Canine Cranial Cruciate Ligament Research Articles

Development and Efficacy of a Canine Pelvic Limb Model Used to Teach the Cranial Drawer and Tibial Compression Tests in the Stifle Joint

Canine cranial cruciate ligament rupture (CCLR) is the most common cause of pelvic limb lameness in dogs. CCLR results in palpable stifle instability secondary to cranial translation of the tibial relative to the femur, and it can be diagnosed during the orthopedic exam using the cranial drawer test (CDT) and tibial compression test (TCT). Accurate diagnosis of CCLR depends on the efficacy in performing these tests. In this study, two three-dimensional canine pelvic limb models were developed: one simulating a normal stifle and one simulating CCLR. Thirty-eight veterinary student participants answered questionnaires and performed both the CDT and TCT on a randomly assigned model. Twenty-one participants also manipulated the models one week later to assess skill retention in the short term. Mean levels of reported confidence in diagnosing CCLR and finding anatomic landmarks for CDT/TCT were significantly higher following model manipulation. Nearly all participants reported that they desired a model for teaching the diagnosis of CCLR. Most participants (92.5%) felt that the tested model would be useful for teaching CCLR diagnosis. Accuracy in diagnosing CCLR with the TCT significantly improved over time. Participant response indicated that while the tested model was effective and desirable, an ideal model would be more durable and lifelike. Further studies are needed to evaluate the developed models' effectiveness for teaching CCLR diagnosis compared to traditional teaching methods.

Single-stage bilateral tibial tuberosity advancement for treatment of bilateral canine cranial cruciate ligament deficiency.

To report complications in dogs with naturally occurring cranial cruciate ligament rupture following single-stage bilateral tibial tuberosity advancement (SS-BTTA) procedures, and to compare these complications to a population of dogs undergoing unilateral tibial tuberosity advancement (UTTA). Medical records and radiographs of client-owned dogs treated with tibial tuberosity advancement between August 2008 and December 2011 were reviewed. Forty-four client-owned dogs with bilateral cranial cruciate ligament rupture that underwent SS-BTTA procedures and 82 client-owned dogs that underwent UTTA procedures were randomly selected from our hospital population. Complications were recorded and analysed. Major complications were defined as fractures or any complication requiring a second surgery. Minor complications were any problem identified that did not require surgical management. Incidence for major and minor complications in the UTTA group was 2.3% and 24.4%, respectively. Incidence for major and minor complications in the SS-BTTA group was 12.5% and 26.1%, respectively. Single-stage bilateral tibial tuberosity advancement procedures had a four- to five-fold increase in odds of a major complication (p <0.050) compared to UTTA. The findings of our study indicate that SS-BTTA procedures are associated with an increased risk of major complications compared to UTTA procedures.

Effect of doxycycline on contralateral canine cranial cruciate ligament rupture. A prospective randomized clinical trial in 69 dogs.

To evaluate whether doxycycline administered to dogs with unilateral cranial cruciate ligament rupture (Uni-CCLR) would decrease the risk of contralateral-CCLR (Co-CCLR). To evaluate predictors for Co-CCLR survival. To evaluate if a predisposition of Labrador Retrievers to Co-CCLR exists when compared to other breeds. In this prospective randomized controlled clinical trial, 69 client-owned dogs with Uni-CCLR were randomly assigned to a doxycycline (group-D: 7.5 mg/kg PO BID x 6 weeks) or non-doxycycline (group-ND: negative control). Medical and imaging data, time from Uni- to Co-CCLR and to follow-up were recorded. Statistics included chi-squared test, logistic regression, Kaplan-Meier survival analysis, log rank test, survival curves, and frailty model (p <0.05). This study included 32 dogs in group-D, and 37 dogs in group-ND. Median follow-up was 54.5 and 61 months, respectively. Contralateral CCLR occurred in 53.1% and 48.6% at medians of 20 and 11 months, respectively. Doxycycline did not significantly decrease the risk of Co-CCLR (p = 0.83). This risk was decreased by 14.2% with each year of age but increased with each increasing kilogram of body weight and each increasing degree of tibial plateau angle by 5.4% and 9.7%, respectively. Labrador Retrievers were not significantly predisposed (p = 0.37). At the dose regimen investigated doxycycline does not decrease the risk for Co-CCLR.

Degenerative changes of the cranial cruciate ligament harvested from dogs with cranial cruciate ligament rupture.

Degenerative cranial cruciate ligament (CCL) rupture is characterized histologically by degenerating extracellular matrix (ECM) and chondroid metaplasia. Here, we describe the progression of chondroid metaplasia and the changes in the expression of ECM components in canine CCL rupture (CCLR). CCLs from 26 stifle joints with CCLR (CCLR group) and normal CCLs from 12 young beagles (control group) were examined histologically and immunohistochemically for expression of type I (COLI), type II (COLII), type III collagen (COLIII) and Sry-type HMG box 9 (SOX9). Cell density and morphology of CCLs were quantified using hematoxylin–eosin staining. The percentage of round cells was higher in the CCLR group than in controls. COLI-positive areas were seen extensively in the connecting fibers, but weakly represented in the cytoplasm of normal CCLs. In the CCLR group, there were fewer COLI-positive areas, but many COLI-positive cells. The percentages of COLII-, COLIII- and SOX9-positive cells were higher in the CCLR group than in controls. The number of spindle cells with perinuclear halo was high in the CCLR group, and most of these cells were SOX9-positive. Deposition of COLI, the main ECM component of ligaments, decreased with increased COLIII expression in degenerated CCL tissue, which shows that the deposition of the ECM is changed in CCLR. On the contrary, expression of SOX9 increased, which may contribute to the synthesis of cartilage matrix. The expression of COLII and SOX9 in ligamentocytes showed that these cells tend to differentiate into chondrocytes.

Two-hole extracapsular technique for the repair of canine cranial cruciate ligament rupture in thirty-eight dogs

Extracapsular technique with lateral fabellar suture (LFS) is one of the commonest surgical techniques for canine cranial cruciate ligament (CRCL) rupture. Among LFS methods, parallel double holes in the tibia are the most effective for the repair of canine stifle joint. The aim of this study was to evaluate the effectiveness of two-hole LFS for canine CRCL rupture. We retrospectively evaluated the outcome of canine CRCL rupture treated with two-hole LFS technique performed by two surgeons from October 2011 to September 2013. Breeds included Beagle (n=5), Yorkshire terrier (n=5), German shepherd (n=4), and so on. Mean body weight was 14.0±11.6 kg (&amp;gt;10 kg: n=16, &amp;lt;10 kg: n=22). Body condition score (5 scales) was as follows: 1 (n=0), 2 (n=1), 3 (n=18), 4 (n=18), and 5 (n=1). There were 18 males [neutered (n=11)] and 20 females [spayed (n=12)]. Mean age was 83.4±44.8 months (&amp;gt;12 months: n=35, &amp;lt;12 months: n=3). The type of rupture was partial (n=17) and complete (n=21). The affected site was right (n=20), left (n=18), and bilateral (n=4). Rehabilitation after operation was needed in 8 cases. There were 12 cases of previous medial patellar luxation operation, and 6 cases of opposite site CRCL surgery. Start of weight bearing and resolution of extension function was on day 1 (n=30), day 2 (n=0), and after day 2 (n=8). There was no evidence of surgical site infection/inflammation in any cases. The results of this study showed that two-hole LFS is an easy and effective technique for the repair of canine CRCL.

Treatment of canine cranial cruciate ligament disease. A survey of ACVS Diplomates and primary care veterinarians.

To describe veterinarians' treatment recommendations and decision-making factors for dogs with cranial cruciate ligament disease (CCLD). An online survey of American College of Veterinary Surgeons (ACVS)-Diplomates (surgeon group) and primary care veterinarians (practitioner group) was performed. The survey included questions on treatment recommendations for common case scenarios (small or large breed dog with complete or partial CCLD), treatment decision factors, non-surgical treatment options, and actual treatment, if any, provided for a client-owned dog as well as one owned by their family or close friend. The response rate was 42% for the surgeon group (n = 305/723) and four percent for the practitioner group (n = 1145/ 27,771). Extracapsular stabilization (ES) was the most common treatment recommendation for CCLD in small (9.1 kg) breed dogs amongst surgeons and practitioners. Tibial plateau levelling osteotomy (TPLO) was the most common treatment recommendation for CCLD in large (27.2 kg) breed dogs amongst both groups. The two most important treatment decision factors were dog size (78% of practitioners, 69% of surgeons) and activity level (63% of practitioners, 52% of surgeons). The most common treatment provided for a dog of their own or close relation in the surgeon group was TPLO (64%) followed by ES (15%), whereas in the practitioner group it was ES (38%) followed by TPLO (30%). Extracapsular stabilization and TPLO are the most commonly employed surgical procedures in the surveyed population; dog size and activity level (but not age) are the major factors influencing treatment decisions.

Ex Vivo Pathomechanics of the Canine Pond-Nuki Model

BackgroundTransection of the canine cranial cruciate ligament (CCL) is a well-established osteoarthritis (OA) model. The effect of CCL loss on contact pressure and joint alignment has not been quantified for stifle loading in standing. The purposes of the study were to measure femorotibial contact areas and stresses and joint alignment following transection of the CCL in an ex vivo model. We hypothesized that transection of the CCL would lead to abnormal kinematics, as well as alterations in contact mechanics of the femorotibial joint.Methodology/Principal FindingsEight canine hindlimbs were tested in a servo-hydraulic materials testing machine using a custom made femoral jig. Contact area and pressure measurements, and femorotibial rotations and translations were measured in the normal and the CCL–deficient stifle in both standing and deep flexion angles.We found that at standing angle, transection of the CCL caused cranial translation and internal rotation of the tibia with a concurrent caudal shift of the contact area, an increase in peak pressure and a decrease in contact area. These changes were not noted in deep flexion. At standing, loss of CCL caused a redistribution of the joint pressure, with the caudal region of the compartment being overloaded and the rest of the joint being underloaded.ConclusionIn the Pond-Nuki model alterations in joint alignment are correlated with shifting of the contact points to infrequently loaded areas of the tibial plateau. The results of this study suggest that this cadaveric Pond-Nuki model simulates the biomechanical changes previously reported in the in-vivo Pond-Nuki model.

Elastin content is high in the canine cruciate ligament and is associated with degeneration

Cruciate ligaments (CLs) are primary stabilisers of the knee joint and canine cranial cruciate ligament disease (CCLD) and rupture is a common injury. Elastin fibres, composed of an elastin core and fibrillin containing microfibrils, are traditionally considered minor components of the ligament extracellular matrix (ECM). However, their content and distribution in CLs is unknown. The purposes of this study were to determine the elastin content of canine CLs and to ascertain its relationship to other biochemical components and histological architecture.Macroscopically normal CLs were harvested from Greyhounds (n=11), a breed with a low risk of CCLD. Elastin, collagen and sulfated glycosaminoglycan content were measured and histological scoring systems were developed to quantify ECM changes using a modified Vasseur score (mVS) and oxytalan fibre (bundles of microfibrils) staining. Elastin contents were 9.86±3.97% dry weight in the cranial CL and 10.79±4.37% in the caudal CL, respectively, and did not alter with advancing histological degeneration. All CLs demonstrated mild degenerative changes, with an average mVS score of 11.9±3.3 (maximum 24). Increasing degeneration of the ligament ECM showed a positive correlation (r=0.690, P<0.001) with increased oxytalan fibre staining within the ECM.Elastin is an abundant protein in CLs forming a greater proportion of the ligament ECM than previously reported. The appearance of oxytalan fibres in degenerative CL ECM may reflect an adaptive or reparative response to normal or increased loads. This finding is important for future therapeutic or ligament replacement strategies associated with cranial CL injury.

Radiographic localization and isometry of the origin and insertion of the canine cranial cruciate ligament

To radiographically define the anatomic origin and insertion of the cranial cruciate ligament translated to the lateral radiographic projection of the stifle (CrCL-Lo and CrCL-Li, respectively), to correlate these landmarks for identification of the CrCL-Lo intraoperatively, and to compare the isometry of the CrCL-Lo to the lateral fabella. Experimental study. Pelvic limbs (n = 12) from dogs weighing 13-26 kg. A radiographic quadrant method was used to localize the CrCL-Lo. Mediolateral radiographic projections of each stifle were taken through a range of motion. Maximum percent change in length between each tibial marker and femoral marker during range of motion determined isometry. The CrCL-Lo is located at the caudal 33% and distal 50% of the lateral femoral condyle using Blumensaat's line or a line from the origin of the long digital extensor (LDE) to the lateral fabella, with no significant difference (P = .766) between the 2 reference lines. The CrCL-Li is located at the proximal 20% of the tibial plateau. No significant difference (P < .05) in isometry was found between the CrCL-Lo and lateral fabella. The CrCL-Lo is located at the caudal 1/3 and distal ½ of the lateral femoral condyle. The CrCL-Lo and lateral fabella are not significantly different in isometry when used as a proximal anchor point in extracapsular stifle stabilization.

The role of muscle activation in cruciate disease

Traditional investigations into the etiopathogenesis of canine cranial cruciate ligament (CCL) disease have focused primarily on the biological and mechanical insults to the CCL as a passive stabilizing structure of the stifle. However, with recent collaboration between veterinarians and physical therapists, an increased focus on the role of muscle activity and aberrant motor control mechanisms associated with anterior cruciate ligament (ACL) injuries and rehabilitation in people has been transferred and applied to dogs with CCL disease. Motor control mechanisms in both intact and cruciate-deficient human knees may have direct translation to canine patients, because the sensory and motor components are similar, despite moderate anatomic and biomechanical differences. Components of motor control, such as muscle recruitment and the coordination and amplitudes of activation are strongly influenced by afferent proprioceptive signaling from peri- and intra-articular structures, including the cruciate ligaments. In people, alterations in the timing or amplitude of muscle contractions contribute to uncoordinated movement, which can play a critical role in ACL injury, joint instability and the progression of osteoarthritis (OA). A better understanding of motor control mechanisms as they relate to canine CCL disease is vitally important in identifying modifiable risk factors and applying preventative measures, for development of improved surgical and rehabilitative treatment strategies. The purpose of this review article is to analyze the influence of altered motor control, specifically pelvic limb muscle activation, in dogs with CCL disease as evidenced by mechanisms of ACL injury and rehabilitation in people.

Surgical stabilization of shoulder luxation in a pot-bellied pig

Case Description-A 4.6-month-old pot-bellied pig was evaluated because of non-weight-bearing lameness (grade 5/5) in the right forelimb of 4 days' duration. Clinical Findings-Clinical and radiographic examination revealed a closed, lateral luxation of the right shoulder joint. Treatment and Outcome-Initial attempts at closed reduction failed to provide adequate stability of the shoulder joint. Open reduction and internal fixation by placement of 2 lateral tension sutures with a system designed for canine cranial cruciate ligament repair provided adequate joint stability and a successful outcome. Conclusions and Clinical Relevance-Stabilization of the shoulder joint with lateral tension sutures after open reduction should be considered for management of lateral shoulder luxation in pot-bellied pigs.

Extra-Articular Stabilization of the Canine Cranial Cruciate Ligament Injury Using Arthrex Corkscrew and FASTak Anchors

The objective of this study was to evaluate the long-term outcome in dogs with cranial cruciate ligament injury that were repaired with an Arthrex Corkscrew or FASTak bone anchor and Fiberwire placed at near isometric points of the stifle. A retrospective study (2006-2010) was conducted by reviewing clinical records of dogs treated for cranial cruciate ligament injury with an extra-articular repair method using anchors preloaded with Fiberwire. A questionnaire was given to owners for evaluation of their dog’s performance prior to surgery and at time of follow-up with a minimum of 12 months post-operative. Owner assessment was rated using a visual analogue scale. Completed questionnaires from 34 owners were received. The mean time to follow up was 27.5 months. Owner assessment of their dog prior to surgery versus at the time of follow up were considered significant (P

Mechanical testing of orthopaedic suture material and a crimp clamp system for the extracapsular stabilisation of canine cruciate-deficient stifles

The cranial cruciate ligament (CCL) provides cranio-caudal stability, prevents hyperextension and constrains medial rotation of the tibia in the canine stifle joint and CCL rupture is the leading cause of hind leg lameness in dogs. Treatment of CCL rupture aims to resolve lameness caused by joint instability and provide good long-term function of the affected hind limb. The extracapsular technique is one of the most popular methods to restore joint stability. The technique involves a suture loop that is placed around the lateral fabella and through the tibial tuberosity. The ideal suture material should be strong, aseptic, easily handled, inexpensive, and provide excellent knot security and knot compactness. A critical property of the loop is the application of either a knot or crimp to maintain the tension on the loop. There is a variety of orthopaedic suture materials used for the extracapsular technique. Our aim was to compare the mechanical properties of four commercially available materials in pure tension. The materials tested were monofilament nylon leader (MNL) 100 lb, MNL 80 lb, Supramid and Silon. Our second objective was to compare the interoperator variability of applying either a knot or a crimp to secure the suture loop. Ultimate tensile strength was greatest with MNL 100 lb (373 N) followed by MNL 80 lb (285 N), Supramid (160 N) and Silon (103 N). Based on our results, we conclude that MNL 100 lb and MNL 80&amp;nbsp;lb are mechanically superior to Silon and Supramid. Our study also shows significant effects for the operator and method of loop fixation (P &amp;lt; 0.0001). Intraoperator differences were also found to be significant, for operator 1 (P &amp;lt; 0.0001), for operator 2 (P &amp;lt; 0.001) and operator 3 (P &amp;lt; 0.01). Our findings indicate that MNL is most suitable orthopaedic material and that loop fixation should remain the method of choice for surgeons treating CCL.

Viscoelasticity of the articular cartilage surface in early osteoarthritis

Structural and biochemical changes in articular cartilage occur throughout the pathogenesis of osteoarthritis (OA). Early changes include proteoglycan loss and collagen network disorganization at or near the articular surface. These changes accompany reductions in mechanical properties of cartilage, yet the relationships between mechanics and structure in early OA are poorly defined. Thus, the overall goal of this work was to measure changes in the microscale mechanics and structure of the articular surface in an in vivo model of OA to better understand the early pathogenesis of cartilage degeneration in this disease. A canine cranial cruciate ligament transection (CCL(x)) model was used. The contralateral joint served as an internal control (Ctl). The frequency dependence of the dynamic indentation modulus (E(∗)) was evaluated, and creep behavior was measured to estimate the instantaneous (E(i,inst)) and equilibrium (E(i,eq)) indentation moduli and longest creep time-constant (τ). These functional parameters were related to microscopic metrics of cartilage structure and biochemistry, measured by polarized light microscopy and digital densitometry of proteoglycan staining by safranin-O. CCL(x) and Ctl cartilage exhibited frequency sensitivity. E(i,inst), E(i,eq), and τ were lower in CCL(x) vs Ctl cartilage. These mechanical changes were accompanied by a reduction in superficial zone thickness and changes in superficial zone collagen organization, as well as a non-significant reduction in superficial zone proteoglycan staining. Changes in the microscale viscoelastic behavior of the cartilage surface are a functional hallmark of early OA that accompany significant changes to the microstructural organization of the collagenous extracellular matrix.

Nitric oxide induces cell death in canine cruciate ligament cells by activation of tyrosine kinase and reactive oxygen species

BackgroundThere is increasing evidence suggesting that development of progressive canine cranial cruciate ligament (CCL) rupture involves a gradual degeneration of the CCL itself, initiated by a combination of factors, ranging from mechanical to biochemical. To date, knowledge is lacking to what extent cruciate disease results from abnormal biomechanics on a normal ligament or contrary how far preliminary alterations of the ligament due to biochemical factors provoke abnormal biomechanics. This study is focused on nitric oxide (NO), one of the potential biochemical factors. The NO-donor sodium nitroprusside (SNP) has been used to study NO-dependent cell death in canine cranial and caudal cruciate ligament cells and to characterize signaling mechanisms during NO-stimulation.ResultsSodium nitroprusside increased apoptotic cell death dose- and time-dependently in cruciate ligamentocytes. Cells from the CCL were more susceptible to apoptosis than CaCL cells. Caspase-3 processing in response to SNP was not detected. Testing major upstream and signal transducing pathways, NO-induced cruciate ligament cell death seemed to be mediated on different levels. Specific inhibition of tyrosine kinase significantly decreased SNP-induced cell death. Mitogen activated protein kinase ERK1 and 2 are activated upon NO and provide anti-apoptotic signals whereas p38 kinase and protein kinase C are not involved. Moreover, data showed that the inhibition reactive oxygen species (ROS) significantly reduced the level of cruciate ligament cell death.ConclusionsOur data support the hypothesis that canine cruciate ligamentocytes, independently from their origin (CCL or CaCL) follow crucial signaling pathways involved in NO-induced cell death. However, the difference on susceptibility upon NO-mediated apoptosis seems to be dependent on other pathways than on these tested in the present study. In both, CCL and CaCL, the activation of the tyrosine kinase and the generation of ROS reveal important signaling pathways. In perspective, new efforts to prevent the development and progression of cruciate disease may include strategies aimed at reducing ROS.

Ex Vivo Biomechanical Evaluation of the Canine Cranial Cruciate Ligament‐Deficient Stifle with Varying Angles of Stifle Joint Flexion and Axial loads after Tibial Tuberosity Advancement

To evaluate the effect of tibial tuberosity advancement (TTA) on cranial tibial thrust (CrTT), retropatellar force (RPF), patellar tendon load (PTL), and patellar tendon angle determined by the tibial plateau angle (PTA(TPA) ) method or common tangent (PTA(CT) ) method in the canine cranial cruciate ligament (CrCL)-deficient stifle joint. Ex vivo cadaver study. Cadaveric canine hind limbs (n=30). Stifle joints were subjected to 3 differing loading conditions using a constrained limb press model (Group 1: 30% body weight axial load at stifle and talocrural joint angles of 135 ± 5° and 145 ± 5°, respectively; Group 2: 30% body weight axial load at stifle and talocrural angles of 145 ± 5° and 135 ± 5°, respectively; and Group 3: 50% body weight axial load at stifle and talocrural joint angles of 135 ± 5° and 145 ± 5°, respectively). The CrCL was transected in situ under load; sensors allowed direct measurement of CrTT, RPF, and PTL. Lateral radiographic projections were used to assess PTA(TPA) and PTA(CT) . Descriptive statistics were used to report CrTT (by design this force returned to 0-point values, defined as the neutral point of advancement [NPA]). At the NPA, RPF was compared with baseline using a 2-tailed sign test. PTL within groups were compared using a paired t-test; pair-wise comparisons of PTA(TPA) and PTA(CT) were performed using a paired t-test. Comparisons between loading conditions were made with a 1-way ANOVA and Tukey's post hoc test. Equivalence tests were used to test mean PTA(TPA) and PTA(CT) for equivalence to 90°. Significance was set at a P-value of .05. CrTT returned to baseline values, and RPF and PTL at NPA were reduced below baseline values in all specimens in a near linear fashion with TTA. At the NPA, PTA(TPA) >PTA(CT) in 2 of the 3 loading conditions, but insufficient evidence to suggest they differed in the third. Mean PTA(TPA) and PTA(CT) varied between loading conditions. The threshold for each of the groups evaluated, at which the PTA could be significantly different from 90°, was larger for PTA(TPA) than PTA(CT) in all groups, as greater variation was observed with PTA(TPA) versus PTA(CT) . This study further supports the claim that reduction of CrTT occurs after TTA in the CrCL-deficient stifle joint through an alteration of PTA. Additionally, RPF and PTL also decrease after TTA. The PTA(CT) may be a more precise method of determining PTA.

Vascular Distribution in Ruptured Canine Cranial Cruciate Ligament

To (1) determine the microanatomic vascular distribution in ruptured canine cranial cruciate ligaments (CCL) using specific vascular immunohistochemical techniques, and (2) compare vessel density between ruptured and intact canine CCL and between different areas of interest in ruptured CCL using histomorphometric analysis. In vitro study. Dogs (n=41) admitted for surgical treatment of ruptured CCL and 19 dogs euthanatized for nonorthopedic conditions. Diseased (variable CCL rupture) and intact (normal control) CCL were processed for immunohistochemical staining specific to vessels (factor VIII, laminin). Mean vascular density was assessed and compared in areas of interest (torn end versus remaining core regions of CCL, proximal femoral versus distal tibial core CCL regions). Ruptured CCL was more vascular than intact CCL; however there was no difference in vascular density between the torn end and the remaining core area of the ruptured CCL. Ruptured CCL was vascularized to a greater degree at the proximal portion than the distal portion of the CCL. Partially ruptured CCLs had a higher vessel density than completely ruptured CCLs. Vascular density is increased in diseased CCL compared with intact CCL. It remains to be determined whether this finding is associated with the cause of CCL rupture or is a result of CCL degeneration and rupture.

Immunohistochemical and Histomorphometric Evaluation of Vascular Distribution in Intact Canine Cranial Cruciate Ligament

To (1) describe vascular distribution in the grossly intact canine cranial cruciate ligament (CCL) using immunohistochemical techniques specific to 2 components of blood vessels (factor VIII for endothelial cells, laminin for basement membrane); and (2) compare the vascularity in different areas of interest (craniomedial versus caudolateral bands; core versus epiligamentous regions; and proximal versus middle versus distal portions) in the intact normal canine CCL. In vitro study. Large, mature dogs (n=7) of breeds prone to CCL disease that were euthanatized for nonorthopedic conditions. Intact CCL were collected from fresh canine cadavers free from stifle pathology. CCL tissue was processed for immunohistochemistry and stained for factor VIII and laminin. Vascular density was determined by histomorphometric analysis. Specific vascular staining was sparsely identified throughout the CCL; however, the proximal portion of the CCL appears to have a greater number of vessels than the middle or distal portion of the ligament. The CCL is a hypovascular tissue and its vascular distribution is not homogeneous.

The effect of tibial tuberosity advancement and meniscal release on kinematics of the cranial cruciate ligament-deficient stifle during early, middle, and late stance

To evaluate the effect of tibial tuberosity advancement (TTA) and meniscal release on cranial-caudal and axial rotational displacement during early, middle and late stance phases in the canine cranial cruciate ligament- (CCL) deficient stifle. In vitro biomechanical study. Eighteen pelvic limbs were evaluated for the effects of TTA on cranial-caudal displacement and axial rotation under a load equivalent to 30% bodyweight, and under the following treatment conditions: normal (intact CCL), CCL deficient, TTA-treated (CCL deficient + TTA), and meniscal release (TTA treated + meniscal release). The limbs were evaluated in the early, middle, and late stance phases using electromagnetic tracking sensors to determine cranial tibial displacement and tibial rotation relative to the femur. Transection of the CCL resulted in significant cranial tibial displacement during early, middle, and late stance (p < 0.0001) and significant internal rotation during early (p = 0.049) and middle stance (p = 0.0006). Performance of TTA successfully eliminated cranial tibial displacement in early, middle, and late stance (p <0.0001); however, the TTA was unsuccessful in normalizing axial rotation in middle stance (p = 0.030). Meniscal release had no effect on cranial-caudal or rotational displacement when performed in conjunction with the TTA. Tibial tuberosity advancement effectively eliminates cranial tibial displacement during early, middle and late stance; however, TTA failed to provide rotational stability in mid-stance.

Risk of canine cranial cruciate ligament rupture is not associated with the major histocompatibility complex

To investigate the association of the major histocompatability (MHC) class II allele haplotype frequencies with the diagnosis of cranial cruciate ligament (CCL) rupture in two breeds of dog. DNA samples from populations of Labrador Retrievers and Golden Retrievers with CCL rupture and general populations of the same breeds were characterised for three DLA class II loci (DRB1*, DQA1* and DQB1*) alleles using sequence-based typing or reference strand-mediated conformation analysis. Although distinct differences in haplotype types, frequencies and homozygozity were observed between the two breeds, no disease specific association could be identified for the development of the CCL rupture within either population. The risk for developing CCL rupture was not associated with DLA haplotype group(s) in Labrador Retrievers or Golden Retrievers, thus the hypothesis that there is an autoimmune basis to CCL rupture was not supported.