteoarthritis of the hip joint. Improvement in force transmission was dosage dependent for the primary outcome measurement (vertical impulse). Results of the study indicate that etodolac is well tolerated by dogs, with minimal adverse effects during an 8-day treatment period. (J Am Vet Med Assoc 1999;214:206–210)

Dorsolateral subluxation of hip joints in dogs measured in a weight-bearing position with radiography and computed tomography.

develop a radiographic procedure to measure dorsolateral subluxation (DLS) of the femoral head in canine coxofemoral (hip) joints in a weight-bearing position. DLS measured on a radiographic projection was compared with DLS measured on computed tomography (CT) images of hip joints in a weight-bearing position. A total of 24 dogs of varying ages were examined including Labrador retrievers, greyhounds, and Labrador-greyhound crossbreeds. Anesthetized dogs were placed in sternal recumbency in a kneeling position in a foam rubber mold. The stifles were flexed and adducted with the femora perpendicular to, and in contact with, the table. To test for DLS, dogs were imaged in this weight-bearing position (DLS test) with routine radiography and CT. For each hip, the DLS score was determined by measuring the percentage of the femoral head medial to the lateralmost point of the cranial acetabular rim on the dorsoventral radiographic projection and the lateralmost point of the central, dorsal acetabular rim on the CT image. Higher DLS scores indicated better coverage of the femoral head by the acetabulum. DLS scores were compared with the distraction index (DI) by grouping joints according to their probability of developing osteoarthritis (OA) as predicted by the DI. The DLS score in the new position ranged from 29% to 71% for radiography and 15% to 59% for CT. Joints classified as OA unsusceptible had a mean score of 64% +/- 1.5% for radiography and 55% +/- 0.8% for CT (n = 10); hip joints having a high probability of developing OA had a score of 39% +/- 2.6% for radiography and 26% +/- 1.9% for CT (n = 8). When the DLS test was repeated on the same dogs at a different time, the intraclass correlation coefficient for the DLS score on the radiographs was 0.85 (left hip) and 0.89 (right hip). There was a strong correlation (r = .89 for both hips) between the DLS score measured on the weight-bearing radiograph and the CT image. A strong correlation also was observed between the DLS score and the DI (r = -.87). The DLS scores for OA unsusceptible joints and joints with a high probability of developing OA were significantly different (P < .05). The DLS test can be performed with CT or routine radiography to measure variable amounts of DLS in weight-bearing hip joints oriented similarly to those of a standing dog. After additional long-term follow-up studies evaluating the development of OA and breed effects are performed, the DLS method may prove useful in studies of normal and abnormal hip joint development related to canine hip dysplasia.

The effect of triple pelvic osteotomy on the articular contact area of the hip joint in dysplastic dogs: an in vitro experimental study.

To investigate the effect of triple pelvic osteotomy (TPO) on articular contact area and acetabular coverage of dysplastic hip joints in dogs. Articular contact area and femoral head coverage by the acetabulum were computed in vitro in normal and dysplastic canine hips. The effect of TPO on articular contact and coverage was then analyzed in the dysplastic hips. Sample Population-Five normal and six dysplastic canine cadaver specimens. Contact area and coverage of loaded hips were computed using serial computed tomography scan images before and after TPO. Three angles of acetabular ventroversion (AVV) were studied (20 degrees, 30 degrees, and 40 degrees). Using a custom-designed hinge plate, angles of spontaneous hip reduction in dysplastic hips were compared with previously recorded angles of reduction determined by the Ortolani test. Contact area significantly increased from 0 degrees to 30 degrees of AVV, then remained virtually unchanged. Coverage significantly increased from 0 degrees to 20 degrees of AVV. Both contact and coverage of normal hips were similar, yet significantly smaller than those of dysplastic hips once reduction had occurred. The experimental angles of reduction were significantly smaller and poorly correlated with the angles of reduction determined by the Ortolani test. Although coverage continued to increase with AVV, the actual joint contact area did not significantly vary after relocation of the femoral head. This study suggests that increasing AVV beyond 20 degrees does not significantly improve the beneficial effects of TPO and therefore should be carefully weighed against increased risks of postoperative complications associated with large angles of AVV.

Biomechanical characterization of passive laxity of the hip joint in dogs

Abstract Objective To investigate the in vitro load/displacement characteristics of the hip joints in dogs as a function of joint position. Sample Population 10 hip joints from 5 healthy dogs. Procedure A material test system was used to generate load/displacement curves for each joint. Joints were mounted in a custom-designed jig that held the joint in fixed anatomic orientations while plotting displacement and corresponding applied loads. All hips were cycled between 40 N of compression and 80 N of distraction. Each hip was tested at 10° increments from 30° flexion to 70° extension. Results When the hips were in a neutral orientation (approximately a standing position), load/displacement curves were characteristically sigmoidal (tri-phasic), indicating that, in this position, displacement was not highly dependent on load. The curves had a central low-stiffness region in which most of the lateral displacement took place. In contrast, when hips were positioned at the extremes of flexion and extension, this central, low-stiffness region was less distinct, and load/displacement curves were more linear, indicating a proportional relation between load and displacement. The load/displacement curve of 1 hip joint in the study deviated markedly from the others in a pattern consistent with cavitation of the synovial fluid. Conclusions When the hip joint is positioned in a neutral position, load-displacement behavior is sigmoidal, whereas when the hip joint is in an extended position, load/displacement behavior is more linear. Clinical Relevance Establishing load/displacement behavior of the hip joints in dogs was an important exercise in establishing the position for and estimating the repeatability of a clinical stress-radiographic method for quantitating joint laxity in dogs. (Am J Vet Res 1997;58:1078–1082)

Within- and between-examiner repeatability of distraction indices of the hip joints in dogs

Abstract Objective To evaluate in vivo repeatability of the distraction index method of evaluating hip joint laxity in dogs. Animals 31 two-year-old Labrador Retrievers. Procedure Each dog was anesthetized and radiographically evaluated for hip joint laxity 4 times: twice by an experienced examiner and twice by an examiner who had no previous knowledge of or training in the technique prior to the first day of testing. Distraction indices (DI) were determined from the radiographs and intraclass correlation coefficients were calculated to evaluate the repeatability of DI measurements between and within examiners. Results Intraclass correlation coefficients were high (range, 0.85 to 0.94). Lower limits of the 95% confidence intervals for the intraclass correlation coefficients ranged from 0.75 to 0.89. Conclusions Between- and within-examiner repeatabilities of DI measurements were high, suggesting that the technique is clinically reliable. Clinical Relevance Distraction index is a reliable measure of hip joint laxity and a good predictor of the risk of development of degenerative joint disease associated with hip dysplasia in dogs. Establishment of high repeatability of DI measurements suggests that the stress-radiographic method may be used by multiple examiners with the expectation of comparable and consistent results. (Am J Vet Res 1997;58:1076–1077)

Synovial fluid cavitation during distraction radiography of the coxofemoral joint in dogs

Objective— To determine risk factors for, and prevalence and short- and long-term effects of, synovial fluid cavitation during distraction radiography. Design— Multicenter prevalence survey. Animals— 6,649 purebred dogs comprising 129 breeds. Procedure— Radiographs from the PennHIP (University of Pennsylvania Hip Improvement Program) Laboratory were subjectively evaluated for evidence of cavitation. Multiple logistic regression was used to determine whether sex, breed, age, weight, distraction index (DI), or examining veterinarian was associated with cavitation. Short-term effects of cavitation were assessed by comparing DI for the hip with cavitation with DI for the contralateral hip in dogs with unilateral cavitation. Long-term effects of cavitation were assessed by comparing DI before and after cavitation was detected. Results— Cavitation was detected in 279 (4.2%) of the radiographs analyzed. Male dogs, Golden Retrievers, and heavier dogs were at a decreased risk for cavitation. Irish Wolfhounds, Irish Setters, Rhodesian Ridgebacks, and Weimaraners had an increased risk for cavitation. Age and DI were not risk factors for cavitation. Mean DI was 0.08 greater in hips with cavitation than in paired hips without cavitation. Significant differences were not detected between DI before and after cavitation, but only 7 dogs were included in this analysis. Clinical Implications— Cavitation is rare during distraction radiography and can increase measured DI. Radiographs should be routinely examined to ensure accurate reporting of DI. (J Am Vet Med Assoc 1997;210: 1294–1297

Open reduction and stabilisation of coxofemoral joint luxation in dogs and cats, using a stainless steel rope inserted via a ventral approach to the hip joint.

Open reduction and stabilisation of coxofemoral joint luxation was made via a ventral approach to the hip joint in dogs and cats, using a transarticular stainless steel rope. A feature of the procedure is transarticular penetration of the rope from the pelvic cavity to the femoral neck by guidance with a guide wire which was previously inserted from the femoral neck into the pelvic cavity and by detection of the guide wire in the pelvic cavity by use of forceps connected to an alarm-ohmmeter. Forty-seven animals (37 dogs and 10 cats) with acute and simple coxofemoral luxation were treated and postoperatively maintained in cage rest without external fixation. Most of the animals regained an almost normal gait within several days.

Magnetic resonance arthrography of the scapulohumeral joint in dogs, using gadopentetate dimeglumine

SUMMARY Six scapulohumeral joints (3 normal joints and 3 joints with radiographic evidence of osteochondrosis) underwent conventional magnetic resonance (mr) imaging and mr scapulohumeral arthrography to evaluate delineation of the articular cartilage. The mr arthrography was performed, using 5 ml of 500 μM gadopentetate dimeglumine (Gd-dtpa) as a contrast medium. Delineation of normal articular cartilage and cartilage defects was less accurate after intra-articular administration of Gd-dtpa. Therefore, it was concluded that mr arthrography with Gd-dtpa is unrewarding for evaluation of osteochondrosis lesions.

Pharmacokinetic studies of methotrexate in plasma and synovial fluid following i.v. bolus and topical routes of administration in dogs.

The pharmacokinetic properties of methotrexate (MTX) in the plasma and synovial fluid (SF) after bolus i.v. and topical administration were studied in dogs to assess the feasibility of topical delivery of MTX for the treatment of rheumatoid arthritis. A MTX gel in Poloxamer 407 containing an absorption enhancer was formulated and topically applied on the elbow and stifle joints of dogs. SF was collected by inserting a needle with syringe into the joint space. Drug concentrations in the plasma, SF and muscle tissues were determined using a HPLC method with fluorimetric detection. Peak MTX concentrations in SF occurred at 38 +/- 5 min following bolus i.v. dose, indicating the presence of a substantial diffusion barrier between the plasma and SF. The plasma/SF concentration ratios of 1.16 +/- 0.25 were maintained after the attainment of distribution equilibrium between the two compartments. The t1/2 values in the plasma (11.2 +/- 1.2 hr) and SF (12.7 +/- 3.7 hr) were similar during the elimination phase, while the MRT in SF (3.24 +/- 0.21 hr) was longer than that in plasma (2.56 +/- 0.20 hr), probably due to the slow distribution of MTX to SF. After topical dose, MTX concentrations in plasma reached the steady state at approximately 4 hr, lasting for approximately 20 hr. The bioavailability of MTX from the gel was 11.8 +/- 3.3% of the applied dose, but muscle tissues beneath the gel application site had significantly higher levels of MTX than untreated muscle tissues. There was no statistical difference in SF concentrations of MTX between drug treated and untreated joints 24 hr after topical dose. Topical delivery of MTX in a hydrophilic gel achieved a sustained C/t profile in plasma and higher drug levels in muscle tissues underneath the dosing site, implicating the potential therapeutic value of the topical formulation.