Applied Anatomy

What criteria is needed for a neurectomy? What complications come with this?

- Criteria is that it must improve with a PD block, no ossification of the DDF, no evidence of DJD of the distal interphalangeal joint, no roughening of the flexor surface of the navicular bone. -Complications may include painful neuroma, nerve re-growth in two years. Also one will have to constantly monitor the foot for the rest of life.

What is a cortical bone sepsis?

-A cortical bone sepsis is a sequestration of bone in which we have sequestrum formation. This is seen related to crushing trauma and periosteal damage. -Clinical signs for acute include exposed bone that takes 2 weeks to develop and for chronic, draining tracts. -Diagnosis is done via physical examination -The sequestrum is the dead part of the bone that lost blood supply, the cloaca is the drainage.

What are the three ways of diagnosing a coxofemoral luxation?

-A coxofemoral luxation may be palpated by placing a thumb in the ischiatic notch and externally rotating the femur. No displacement of the thumb when the femur is rotated indicates luxation. -Luxation can also be apparent when the greater trochanter is distal to the axis of a line between the cranial dorsal iliac spine and the ischiatic tuberosity. -Lastly, with a craniodorsal luxation, the greater tubercle can be palpated on or dorsal to a line drawn between the cranial dorsal iliac spine and the ischiatic tuberosity. This will appear externally as the luxated leg looking slightly shorter than the other leg.

What is characteristic of a gallop?

-A gallop is four beat gait with at least one flight phase. -It maybe transverse or rotary. -It is very fast but fatiguing -Flexion and extension greatly increase the effective stride length.

what is characteristic of a pace?

-A pace is a 2 beat gait during which the body is alternately supported by the fore and hindlimbs of the same side of body. -It is good for endurance, though not as stable as the trot. Requires less muscular exertion.

What is included in a second class lever system? What is an example?

-A second class lever system is when the resistance is positioned between the fulcrum and the force. -In this system, mechanical advantage is always gained. -The speed and magnitude of movement on the lever arm at resistance is always less than that of the applied force. -Applied and resultant forces oriented in the same direction. -An example of second class lever system is Extension of Tarsal Joint by Gastroc. In this example, the resistance is the tarsal joint, the fulcrum is the foot on ground, and the force is the gastroc. So as the leg extends, the system moves about the foot.

What is characteristic of a trot?

-A trot is a two-beat gait during which the body is supported by one diagonal limb pair at a time (sometimes with flight phase in between) -This is suited for rough, irregular ground and for long distance at a fair speed.

What is characteristic of a walk?

-A walk is four-beat gait in which phases of 2 legged support alternate with phases of 3-legged support. -The center of mass is almost always located within the support triangle on the ground.

How much of the ground distance traveled by the limb comes from the movement of the coxal joint?

-About 70%.

What two things make up adaptations for speed? What is stride? What were humans adapted for?

-Adaptations for speed come from stride length and stride rate. -Stride is one cycle of limb movement. -Increases in stride length involve trunk extension and flexion -Increases in stride rate include reduced limb mass, distally. -Humans were adapted for dexterity

Does the "all or none" event occur with a whole muscle event?

-Although an individual muscle fiber contraction is an "all or none" phenomenon, the all or none does not apply to the whole muscle (or nerve). Some fasciculi of a given muscle can contract while others are relaxed and vice versa. -This is one of the ways a single muscle can both flex and extend the same joint.

If you can't tell where the pinching is coming from on the spinal cord via normal x-ray producing the cervical spinal deficits, what is an alternative route?

-An alternative route is using dye in the spinal column and looking at the dorsal and ventral dye columns.

What is athrodesis?

-Athrodesis is damage in the cervical spinal column resulting in wobbler syndrome. -You will want to fuse unstable articulations to reduce the spinal cord compression -Or you can use a ventral approach and basket placement between 2 end plates. Fusion then results in atrophy of soft tissues that surround the cord.

What is wrong with this horse based on picture and radiograph?

-Based on the picture, we see a swollen fetlock, small coronary band and small hoof indicating foot isn't in use. -Based on the radiograph, we see a cycstic lesion and an osteoarthritis causing the bulging at the fetlock.

What joint connects the pelvis to the sacrum? What type of joint is this and how much movement and force can it withstand?

-Being that the sacrum is fused, there is only about 7 degrees of movement. -It is connected to the pelvis via the sacroiliac joint which is a composite joint that is part synovial and part fibrocartilaginous. -This joint can withstand tremendous forces as it connects trunk to hindlimbs.

How do carnivores achieve speed? How is their limb specialization? Is the wolf or the cat more adapted for dexterity? How do their canines differ?

-Carnivores achieve speed through spine flexation. -Their limb specialization is moderate. -Cats are adapted more for dexterity. -The canines of a wolf are elliptical -The canines of a cat are rounded

What are the symptoms of chondrodystrophy?

-Chondrodystrophy is cartilage defect. -It involves premature closing of the appendicular physes leading to dwarfism and angular limb deformities. -An example of this is valgus deformity of the distal antebrachium with secondary varus deformity of the proximal antebrachium from premature closure of the distal ulnar physis -This disease leads to premature degeneration of the IV discs and is found commonly in basset hounds

What are the classical findings of heel pain/navicular disease? What are important PE findings?

-Classical findings of navicular disease are poor confirmation, small foot compared with body size, mild to moderate intermittent lameness perceived as a shoulder lameness. -Important PE findings are contracted heels, atrophied frog, bilateral lameness with one foot more affected than the other. -Lameness will switch to contralateral limb after PD block of the more affected foot.

What are the clinical signs of damage to the cervical spine and what treatments are available?

-Clinical signs include pain to tetraplegia. which is the ratio of vertebral canal diameter to spinal cord diameter being greater in the cervical spine. -Treatment includes cage rest to surgical decompression by removing ventral slot.

Contraction of which muscle would prevent extension of the humeral joint during flexion of the cubital joint by the biceps brachii?

-Contraction of the *Deltoideus muscle* would prevent extension of the humeral joint during flexion of the cubital joint by the biceps brachii.

What are the cranial muscles of the thigh and what do they work to do?

-Cranial muscles of the thigh work as flexors of the coxal joint. -These include the rectus femoris and illiopsoas which is the primary flexor of the coxal joint.

What is circled on either side of the tail?

-Damage to the L-S and S-I region. Called hunters bumps and are SI luxations

The Thoracolumbar spine consists of what vertebrae? What nerve signs does it send out? What breed is most at risk in dogs for damage? What will treatments be for these damages?

-Damage to the thoracolumbar spine is found 80% in T11-12 to L2-3. -These neurons send out sign to upper motor neurons for pelvic limbs. -Daschunds are most at risk due to overrepresentation. -Treatment for these damages include medical such as cage rest and pain meds, to surgical decompression

What muscles make up the caudal group of muscles for the humeral joint and are innervated by axillary?

-Deltoideus -Teres major -Teres minor

How is diagnosis made for the suspsensory ligament desmitis? Where is the diagnostic nerve block performed?

-Diagnosis for suspensoty is made with lameness examination looking at origin and branches. -The diagnositic nerve block for the pelvic limb is the deep branch of the lateral plantar nerve.

In distal sesmoidean ligament desmitis, What can lameness be graded, what may palpation show, what block can be performed, and what is it confirmed by?

-Distal sesamoidean ligament desmitis, lameness can be graded 3/5. -Palpation may reveal swelling below the fetlock -Abaxial sesamoid block localizes the area of pain. -It is confirmed with ultrasound.

Distal tarsus arthritis can be expressed how? Which type of horse is it common in?

-Distal tarsus arthritis can be expressed by bone spavin in a DJD, and confirmation and work dependent. -Positive to flexion test -And intraarticular block confirms the arthritis. -The breeds most effected are stadium jumpers and standard breds.

What is down sound?

-Down sound means that the head comes down when the sound limb is touching the ground.

What is wrong with this horse?

-Dropped elbow -fracture of ulna, olecranon, proximal radius, distal humerus, and radial nerve paralysis.

How do the neck and head move as the dog moves during a trot and gallop?

-During the trot and gallop the neck thrusts forward such that the head hangs from it like an outstretched cantilever. It works in carriage of the head and neck to effect the center of gravity. -This movement moves the center of gravity farther forward to let animal get behind it more to allow more propulsion forward.

In the equine species, what does Elongation of distal bones lead to? What does migration of distal muscles proximally result in?

-Elongation of distal bones leads to increases in leverage and use of power giving speed and endurance. -Migration of distal muscles proximally result in ligamentous support and a high degree of automacity of the lower leg. -Horses have rear wheel drive.

How do epaxial and hypaxial muscles move? How does the dog have a bridge arch skeleton?

-Epaxial cause extension (dorsiflexion) of the vertebral column and lateral bending when contracted unilaterally. -The abdominal and hypaxial muscles cause flexion of the vertebral column. -The dog has a bowstring constraction with the apex of the bow at the caudal thoracic region

What muscles make up the extensor group and the flexor groups of the Cubital joint?

-Extensors include the Triceps brachii, tensor fascia antebrachii, and the anconeus? -The flexor group include the biceps brachii and the brachialis m.

What can effect the arc of the foot flight?

-Fibrotic myopathy causes the foot to slap down. This effects the arc of foot flight.

What is involved in first class lever system? What is an example of this system?

-First class lever system involves a fulcrum positioned between the force and the resistance. -With the first class lever system, mechanical advantage may be gained or lost depending upon placement of the fulcrum -The speed and magnitude of movement on lever arm at resistance may be greater or smaller than that at applied force. -Applied and resultant forces oriented in opposite directions. -An example of the first class lever system is the cubital joint extension in which the fulcrum is the cubital joint, the resistance is the paw on the floor and the force is the triceps brachii muscle contracting

What are damages that can occur to the thoracic spine? How will it heal? If the horse can't move it's head up and down, what could be damaged vs. if it can?

-Fractured withers can result in pain, depression of withers, and T4-T10 are most commonly fractured. -They will heal without repair but need change of saddle pads or blankets. -If it can't move its head up and down could be nuchal lig. -If it can, then it's a problem post withers.

What three things are shown from left to right.

-From left to right, Patella, medial trochlear ridge, lateral trochlear ridge with sclerotic tissue

How does hyaline cartilage heal in the joint damage? Where is the articular cartilage thinner?

-Full thickness loss results in formation of fibrocartilage. -Partial thickness defects do not change. -The articular cartilage is thinner at the fetlock.

If a horse is leaping over water, how does this effect his confirmation?

-Going over water effects how he extends his thoracic limbs. He's in a front to back movement.

Other than Secrateriats overall composition, what helped make him a superior athlete?

-He had a long sloping shoulder that gave him length of stride and large gluteal muscles that gave him power -He was the only horse to have a 110 degree stride.

What type of cartilage is found in joints? What other structures make up a joint?

-Hyaline Type II, articular cartilage is found in joints. -Joints are also made up of Fibrous joint capsule, ligaments, synovial membrane/fluid, and subchondral bone.

-If damage occurs in the cervical spine, what can happen? What is common in the thoracic spine?

-If damage occurs in the cervical spine can see wobbler's syndrome. two top signs include proprioceptive deficits and pain. -If in the thoracic spine can see fractures.

IF the scapula is fixed, but the distal humerus is free to swing caudally, what muscle can flex the humeral joint? If the distal scapula is free to rotate caudally, but the distal limb is relatively fixed, what muscle can work to extend the humeral joint?

-If the scapula is fixed, but the distal humerus is free to swing caudally, the latissmus dorsa can flex the humeral joint. -If the distal scapula is free to rotate caudally, but the distal limb is relatively fixed, the latissimus dorsi can work to extend the humeral joint.

If there is stifle effusion, we want to look at what? If we have a medial condyle of the distal femur that has a cyst, what is type I lesion and what is a type II?

-If there is stifle effusion, we want to look at the medial epicondyle -If we have a distal femure that has a cyst, type I lesion is narrow and type II is wide.

In C-spine arthrodesis, when are the best clinical signs seen? When is the best prognosis? Surgery at C6 and C7 may result in what?

-In C-spine arthrodesis, the best clinical signs are at less than 3 weeks. -Best prognosis is a dynamic compression of spaces from C3-C5. -Surgery at C6 and C7 may show acute or post op fatality.

What is involved in a third class lever system? What is an example?

-In a third class lever system, the force is positioned between the resistance and the fulcrum. -In this system, mechanical advantage is always lost -Speed and magnitude of movement on lever arm at resistance is always greater than that at applied force -Applied and resultant forces are oriented in the same direction. -An example of a third class system would be Flexion of the Cubital Joint by Biceps Brachii in which the resistance is the carpal joint, the fulcrum is at the cubital joint, and the force is the biceps brachii bringing the antebrachium forward

What pathological signs do we see in lumbosacral disease?

-In lumbosacral disease, we see pathological changes in degenerative lumbosacral stenosis contributing to compressio of the nerve roots. -These changes include: -Bulging of the disk or anulus fibrosus -thickening of the dorsal anulus fibrosus -mechanical instability and subluxation of L7-S1. -Osteophyte formation around the spinal canal and around articular process joints. -Thickening of the joint capusle of the articular process joints -Thickening of the yellow ligament. -Lumbosacral disease can cause pain, paresis, and sphincter distrubances.

In tendon lacerations, the limb poster is direct result of what? Suspensory injuries are due to what? What does this look like anatomically?

-In tendon lacerations, limb posture is a direct results of loss of the tendon function. -Suspensory injuries are high speed injuries. -They result from loss of suspensory apparatus. Anatomical loss of suspensory apparatus leads to extreme hyper extension of the fetlock joint. - This can not be reconstructed surgically-the apparatus is under tension.

In IV Disk Disease, how many are of thoracolumbar origin? How many extrusions occur between T11 and L3? How many are of lumbosacral origin? And how many are in the cervical region?

-In the IV Disk Disease, about 85% of disk extrusions are of thoracolumbar origin -about 80% are between T11 and L3 -less than 6% are lumbosacral -about 15% are in the cervical region.

Is the thoracic spine flexible or stiff in the canine?

-In the canine, the spine is relatively inflexible and provides a solid base for the ribs and extrinsic muscles of the thoracic limb.

What type of disk extrusion occurs more cranially in the cervical spine in chondrodystrophic breeds? What are more caudally in large breeds? What is cervical vertebral instability and what type of dogs does it result in and what does the disease lead to?

-In the cervical spine, disk extrusion type I tend to occur more cranially commonly in C2-C3, in chondrodystrophic breeds, and protrusion Type II are more caudally located at C6-C7 in large breeds. -Cervical Vertebral Instability is also known as wobbler syndrome. -It occurs in adult dobermans and young great danes. -It tends to occur more caudally and leads to malformation/malarticulation of the vertebral bodies, vertbral tipping and subluxation, IVDD, ligamentous hypertrophy

Which flexor tendons predominate in the first part and last part of the loading phase?

-In the first part the SFT predominates -In the last part the DFT predominates

What is shown in the image?

-In the image, we see the straight sesamoidean ligament with a hole in it.

How does body composition and physique differ in the speed type of dog and the strength type of dog?

-In the speed type, the body will long and slim with reduced distal muscle mass. The hindlimb muscle mass will exceed the front, the dog has stretchier tendons, and the limb bones elliptical in cross-section -In strength, the dog takes on a more stockier appearance with a rounder body shape and wide stance. The distal limbs are strong and the muscle mass is relatively equal from hind to forelimb. tendons are shorter and inelastic, and the limb bones round in cross-section giving them a two times greater to breaking ability.

What is the difference between the stance phase and the swing phase?

-In the stance phase, the portion of the stride during which the limb is in contact with the ground. -The swing phase is the portion of the stride during which the limb is not in contact with the ground.

What happens in Infraspinatus Contracture? What clinical signs are seen and what treatment is available?

-Infraspinatus contracture is secondary to trauma. -Initial lameness and pain are seen followed by gait abnormality due to progressive muscle fibrosis and contracture 2-4 weeks after injury. -Clinical signs of infraspinatus contracture include dramatic external rotation of the limb and circumduction as the animal tries to walk. -Treatment includes tenotomy of infraspinatus insertion.

What is intra-articular medication?

-Intra-articular medication is the direct administration of a drug into a synovial structure to diagnose treatment of the joint disease.

What are clinical results of osteoarthritis? What are therapeutic goals of osteoarthritis?

-Joint effusion, loss of range of motion, and lameness. -This accounts for the vast majority of wastage within the performance horse industry. -Therapeutic goals include preventing further degradation of articular cartilage, early medical intervention, and early arthroscopic intervention to prevent fractures and OCD.

What are problems that arise from T and L spine?

-Kissing spine ( can result in ventral ligament tear), dorsal process of L spine overlap, Pain

What does collateral ligaments injury lameness?

-Lameness can be mild at the walk, but significantly worse at when the horse turns. Joints are unstable - in the medial to lateral plane, and require radiographic examination to include stressed views. -MCP joint -Carpus -Tarso-metatarsal joint

How is lameness graded? If lameness is difficult to identify then what should be used? What other ways can lameness be evaluated?

-Lameness is graded I-V -If lameness is difficult to identify then the lunge line should be used. -You can also evaulate stride and use manipulation/flexion tests to determine lameness

What are the lateral and medial stabilizers of the humeral joint that keep traumatic luxations from happening?

-Lateral stabilizers include the Supraspinatus muscle and the infraspinatus. -The Medial stabilizers include the subscapularis and the coracobrachialis

If there is to be elbow luxation of the cubital joint, why do most luxate laterally in the dog? What signs are seen in the elbow luxation and what treatment is available?

-Luxation occurs mostly laterally due to the difference in size of the medial and lateral condyles of the humerus. - Elbow luxation is seen as non-weight bearing with severely swollen elbow region. -The limb is held in a slightly flexed position. -Treatment includes reduction of luxation and stabilization in extended position.

What are developmental orthopedic diseases that can occur in the pelvic limb?

-MTP joint getting OCD fragments and subchondral bone cysts. -Tarsus getting OCD fragments. -Stifle getting OCD fragments and subchondral bone cysts.

What are the medial muscles of the thigh and what actions do they have?

-Medial muscles of the thigh work to adduct the limb mostly. They include: 1) Adductor (extends coxal joint) 2) Pectineus 3) Gracilis (extends coxal and flexes genual joints) 4) Sartorius mostly flexes the coxal joint.

What happens to most muscles in locomotion? How is this advantageous?

-Most lever systems involved in locomotion lose mechanical advantage, instead of favoring speed and magnitude of movement. -This is usually advantageous since a small linear contraction of a muscle belly can produce a relatively large resultant motion in the body as whole.

What do most performance horses have in the health of their carpus?

-Most performance horses have mild lameness at speed with OC fractures. -Most have joint effusion and are painful to palpation -Most have acute fractures that should be treated with arthroscopic removal.

Is all movement produced by lever system? If not, why?

-Not all movement is produced via lever. -Some muscles do not have direct skeletal connections. An example would be the orbicularis oculi and the cremaster muscle.

For a coxofemoral luxation, what two treatments are available that help stabilize after reduction?

-One treatment is a closed reduction without surgery -Another treatment is an open reduction where the bone is cut and manipulated surgically. -The leg will then be placed in an Ehmer sling to keep it in place.

What do you look for with a visual inspection at rest for a horse?

-Overall confirmation -Foot symmetry which is very important -Signs of inflammation such as heat, edema, pain -soft tissues such as the tendons and ligaments -Muscle symmetry -And hoof testers

In an acquired flexural deformity what does the pathogenesis look like?

-Pathogenesis is not tendon contracture -This is more likely asynchronous growth between bone and soft tissue Shown as a "bow string"

If the SDF is messed up what will we see? DDF? Suspensory ligament?

-SDF messed up with gives dropped fetlock -DDF gives toe off ground -Suspensory ligament gives fetlock on ground

What was the result of the silver fox study by Belyaev? What are dogs selected for today?

-Silver foxes were chosen based on temperment and tamability. -After generations, alterations in their physical characteristics began to show: dappled coats, floppy earsr, curly tails, shorter snouts -Dogs are selected for aesthetic traits

What are slab fractures?

-Slab fractures go from joint to joint. -Usually found in thoroughbreds and quarter horses. -Clinically, they show acute lameness, effusion, very positive to flexion -Use a skyline image to see them. -The joint can collapse leading to intra-articular ligament damage.

What are some characteristics of tarsal lameness?

-Some horses with lameness locailized to the tarsus have origin of the suspensory dismitis. -Degree of lameness can be very similar but the desmitis appears to not improve with time off/rest. -Blocks may or may not definitively point to one problem or another. -Both radioraphic and ultrasonographic examinations may be indicated.

What are the classifications of lameness in a horse? What do you look for when you evaluate stride? What is lacking in phases for a horse that has laminitis? What about a horse with stifle lamness?

-Supporting limb -Swinging limb -Mixed -Complementary -When evaluating stride, one should look for phases in leg movement such as bring leg cranial and caudally, arc of the foot flight, path of the foot flight, foot strikes, joint flexion angles, and symmetry. -A horse with laminitis has no caudal phase. -A horse with stifle lameness has toe draggin.

What are characteristics of suspensory ligament degeneration?

-Suspensory ligament degeneration occurs in aged horses broodmares. -It is usually bilateral -It is degeneration of the suspensory lig above the fetlock -Treatment is supportive shoeing and symptoms are arthrodesis.

How does one look at symmetry?

-Symmetry is evaluated through the gait at the trot after the flexion test and compared with the contralateral limb's response

What is the meaning of synovitis, capsulitis, and sprain? What do intra-articular fractures result in?

-Synovitis means inflammation of the synovial membrane. -Capsulitis means inflammation of the fibrous joint capsule. -Sprain is injury of the specific ligaments associated or around with the joint (desmitis is better term) -Intra-articular fractures result in osteochondral fragments. -Meniscal desmitis at the fetlock joint.

What is the term for the muscular attachment of the scapula to the trunk? In what two ways does the scapula move?

-Synsarcosis is the attachment of the scapula to the trunk. -The scapula moves in Rotation and translation of the entire bone. -In rotation, there is instantaneous center of rotation at the dorsal edge, the location of which is stabilized by the opposing actions of rhomboideus muscle and serratus ventralis muscle. -The translation of the entire bone contributes to the stride length. It moves downward and forward during protraction in the swing phase. It moves upward and backward during retraction in the stance phase. -Movement of the scapula contributes greater than 65% of step length.

What are the different forms of fracture that can occur in a horse long bone?

-Tension which is pulling from tendons in either direction -Compression of the long bone in either direction. Common for condylar fracture -Bending toward the site of impaction -Shear via short oblique where one half goes one way and the other half goes the other. -Torsion with a long oblique that spirals -Combined loading where there's twisting and compression

What is #9 , #10? What view is this?

-The #9 is the medullary cavity -The DDF tendon sits next to #10. - This view is skyline

How does the IV disk function?

-The IV disk functions whereas the various ligaments and joints between the articular processes tend to control torsional, bending, and shear forces, the IV disk is built to withstand compressive forces. -They act as a hydrolic shock absorber and distribute the force out evenly..

The applied force necessary to cause or prevent movement depends on what and is subject to what?

-The applied force necessary to cause or prevent movement depends on the perpendicular distance of forces from fulcrum. -This applied force is subject to change throughout the range of motion.

How can the Biceps Femoris extend or flex the genual joint?

-The biceps femoris can extend the genual joint by contracting those fibers which pull proximally on the patella. -Biceps femoris can flex the genual joint by contracting those which are positioned caudal to the rotational axis of the joint.

What type of energy does canine locomotion use?

-The canine locomotion uses passive mechanics to use elastic energy stored in tendons. -The further a muscle is from the body, the more it is involved in storage of elastic energy and in compensating for varied terrain through regulation of limb compliance.

What are the caudal muscles of the hip in the dog and what do they act to do?

-The caudal muscles of the hip work to have counter medial rotation of the gluteal muscle, which is otherwise largely insignificant and they include: 1) External obturator m. 2) Internal obturator 3) Gemelli 4) Quadratus femoris

What are the caudal muscles of the thigh and what do they act to do?

-The caudal muscles of the thigh are extensors of the coxal joint with variable action on the genual joint and they include: 1) Biceps femoris 2) Semitendinous m -both of which also extend tarsocrural joint. 3) Semimembranousus m.

Where is the center of gravity in a dog? How is labor divided amongst its hind limbs, forelimbs, and spine?

-The center of gravity is behind the scapula at mid-chest level. -The forelimbs carry more weight, about 60% but they are designed to catch the body weight as it's thrown forward by the pelvic limbs and minimize wasteful energy expenditure -The hindlimbs on the other hand are mostly associated with propulsive forces and the spine functions in propulsion and lengthening stride in faster gaits.

What joint is mostly involved in hindlimb retratction and propulsion of the body? What muscles are involved?

-The coxal joint extension is what helps in hindlimb retractions and propulsion of body. -The hamstring muscles, gluteal muscles, and adductor are involved and most active during the latter part of the swing phase and initial part of stance phase. -The coxal joint is continued in the later portion of the stance phase by the muscles which also flex the genual joint, the hamstring and gracilis.

What type of joint is the coxal joint? How does it function?

-The coxal joint is a spheroidal joint between the acetabulum and femoral head. -It functions mainly in flexion/extension. A more versatile movement is possible in the carnivore, less so in the large animal.

What are the craniolateral muscles of the crus and what do they act as?

-The craniolateral muscles of the crus act to do flexion of the tarsal, and extension of the digital joints -They include cranial tibial m. -Long digital extensor -Lateral digital extensor -Peroneus longus -The caudal muscles of the crus include the extension of the tarsal, flexion of the digital. These are the the gastrocnemius, SDF, and DDF.

The diaphragm contracts during ______ causing the dome to move ______.

-The diaphragm contracts during inspiration causing the dome to move caudally.

What is the extensor of the coxal joint and what are the flexors?

-The extensor of the coxal joint is the quadriceps femoris which is innervated by femoral nerve. -The flexors have mostly secondary actions of muscles which act on the other joints. These include the biceps femoris, semitendinosus, semimembranosus, and Gracilis

How much do the genual and tarsal joints move during locomotion? What are the prevented by?

-The genual and tarsal joints move very little during locomotion. They are prevented from flexing by the quadriceps femoris and the caudal muscles of the crus. -These muscles become active during the latter portion of the swing phase in preparation of touchdown. -Flexion of the tarsocrural joint at lift off is due to contraction of the craniolateral muscles.

What type of joint is the genual joint and what type of movement does it have?

-The genual joint is a complex condylar synovial joint with meisci and lots of ligaments. -It has motion consisting of complex combination of gliding, rotation, and flexion/extension.

Hindlimb protraction during the swing phase is largely due to what?

-The hindlimb protraction during the swing phase is largely due to the flexors of the coxal joint which are iliopsoas, tensor fascia latae, sartorius, and rectus femoris.

What is wrong with the confirmation and what are the bumps at 1 and 2 from?

-The horse has severe bowed knee and pigeon toed. -The lumps are secondary changes due to the deformity and angulation.

Which is a distal interphalangeal joint flexure deformity? And which is metacarpophalangeal joint?

-The left is distal interphalangeal joint and the right is metacarpophalangeal joint.

Which part of the spine has most movement that contributes directly to locomotion? What does the summation of movement of individual joints result in? What does this summation contribute? How is flexibility distributed?

-The lumbar spine has the most movements that contribute directly to locomotion. -The summation of movements of individual joints in the lumbar spine result in flexion and extension over 50 degrees. -This contributes to over 50 degrees to stride length. -The flexibility is not distributed evenly over the lumbar spine, instead it increases as you move more caudally.

What makes the lumbosacral joint so flexible?

-The lumbosacral joint is so flexible due to the shape and thickness of the intervertebral disk. -There is 58% greater thickness but not only 20% greater cross-sectional area -The intervertebral disk wedge-shaped making it wider at the lower edge.

What type of injury is usually common to go along with the cranial cruciate ligament rupture?

-The meniscal injury is a common sequella due to the altered joint dynamics. -The meniscus usually injured the most is the medial one. This is because there is no femoral attachment. It can't really move because it's anchored by the connective issue and other structures surrounding it.

What is the most common cause of hindlimb lameness in the dog?

-The most common cause of hindlimb lameness in the dog is the cranial cruciate ligament rupture. -It is typically progressive and degenerative. -Contributing factors include abnormal conformation/ait, increased tibial plateau angle, obesity, and lack kof fitness have been implicated but a causal relationship has not been proven. -A considerable amount of animals with unilateral rupture will subsequently rupture the contralateral ligament.

What is the nucleus pulposus a remnant of? What does it allow for and what is it made of?

-The nucleus pulposus is a remnant of notochord which is a hydraulic shock absorber. It allows disk deformity and dissipation of forces equally over anulus firbrosus and vertebral end plates. -It is made up of hydrophilic proteoglycans and 80-85% water, but with age it becomes more collagenous. -In contrast, the anulus fibrosus is mostly collagen.

When is peak vertical force reached by the forelimbs in comparison to the hindlimbs? When do the forelimbs decelerate in comparison to the hindlimbs?

-The peak veritcal force is reached by the forelimbs in the middle of the stance phase and by the hindlimbs much easier. -The forelimbs decelerate more sharply and for longer than the hindlimbs which generate propulsion after just a third of the stance phase.

What are development abnormalities that can go wrong with the pelvic limb?

-The pelvic limb has several and consistent anatomic locations where developmental lesions can occur. -Signalment is important here -Joint effusion is the most common clinical sign. -Pain or lameness can dictate outcome.

What limb is commonly effected in fracturing of the accessory carpal bone which is common in race dogs? What causes this fracture? What is another form of damage in hyperextension injury? And what other injury occurs with racing dogs?

-The right limb is commonly effected with accessory carpal bone fracture in racing dogs. -This is due to hyperextension of the carpus at high speeds. -The two injuries seen associated are proximal avulsion at the insertion of the flexor carpi ulnaris on accessory carpal and distal avulsion at attachment of the intercarpal ligaments to base of accessory carpal bone. -Another form of damage is to the carpal fibrocartilage. of the palmar carpal ligament. -Dislocation of interphalangeal joints is also seen in racing dogs in which the dorsal elastic ligament remains intact with the ditsal interphalangeal joint luxation and the nail will tip upwards. This is known as "knocked up" or "sprung" toe.

If the stated action of a given muscle is not what occurs when it contracts, then what it is? What happens when the resistance force equals the applied force? What happens it he resistance force is larger than the applied?

-The stated action of a muscle is not when it contracts, but is instead what the applied force generated by the muscle attempts to do. -If the resistance force equals the applied force, then no movement occurs but we will see an increase in tension due to isometric contraction. -If the resistance force is greater than the applied force, then we see the opposite will occur unless more muscles contract to aid the one under consideration since muscles rarely act individually.

The more articular cartilage damage present...?

-The worse the prognosis for return to function.

What is wrong in the radiograph and what is wrong with the diagnosis?

-There is contracted tendons. -This is a problem because tendons should not contract. This is congenital or acquired and leads to progressive distortion to the joint angles.

On racing greyhounds, why are 90% of hindlimb injuries on the right side? What do these injuries tend to be?

-They are the right side due to the way the dog is running around the track. -The gracilis tends to be ruptured and the central tarsal bone becomes fractured.

Which bone do carpus slab fractures effect?

-Third carpal bone. Has a radial facet and an intermediate facet.

What is wrong with this horse and what treatment does it need?

-This horse has flexural limb deformity at the metacarpophalangeal joint. -The horse is camped out behind. To treat this horse, both checks need to be cut. Extensor tendons aren't strong enough it be where they should. -Cutting the check will increase 2-3 cm of musculotendenous structure movement. -If it's a mild case, you can transect one check or the other. But if it's severe, then transect both.

If a horse presents with club foot, what is the diagnosis?

-This is because of acquired flexural deformity which can be unilateral or bilateral. -If the issue is in the metacarpophalangeal joint, then this presents SDFT contracture. -If it's distal interphalangeal, then it's DDFT contracture and this presents the club foot.

What is etiopathogenesis of carpal OC fractures?

-This is caused by repetitive trauma from training and results in changes to the subchondral bone or cartilage. -It's acute if "bad steps" -Shows poor confirmation or gait and poor fitness.

What is wrong? how is it fixed?

-This is fracture. -P1 has gone down to P2 and P2 fractured. -It has gone into the joint. -Only way to fix is to fuse the joint just on top of P2.

What is this indicating?

-This is indicating proximal suspensory desmitis.

What is wrong with this horse?

-This is known as Type II Distal Interphalangeal joint in which the DDF tendon is too short. The horse can't put the heel on the ground and coffin bone is pointing straight down.

What is synovitis/capsulitis? what causes it?

-This is soft tissue inflammation of the articular cartilage. -It is caused by indirect damage from inflammation which will eventually result in degenerative joint disease.

What type of lever system would be the pull of the gluteal mm. on the greater trochanter when the femur is free to swing caudally?

-This would be a first class lever system because the fulcrum is located between the force and the resistance at the hip joint, the resistance is at the stifle joint, and the force is the gluteal muscle pulling up.

What type of lever system would be the extension of the carpal joints by the extensor carpi radialis muscle?

-This would be a third class lever system because the force is located between the resistance and the fulcrum. -The Force is the attachment of the extensor carpi radialis and contraction of this muscle, the fulcrum is at the carpal joint, and the resistance is the foot on the ground -This is the most common lever system

What conformation, although not typically ideal, is seen standard in the arabian?

-Thoracic limb is too far forward/ straight and the hock is behind the horse. -They tend to be very far camped-out

What treatment is available for suspensory ligament desmitis?

-Treatment depends on the degree of lameness -Rest, peri-ligament injections, shockwave therapy, neurectomy of deep branch of lateral plantar nerve, and fascia release are all forms of treatment.

If there is damage to the sustentaculum tali and we have effusion in the tarsal canal, what treatments are there?

-Treatments include aggressive debridement and arthroscopic approach

What treatments should be performed for lumbosacral disease?

-Treatments include cage rest and pain meds to surgical decompression via dorsal laminectomy.

For a tarsal bone spavin, what are the intra-articular treatments?

-Treatments include steroid and alcohol to the distal tarsus joint. -Alcohol will destroy articular cartilage -You will need an arthrogram to see if there is communication with the talocalcaneal joint and if so then it's bad.

What is type I traumatic arthritis?

-Type I is synovitis or capsulitis without disturbance of articular cartilage or disruption of major supporting structures. It includes Acute synovitits, capsulitis, and most sprains.

What is Type III traumatic arthritis?

-Type III is post-traumatic osteoarthritis with disruptive trauma in which major residual damage is present. -Patients end up having deformity, limited range of motion, and instability of joint.

What is ventilation coupled to? What does this create?

-Ventilation is couple to stride frequency. 1:1 in the gallop. -This is visceral piston.

If there is damage to the ribs and damage to the lungs, what will we look for on a radiograph?

-We will look for air pocket dorsally.

If there is head bob what does this mean? The musculature that moves the most is what? If the head is rolling forward and down what does this indicate?

-With head bob, this means lameness -The musculature that moves the most is lame -The head rolling forward and down indicates lameness in the thoracic limb. -If we see large gluteal action it means lameness in hind limb

What kind of fractures can be present in metacarpal fractures in horses? If there is displaced fracture, what does this mean?

-You want to first asses an articular damage of metacarpal fracture at the condyles. -Fractures can be incomplete, complete non-displaced, complete displaced, lateral vs. medial location. -Displaced fracture is joint fragmentation.

What are the differences between an agonist, antagonist, synergist, and fixator in terms of muscles?

1) *An agonist* is a muscle that produces a certain referenced effect or movement 2) *An antagonist* is a muscle capable of actively opposing that movement 3) *A synergist* is a muscle that may neither facilitate or oppose the movement but may modify the action of the agonist such as by eliminating unwanted side effects. 4) *A fixator* is a muscle that is employed to stabilize the joint rather than produce movment of it. An example would be the surpra and infraspinatuses laterally for the shoulder joint and the coracobrachialis medially.

What are two ways that stress can produce cartilage damage in a horse?

1) Abnormal stress on normal cartilage. This is from heavily athletic activity and instability. 2) Normal stress on abnormal cartilage which is from synovitis/capsulitis and subchondral bone damage from repetative damage. -Injury could also result from increased inflammatory proteins, speed up joint injury, and viscious cycle of inflammation

What muscles make up the Girdle Muscles?

1) Cranial group of muscles including the trapezius, omotransversarius, and brachiocephalicus all leading to protraction of the limb. 2) Latissimus dorsi which retracts and draws trunk forward during stance phase. 3) Superficial pectoral which adducts the limb and assists in protraction/retraction depending on limb position 4) Rhomboideus which raises the limb and holds the scapula against the trunk but also draws the dorsal portion of scapula cranially thereby retracting the limb. 5) Serratus Ventralis which supports the trunk. Has a cervical part that retracts the limb and thoracic part that protracts the limb. 6) Deep pecs which support trunk and retract limb/draw trunk forward.

What are techniques for diagnosing a cranial cruciate ligament rupture? And what are treatments?

1) Diagnosis: -Cranial Drawer -Tibial thrust (push the tibia into the femur while simultaneous contracting the gastroc) 2) Treatment -Lateral fabellotibial suture (an extracapsular technique, better for small dogs and most common) -Tibial plateau leveling osteotomy -Tibial tuberosity advancement

What are the three elements of efficient locomotion in the horse?

1) Phases of the stride with preloading prior to impact and muscle function vs. tendon strain during stance phase. 2) Static Weight bearing of limbs/foot such as front vs. hind. 3) Dynamic loading characteristics of limb and foot in which the positions of the feet at ground impact and throughout the stance phases of the stride. This is seen in impact in which the foot is loaded quickly but not fully, slide where it's neccessary to reduce concussion and to engage tendons and ligaments in sequence, thrust where the foot is receiving max load at midstance, and Heel off and breakover in which many factors both anatomical and mechanical occur in sequence

Which bones do we see at 1, 2, and 3? In a horse

1) Radial carpal 2) Intermediate carpal 3) Ulnar carpal

What are the different front leg conformations that a horse may have? Which is ideal?

1) Straight legs are most ideal. 2) Splay footed is valgus deformity of metacarpal phalangeal jt. where the feet point out 3) Pigeon toed where the feet point in 4) Knock-kneed where the knees point in and there is a narrow front with a wide base. 5) Base Narrow where the more distal part of the limbs are closer together 6) Bow kneed is winged out and is a varus carapal deformity. -when looking at some of these deformities form the side, we can see either over at the knee or back at the knee.

What are the different hind limb deformities and what is most ideal?

1) Straight legs is most ideal. 2) Slight cow-hocked is how some quarter horses are where the hocks are more inward. 3) Extreme cow hock 4) Bow legs Pigeon toes 5) Narrow base 6) Wide base where legs are really far apart. -From the side, some of these deformities can look like: -sickle-hocked, where the hock is at a sharp point -Camped out behind where the fetlock is behind the standard line -Leg too straight where everything is in front of the standard line and the suspensory is at risk of damage at this point.

What are the two parts to the swing phase and what are the three parts to the loading phase?

1) Swing -Flexion -Extension, protraction, and retraction 2) Loading -Impact and slide -Mid-stance -Maximum load of suspensory apparatus.

How many canine joint luxations come from the coxofemoral luxation? How many are due to HBC? How many luxate craniodorsally? and why does this happen?

90% of all canine joint luxations are coxofemoral luxation. 85% due to HBC 75% luxate craniodorsally -This is because the gluteal muscles pull it forward once the greater trochanter is out of the acetabulum.

How far should a horse be able to flex its fetlock and carpus?

A horse should be able to flex its fetlock 90 degrees and should be able to flex it's carpus 120 degrees. If the horse can't make the degree of flexion then it could have fibrosis occuring.

What is pictures at the spinal column?

Arthritic facet

As size of the animal increases, how does surface area and volume change? Does a daschund have a long back or short legs

As the animal increases in size, the surface area increases by a power of 2 and volume increases by a power of 3. -For a daschund, The back is proportional to the rest of the body but the legs are too short.

What is wrong at 1 and 2

At 1, it's an osteochondral fracture. -At 2, it's a sesamoid fracture.

What is circled?

Both show a subchondral cyst.

What is caudal heel pain in the horse from?

Caudal heel pain is from navicular disease. -It is a degenerative process that changes the bone-initiation and progression of the disease as a result of excessive and prolonged compressive forces on the bone. -Important factors are signalment, conformation, and use. -Navicular disease can slowly atrophy the leg.

What bone changes appear coupled in the animal?

Changes in pelvic shape, limb bones, and skull appear genetically coupled.

What is wrong?

Displaced condylar fracture

What is wrong?

Distal tarsus degeneration -Bone spavin.

What is this the cause of?

Failed neurectomy and spur formation.

What are the two types of IV Disk Disease? What are characteristic of these diseases and what type of breeds are they found in?

IV disk diseases are divided into: 1) Hansen Type I disease. -This is called Chondroid metaplasia in which there is extracellular matrix degredation, mineralization of the nucleus puplous and cell death. -There is a decrease in GAG proteins, decease in water, and decrease in shock absorption and deformability. -It leads to rupture of the dorsal anulus and massive extrusion of the nucleus pulposus. -This is found in Chondrodystrophic breeds. 2) Hansen Type II in which we have Fibroid metaplasia where the nucleus pulposus is gradually replaced by fibrocartilage and we see a bulging out of the dorsal anulus. -This is found in non-chondrodystrophic breeds.

What is the spinal range of the intercapital ligaments?

Intercapital ligaments go from T2 to T10

What are the lateral muscles of the hip in the dog and what action do they have?

Lateral muscles of the hip include: 1) Superficial gluteal muscle that acts in abduction with some extension 2) Middle gluteal with piriformis which acts in extension. 3) Deep gluteal muscle which acts in extension 4) Tensor fascia latae which acts in flexion

Will a disk protrusion at L7-S1 likely cause significant spinal cord compression due to the large size of the disk?

No

which bone was injured?

P1 fractured

What is wrong with this horse?

Tendon Laceration

In vertebrates, what makes up the lever system?

The lever system includes: 1) A rigid bar, the lever arm: skeletal components mostly long bones 2) A point of rotation along the bar, the fulcrum: usually a joint or foot that is on the ground 3) A resistance: Gravitational pull, inertia of body parts, or placement of body parts against relatively immoveable objects. 4) An applied force: muscle contraction

What is in the radiograph?

The navicular bone is diseased.

What are these examples of?

These are Type I/II bone lesions part of developmental disease in the hind limb -Plantar proximal P1 fragment. -The second image is a type II un-united palmar or plantar process of the proximal phalanx.

A fibrotic myopathy of the hindlimb effects what? What type of lameness is this?

This effects the semimembranousus and the semitendonosus. This lameness is mechanical.

What is circled?

This is an OCD Type II lesion in joint.

What is Type II traumatic arthritis?

Type II is disruptive trauma with damage to the articular cartilage or significant damage to major supporting structures. It includes severe sprains, intra-articular fractures, and meniscal desmitis.

What is seen here?

We see nuclear scintigraphy being used. Arrow is pointing to increases bony turnover.

What is present?

bone chip of distal radial carpal bone

diagnosis?

third carpal slab fracture.