Changes in the canine stifle joint following rupture of the anterior cruciate ligament

Sixty–four dogs with rupture of the anterior cruciate ligament in one or both stifle joints were referred to the Royal Veterinary College, London for treatment. Details of the pathological changes in the joints were recorded at the time of open surgery in fifty–seven and these changes are discussed. A post–mortem examination was made on one dog and the joint lesions were studied more closely.     

In vivo evaluation of intra-articular protection in a novel model of canine cranial cruciate ligament mid-substance elongation injury

OBJECTIVES: To evaluate the effects of intra-articular protection (IAP) on the canine cranial cruciate ligament (CrCL) and stifle in a CrCL midsubstance elongation injury model. STUDY DESIGN: Experimental longitudinal cohort study. ANIMALS: Skeletally mature female mixed breed hounds (n=12; mean+/-SEM weight, 25.6+/-0.7 kg). METHODS: After CrCL elongation in 1 stifle of each dog, IAP was applied in 6 joints. In vivo assessment included radiographs, cranial-caudal joint translation, gait analysis, and synovial fluid levels of 3B3(-) (proteoglycan epitope) and C2C (collagen II neoepitope) up to 12 weeks after surgery. Joint translation and rotation were quantified at necropsy. CrCL midsubstance length was determined before and after elongation and at necropsy. CrCLs were subjectively assessed with light microscopy. Comparisons were made between stifles containing elongated CrCLs with and without IAP and unoperated controls. RESULTS: Four weeks after surgery, ground reaction forces were significantly decreased in operated limbs. Absolute C2C levels were significantly elevated in operated stifles 4 weeks post-surgery. C2C and 3B3(-) levels normalized to total protein were significantly elevated in IAP+ stifles 8 weeks after surgery. Protected CrCLs appeared to have decreased granulation tissue and better collagen fiber alignment. CONCLUSIONS: IAP has negligible effects on the canine stifle based on the response variables evaluated in this 12-week study. Protection of elongated CrCLs may promote reduced, organized scar formation. CLINICAL RELEVANCE: These results support the healing capacity of the canine CrCL midsubstance following elongation injury and IAP application to potentially reduce cicatrix formation in elongated CrCLs.     

Evaluation of a canine cranial cruciate ligament repair system for use in equine laryngoplasty

OBJECTIVE: To report the use of a nylon suture system (Canine Cranial Cruciate Ligament Repair System; Securos Inc Veterinary Orthopedics) as a prosthesis for equine laryngoplasty. STUDY DESIGN: Experimental and prospective clinical study. ANIMALS: Cadaver specimens (n = 5) and 7 horses with left laryngeal hemiplegia. METHODS: A commercially available monofilament nylon suture system was implanted as a laryngeal prosthesis. Arytenoid cartilage abduction was achieved with a tensioning device applied to the suture prosthesis during transnasal endoscopic observation. Suture fixation was achieved with crimping clamps and a crimping device. RESULTS: The nylon suture system was suitable as a laryngeal prosthesis for arytenoid cartilage abduction. The ratchet mechanism of the tensioning device facilitated abduction of the arytenoid cartilage and suture fixation was achieved by the crimped clamp without any loss of tension. Postoperatively, there was a slight loss of tension in 4 horses and complete loss of tension in 1 horse because of cartilage failure. After convalescence, none of the horses had abnormal respiratory noise, exercise intolerance or cough. CONCLUSIONS: A nylon suture system designed for canine cranial cruciate ligament repair was used successfully as a laryngeal prosthesis and facilitated control of the degree of arytenoid cartilage abduction during laryngoplasty. CLINICAL RELEVANCE: For improved control of the degree of arytenoid cartilage abduction during laryngoplasty, use of a nylon suture system with metal crimps should be considered.     

Short-term and eight to 12 months results of a tibial tuberosity advancement as treatment of canine cranial cruciate ligament damage

OBJECTIVE: To describe the perioperative complications and the six weeks and eight to 12 months outcome of cases of canine cranial cruciate ligament damage treated with a tibial tuberosity advancement. METHODS: The medical records including the six weeks' postoperative re-evaluation and radiographs of dogs with a tibial tuberosity advancement (70 operated stifles) were analysed regarding the short-term outcome and the recorded complications. A questionnaire for the evaluation of the eight to 12 months outcome was sent to the owners and the answers tabulated. RESULTS: The complication rate was comparable with previous reports of cranial cruciate ligament rupture treated with a tibial tuberosity advancement or a tibial plateau leveling osteotomy (TPLO). The most frequent complication was a symptomatic late secondary meniscal damage in six cases (8.5 per cent). These cases were successfully treated with a partial meniscectomy during a minimal invasive procedure. The six-week re-evaluation showed advanced healing of the tibial crest osteotomies in 94 per cent of the cases and a significant reduction of the lameness in all dogs. Eighty-three per cent of the owners reported that their dogs are never lame or only after heavy exercise eight to 12 months after the tibial tuberosity advancement procedure. Sixty-five per cent of the owners stated the overall treatment to be excellent, 28 per cent good. CLINICAL SIGNIFICANCE: The six weeks' follow-up examination and the questionnaire revealed results of the tibial tuberosity advancement comparable to previously published studies, stating that the lameness and the activity level of the patients with cranial cruciate ligament disease greatly improved after the tibial tuberosity advancement.     

Rupture of the anterior cruciate ligament of the dog: a survey from practices in the Kent region BSAVA

The incidence and treatment of rupture of the canine anterior cruciate ligament are presented from reports over a 3-month period by members of the Kent Region BSAVA.     

Multivariate analysis of morphometric characteristics to evaluate risk factors for cranial cruciate ligament deficiency in Labrador retrievers

Objectives: To determine the combination of conformation characteristics of the pelvic limbs of Labrador Retrievers that best discriminates between limb at risk to develop cranial cruciate ligament (CCL) disease and limbs at low risk using radiographs, computerized tomography (CT) images, and dual‐energy X‐ray absorptiometry (DEXA). Study Design: Cross‐sectional clinical study. Animals: Twelve clinically normal and 9 unilaterally CCL‐deficient Labrador Retrievers. Methods: The pelvic limbs of normal dogs were considered as non‐predisposed to CCL disease and the contralateral limbs of CCL‐deficient dogs as predisposed. Conformation variables, obtained from femur and tibial radiographs, pelvic limb CT images and DEXA studies, of predisposed pelvic limbs were compared with the conformation variables from pelvic limbs of the low‐risk group. An ROC curve analysis was used to assess the discriminating properties of conformation variables for several combinations. Results: We determined that a combination of tibial plateau angle (TPA) and femoral anteversion angle (FAA) measured on radiographs was optimal for discriminating predisposed and non‐predisposed limbs for CCL disease in Labrador Retrievers. Conclusions: Assessing predisposition to CCL disease with a combination of conformational measurements is better than using univariate parameters. In the future, TPA and FAA may be used to screen dogs suspected of being susceptible to CCL disease.     

Biomechanical comparison of orthofix pins and cortical bone screws in a canine humeral condylar fracture model

OBJECTIVE: To compare shear stability of simulated humeral lateral condylar fractures reduced with either a self-compressing pin or cortical bone screw. STUDY DESIGN: In vitro biomechanical tests. SAMPLE POPULATION: Bilateral cadaveric canine humeri (n=18) without evidence of elbow disease. METHODS: Lateral condylar fracture was simulated by standardized osteotomy. Bone fragments were stabilized with a self-compressing pin or a cortical bone screw (2.7 or 3.5 mm) inserted in lag fashion. Specimens were mounted in a materials testing system and the condylar fragment displaced in a proximal direction until failure. Mechanical testing variables derived from load-deformation curves were compared between stabilization methods using a Student's paired t-test. RESULTS: There were no statistically significant differences for mechanical testing variables between pin and screw stabilized specimens at expected walk and trot loads. Three yield points subjectively coincided with yield of the interfragmentary interface (Y1), bone at the implant interface (Y2), and implant deformation (Y3). Displacements at Y1 were 48-156% greater for pin than screw stabilized specimens. Y2 and Y3 loads were higher for screw than pin stabilized specimens, but likely supraphysiologic for dogs convalescing after surgical repair. CONCLUSIONS: A self-compressing pin or a cortical bone screw inserted in lag fashion both provided adequate strength in applied shear to sustain expected physiologic loads through the repaired canine elbow during postoperative convalescence. CLINICAL RELEVANCE: Because self-compressing pins were easy to implant and mechanical properties were not significantly different than cortical screws at expected physiologic loads, pins should be considered for the repair of traumatic humeral condylar fractures.     

In vitro comparison of proximal ulnar osteotomy and distal ulnar osteotomy with release of the interosseous ligament in a canine model

Objective: To determine the effect of proximal ulnar osteotomy (PUO), distal ulnar osteotomy (DUO), and DUO with release of the interosseous ligament (DOLR) on displacement of the proximal ulna at the radioulnar joint. Study Design: Experimental mechanical study. Sample Population: Cadaveric, skeletally mature canine thoracic limb pairs (n=11). Methods: Thoracic limbs disarticulated at the elbow were randomly assigned to 1 of 2 groups: (A) limbs were tested with no treatment (NOTX), then with PUO; (B) limbs were tested with DUO followed by DOLR. A distraction force was applied to the proximal ulna with the distal limb secured in a frame, and displacement of the proximal ulnar segment at the radioulnar joint was recorded. Results: Mean displacement was 0.36 mm (95% confidence interval [CI]: 0?1.12 mm) in the NOTX group, 4.68 mm (95% CI: 3.82–5.55 mm) for PUO limbs, 0.95 mm (95% CI: 0.52–1.39 mm) for the DUO group, and 4.36 mm (95% CI: 3.71–5.02 mm) for the DOLR group. Mean ulnar displacement of the DOLR group was significantly different compared with the DUO group, but there was no significant difference between the PUO and DOLR groups. Conclusions: No significant difference was observed in displacement of the proximal ulnar segment after DOLR compared with PUO.     

Changes in the local regulation of insulin-like growth factors I and II and insulin-like growth factor-binding proteins in osteoarthritis of the canine stifle joint secondary to cruciate ligament rupture

OBJECTIVES: To investigate changes in concentrations of insulin-like growth factors I (IGF-I) and II (IGF-II) and the expression of IGF-binding proteins (IGFBP) in synovial fluids from dogs with naturally occurring osteoarthritis (OA) of the canine stifle joint secondary to cranial cruciate ligament (CCL) rupture. STUDY DESIGN: Prospective study with synovial fluid sampling from diseased and contralateral unaffected joints at 0, 1.5, and 5 months. SAMPLE POPULATION: Eleven dogs with unilateral CCL deficiency, with unaffected contralateral joints. METHODS: IGF-I and IGF-II concentrations in synovial fluids were estimated by radioimmunoassay at 0, 1.5, and 5 months; Western ligand blotting was performed for intact IGFBPs at 0, 1.5, 5, and 9 months. Both stifle joints were radiographed at 0, 7, and 13 months. RESULTS: The IGF system is altered after CCL rupture and during development of early OA. Mean IGF-I and IGF-II concentrations in index stifle joints at study entry were 201.6 microg/mL and 345.7 microg/mL, respectively, compared with 57.7 microg/mL and 79.4 microg/mL, respectively, for contralateral joints. Index joint IGF concentrations increased after surgical treatment and then declined, although they remained higher than contralateral joints. Index joints had increases in IGFBP-3 and -4, and a decrease in IGFBP-2 expression compared with contralateral joints. CONCLUSIONS: Although IGF concentrations are increased in canine OA, alterations in IGFBP profiles may limit the tissue availability of IGF. CLINICAL RELEVANCE: Manipulation of the IGF system may provide an opportunity for novel treatments of OA in dogs.     

Pharmacological effects of a C-phycocyanin-based multicomponent nutraceutical in an in-vitro canine chondrocyte model of osteoarthritis

Multicomponent nutraceuticals are becoming increasingly popular treatments or adjunctive therapies for osteoarthritis in veterinary medicine despite lack of evidence of efficacy for many products. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of a commercially available C-phycocyanin-based nutraceutical and select constituent ingredients in an in-vitro model of canine osteoarthritis. Normal canine articular chondrocytes were used in an in-vitro model of osteoarthritis. Inflammatory conditions were induced using interleukin-1β. The nutraceutical preparation as a whole, its individual constituents, as well as carprofen were evaluated at concentrations of 0 to 250 μg/mL for reduction of the following inflammatory mediators and indicators of catabolism of the extracellular matrix: prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TFN-α), interleukin-6 (IL-6), metalloproteinase-3 (MMP-3), nitric oxide, and sulfated glycosaminoglycans (sGAGs). Validated, commercially available assay kits were used for quantitation of inflammatory mediators. The antioxidant capacities, as well as cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) inhibitory activities of the whole nutraceutical preparation and select constituents, were also assessed using validated commercially available assay kits. The antioxidant capacity of the nutraceutical and constituents was concentration-dependent. The nutraceutical and constituents appear to display anti-inflammatory activity primarily through the inhibition of COX-2. The nutraceutical displayed similar strength to carprofen in reducing TNF-α, IL-6, MMP-3, nitric oxide, and sGAGs at select concentration ranges. The C-phycocyanin (CPC)-based nutraceutical and constituents may be able to mediate 3 primary pathogenic mechanisms of osteoarthritis: inflammation, chondral degeneration, and oxidative stress in vitro. The nutraceutical may be clinically useful in veterinary medicine and its efficacy should be further investigated in vivo.     

Induction of a barrier membrane to facilitate reconstruction of massive segmental diaphyseal bone defects: an ovine model

OBJECTIVES: To report an ovine model that can be used to evaluate the efficacy of bone substitutes for repair of segmental diaphyseal bone defects. STUDY DESIGN: Experimental study. ANIMALS: Eleven 2-year-old Pré-Alpes Sheep. METHODS: Mid-diaphyseal metatarsal bone defects (25 mm long) were stabilized by a dynamic compression plate over a polymethylmethacrylate (PMMA) cement spacer, and by external coaptation. The PMMA spacer was removed at 6 weeks by incising the encapsulating membrane. The defect remained unfilled (Group 1; n=5) or was filled with morselized autologous corticocancellous graft (Group 2; n=6), the membrane sutured closed, and external coaptation applied for 6 months, when healing was evaluated. RESULTS: Radiographic, computed tomographic, and histologic examinations at 6 months after the 2nd surgery revealed non-union in ungrafted defects whereas grafted defects showed bone healing. The induced membrane had blood vessels, CBFA1+ cells, and very few macrophages entrapped in a collagenous tissue positive for type I collagen. CONCLUSION: This ovine metatarsal defect model resulted in a critical-size defect (non-union) that healed when grafted. The PMMA-induced membrane constrained the graft, was well vascularized, and may have osteogenic properties. CLINICAL RELEVANCE: This model may be useful to evaluate new strategies in bone tissue engineering because the PMMA-induced membrane may help confine bone morphogenetic proteins, skeletal stem cells, or other agents to the defect cavity where they could be useful to enhance bone formation.     

Development of a 3D model of the equine distal forelimb and of a GRF shoe for noninvasive determination of in vivo tendon and ligament loads and strains

REASONS FOR PERFORMING STUDY: As critical locomotion events (e.g. high-speed and impacts during racing, jump landing) may contribute to tendinopathies, in vivo recording of gaits kinematic and dynamic parameters is essential for 3D reconstruction and analysis. OBJECTIVE: To propose a 3D model of the forelimb and a ground reaction force recording shoe (GRF-S) for noninvasively quantifying tendon and ligament loads and strains. METHODS: Bony segments trajectories of forelimbs placed under a power press were recorded using triads of ultrasonic kinematic markers linked to the bones. Compression cycles (from 500-6000 N) were applied for different hoof orientations. Locations of tendon and ligament insertions were recorded with regard to the triads. The GRF-S recorded GRF over the hoof wall and used four 3-axis force sensors sandwiched between a support shoe and the shoe to be tested. RESULTS: Validation of the model by comparing calculated and measured superficial digital flexor tendon strains, and evaluation of the role of proximal interphalangeal joint in straight sesamoidean ligament and oblique sesamoidean ligament strains, were successfully achieved. Objective comparisons of the 3 components of GRF over the hoof for soft and hard grounds could be recorded, where the s.d. of GRF norm was more important on hard ground at walk and trot. CONCLUSIONS: Soft grounds (sand and rubber) dissipate energy by lowering GRF amplitude and diminish bounces and vibrations at impact. At comparable speed, stance phase was longer on soft sand ground. POTENTIAL RELEVANCE: The conjugate use of the GRF-S and the numerical model would help to quantify and analyse ground/shoe combination on comfort, propulsion efficiency or lameness recovery.