bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Total Meniscectomy versus Caudal Pole Hemimeniscectomy on the Stifle Joint of the Sheep
Authors: Bellenger C. R. , Ghosh P. , Numata Y. , Little C. , Simpson D. S.
Published: March 2018

Total medial meniscectomy and caudal pole hemimeniscectomy were performed on the stifle joints of twelve sheep. The two forms of meniscectomy produced a comparable degree of postoperative lameness that resolved within two weeks of the operations. After six months the sheep were euthanatised and the stifle joints examined. Fibrous tissue that replaced the excised meniscus in the total meniscectomy group did not cover as much of the medial tibial condyle as the residual cranial pole and caudal fibrous tissue observed following hemimeniscectomy. The articular cartilage from different regions within the joints was examined for gross and histological evidence of degeneration. Analyses of the articular cartilage for water content, glycosaminoglycan composition and DNA content were performed. The proteoglycan synthesis and release from explanted articular cartilage samples in tissue culture were also measured. There were significant pathological changes in the medial compartment of all meniscectomised joints. The degree of articular cartilage degeneration that was observed following total meniscectomy and caudal pole meniscectomy was similar. Caudal pole hemimeniscectomy, involving transection of the meniscus, causes the same degree of degeneration of the stifle joint that occurs following total meniscectomy.

The effect of total medial meniscectomy versus caudal pole hemimeniscectomy on the stifle joint of sheep was studied experimentally. Six months after the operations gross pathology, histopathology, cartilage biochemical analysis and the rate of proteoglycan synthesis in tissue culture were used to compare the articular cartilage harvested from the meniscectomised joints. Degeneration of the articular cartilage from the medial compartment of the joints was present in both of the groups. Caudal pole hemimeniscectomy induces a comparable degree of articular cartilage degeneration to total medial meniscectomy in the sheep stifle joint.
Use of a DeVita Pin to Maintain Reduction of a Dislocated Total Hip Prosthesis in a Dog
Authors: Marcellin-Little D. J. , Roe S. C. , Marti J. M.
Published: March 2018

A two-year-old, female spayed Labrador Retriever with bilateral coxofemoral osteoarthritis received an uncemented total hip prosthesis in her left hip. The acetabular component was positioned in a slightly anteverted position. Five weeks after implantation, following a traumatic incident, the prosthetic hip dislocated without disruption of the femoral or the acetabular components. An open reduction of the luxation was performed, followed by a capsulorraphy and placement of a DeVita pin to secure the reduction. The pin migrated cranially to the epaxial musculature and was removed four weeks after its placement. One year after placing the DeVita pin, a followup examination found the animal not to be lame and without any physical or orthopaedic abnormalities.

A DeVita pin was used to maintain reduction of a traumatically dislocated uncemented total hip prosthesis, five weeks after implantation.
Stabilization of a Physeal Fracture Using an Orthofix® Partially-threaded Kirschner Wire
Authors: Lewis D. D. , Newell Susan M. , Lanz O. I.
Published: March 2018

Successful treatment of humeral condylar fractures requires accurate reduction and rigid internal fixation which can be difficult to achieve in toy and/or miniature breed dogs. Stabilization of a Salter-Harris type IV physeal fracture of the numeral condyle was simplified by using Orthofix® partially-threaded Kirschner wire and provided excellent clinical results in a 1.5 kg miniature pinscher
Revision of Aseptic Loosening of the Femora] Implant in a Dog Using Cable Cerclage
Authors: Cross A. R. , Lanz O. I. , Blaeser L.
Published: March 2018

Aseptic loosening of the femoral implant (ALFI) has been reported in 7.2% of total hip arthroplasty procedures in the dog. In this case report, ALFI was diagnosed in a nine year old male German Shepherd, seven years after the initial cemented total hip arthroplasty was performed. The revision of the ALFI was performed using a longitudinal osteotomy to extract the polymethylmethacrylate and the titanium femoral prosthesis was replaced with a cobalt chromium model. The osteotomy and an iatrogenic femoral fracture were repaired using four 1.3 mm cables. Postoperative radiographs revealed satisfactory alignment, reduction of the osteotomy and adequate positioning of the femoral prosthesis.

Case report describing the revision of aseptic loosening of the femoral implant seven years after the initial total hip arthroplasty was performed. The revision utilized four 1.3 mm cable cerclage.
Initial Clinical Experience with the IMEX™ Circular External Skeletal Fixation System
Authors: Radasch R. M. , Beale B. S. , Stallings J. T. , Lanz O. I. , Welch R. D. , Samchukov M.L. , Lewis D. D.
Published: March 2018

The IMEX™ Circular External Skeletal Fixation (CESF) System was used to stabilize fractures (12 radius and ulna and five tibia and fibula) in 15 dogs and two cats and arthrodeses (two pancarpal, one talocrural and one pantarsal) in four dogs. The ages of the animals with fractures ranged from six months to nine years (mean ± SD: 2.7 ± 2.5 years; median: 2.0 years) and the body weights of dogs with fractures ranged from 5.4 kg to 48.6 kg (mean ± SD: 21.3 ± 12.6 kg; median: 22.7 kg). The ages of the dogs having arthrodeses ranged from eight months to two years (mean ± SD: 18±10 months; median: 18 months) and body weights of dogs with arthrodeses ranged from 19.0 kg to 29.1 kg (mean ± SD: 22.7 ± 4.7 kg; median: 21.4 kg). Ten fractures were open and four had been previously managed with another form of stabilization. Ten fractures were comminuted and all of the fractures involved the diaphysis; two extended to the distal metaphysis. An extensive open reduction was used on three, a limited open reduction on seven and a closed reduction on seven fractures. Arthrodeses were performed via a limited open approach, for debridement of the articular cartilage and implantation of a cancellous bone graft. Most animals placed substantial weight on the affected limb within a few days following the operations. Wire and pin track inflammation was the most common complication during the convalescent period and was often associated with a decrease in weight-bearing. Sixteen fractures achieved radiographic union (mean ± SD: 46 ± 13 days; median: 43 days) long-term function (direct examination: mean ± SD: 76 ± 38 days; median: 43 days; telephone communication: mean ± SD: 366 ± 247 days; median: 381 days) was assessed as excellent in 10 animals and good in seven. All of the arthrodeses achieved radiographic union (mean ± SD: 74 ± 31 days; median: 71 days). Longterm function (direct examination: mean ± SD: 185 ± 182 days; median: 102 days; telephone communication: mean ± SD: 485 ± 22 days; median: 590 days) was assessed as good in two dogs and fair in two dogs. Our results establish the utility of the IMEX™ CESF System for stabilizing fractures and performing arthrodeses in dogs and cats.

The IMEX™ Circular External Fixator System was used to stabilize radius and ulna or tibia and fibula-fractures in 15 dogs and two cats and perform arthrodeses ir four dogs. Sixteen fractures and all four arthrodeses achieved radiographic union. Limb function was assessed as excellent in ten animals, good in nine animals and fair in two dogs.

Presented at the 23rd Annual Conference of the Veterinary Orthopaedics Society, Telluride, CO, USA March 5, 1996 University of Florida Journal Series #547.
Initial Clinical Experience with the IMEX™ Circular External Skeletal Fixation System
Authors: Radasch R. M. , Beale B. S. , Stallings J. T. , Welch R. D. , Samchukov M. L. , Lanz O. I. , Lewis D. D.
Published: March 2018

The IMEX™ Circular External Skeletal Fixation (CESF) System was used to treat 10 antebrachial deformities in nine dogs. The mandible of one dog with prognathism was also lengthened. Dogs ranged in age from four to 18 months (mean ± SD: 9 ± four months; median: eight months) and body weight from 2.6 to 46.0 kg (mean ± SD: 23.9 ± 11.2 kg; median: 24.2 kg). Linear distractions were performed with linear motors or threaded rods with paired nylon nuts securing the connecting rods to rings placed between ring blocks. Hinges and angular motors were used to correct angular deformities. A latency period of two to six days and a distraction rate of 1 mm/day, with a twice daily rhythm, were used. Distraction periods ranged from 12 to 32 days (mean ± SD: 21 ± 8 days; median: 25 days). Lengthening achieved ranged from 11 to 40 mm (mean ± SD: 20 ± 9 mm; median: 18 mm) or 6 to 30% (mean ± SD: 15 ± 8%; median: 13%) of the distracted bone’s initial length. All dogs had substantial improvement of their deformity and effective regenerate bone formation. Flexure contracture and wire and pin track inflammation were common complications during the convalescent period. Functional and cosmetic results (direct examination: mean ± SD: 130 ± 65 days; median: 123 days; telephone communication: mean ± SD: 351 ± 133 days; median: 324 days) were assessed as excellent in six, good in three and fair in two dogs and excellent in five, good in four and fair in one dog, respectively. The IMEX™ CESF system allowed precise deformity correction with minimal morbidity which was attributable to the system’s zero tolerance, zero motion properties.

The IMEX™ Circular External Skeletal Fixator System was used to treat antebrachial deformities in nine dogs and to lengthen the mandible of one dog with prognathism. Functional results were assessed as excellent in six dogs, good in three dogs and fair in two dogs. Cosmetic results were assessed as excellent in five dogs, good in four dogs and fair in one dog.

Presented at the 23rd Annual Conference of the Veterinary Orthopaedics Society, Telluride, CO, USA, March 5, 1996. University of Florida Journal Series #547.
Qualitative and Quantitative Scintigraphic Imaging to Predict Fracture Healing
Authors: Johnson Ann L. , Chambers M. , Smith C. W. , Kneller S. , Twardock A. R. , Schaeffer D. J. , Averill S. M.
Published: March 2018

Purpose: Evaluate the value of 24- hour postoperative quantitative bone scintigraphy to identify devascularized fragments and predict delayed fracture bridging in canine clinical patients; to determine the effect of fracture type, fixation type, age, sex, and weight on fracture bridging and the quantitative scintigraphic ratios; and to evaluate the relationship between qualitative scintigraphic assessment and quantitative scintigraphic ratios. Methods: Forty-two adult dogs, with diaphyseal long bone fractures treated with minimally invasive biological or invasive surgical techniques, were evaluated with 24-hour postoperative bone scintigraphy and six and 12 week postoperative radiographs. Fractured bones were classified as simple, moderately multiple, or severely multiple. Bone scintigrams were qualitatively and quantitatively analyzed. Radiographs were made at six and 12 weeks after the operation and graded as fracture gap(s) bridged or not bridged with bone opacity material. The data was evaluated statistically to determine the relationship between age, sex, and weight of the dogs, fracture type, fixation type, and results of scintigram analysis to fracture bridging at six and 12 weeks. Results: Fourteen of the 42 fractures were bridged at six weeks after the operation and 33 at 12 weeks. Prediction of fracture healing was not possible. There was not any statistical relationship of fracture type, fixation, sex, nor weight to bridged fractures or non-bridged fractures at six and 12 weeks. There was a trend toward more of the fractures with multiple fragments treated with minimally invasive biological techniques to be bridged by 12 weeks when compared to similar fractures treated with invasive techniques. The mean age of dogs with bridged fractures at six and 12 weeks was significantly lower than the mean age of dogs with non-bridged fractures at six and 12 weeks. Qualitative scintigraphic assessment scores were not significantly related to the quantitative scintigraphic ratios or to fracture bridging. Conclusions: Neither qualitative nor quantitative assessment of bone scintigrams 24 hours after the operation could be used to predict fracture bridging at six or 12 weeks postoperatively.

The value of 24-hour postoperative qualitative and quantitative bone scintigraphy to predict fracture bridging by 12 weeks in canine clinical patients with diaphyseal long bone fractures was evaluated. Neither qualitative nor quantitative assessment of bone scintigrams 24 hours after the operation could be used to predict fracture bridging by 12 weeks.

Supported in part by a grant from the AO Vet Centre, Zurich, Switzerland.
Scintigraphy in the Evaluation of Osteoarthritis of the Canine Stifle Joint
Authors: Barr A. R. S. , Patteson M. W. , Dieppe P. A. , Innes J. F.
Published: March 2018

The aim of this study was to investigate the role of scintigraphy in the evaluation of osteoarthritis of the canine stifle joint. Forty dogs with osteoarthritis of the stifle joint were examined scintigraphically using 99mTechnetium hydroxymethylene diphosphonate (99mTc-HMDP). Early (perfusion) and late (bone) scans of both stifle joints from each dog were obtained. Preliminary review of scans suggested three grades of early phase isotope retention (0, 1, 2) and two abnormal patterns of late phase retention (“generalised” and “marginal”). The reproducibility of these gradings/groupings was tested using unweighted kappa (ĸ) tests and found to be good (ĸ = 0.58) to excellent (ĸ = 0.93). Of 73 early phase scans, 35 (48%) showed some abnormality as did 61 (85%) of 72 late phase scans. Where both early and late phase scans were available (n = 65), 58 (89%) were considered abnormal. Results of scans were compared to clinical, radiographic and surgical observations. Scintigraphy was associated with clinical and radiographic data (ρ <0.05) but also appears to provide additional information. The marginal pattern was associated with bodyweight (ρ = 0.018), instability (odds ratio [OR] = 8.82), osteophytosis (OR = 18.64) and intra-articular mineralisation (OR = 31.09). Although not reaching statistical significance, the marginal pattern tended to be associated with articular cartilage fibrillation as observed at arthrotomy. The generalised pattern was seen in the absence of instability, effusion and osteophytosis. Scintigraphy appears to be a useful method for staging osteoarthritis of the canine stifle joint, as well as providing a means to study disease mechanisms.

Osteoarthritic canine stifle joints were examined scinti-graphically (early and late phase scans), clinically, radio-graphically and visually at surgery. Abnormal scan grades and patterns were defined, and the reproducibility of these gradings/groupings was tested and found to be good to excellent. Scintigraphic findings were associated with other disease measures but it appears that scintigraphy supplies additional information. Scintigraphy provides a useful method with which to investigate osteoarthritis of the canine stifle joint.
Healing of Circular Defects in the Rabbit Medial Meniscus Can Occur Spontaneously and Is not Improved by Intra-Articular Hyaluronic Acid
Authors: Hope N. , Ghosh P. , Collier S.
Published: March 2018

The aim of this study was to determine the effects of intra-articular hyaluronic acid on meniscal healing. Circular defects, 1.0 mm in diameter, were made in the anterior third of the medial meniscus in rabbits. In one joint, 0.4 ml hyaluronic acid (Healon®) was instilled, and in the contralateral (control) joint, 0.4 ml Ringer’s saline. Four rabbits were killed after four, eight and 12 weeks and the menisci examined histologically. By eight weeks most of the lesions had healed by filling with hyaline-like cartilage. Healing was not improved by hyaluronic acid treatment. The repair tissue stained strongly with alcian blue, and the presence of type II collagen, keratan sulphate, and chondroitin sulphate was demonstrated by immunohistochemical localisation. In contrast to the circular defects, longitudinal incisions made in the medial menisci of a further six rabbits did not show any healing after 12 weeks, indicating that the shape of the lesion largely determined the potential for healing.

The effect of hyaluronic acid on meniscal healing was tested in a rabbit model. With one millimeter circular lesions in the medial meniscus, healing by filling with hyalinelike cartilage was not significantly affected by the application of hyaluronic acid intra-articularly at the time of surgery, compared to saline controls, as assessed histologically four, eight and 12 weeks after the operation.
Evaluation of the Leeds-Keio Synthetic Replacement for the Cranial Cruciate Ligament in Dogs: An Experimental Study
Authors: Griffey S. , Massat B. J. , Vasseur P. B.
Published: March 2018

Eight conditioned research dogs, whose body weight was between 25 and 30 kg, had unilateral implantation of a Leeds-Keio (LK) synthetic implant (Dacron polyester) immediately after severance and removal of the cranial cruciate ligament (CCL). A rectangular- shaped autograft, composed of fascia lata, was placed within the LK implant in four of the eight dogs; the other four dogs received the LK implant only. Modified Robert Jones bandages were placed on the limbs that had been operated upon; the bandages were left in place for 48 hours. After that time the limbs were not splinted. The dogs were confined to 1.5 m X 3 m kennels, with twice daily leash walks for the duration of the study. Although the joints that received the LK implants were stable immediately after the operation, they all developed progressive effusion, crepitation and instability accompanied by clinically apparent lameness. All of the dogs were euthanatized three months after the operations. Gross examination of the eight joints that had been operated upon confirmed the presence of degenerative joint disease. Three of the eight dogs had “bucket handle” type tears of their medial meniscus in the joints with the LK implant, and the medial menisci in the other five stifle joints that received LK implants had a fibrillated surface texture. Five of the eight LK implants had either ruptured completely or were stretched and frayed to the point where mechanical testing was not justified. Mean breaking strength of the 3 intact LK implants was 6.6% of the contralateral, control CCL. Ingrowth of fibrous tissue into the LK implants was minimal. The synovium from all joints with LK implants had moderate to severely increased cellularity within the synovial villi and supporting stroma consisting predominantly of lymphocytes, plasma cells and macrophages. Multinucleated giant cells formed aggregates around irregular shaped strands of particulate material which was translucent and refractive. Under polarized light, these particles were bright yellow to green consistent with Dacron particles. It was concluded that the LK implant, as implanted in this study, was not a satisfactory replacement for the CCL in dogs.

The Leeds-Keio synthetic replacement for the canine cranial cruciate ligament was implanted in eight dogs. All eight dogs developed progressive instability and secondary degenerative joint disease over a period of three months after the operation. It was concluded that the Leeds-Keio ligament, as implanted in this study, is not satisfactory for use in dogs.
Mechanical Strength of Synthetic Casting Tape for Application to Fracture Treatment of Farm Animals
Authors: Kawamoto Y. , Nuta S. , Tomizawa N. , Hara S.
Published: March 2018

Compressive and torsional strength of cyclindrically formed synthetic casting tape for animals (Vetcast Plus™), composed of polyurethane-impregnated glass fibres, was investigated to determine its adequate application to fracture treatment of farm animals. After the completion of curing reaction, six-layered samples of the synthetic casting tape tolerated a compressive load of 6630 N (680 kgf). The sixlayered casting tape had also a torsional strength of 64 N · m. The compressive strength increased with time after the initiation of curing reaction. The time required for practical curing (achieving more than 60% of a final strength) was only 30 min, and that for complete curing 120 min. It was demonstrated that efficacious and safe fracture treatment of farm animals could be carried out using the synthetic casting tape for animals when a layer number appropriate to the total body weight of the patient animal was employed. The information obtained in this study is thought to be very useful in clinical practice.

Mechanical strength of poly-urethane-impregnated synthetic casting tape was investigated to determine its adequate application to fracture treatment of farm animals. It was demonstrated that mechanical strength of cylindrically formed samples of the casting tape depended upon the layer number, and the six-layered sample tolerated a compressive load of 6630 N and a torsional load of 64 N · m when completely cured.
Fractures of the Proximal Ulna in Dogs
Authors: Muir P. , Johnson K. A.
Published: March 2018

In a retrospective study of fractures of the proximal ulna in dogs, 22 cases were identified over a 12-year period. Follow-up data was available for 13 dogs. Fractures of the proximal ulna were often comminuted, and most commonly had an intra-articular component affecting the ulnaro-humeral joint. Common causes included: motor vehicle trauma and falls from a height. Blunt thoracic trauma and additional orthopaedic injuries were often seen with the more severe types of fractures.

Healing of intra-articular proximal ulnar fractures usually occurred after anatomical reconstruction and rigid internal fixation. Secondary osteoarthritis was minimal. The pin and tension band technique gave satisfactory results for simple non-articular fractures of the olecranon, but for intra-articular fractures this fixation method was associated with a greater incidence of complications such as: implant breakage, delayed union and infection. Implant loosening or breakage and delayed union were not observed, when fracture fixation with bone plates placed on the caudal or lateral aspects of the ulna was performed. Localized infection associated with a bone plate was identified in one of 10 patients and plate removal was carried out after the fracture had healed.

Fractures of the proximal ulna in 13 dogs were frequently intra-articular and comminuted. Most fractures stabilized with tension band fixation or a small bone plate on the caudal surface of the ulna healed with minimal secondary osteoarthritis. However, complications with tension band fixation were common.
Surgical Procedure Simulation via Three Dimensional Computer Aided Reconstruction of Dysplastic Canine Hips
Authors: Miller C. W. , Dobson H. , Binnington A. G. , Riley S. M.
Published: March 2018

The purpose of this study was to evaluate the use of three dimensional imaging techniques in veterinary orthopaedic surgery to measure hip congruity and predict changes in congruity resulting from triple pelvic osteotomies of canine hips. Preoperative, postoperative, and post-simulation measurements of congruity were obtained from eight canine hips by determination of Norberg angles from ventrodorsal pelvic radiographs (1), and lateral centre-edge (CE) angles from three dimensional (3 D) reconstructions of computed tomography (CT) scan data (2). Half of the hips were treated with a triple pelvic osteotomy with 30 degrees of axial rotation, and the other half served as approached but unoperated controls. Each measurement was performed three times by a single evaluator blinded to the identity of each hip. Lateral centre-edge angle measurements were more precise than Norberg angle measurements as determined by the calculated measurement of reliability (R = 0.78 and 0.68 respectively). Triple pelvic osteotomy resulted in an increase in congruity (as measured by lateral CE angles) of 52.2 ± 4.6 degrees compared to -3.0 ± 6.3 degrees in the control hips. The medical imaging programme used to perform the 3D reconstructions from CT scan data also allowed manipulation of the resulting preoperative 3D images to simulate on the computer screen the triple pelvic osteotomies performed on the gross specimens. Surgical procedure simulation predicted the change in congruity (as measured by lateral CE angles) of operated hips to be 43.5 ± 8.8 degrees. The images obtained by 3D reconstruction were very sensitive indicators of gross hip morphology. Visualization of structures, superimposed or surrounded by bone, was easily performed on the computer by interactive manipulation of the three dimensional CT scan reconstructions. In addition to its unique imaging capabilities, this technique appears to be a useful method for non-invasive measurement and prediction of the effects of triple pelvic osteotomy on hip congruity in dogs.

Three dimensional (3D) computer aided image reconstructions were performed on tomographic scan data collected from dysplastic canine pelves before and after triple pelvic osteotomy (TPO). Descriptions of imaging capabilities and the application of lateral centre-edge angles for the determination of hip congruity are reported. Simulations performed on the computer accurately predicted the changes in congruity achieved by surgery.
Technique and Results for Total Hip Replacement in Sheep: An Experimental Model
Authors: Olmstead M. L. , Litsky A. S. , Bruns D. P.
Published: March 2018

Fifty healthy adult Suffolk cross sheep were evaluated as a research animal for cemented total hip replacement. The surgical technique, peri-operative care, and long-term evaluation of the animals is reported. A modular cemented canine hip replacement system was used in this project. Postoperative fractures of the operated femur were observed in five animals. Two sheep developed septic loosening of the acetabular components. Two sheep experienced immediate postoperative luxations. One animal developed an acetabular fracture and infection. Five sheep exhibited mild lameness of the operated limb one year postoperatively, while all others had a normal gait. Postoperative activity level played a significant role in the development of femur fractures.

Fifty adult Suffolk cross sheep were evaluated as a research animal for cemented total hip replacement. The surgical technique, peri-operative care and long-term evaluation of the animals are reported.
Microangiographic Pattern of Bone Healing in Canine Tibial Osteotomies Treated with Type II External Fixators
Authors: García F. , Fuente J. , Peña T. , Prandi D. , Camón J. , Román F. , Manzanares M. C. , Franch J.
Published: March 2018

The morphological aspects of the vascular response, which develops in the fracture-healing process of osteotomies treated with external fixators, were evaluated by means of microangiography. Bilateral transverse midshaft osteotomies were performed in the tibiae of 16 dogs. The osteotomies were reduced by means of a Type II external skeletal fixator, and the clinical and radiographic courses were assessed weekly until the moment of euthanasia. Four dogs each were euthanatized at one, two, four and eight weeks postoperatively. After heparinization and euthanasia both femoral arteries were perfused with micronized barium sulphate, and microangiograms were performed in decalcified mid-tibial sagittal slices. Initial intramedullary revascularization as well as gap supply were already observed in some one-week microangiograms, and they were well developed in all of the two-week microangiograms. A network of parallel extraosseous blood vessels, orientated perpendicularly to the cortical surface, first appeared in the two-week microangiograms. Four weeks after the osteotomy, the extraosseous network showed its greatest degree of development whereas in the eight-week microangiograms most of the osteotomies showed only some traces of the abovementioned vascular reaction. It can be concluded that the microangiographic pattern developed in external fixated osteotomies shows many similarities with those described in experimental fractures, reduced by other means, with the earlier development of all of the vascular phenomena being the most important difference.

Microangiography was used to determine the morphological characteristics of the vascular response developed in the tibial experimental fractures healing process.
An Animal Model for Research on Wound Healing over Exposed Bone
Authors: Swaim S. F. , Stuart S.W. , Bradley D. M.
Published: March 2018

Many wounds such as degloving injuries, or dermal ulcerative processes may have exposed bone. This presents a problem in wound healing. Various procedures such as tissue flaps, skin expansion, skin grafts, or open wound healing may be used to treat wounds with exposed bone. The development of a healthy granulation tissue bed provides the supportive structural matrix and vasculature needed to promote wound healing over exposed bone. This is beneficial when flaps or expanded skin are used and is necessary if skin grafts or open wound healing are used for treatment. This paper describes an animal model and surgical technique that can be used in studying factors that might enhance wound healing over exposed bone. A technique is described whereby a rectangular defect with exposed bone is made over the second metatarsal bone of New Zealand white rabbits. Using subjective observations and objective planimetry, the rate of healing can be evaluated. The animal model and technique provide a means of evaluating effects of medications and bandages on the healing of wounds with exposed bone. The model could also be considered a model for wounds with delayed healing.

This paper describes an animal model and surgical technique that can be used to study wound healing over exposed bone. The surgical technique involves the creation of a rectangular defect over the second metatarsal bone of New Zealand White rabbits, with removal of the overlying periosteum. Various topical medications and/or bandage materials can be evaluated as to their effects on the healing of wounds with exposed bone. Bilateral defects can be created, with the animal serving as its own control. Subjective and objective evaluations involving planimetry, histopathologic, biochemical, or immunohistochemical analyses of harvested tissues may be conducted.
The Expression of IL-1, IL-6, and TGF-β in the Synovial Fluid of Horses with Surgically-Induced Transient Synovitis
Authors: Barber S. M. , Gordon J. R. , Theoret Christine
Published: March 2018

This study investigates the presence of various cytokines in the synovial fluid of three horses with surgicallyinduced synovitis in one antebrachiocarpal joint. Synovial fluids were sampled from experimental and control joints, preoperatively and at two and 30 days post-operatively. Samples were analyzed for interleukin-1 and interleukin- 6 bioactivities with a bioassay, and for transforming growth factor-beta protein by ELISA. Peak cytokine levels were detected on day two post-synovectomy, and returned to pre-operative levels by 30 days post-synovectomy (Interleukin-6 in treated joints: day #0; 0.53 ±0.2, day #2; 9.8 ± 0.7, day #30; 0.4 ± 0.2. Transforming growth factorbeta in treated joints: day #0; 314 ± 69, day #2; 1101 ± 325, day #30; 321 ± 101). Arthrocentesis alone (i.e. control joints) caused no increase in interleukin- 1, interleukin-6 and transforming growth factor-beta levels. Interleukin-1 and interleukin-6 are thought to both prevent anabolic and enhance catabolic effects within articular cartilage matrices, whereas it has been proposed that transforming growth factor-beta may have a protective effect on the articular cartilage. This study is the first to document elevated transforming growth factor-beta levels in equine joints.

This study documents elevated levels of transforming growth factor-beta, interleukin-1 and interleukin-6 in the joints of horses with surgically-induced transient synovitis.
Comparison of Cemented and Non-cemented Allografts in Dogs with Osteosarcoma
Authors: Steinheimer D. , Park R. D. , Powers B. E. , Straw R. C. , Endenburg N. , Withrow S. J. , Kirpensteijn J.
Published: March 2018

This study compares the radiographic and histological appearance of cemented and non-cemented massive cortical allografts in dogs that underwent a limb sparing procedure for osteosarcoma of the distal radius. Treatment consisted of removal of the affected bone and pancarpal arthrodesis using non-cemented (n = 13) or cemented (n = 47) fresh-frozen allografts. Allografts were evaluated using a radiographic and histological scoring system and compared statistically between groups. Allografts with better healing received a higher radiographic score and a lower histological score. The mean radiographic scores, for proximal union and distal union, were significantly greater in the non-cemented group at most evaluation periods. Complications after the operation included screw, plate, allograft and host bone failure, infection and local tumour recurrence. Screw failure in the allograft and allograft failure were significantly more common in the non-cemented group. Histological examination was performed on 44 dogs and cement increased the mean combined histological scores, and mean healing scores of the distal host-graft interface significantly. The use of cemented allografts significantly decreases complications associated with implant loosening or allograft failure but may slightly delay allograft healing. At this point, the clinical relevance of the delay in healing is questionable and the benefits of intramedullary PMMA would appear to outweigh this relative delay in healing.

This study evaluated 60 radial allografts after limb sparing procedures using a standardized radiological and histological scoring system. The use of cemented allografts significantly decreased complications associated with implant loosening or allograft failure but may slightly delay allograft healing.
Bilateral Pes valgus Deformity in a Shetland Sheepdog
Authors: McCarthy P. E.
Published: March 2018

An eight-month-old, 19.7 kg, male Shetland Sheepdog was diagnosed with a valgus deformity present in both hindlimbs. Anamnesis failed to reveal a traumatic incident to explain the deformities. Bilateral tibial osteotomies and placement of an external skeletal fixation were used in the correction of the defects. Several reports exist concerning angular limb deformities of the rear limb in Shetland Sheepdogs. These facts may represent a breed at risk for such defects.

An eight-month-old Shetland Sheepdog with bilateral valgus deformities of the tibiotarsal joint was managed by staged bilateral corrective tibial osteotomies and placement of an external skeletal fixation. Reports of angular limb deformities of Shetland Sheepdogs are reviewed.
Detection of Stress-Generated Potentials in Fracture Callus
Authors: Marsico P. J. , Roe S. C.
Published: March 2018

Stress generated potentials (SGPs) are present in cortical bone and are thought to contribute to osteocyte perception of load. Because callus also develops and remodels in response to mechanical stimulus, SGPs may be the signaling mechanism in this tissue. The feasibility of the measurement of SGPs in fracture callus was investigated in this study. Osteotomies were performed on the right ulna of 15 Mongrel dogs and allowed to heal without fixation. The ulnae were harvested at six, 12, and 18 weeks; each callus instrumented with electrodes and SGPs recorded during broad band dynamic vibrational excitation. The results of these measurements indicate that SGPs can be detected in fracture callus. Refinement of the measurement techniques may lead to a better understanding of these potentials and how they change with load magnitude and stage of healing. Understanding of SGPs in vivo may also contribute to development of electromagnetic fracture healing stimulation methodologies.

Stress generated potentials (SGPs) are a probable mechanism through which cells in cortical bone sense and respond to load. In this study, SGPs were identified in fracture callus, a tissue that also responds to load by remodeling. Further study of these potentials may assist in the development of methods for stimulation of fracture healing.

This material was presented at the American College of Veterinary Surgeous Magazine Meeting, Washington, DC, October, 1994.
Force Plate Analysis of Dogs with Bilateral Hip Dysplasia Treated with a Unilateral Triple Pelvic Osteotomy: A Long-term Review of Cases
Authors: Cockshutt Joanne R. , Dobson H. , Miller C. W. , Holmberg D. L. , Taves Connie L. , Tano Cheryl A.
Published: March 2018

A retrospective case series study was done to determine the long-term outcome of operations upon dogs treated for canine hip dysplasia by means of a triple pelvic osteotomy (TPO). Twentyfour dogs with bilateral hip dysplasia, that received a unilateral TPO between January 1988 and June 1995, were re-examined at the Ontario Veterinary College. The assessment included physical, orthopedic and lameness examinations, standard blood work, pelvic radiographs and force plate gait analysis. They were compared to bilaterally dysplastic dogs that had not been treated, and also to normal dogs. Force plate data analysis demonstrated a significant increase in peak vertical force (PVF) and mean vertical force over stance (MVF) in the limb that underwent surgical correction by means of a TPO, when compared to the unoperated hip. It was determined that performing a unilateral TPO on a young dysplastic dog resulted in greater forces and weight bearing being projected through the TPO corrected limb when compared to the unoperated limb.

Dogs with bilateral hip dysplasia treated with a unilateral triple pelvic osteotomy (TPO) were assessed by force plate gait analysis, radiographs and orthopedic examination. There was a significant increase in hip Norberg angles over time, although degenerative changes did progress. Limbs that had been operated upon had significantly greater peak and mean ground reaction forces than limbs that had not received an operation.
Clinical Response to Antibiotic Impregnated Polymethyl Methacrylate Bead Implantation of Dogs with Severe Infections after Limb Sparing and Allograft Replacement -18 Cases (1994-1996)
Authors: Withrow S. J. , Straw R. C. , Powers B. E. , Wember E. W. , Jameson V. J. , Wilkins R. M. , Allen R. E. , Dernell W. S.
Published: March 2018

Successful treatment of severe orthopaedic infections in people and animals has been augmented by the use of antibiotic impregnated polymethyl methacrylate (PMMA) bead implantation at the site of infection. High local wound concentrations of antimicrobials can be achieved without resulting in toxic levels systemically. Clinical, radiographic and pathological response was evaluated following PMMA beads impregnated with vancomycin and tobramycin implanted in 18 dogs with severe infections following “limb sparing” operation with allograft replacement for osteosarcoma. A variety of aerobic and anaerobic bacterial organisms were cultured from the sites of infection and numerous systemic antimicrobial drug combinations were used in an attempt to control the infections prior to the implantation of the beads. In 12 of 18 (67%) dogs implanted, clinical signs of infection resolved within a median of four weeks post implantation. Three of 12 (25%) had recurrence of signs at a median of 17 weeks post implantation. This was not a randomized, prospective controlled trial and limitations to the study exist, the most notable being the variability in individual patient treatment. However, antibiotic impregnated PMMA bead implantation may play a role in the treatment of severe infections in dogs.

Eighteen dogs with severe infections were implanted with polymethyl methacrylate beads impregnated with tobramycin and vancomycin. In 67% of dogs implanted, clinical signs of infection resolved within a median of four weeks. Antibiotic impregnated PMMA bead implantation may play a role in the treatment of severe orthopedic infections in dogs.

This study was supported in part by grant number 2 PO1 CA 29582 from the National Cancer Institute. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Cancer Institute, USA.
Backscattered Electron Imaging of the Calcified Tissues Present in Bone Healing
Authors: García F. , Camón J. , Manzanares M. C. , Franch J.
Published: March 2018

The aspect of calcified tissues involved in fracture healing was studied by means of backscattered electron imaging. Bilateral transverse midshaft osteotomies were performed in the tibiae of 16 dogs. The osteotomies were reduced by means of a type II external skeletal fixator, and the clinical and radiographic course was assessed weekly until the moment of euthanasia, one, two, four and eight weeks after the operations. The osteotomized areas were removed and their structure examined in the scanning electron microscope, using backscattered electron images, to determine the general aspect of the extracellular matrix of the calcified tissues present. Four different tissues were observed: lamellar bone, woven bone, calcified cartilage and chondroid tissue. The backscattered electron contrast and fibre arrangement of the matrix, as well as the size and shape of the cellular lacunae, allow identification of the tissue. Chondroid tissue, which seems to have a leading role in the early phases of fracture healing, shows a characteristic pattern of a highly calcified and fibrous matrix with a large number of irregular and confluent cell lacunae.

The morphological characteristics of the calcified tissues involved in fracture healing were studied by means of backscattered electron imaging. Lamellar bone, woven bone, calcified cartilage and chondroid tissue were the four calcified tissues observed during the healing process of canine midshaft tibial experimental fractures.
Looming changes in the management of “osteoporosis”: A preview for clinicians
Authors: Frost H. M.
Published: March 2018

Normally, strong muscles make strong load-bearing bones, and persistently weak muscles make weak ones. We now have a general understanding of how and why that happens. Unexpectedly that understanding also affects our understanding of the nature, pathogenesis and study of disorders currently classified as “osteopaenias” and “osteoporoses”. Such things promise to change how we view, study and manage those disorders. At present, those things incite discussions among authorities that in time should lead to a new accepted “wisdom” about those disorders. Many clinicians who manage patients on a daily basis would probably like to know what issues that process concerns. Because of the importance of those issues to so many millions of this planet's present and future six billion souls, and because of their bearing on the related research, one could argue that clinicians and researchers are entitled to know about those issues. For that reason this article summarizes some of them, of course as I seem them.

It is understood that other times, places and people would resolve any questions about those issues, and that any new accepted wisdom that depends upon their resolution should lie in the future.

Recent recognition of the effects of muscle and biomechanics on the biologic ‘‘machinery” that determines whole-bone strength and bone health incite many changes in formerly accepted views about the nature, diagnosis, pathogenesis, study and management of the group of different disorders that are currently considered as falling under the umbrellas of “osteoporosis” and “osteopaenia”. This article acquaints interested physicians with some of those changes and the reasons for them. It should take time, probably several years, for those changes to gel into an accepted new standard of care for such disorders. Meanwhile currently accepted standards of care could and probably should be followed.
Palpation and dorsal acetabular rim radiographic view for early detection of canine hip dysplasia
Authors: Dupuis J. , Beauregard G. , Breton L. , Paré J. , Charette B.
Published: March 2018

The objectives of this study were to standardize a palpation technique and to determine within and between examiners, the repeatability in interpreting the angle of reduction, subluxation and the acetabular slope measurements. Also it was desired to ascertain the effect of pelvis positioning on the acetabular slope measurement on sixmonth- old dogs. On palpation examination fifty-three (53) dogs had their angles of reduction and subluxation measured. A radiographic examination including a standard hip-extended view, a compression and a distraction view and a dorsal acetabular rim view were performed on each dog.

The within examiner repeatability was excellent for both the angle of reduction and subluxation (r = 0.975, p = 0.82 and r = 0.977, p = 0.81 respectively). The between examiners repeatability was good for the angle of reduction (r = 0.843, p = 0.51) but only a fair correlation was found for the angle of subluxation (r = 0.652, p = 0.83). For the acetabular slope measurement, an excellent within examiner correlation was observed (r = 0.940, p = 0.52). However, though a good correlation was found between examiners, a significant difference was found in the measurements of the three examiners (r = 0.780, p < 0.0001). The under- or overrotation position slightly changed the slope measurement but a fair correlation was still observed with the perfect position (r = 0.769, p = 0.074 and r = 0.684, p = 0.061 respectively). If the pelvis is turned to one side, a correlation was not found (r = 0.090, p = 0.847). The high repeatability of the angle of reduction measurement in six-month-old dogs suggests that it may be used by multiple examiners, with the expectation of comparable and consistent results. The modified method of the acetabular slope measurement improved the correlation, but a significant difference was still observed between examiners.

Early detection in life of canine hip dysplasia is important. The angle of reduction and the acetabular slope have been evaluated as diagnostic tools. With regard to its repeatability between examiners, the use of the angle of reduction by multiple examiners will be acceptable. The correlation between examiners in the acetabular slope measurement was good but a significant difference was present. Part two is now being analyzed.
Intraarticular measurement of forces acting on the canine medial meniscus during motion
Authors: Schmökel H. , Schawalder P. , Messmer M.
Published: March 2018

Meniscal injuries are currently under much clinical investigation. With regard to tissue engineering strategies for meniscal repair or replacement, the direct measurement of forces applied on the meniscus, during range of motion, could provide important information. This in vitro study using canine cadaver limbs evaluated the possibility of measuring the tibial reaction force, at the medial meniscal level, with film pressure sensors.

The sensors were placed between the medial meniscus and the tibial plateau. With different preloads of the stifle, in proportion to the dog’s total body weight measurements were taken under constant motion with intact and artificially transected cranial cruciate ligament. With an intact cranial cruciate ligament the force peak, under the cranial horn, was found in extension, and under the caudal horn in flexion. Transection of the cranial cruciate ligament led to a rise in mean force under both of the horns. The rise in mean force was higher under the caudal horn compared to the cranial horn. Transection of the cranial cruciate ligament resulted in an altered curve pattern under the caudal medial meniscal horn, which was most apparent with the highest preloads. The sensors were easy to apply, the results substantiated commonly accepted biomechanical predictions and the experimental set-up was found to be a useful tool for the investigation of forces acting on the menisci.

A thin film pressure sensor was implanted under the cranial and caudal medial meniscal horn in 18 canine cadaver stifles and the forces recorded during a constant range of motion with intact and artificially transected cranial cruciate ligaments. The results reflected biomechanical predictions, and the experimental set-up was found to be a useful tool in the investigation of forces acting on the menisci.