陳冠升. Radiography Technique. Fundamentals of Orthopedic Radiology in Dogs and Cats. Correct/Straight positioning +

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1 Fundamentals of Orthopedic Radiology in Dogs and Cats DVM, MVS, PhD, MACVS-Veterinary Radiology 國立中興大學獸醫學院 台灣獸醫外科專科醫學會 Radiography Technique Heavy sedation or general anaesthesia are required Positioning Reduce motion Radiation safety Low kvp and high mas Good contrast Proper collimation and centering Decrease image distortion and scattering Irish Vet J 60(4) Radiography Technique Correct/Straight positioning + knowledge of normal radiographic anatomy II Successful interpretation!!! Radiography Technique 2 views Bone Centering is on the centre of the bone of interest Collimation includes joints Joint Centering on the center of the joint of interest Collimation includes proximal and distal aspect of bones Additional radiographs Flexed, stressed or oblique for complete evaluation Contralateral limb Inadequate collimation Include too much soft tissue Increase scattering Decrease definition/resolution Same kvp and mas

2 Where to look. *Inadequate collimation and radiation safety Developmental orthopedic diseases often occur in very specific anatomic locations! Bone Anatomy E epiphysis ( 骨端 ) P physis ( 生長板 ) M Metaphysis ( 骨骺 ) D Diaphysis ( 骨幹 ) A Apophysis ( 骨隆起 ) Joints Cartilage Soft tissue opacity E P M D A P D M E D M E P Proper Centering and Collimation Minimal image distortion Decrease scattering Ideal image quality for interpretation Bone Development Some Normal Radiographic Feature of The Appendicular Bone Nutrient foreminae Present in all long bones Cut-back zone Mach line 2 cortical surfaces are superimposed

3 Diaphyseal Region Conditions Primarily Affecting BONES Diaphyseal region Panosteitis Metaphyseal and Physeal regions Hypertrophic osteodystrophy (HOD) Retained cartilage core Scottish Fold cat osteochondrodysplasia Incomplete ossification of the humeral condyle Panosteitis Young, large breed dogs Unknown Self-limiting disease < 12 months of age Shifting lameness Radiographic findings Lesions often originate at the diaphysis near the nutrient foramen. Increase medullary cavity opacity Commonly seen in the humerus, radius, ulna and femur. Different stage of Panosteitis PANOSTEITIS PIC D D Physeal Region Physeal trauma Epiphyseal Region Congenital hypothyroidism Mucopolysaccharidosis Generalized Nutritional secondary hyperparathyroidism Others *Malformation or agenesis *Trauma+/- fracture *Soft tissue injury *Foreign body(manus) Early: nodular opacities similar to cortical bone within the diaphysis Late: diffusely increased opacity with continuous periosteal reaction Metaphyseal and Physeal Regions Hypertrophic osteodystrophy (HOD) Rapid growing, large/giant breed 2-7 months Fever, lethargy, diarrhea Distal radius and ulna, distal tibia and fibula mostly affected Premature closure of the distal ulnar physis Angular limb deformity (Valgus) Unknown cause: Oversupplementation of minerals and vitamins Hypovitaminosis C Virus (distemper). M M

4 HOD Thrall. Text book of veterinary diagnostic radiology. 5th. Ed. A transvers lucent zone within the metaphysis, parallel to the physis. double physes Irregular periosteal cuff around the metaphysis Metaphyseal and Physeal Region Retained cartilage core Large breed dogs Commonly seen on distal ulna metaphysis Disruption of the endochondral ossification Retention of hypertrophic chondrocytes M M Cause angular limb deformity DJD of the elbow and carpal joints Normal Radiographic findings Triangular radiolucent region A sclerotic rim Slight cranial bowing of radius Thickened caudal radial cortex mirc.veterinaryradiology.net

5 Metaphyseal and Physeal Region Incomplete ossification of the humeral condyles Should fuse by ~84 days after birth. Spaniels and others Severe degenerative changes and ankylosis of tarsocural joint Angular Deformity Valgus or varus Premature closure of the distal ulnar physis (most common) Physeal trauma May not be seen radiographically initially HOD Retained cartilage core Courtesy of Dr 蔡盈庫 Metaphyseal and Physeal Region Scottish Fold cat osteochondrodysplasia Simple autosomal dominant trait Shorter than normal Stiff and swollen joints difficult to jump or climb Predominant abnormalities seen around the distal joints Main radiographic feature Symmetrical carpal and tarsal ankylosis Physeal Region Contribution of growth of the radius and ulna Angular deformity Physeal Trauma Salter-Harris types Thrall. Text book of veterinary diagnostic radiology. 5th. ed % 65% 15% 85%

6 Courtesy of Dr 林建良 Epiphyseal region 1. Congenital Hypothyroidism Disproportionate short-limb dwarfism Epiphyseal dysplasia Bowed limbs and long necks and trunks Easily seen in Proximal tibia Humeral and femoral condyles Cuboid bone Carpus and tarsus Short vertebral Endplate dysplasia E E R Physeal trauma Congenital Hypothyroidism Normal In Practice (2006) 28, L Thrall. Textbook of veterinary diagnostic radiology. 5th. ed. 2008

7 Epiphyseal region - Continued 2. Mucopolysaccharidosis Abnormal of glycosaminoglycan catabolism Stunted, lame and visual deficit Disproportionate dwarfism Facial dysmorphia - broad maxilla, widespread eyes and short ears. Hyperextension of the distal extremity joints MUCOPOLY PIC Hip luxation and femoral head epiphysis remodeling Epiphyseal dysplasia Generalized Nutritional hyperparathyroidism Ca/P imbalance Generalized osteomalacia Mucopolysaccharidosis Epiphyseal dysplasia Osteopenia Generalised decreased bone opacity Similar to soft tissue opacity Thin cortex Spinal deformity Pathologic folding fracture Disorders Affecting Growing JOINTS 1. Osteochondrosis, osteochondritis dissecans (OCD) 2. Elbow dysplasia Ununited anconeal process (UAP) Fragmented medial coronoid process (FCP) OCD of the medial humeral condyle 3. Hip dysplasia (HD) 4. Legg-Calvé-Perthes

8 1.Osteochondrosis and OCD Young, rapidly growing large-breed dogs Common sites Caudal humeral head (lateral view) Medial aspect of distal humeral condyle (Cr-Cd view) Lateral condyle of femur (Cd-Cr view) Medial and lateral trochlear ridges of talus (Cd-Cr view) SHOULDER OCD ELBOW OCD Courtesy of Dr 林建良 ELBOW OCD R L R mirc.veterinaryradiology.net

9 STIFLE OCD 2.Elbow Dysplasia Ununited anconeal process L Courtesy of Dr 林建良 Should be fused to the olecranon by 150 days German shepherd and other large breeds Extreme flexed mediolateral view is required. Fragmented medial coronoid process (FCP) Medium- and large-breed dogs Male > Female Clinical signs: 4-6 months of age Medial coronoid process Unilateral l or bilateral l Cranial 25 lateral - caudomedial oblique (Cr-25 -L, Cd-M oblique) Evans. Guide to the dissection of the dog, 7 th ed R HOCK OCD L HOCK OCD Ununited Anconeal Process Courtesy of Dr 林建良 Courtesy of Dr 林建良 Arthritic findings Joint incongruity Osteophytes on anconeal process Changes on medial coronoid process Subtrochlear sclerosis Lateral epicondylar osteophytes R Normal

10 FCP Courtesy of Dr 林建良 Changes on medial coronoid process Technique of Caudal Extension View Generalised anaesthesia Includes lumbar vertebrae and stifle joints Evaluation of the quality of the image Dorsal spinous process of spine Wings of ilium Obturator foramens Patellae (Cr-25 -L, Cd-M oblique) Thrall CT provides the best visualisation of FCP UAP, FCP 3. Hip Dysplasia Courtesy of Dr 林建良 Changes on coxofemoral joints Perifoveal cartilage erosion Round ligament hypertrophy Synovitis Synovial effusion => joint laxity Cannot be seen radiographically Thrall. Textbook of veterinary diagnostic radiology. 5th. ed. 2008

11 Hip anatomy A C D B E A : Cranial effective acetabular margin B : Cranial acetabular edge C : dorsal acetabular edge D : caudal acetabular edge E : acetabular fossa Advanced remodeling of HD Remodeling of the femoral head and neck Osteophytes on the femoral head, neck and cranial effective acetabular margin New bone formation at the acetabular fossa Irregular subchondral bone Hip Dysplasia Morgan line Enthesophyte Radiographic findings Flattened cranial acetabular edge Wedge-shaped joint space Center of femoral head is lateral to the dorsal acetabular edge Norberg angle < 105 degree Parallel to the trochanteric fossa Early sign of degenerative joint disease 4. Legg-Calvé-Perthes Disease Aseptic necrosis of the femoral head Young toy and small breed Early stage: a mottled or linear pattern of lucencies in the femoral head Progressing: flattening and irregular femoral head (remodeling), subluxated coxofemoral joint Can be unilateral or bilateral Narrowed joint space

12 Radiographic signs of joint disease 1. Increased synovial mass 2. Perichondral osteophyte 3. Enthesophyte formation 4. Erosion of the subchondral bone surface 5. Joint mice/intraarticular mineralization 6. Increased subchondral bone opacity 7. Subchondral bone cyst formation Thrall. Text book of veterinary diagnostic radiology. 5th. ed Osteoarthritis Weight bearing joints Such as hip, stifle Slowly progressive degenerative joint disease Synovial effusion and cartilage degradation Aging change, or a result of a developmental or acquired disorder Developmental: FCP, UAP, HD, Patellar luxation, conformational valgus/varus Acquired: trauma (cranial cruciate ligament rupture, joint instability, joint malalignment ) Age-related cartilage degeneration Osteophytes vs enthesophytes Osteophytes Abnormal cartilage load => cartilage fibrilation => loss of cartilage => synovial hyperplasia => osteophyte Initially consist of cartilage, then mineralised => bony outgrowths Evans&deLahunta. Guide to the dissection of the dog. 7 th ed. Enthesophytes Enthesis: the point of insertion of a tendon, ligament, joint capsule or fascia to bone Enthesitis: inflammation of the site of tendon of ligament attach to bone Enthesophyte, a bony spondylopathy at an enthesis New bone formation / degenerative change

13 FULLY FLEX EL Increased subchondral bone opacity Erosion of subchondral bone Feline arthritis Older than 12 years old > 90% Clinical signs are subtle Fabcat.org

14 Sprains/trauma Clinical examination Radiographic examinations Documenting the presence and magnitude of the sprain and identifying avulsed osseous fragments. Radiographic feature Dog Periarticular soft tissue swelling Avulsion fracture Joint instability of subluxation Spatial derangement of the osseous components of a joint Common causes of lameness Young All age Large Small 1.OCD 2. ED 3. HD 4. Panosteitis 5. HOD 6. Retained cartilage core 7. Trauma (CCL, physeal..) 8. Chondrodysplasia 9. Nutritional 1. Legg-calves-Perthes 2. Incomplete OHC 3. Trauma 4. Nutritional 1.Tenosynovitis 2. Avulsion 3. Trauma 4. Patella luxation 5. Neoplasia 6. Infection 7. Immune mediated 8. SLE Stressed View Summary Evaluation of developmental orthopedic disorders requires high quality orthogonal radiographs centered on the area of interest Remember the specific anatomical locations for developmental orthopedic diseases Bone or joint Age of closure of growth plate ABCS A : Alignment Thrall. Text book of veterinary diagnostic radiology. 5th. ed B : Bone (epiphyses, physes, metaphyses, diaphyses) C : Cartilage (joint space) S : Soft tissue Cause of osteoarthritis in cats Primary SFCOD MPS Age-related cartilage degeneration Secondary Congenital Hip dysplasia Trauma Infectious/inflammatory Nutritional Hypervitaminosis A Neuropathic Diabetes mellitus Immune mediated Rheumatoid arthritis Progressive proliferative polyarthropathy SLE idiopathic polyarthritides

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