Cranial Cruciate Ligament Transection Research Articles

Effect of Cranial Cruciate Ligament Transection during TPLO on Patellar Desmitis in Dogs with Partial Cranial Cruciate Ligament Rupture.

The aim of this study was to assess the protective effect of transecting a partially ruptured cranial cruciate ligament (CCL) during tibial plateau levelling osteotomy (TPLO) surgery on postoperative patellar ligament thickness (PLT) and shortening. Dogs with partial CCL rupture that underwent a unilateral TPLO were included. The population was divided into two groups: remnant CCL transected (study group) and left in situ (control group). Preoperative and 6-week postoperative measurements of PLT, in three specific locations, and patellar ligament length (PLL) were collected. Risk factors for PLT and shortening were also included. Fifty-two dogs (56 stifles) with partial CCL rupture were retrospectively included. Twenty-nine stifles (51.8%) had the remnant CCL transected (study group) and 27 stifles (48.2%) had the remnant CCL left in situ (control group). Significant differences were found on PLT measurements between pre- and 6-week post-surgery for all three ligament locations with greatest difference at the middle region. Median PLL was significantly shorter 6-week post-surgery for both groups. No significant differences in PLT nor PLL were identified between procedures where the remnant was transected or not. This study did not identify a protective effect of transecting the CCL remnant on PLT or patellar ligament shortening, contrary to other reports within the literature. Further investigation is needed in the form of prospective studies with higher number of cases to understand the clinical implications of patellar ligament thickening and shortening in dogs.

Biomechanical effects of cranial closing wedge osteotomy on joint stability in normal canine stifles: an ex vivo study.

Cranial closing wedge osteotomy (CCWO) is a functional stabilisation technique for cranial cruciate ligament (CrCL) ruptures. This biomechanical study aimed to evaluate the influence of CCWO on the stability of the stifle joint. Eighteen Beagle stifle joints were divided into two groups: control and CCWO. The stifle joints were analyzed using a six-degree-of-freedom robotic joint biomechanical testing system. The joints were subjected to 30N in the craniocaudal (CrCd) drawer and proximal compression tests and 1 Nm in the internal-external (IE) rotation test. Each test was performed with an extension position, 135°, and 120° of joint angle. The stifle joints were tested while the CrCLs were intact and then transected. In the drawer test, the CCWO procedure, CrCL transection, and stifle joint flexion increased CrCd displacement. The CCWO procedure and CrCL transection showed an interaction effect. In the compression test, the CCWO procedure decreased and CrCL transection and stifle joint flexion increased displacement. In the IE rotation test, CCWO, CrCL transection, and stifle joint flexion increased the range of motion. CCWO was expected to provide stability against compressive force but does not contribute to stability in the drawer or rotational tests. In the CCWO-treated stifle joint, instability during the drawer test worsened with CrCL transection. In other words, performing the CCWO procedure when the CrCL function is present is desirable for stabilizing the stifle joint.

Effects of SKCPT on Osteoarthritis in Beagle Meniscectomy and Cranial Cruciate Ligament Transection Models.

Osteoarthritis (OA) affects >500 million people globally, and this number is expected to increase. OA management primarily focuses on symptom alleviation, using non-steroidal anti-inflammatory drugs, including Celecoxib. However, such medication has serious side effects, emphasizing the need for disease-specific treatment. The meniscectomy and cranial cruciate ligament transection (CCLx)-treated beagle dog was used to investigate the efficacy of a modified-release formulation of SKI306X (SKCPT) from Clematis mandshurica, Prunella vulgaris, and Trichosanthes kirilowii in managing arthritis. SKCPT's anti-inflammatory and analgesic properties have been assessed via stifle circumference, gait, incapacitance, histopathology, and ELISA tests. The different SKCPT concentrations and formulations also affected the outcome. SKCPT improved the gait, histopathological, and ELISA OA assessment parameters compared to the control group. Pro-inflammatory cytokines and matrix metalloproteinases were significantly lower in the SKCPT-treated groups than in the control group. This study found that SKCPT reduces arthritic lesions and improves abnormal gait. The 300 mg modified-release formulation was more efficacious than others, suggesting a promising approach for managing OA symptoms and addressing disease pathogenesis. A high active ingredient level and a release pattern make this formulation effective for twice-daily arthritis treatment.

Instantaneous center of rotation in the canine femorotibial joint: Ex vivo assessment of a tool to evaluate joint stabilization surgeries

Cranial cruciate ligament rupture is a common cause of femorotibial joint instability in the dog. Numerous techniques including several tibial osteotomies have been described for stabilization, but there is no current consensus on the best method. The instantaneous center of rotation (ICR) can aid investigations of pathological joint movement, but its use is problematic in the femorotibial joint due to combined rotation and translation during flexion and extension. Using fluoroscopic images from an earlier cadaveric study of canine joint stability, an interpolation method was used to create repeatable rotational steps across joint situations, followed by least squares approximation of the ICR. The ICR in intact joints was located mid-condyle but displaced significantly (P < 0.001) proximally following cranial cruciate ligament transection and medial meniscal release. Individual joints appear to respond differently to destabilization. Triple tibial osteotomy partially restored ICR location during early movement from flexion to extension. Joint instability significantly altered the proportions of rolling and gliding movement at the joint surface (P < 0.02), which triple tibial osteotomy partially improved. While triple tibial osteotomy restores joint stability ex vivo and clinically, normal biomechanics of the joint are not restored. The methods described here may prove useful for comparison of osteotomy techniques for stabilization of the cranial cruciate ligament deficient femorotibial joint in dogs.

Improved Joint Health Following Oral Administration of Glycosaminoglycans with Native Type II Collagen in a Rabbit Model of Osteoarthritis.

Simple SummaryOsteoarthritis is an incurable chronic disease. For this reason, new therapies are constantly emerging to improve clinical signs and the quality of life of our pets. Chondroitin sulfate, glucosamine and hyaluronic acid have been proven effective and are the most widely used in many formulations. In the present study, adding native type II collagen to the combination of chondroitin sulfate, glucosamine and hyaluronic acid showed improvements on osteoarthritis progression in an experimental model of osteoarthritis induced by transection of the cranial cruciate ligament of the knee in New Zealand white rabbits. Disease progression was monitored at different time points using magnetic resonance imaging biomarkers, measurement of hyaluronic acid in synovial fluid, and macroscopic and microscopic evaluations of cartilage, synovial membrane and subchondral bone. Overall, our results showed that adding native type II collagen to a combination of glycosaminoglycans allows a significantly slower osteoarthritis progression, compared to glycosaminoglycans alone.A prospective, experimental, randomized, double blinded study was designed to evaluate the effects of glycosaminoglycans, with or without native type II collagen (NC), in an osteoarthritis model induced by cranial cruciate ligament transection. The following compounds were tested: chondroitin sulfate (CS), glucosamine hydrochloride (GlHCl), hyaluronic acid (HA) and NC. Fifty-four female 12-week-old New Zealand rabbits were classified into three groups: CTR (control–no treatment), CGH (CS + GlHCl + HA) and CGH-NC (CS + GlHCl + HA + NC). Each group was subdivided into three subgroups according to survival times of 24, 56 and 84 days. Over time, all rabbits developed degenerative changes associated with osteoarthritis. CGH-NC showed significantly improved values on macroscopic evaluation, compared to CTR and CGH. Microscopically, significantly better results were seen with CGH and CGH-NC, compared to CTR, and synovial membrane values were significantly better with CGH-NC compared to CGH. A significant improvement in magnetic resonance imaging biomarkers was also observed with CGH-NC in cartilage transversal relaxation time (T2) and subchondral bone D2D fractal dimension in the lateral condyle. In conclusion, our results show beneficial effects on joint health of CGH and CGH-NC and also supports that adding NC to CGH results in even greater efficacy.

Effect of center of rotation of angulation-based leveling osteotomy on ex vivo stifle joint stability following cranial cruciate ligament transection and medial meniscal release with and without a hamstring load.

ObjectiveTo evaluate the effect of center of rotation of angulation (CORA)‐based leveling osteotomy (CBLO) and hamstring load on stifle stability following cranial cruciate ligament transection (CCLx) and medial meniscal release (MMR).Study designEx vivo experimental study.Sample populationCadaver hind limb preparations (n = 7).MethodsAfter instrumentation, constant quadriceps and gastrocnemius loads with an optional hamstring load in a 3:1:0.6 ratio were applied, and stifles were extended from fully flexed using an electrical motor during fluoroscopic recording. The recording process was repeated after each of CCLx, MMR and CBLO and the extracted landmark coordinates were used for calculation of cranial tibial translation (CTT) and patellar ligament angle (PTA).ResultsMean initial tibial plateau angle was 28.1°: post‐CBLO the mean was 9.7°. Cranial tibial translation developed from 50° and 75° with CCLx and MMR respectively (p < .04, < .02) without hamstring loading. Hamstring loading mitigated CTT due to CCLx and delayed CTT until 120° for MMR (P < .02) in this model. CBLO prevented CTT, except at 140° without hamstring loading (P = .01). Similar results were seen for PTA, but CBLO curves were parallel to and lower than intact values at all tested angles (P < .04), consistent with induced effective joint flexion.ConclusionCBLO to a target tibial plateau angle of 10° largely eliminated CTT induced by CCLx and MMR. Hamstring loads of 20% quadriceps load improved stifle stability in this model.ImpactStifle stability following CBLO appears to be multifactorial and depends on meniscal integrity, joint angle, and hamstring strength.

Three-dimensional kinematic evaluation of lateral suture stabilization in an in vitro canine cranial cruciate deficient stifle model.

The impact of surgical correction of cranial cruciate ligament rupture (CCLR) on 3D kinematics has not been thoroughly evaluated in dogs. The success of current techniques remains limited, as illustrated by suboptimal weightbearing and progression of osteoarthritis. The inability to restore the stifle’s 3D kinematics might be a key element in understanding these suboptimal outcomes. The objective of this study was to evaluate the impact of lateral suture stabilization (LSS) on the 3D kinematics of the canine stifle joint. We hypothesized that LSS would not restore 3D kinematics in our model. Ten cadaveric pelvic limbs collected from large dogs (25–40 kg) were tested using a previously validated apparatus that simulates gait. Three experimental conditions were compared: (a) intact stifle; (b) unstable stifle following cranial cruciate ligament transection (CCLt) and (c) CCLt stabilized by LSS. Three-dimensional kinematics were collected through 5 loading cycles simulating the stance phase of gait and curves were analyzed using a Wilcoxon signed-rank test. LSS restored baseline kinematics for the entire stance phase for cranial and lateromedial translation, flexion, and abduction. It restored distraction over 90% of the stance phase. Internal rotation was limited, but not restored. This in vitro study had limitations, as it used a simplified model of stifle motion and weight-bearing. The results of this study report that LSS can restore physiologic 3D kinematics largely comparable to those of healthy stifles. Suboptimal outcome in patients following CCLR stabilization by LSS may therefore result from causes other than immediate postoperative abnormal 3D kinematics.

Biomechanical evaluation of bovine stifles stabilized with an innovative braided superelastic nitinol prosthesis after transection of the cranial cruciate ligament.

To determine the stability bovine stifles stabilized with nylon or nitinol superelastic prostheses after transection of the cranial cruciate ligament (CCL). Ex vivo study. Stifles (n=15) harvested from adult bovine cadavers. The stifles were randomly assigned pairwise to a ligament reconstruction technique (n=5): (1) and (2) Hamilton's technique using a prosthesis made of 24 nitinol strands (0.39 mm) braided at 40°or single 600-lb test nylon implant, and (3) nitinol prosthesis placed in femoral and tibial bone tunnels (bone-to-bone). Craniocaudal tibial translation at ±2000 N was applied to the tibia, and mediolateral angular displacement via measured under torsional tibial loading at ±60 Nm on three occasions: intact CCL, transected, and stabilized. Outcomes were evaluated with a mixed effect linear model for repeated measures. Bone-to-bone using nitinol was the only repair that decreased tibial translation after CCL transection (p= .001) with a 23% change magnitude compared with intact CCL. Hamilton was the only stabilization reestablishing angular displacement, similar to intact CCL (p=.109 and .134 for nitinol and nylon). Bone-to-bone nitinol stabilization decreased angular displacement after CCL-transection with an 8% change magnitude (p=.040) without returning to normal values. CCL replacement with nylon did restore joint stability. Nitinol prostheses passed through single femoral and tibial bone tunnels (bone-to-bone) were the only techniques reducing tibial translation. Bone-to-bone stabilization with a nitinol prosthesis may be considered as an alternative to nylon for CCL replacement in cattle. These results provide evidence to justify clinical evaluation in cattle undergoing CCL replacement.

Comparison of Three Imaging Methods for the Evaluation of Osteoarthritis Induced by Cranial Cruciate Ligament Transection in Rabbits

Background:Osteoarthritis is a degenerative joint disease that affects specially cartilage, meniscus, and tendons. Ligaments, muscles, subchondral bone and synovium. This pathology is a common condition limiting the quality of life of patients. Imaging modalities have also been used for evaluation the progression of the osteoarthritis, or degenerative processes induced by acute injury. In order to use more accessible imaging modalities for experimentation, this study aimed to compare radiographic, computed tomography, and ultrasound findings in the evaluation of osteoarthritis induced by the cranial cruciate ligament transection model in rabbits.Materials, Methods &amp; Results:Twenty-four male Norfolk rabbits aged approximately 5 months old were used. All rabbits were submitted to cranial cruciate ligament transection of the left stifle and evaluated 45 days after the surgery. The radiographic findings were subchondral bone sclerosis (33.33%); joint space narrowing (66%); presence of osteophytes at medial femoral condyle (4.16%), lateral femoral condyle (4.16%), medial fabela (20.83%), lateral fabela (8.33%) and sesamoid of the popliteal muscle (4.16%). No osteophytes were seen at medial and lateral tibial condyles. The tomographic computed findings were joint space narrowing (62.5%); presence of osteophytes at medial femoral condyle (75%), lateral femoral condyle (54.16%), medial fabela (66.66%), lateral fabela (37.5%), medial tibial condyle (75%), lateral tibial condyle (20.83%) and sesamoid of the popliteal muscle (37.5%). The ultrasound findings were synovial hypertrophy (95.83%); effusion in the suprapatellar recess (75%), distal tibial recess (16.66%) and cranial joint space (75%); changes (hyperechogenic foci and heterogeneity) of the lateral meniscus (50%) and medial meniscus (25%); increased thickness of the medial condyle (54.16%) and lateral condyle (45.83%); irregularity of the medial condyle (66.66%) and lateral condyle (58.33%); alterations of the patellar tendon (12.5%) and extensor ligament (effusion and increased echogenicity) (20.83%).Discussion: Osteoarthritis is a degenerative joint disease and is common condition which limiting the quality of life of patients. Many studies performed in rabbits have evaluated the development of osteoarthritis through post-mortem macroscopic or microscopic assessments. Imaging modalities have also been used for evaluation the progression of the osteoarthritis, or degenerative processes induced by acute injury. High quality radiographs are accurate in identifying structural changes resulted from osteoarthritis, but computed tomography allows earlier identification in relation to conventional radiography. The three imaging modalities were helpful to identify the osteoarthritis, but the findings were different and compatible with each analysis method. The computed tomographic detected a higher number of osteophytes than plain radiographs. Also, osteophytes did not visualized by radiographic examination, such as medial tibial condyle and lateral tibial condyle, were identified by computed tomography. In turn, the ultrasound examination enabled identification of lesions did not seen on radiographic and computed tomography examinations. Synovial hypertrophy and joint effusion had the highest percentage. In human patients, ultrasound examination has been used to assess hypertrophy and inflammation of the synovium due to osteoarthritis. In conclusion, computerized tomography images provided more information than plain X-ray images and can be complemented by ultrasound examination to identify osteoarthritis induced by cranial cruciate ligament transection in rabbits.Comparison of Three Imaging Methods for the Evaluation of Osteoarthritis Induced by Cranial Cruciate Ligament Transection in Rabbits

Use of hyaluronic acid associated with triamcinolone acetonide or ozone gas in the treatment of induced osteoarthritis in rabbits.

ABSTRACTPurpose:To evaluate the effects of the intra-articular application of hyaluronic acid associated with triamcinolone acetonide, and ozone gas in the treatment of induced osteoarthritis in rabbit’s stifles.Methods:Twenty-one Norfolk rabbits were submitted to cranial cruciate ligament transection of the left stifle. After six weeks of the surgery, the rabbits were randomized assigned into three groups: G1 (control) – saline solution (0.9%); G2 – hyaluronic acid associated with triamcinolone; G3 – ozone gas, submitted to three intra-articular applications every seven days.Results:Significant differences occurred: osteophytes at medial femoral condyle (G2 > G1, G2 > G3) on radiography exam; thickening of the medial condyle (G1 > G3, G2 > G3) on ultrasound exam; osteophytes at lateral tibial condyle (G2 > G1, G2 > G3), and medial femoral condyle (G1 > G2, G3 > G1) on computed tomography. Histologically, mean values of chondrocytes in the femur and tibia in G3 and G2 were statistically lower.Conclusions:The intra-articular injection of hyaluronic acid associated with triamcinolone accentuated degenerative joint disease by imaging and macroscopic evaluations, and by histological findings, this treatment and the ozone gas treatment showed similar effects and were inferior to the saline solution (0.9%).

Synergistic Effect of Carboxymethyl Chitosan and Adipose-Derived Mesenchymal Stem Cells on Osteoarthritis Model in Rabbits

The purpose of this study is to investigate the clinical effects of carboxymethyl chitosan (CMC) and adiposederived mesenchymal stem cells (MSCs) on osteoarthritis (OA). Thirty New Zealand white rabbits were used as cranial cruciate ligament transection and partial meniscectomy models. The rabbits were divided into five groups (n = 6) according to the intra-articular injection materials: the control group with PBS, the HA group with hyaluronic acid, the CMC group with CMC, the MSC group with MSCs emerged in PBS, and the MSC+CMC group with CMC and MSCs. Knee thickness, extension angle, gross morphology, histopathology and immunohistochemistry were performed to evaluate the effects of CMC and MSCs on rabbit OA. On the morphologic and histologic examination, the articular surfaces of the femur and tibia were markedly damaged in control group with higher Mankin score and lower cartilage surface thickness. However, OA related cartilage defects were alleviated by the treatment of MSC and/or CMC. The expressions of apoptotic and inflammatory cytokines were decreased and cartilage extracellular matrix (ECM) related collagens I and II were enhanced by the treatment of MSC and/or CMC. In conclusion, this study showed that CMC and MSC treatments have a beneficial effects on OA via the protection of cartilage damage, the stimulation of ECM, and the inhibition of inflammatory and apoptotic reaction.

Effect of stifle flexion on the position of the cranial tibial artery relative to the proximal tibia in dogs.

To determine the effect of stifle flexion on the proximity of the cranial tibial artery to the proximal tibia in canine stifles with an intact or transected cranial cruciate ligament (CCL). Ex vivo randomized blinded computed tomographic angiographic study. Fifteen pelvic limbs from eight greyhound cadavers. The femoral artery and vein were cannulated and injected with 10 mL of iohexol. Each limb was placed in lateral recumbency on an acrylic sheet with predrawn femoral and tibial lines representing angles of stifle extension. Computed tomography was performed before (limbs 1-15) and after (limbs 10-15) CCL transection. The shortest distance between the cranial tibial artery and proximal tibia (dCrTA-PT) was measured at a distance of one patellar length from medial intercondylar tubercle. Median dCrTA-PT in intact specimens at 70°, 90°, 110°, and 135° was 2.04, 2.05, 2.28, and 2.51 mm, respectively (P = .008). Pairwise comparisons identified a difference between 70° and 135° (P = .007). Mean dCrTA-PT in transected specimens at 70°, 90°, 110°, and 135° was 2.60, 2.57, 2.90, and 2.79 mm, respectively (P = .208). Median overall dCrTA-PT was 2.24 mm in intact specimens (limbs 1-15, all four angles of extension combined) and 2.76 mm in transected specimens (limbs 10-15, all angles combined; P = .01). Flexion of the stifle resulted in a negligible decrease in dCrTA-PT in intact specimens but had no effect in CCL transected stifles. The angle of stifle extension does not appear to have any clinically significant effect on the proximity of cranial tibial artery to the proximal tibia.

Modelling the Effects of Cranial Cruciate Ligament Transection, Medial Meniscal Release and Triple Tibial Osteotomy on Stability of the Canine Stifle Joint.

The aim of this study was to evaluate the ex vivo effects of sequential cranial cruciate ligament transection (CCLx), medial meniscal release (MMR) and triple tibial osteotomy (TTO) on canine stifle stability compared with the intact state, across a wide range of joint angles. Nine right hind limb preparations were instrumented to provide constant quadriceps and gastrocnemius loads in a 3:1 ratio, and extended from full flexion during fluoroscopic recording. Recordings were repeated after each of CCLx, MMR and TTO. Fluoroscopic landmarks were used to calculate tibial subluxation and patellar ligament angle. Medial meniscal release resulted in additional cranial tibial subluxation compared with CCLx. Triple tibial osteotomy restored stifle stability up to a joint angle of 125 degrees. The presence of the crossover angle could be inferred from the patellar ligament angle and subluxation curves. Our results suggest that in the cranial cruciate ligament-deficient stifle, the crossover angle at which loading shifts between the caudal and cranial cruciate ligaments is dependent on both loading and integrity of the medial meniscus. Triple tibial osteotomy improves stifle stability over a wide range of joint angles under a quadricep to gastrocnemius loading ratio of 3:1 by converting cranial tibial thrust to caudal tibial thrust, due to TTO increasing the amount of joint extension required to reach the crossover angle.

Effect of tibial rotation on the tibial plateau angle measurement in dogs: An ex vivo study.

To determine the effect of tibial rotation on radiographic tibial plateau angle (TPA) measurement in normal and cranial cruciate ligament (CrCL)-deficient stifles. Cadaveric study. Five pairs of canine cadaver hind limbs with no stifle osteoarthritis. Mediolateral radiographs of each specimen were obtained at 0°, 10°, 20°, and 30° of internal and external rotation of the tibia with both intact and transected CrCL. Two Kirschner wires were placed at the cranial and caudal landmarks of the tibial plateau, and the 0° views were imaged again, representing the anatomic TPA. Five observers measured the TPA twice on all images. Measurements were compared by using a mixed-model ANOVA. Intraobserver and interobserver variability were evaluated by using the coefficient of variation. Tibial plateau angle did not differ among the anatomic, CrCL-intact, and CrCL-deficient 0° views or between the CrCL-intact and CrCL-deficient views at the various tibial rotations. The only difference detected was between CrCL-intact stifles radiographed at 0° and external rotation (range, 1.16°-1.6°; P = .016, P = .001, and P < .001). Tibial rotation, CrCL transection, and their interaction all failed to influence intraobserver and interobserver variability (P > .05). In CrCL-deficient stifles, tibial rotation of up to 30° internally and externally did not result in clinically relevant changes in TPA measurements. The TPA can be successfully measured with up to 30° of internal and external tibial rotation in CrCL-deficient stifles with no osteoarthritic changes.

Variables Affecting Thigh Girth Measurement and Observer Reliability in Dogs.

Objective: The purpose of the study reported here was to describe variables affecting thigh girth measurements preoperatively and 2 weeks after surgical stabilization of the stifle and to examine inter- and intra-observer reliability.Animals: Ten hound-type dogs with experimental, unilateral, cranial cruciate ligament transection, and surgical stabilization.Procedures: Dogs were placed in lateral recumbency for measurements of thigh circumference after the stifle was placed in flexed (F), estimated standing (S), and extended (E) positions. Measurements were made at 50 and 70% of thigh length (TL), with hair unclipped and then clipped prior to surgery, before and 2 weeks after cruciate ligament transection and stifle stabilization, and with and without sedation. A spring tension measuring tape was used to determine thigh girth that allowed a consistent amount of end-tension to be applied to the tape. All measurements were made by two blinded individuals in triplicate, data were recorded for each set of measurements and the mean of the three measurements for each condition was used for analysis.Results: Thigh girth was significantly greater at the more proximal site of 50% TL (36.7 ± 2.6 cm) when compared to the 70% TL (31.7 ± 2.7 cm) (P = 0.001). Sedation did not significantly affect thigh girth at any stifle position at the 70% and 50% TL. Although there were no differences in thigh circumference between the flexion and standing positions at 50% TL (F 38.2 ± 2.8 cm, S 38.1 ± 2.9 cm) and 70% TL (F 33.6 ± 1.6 cm; S 33.6 ± 1.8 cm), full extension of the stifle resulted in significantly less thigh girth (50% TL 36.6 ± 2.6 cm, P = 0.006; 70% TL 31.7 ± 2.6 cm, P = 0.006). Significant decreases in thigh girth were seen after surgery in all limb positions at both measurement sites. The highest correlations between Observer 1 (OB1) and Observer 2 (OB2) with least differences in measurements were with the stifle in the extended position. Agreement between two observers using standard measuring technique was significant at both the 50% (OB1: 34.10 ± 2.93 cm, OB2: 34.08 ± 2.65 cm, P = 0.007, ICC = 0.984) and 70% (OB1: 29.89 ± 2.43 cm, OB2: 30.04 ± 2.30 cm, P = 0.004, ICC = 0.981) TL positions with the stifle placed in extended position.Conclusion and Clinical Importance: Thigh girth measurement may be useful as an outcome measure when appropriate measuring technique is used. It is recommended that thigh girth be obtained at a distance of 70% thigh length, with the leg in an extended position while in lateral recumbency, and the dog relaxed or under sedation. Further studies should be performed in a variety of clinical situations.

Evaluation of an arthroscopic stifle lever for stifle joint distraction in toy breed dogs.

Arthroscopy has become an attractive modality in the diagnosis and treatment of joint diseases in toy breed dogs. However, the application of arthroscopy is limited by small joint space. Our objective was to evaluate the efficacy of a stifle lever for joint distraction during stifle arthroscopy in toy breed dogs. Paired stifles (n = 32 each) collected from 16 cadavers of toy breed dogs were randomly assigned to one of two groups: the stifle lever group or the external manipulation group. All stifles underwent arthroscopic cranial cruciate ligament transection, and the visualization of the medial meniscus was evaluated. Medial meniscal release (MMR) was then performed. Following arthroscopic examination, the success rates of MMR and damages of tibial and femoral cartilages were evaluated. Visualization of the medial meniscus was significantly better, and meniscal probing was significantly easier, in the stifle lever group than in the external manipulation group (p = 0.001). There were no significant differences between groups for MMR success or articular cartilage damage. Using the stifle lever on arthroscopic examination improved visualization and probing on the medial meniscus in toy breed dogs. The stifle lever can be used as a good modality in assessing medial meniscal pathology in toy breed dogs.

Use of a custom-made limb-press model to assess intra- and extracapsular techniques for treating cranial cruciate ligament rupture in cats.

Objectives This study aimed to compare the under-and-over technique, a type of intracapsular treatment, and the standard fabella-tibial suture, a method for extracapsular treatment, in achieving immediate, postoperative stifle stability after cranial cruciate ligament (CrCL) rupture by using a feline, custom-made limb-press model. Methods Cadaveric feline hindlimb specimens (n = 14) were positioned in the limb press at predefined joint angles (stifle joint: 120°; hock joint: 120°), and vertical loads of 5%, 10%, 20% and 30% body weight were applied statically. Mediolateral radiographic views were obtained of the stifles under each load before and after CrCL transection, as well as after treatment with either of the two surgical techniques, and differences in distance between two predefined radiographic points for each radiograph were analysed. Results The general linear model showed a significant effect of load ( P <0.01) and technique ( P = 0.004) and a significant interaction between load and technique ( P = 0.006) regarding craniocaudal stifle stability. Distances between predefined tibial and femoral reference points were consistently higher in transected CrCLs than in intact stifles. All standard fabella-tibial suture-treated stifles (n = 7) were stable at all loads tested. Of the seven under-and-over technique-treated stifles, one was unstable at 20% body weight load and three at 30% body weight load. Conclusions and relevance Our model, which appropriately reproduced certain aspects of domestic shorthair cat stifle mechanics, indicated that a 40 lb monofilament nylon prosthesis, tightened at 20 N, produces more favourable biomechanical stabilisation of craniocaudal cruciate-related stifle instability than a 0.5 cm wide strip of fascia lata applied intracapsularly.

Evaluation of the relationship of tibiofemoral kinematics before and after total knee replacement in an in vitro model of cranial cruciate deficiency in the dog.

To investigate the relationship between tibiofemoral kinematics before and after total knee replacement (TKR) in vitro. Eight canine hemipelves. A modified Oxford Knee Rig was used to place cadaveric limbs through a range of passive motion allowing the kinematics of the stifle to be evaluated. Four measurements were performed: a control stage, followed by a cranial cruciate transection stage, then following TKR with the musculature intact stage, and finally TKR with removal of limb musculature stage. Joint angles and translations of the femur relative to the tibia, including flexion-extension versus adduction-abduction, flexion-extension versus internal-external rotation, as well as flexion-extension versus each translation (cranial-caudal and lateral-medial) were calculated. Significant differences were identified in kinematic data from limbs following TKR implantation as compared to the unaltered stifle. The TKR resulted in significant decreases in external rotation of the stifle during flexion-extension compared to the limb prior to any intervention, as well as increasing the abduction. The TKR significantly increased the caudal translation of the femur relative to the tibia compared to the unaltered limb. When compared with the cranial cruciate ligament-transection stage, TKR significantly decreased the ratio of the external rotation to flexion. All three test periods showed significant differences from the unaltered stifle. The TKR did not completely restore the normal kinematics of the stifle.

Treatment of cranial cruciate ligament rupture in the feline stifle. Biomechanical comparison of a standard fabella-tibial suture and lateral sutures placed between quasi-isometric points.

To determine whether a lateral suture placed with bone anchors between quasi-isometric points in a cat is superior to a standard fabella-tibial suture for the stabilization of cranial cruciate ligament (CrCL) rupture compared to an intact stifle joint. Biomechanical cadaveric study. Six stifle joints with intact cruciate ligaments from three skeletally mature cats were placed in a loading mounting set and tested with axial loads of 20N and 60N at three different joint angles (75°,130° and 160°). The procedure was repeated with a transected CrCL; a stabilized stifle joint after a combination of three lateral suture techniques (fabella-tibial suture technique [SFT]; femoro-tibial suture technique 1 [FTS-1] and femoro-tibial suture technique 2 [FTS-2]). Radiographic examination of the relative position of the tibia to the fixed femur was compared. Stabilization of the stifle joint with lateral sutures had comparable stability to the intact specimens in the cranio-caudal direction (p = 0.2) but not in the proximo-distal direction for the SFT (p = 0.04) and FTS-2 technique (p = 0.03). There was no significant difference between the three stabilization techniques (p >0.05). Lateral sutures placed with bone anchors at quasi-isometric points performed better than SFT and FTS-2 in stabilizing the feline stifle after CrCL rupture in the proximo-distal plane. Biomechanical stability in the cranio-caudal plane after placement of a lateral suture across the feline stifle was similar to the intact CrCL.

Effects of tibial plateau angle and spacer thickness applied during in vitro canine total knee replacement on three-dimensional kinematics and collateral ligament strain.

To quantify the 3-D kinematics and collateral ligament strain of stifle joints in cadaveric canine limbs before and after cranial cruciate ligament transection followed by total knee replacement (TKR) involving various tibial plateau angles and spacer thicknesses. 6 hemi-pelvises collected from clinically normal nonchondrodystrophic dogs (weight range, 25 to 35 kg). Hemi-pelvises were mounted on a modified Oxford knee rig that allowed 6 degrees of freedom of the stifle joint but prevented mechanical movement of the hip and tarsal joints. Kinematics and collateral ligament strain were measured continuously while stifle joints were flexed. Data were again collected after cranial cruciate ligament transection and TKR with combinations of 3 plateau angles (0°, 4°, and 8°) and spacer thicknesses (5, 7, and 9 mm). Presurgical (ie, normal) stifle joint rotations were comparable to those previously documented for live dogs. After TKR, kinematics recorded for the 8°, 5-mm implant most closely resembled those of unaltered stifle joints. Decreasing the plateau angle and increasing spacer thickness altered stifle joint adduction, internal rotation, and medial translation. Medial collateral ligament strain was minimal in unaltered stifle joints and was unaffected by TKR. Lateral collateral ligament strain decreased with steeper plateau angles but returned to a presurgical level at the flattest plateau angle. Among the constructs tested, greatest normalization of canine stifle joint kinematics in vitro was achieved with the steepest plateau angle paired with the thinnest spacer. Furthermore, results indicated that strain to the collateral ligaments was not negatively affected by TKR.