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vet-tech-animal-diseases-2-musculoskeletal-diseases-part-2

Home Get App Take Quiz Create Fracture any interruption in the cortices of a bone always shave and look for hole in skin hard to break a bone on an animal - need to make sure it was an accident Cortex of a bone the outer or superficial part of an organ or bodily structure (e.g. bone) Open Fracture aka compound fracture the bone has pentrated the skin and been exposed to the environment worst kind of fracture not sterile bone may retract back in, but still considered open as skin broken and hole all the way to bone bacteria can get in (or probably has if bone retracted) and infect bone Osteomyelitis infection of the bone very painful fracture will not heal attend to wound cleaning - surgically open the wound, lavage, etc Closed fracture the skin remains intact, although the bone is fractured Classification of bone fractures shaft (metaphyseal) fractures Greenstick simple comminuted Greenstick fracture fracture through one portion of the cortex no displacement of bone e.g. down middle of shaft or partially across, but not all the way across must take x-ray in the correct plane or you won't see it for x-rays: - first do AP & lateral - if not seeing anything, take lateral, cranial, caudal & other directions Simple fracture bone is broken through entire cortex forms 2 (& only 2) separate pieces may be transverse, oblique or spiral Transverse simple fracture straight across hardest to repair hard to get good rotational therapy Oblique simple fracture slanted Spiral simple fracture occurs with rotation eg tibia when skiing without quick release bindings Comminuted fracture the bone is broken into multiple fragments large fragments are referred to as butterflies problematic - periosteum brings blood to bone - if pieces don't have periosteal attachment, will die w/in 10-15 days & will have painful draining necrotic abcess Compression fracture occur in short bones & flat bones (in juveniles, on long bones as well) Fracture classification epiphyseal fracture - juvenile animals -- involve the growth plates - physis (weak point in bone) -- salter fractures - classified as 1-5 -- not as big a deal in animals as humans (angulation in joints can compensate) adult animals - Y fractures - T fractures Bone healing requires: - stabilization of fractured bone ends -- multiple methods - sterile environment -- closed vs. open fracture - formation of callus -- problematic for epiphyseal fractures Callus connective tissue scaffolding to hold bone big problem in joint as it interferes with movement Causes of bone fracture trauma pathological fractures Fractures from Trauma requires significant force to fracture a bone rule out abuse - report it to vet -> ASCPA, animal control Pathological fractures there is a primary disease that weakens the bone 2 major causes: - cancer (neoplasia) - metabolic disease Pathological fracture - cancer primarily osteosarcoma treatment is amputation Metabolic disease primary hyperparathyroidism - regulates calcium & posphorus balance chronic renal failure (pseudohyperparathyroidism) improper diet - fresh diet done wrong - can be irreversible Clinical signs of fracture disease history of trauma - something had to happen to break the bone pain or localized tenderness - frequently swelling deformity - especially in through & through fractures loss of function - three legged lame crepitus - can feel bone ends moving against each other localized swelling or bruising sometimes see animals that defy explanation - lab w/ fractured ramus of mandible accidentally hit by baseball bat - happy as can be - adrenaline can mask much pain for ~45 min - 1 hour Fracture disease diagnosis history - trauma? physical exam - muzzle, treat gently, lots of pain - palpation - bones wiggle imaging - radiographs -- 2 views -- often may need to sedate as need to move leg around Fracture disease treatment requires: - reduction of bones ends - correct anatomical position - stabilization of bone ends - sterile environment -- risk of osteomyelitis method determined by: - open or closed - age of patient - juveniles heal fast; elderly very slowly - which bone is fractured - type of fracture - size of the animal - species - e.g. horse w/ broken leg is put down - how does bone normally fit together? - what will normally pull on it (distractive forces)? Osteomyelitis inflammation of bone or bone marrow, usually due to infection Methods of fracture repair splints casts pins plates screws external fixators or combinations of these Splints and casts effective for: - closed fractures - distal extremities -- below stifle/elbow - young animal -- heal really quickly -- can change splint as they grow can get plastic casts in various sizes that can be trimmed to fit Thomas splint for fractures of femur & humerus aluminum loop hooked to greater trochanter tape bottom to foot ~10 - 12 week healing time low cost method to fix Casts similar to splints older animal - once stopped growing; ~6 - 18 months destructive animal - casts are fiberglass; can't chew off large or heavy animal - can't do cat or chihuahua - need to have a cast saw in-house to get it off toes showing/not - 2 schools of thought: - 1. encase foot -- pro: no bands of pressure -- con: can't see foot swelling if too tight - 2. toes exposed -- pro: can see swelling if too tight - which you use will depend on what vet prefers (can be different for each vet in a practice) if too tight, foot will tingle & animal will chew at foot owner: - need to keep clean/dry (vet wrap shrinks when wet) - observe whether animal chewing at splint/cast, need to come in as too tight Pins & Wires everything must be ultra-sterile intramedullary pins (steinman pins) - usually titanium - open or closed placement -- open placement lets you see fracture & guide pin more carefully -- need to be really good if closed - Jacobs chuck used to place it (separate surgery pack for chuck, key & extender) - basically a rod down the center of the bone simple fractures - transverse, oblique, spiral - only 2 pieces of bone - flat bones -- bend pin slightly; ends stick out -- figure 8 with wires wires to improve stbilization - cerlage - circle - passed completely around - hemicerlage - through bone & around - stainless steel suture wire Plates & screws sometimes you can't pin bones comminuted fractures - lots of pieces flat bones large breeds - could bend pins ASIF (Association suisse internal fixation) - developed for alpine skiers w/ spiral fracture of tibia - must go there for advanced training - need specialized equipment -- specialize titanium plates & screws -- ~$10,000 - $15,000 for sterilizable tool case with plates & screws -- also need compressed air & special drills to drill holes for screws & tap to drill threads -- then can put screws in -- if don't use tap, will create microfractures in the bone when put screw in sterility mandatory - stay in the body - never come out - if bone infected, must take care of that first no callus as no movement in the bone unlike with pins & wires/splints/casts muscle can get tie down between femur & quads in connective tissue - can also happen on humerus, but usually not External fixators sometimes can't use internal fixators - infection, open, owner $, etc Kirschner apparatus - open fractures - comminuted fractures - abnormal bone conformation - cost considerations - inability to find plates for small animal, e.g. cat even if a practice doen't do internal fixation, it may do this Pathologic fractures concomitant illness weakens bone leading to fractures - cancer (neoplasia) -- most common is osteosarcoma - metabolic disease -- primary hyperparathyroidis - extremely rare -- chronic renal failure (pseudohyperparathyroidism) -- improper diet - eg raw feeding w/o balancing Ca & K Osteosarcoma osteo - bone sarcoma - tumor arising from connective tissue large breed dogs - usually older long bones - radius & ulna - femur - tibia, scapula, humerus intermittent lameness pathologic fracture most common orthopedic tumor in kids highly malignant tumor - generally by the time dx, it's too late frequent metastasis to lungs doesn't occur frequently in cats Osteosarcoma diagnosis difficult to diagnose - owner thinks it is arthritis, until eventually, dog lands on leg, breaks it, screams - dx before break, exam - looks a lot like pan-o radiographs - limb -- by the time you find it in the bone, it has usually spread -- may see starburst pattern - disease destroying bone while body trying to repair causes abnormal architecture - lungs -- looking for metastasis -- if see them, they will be dead w/in 3 months definitive dx - biopsy = cellular understanding of disease, e.g ELISA, histopathology, biopsy) Osteosarcoma treatment can easily spend $10,000 usually only if no obvious metastasis in chest amputation - heals ~ 2 weeks - humans would be disabled and/or disfigured - dogs don't care - happy cause they aren't in pain radiation - only after amputation - local only - don't lose fur - usually daily for 6 weeks chemotherapy - only after amputation - cis-platin (drug) -- toxic in cats -- chemotherapeutic -- costly - usually weekly - don't usually get vomiting euthanasia - can't repair pathological fracture Osteosarcoma prognosis grave die w/in 12 months of dx even with aggressive treatment - even with amputation and chemo - range 3 months to 2 uears - eventually start coughing & can't breath Hyperparathyroidism & pseudohyperparathyroidism Ca:P must remain in balance w/in the body Parathyroid gland responsible for maintaining appropriate blood calcium levels by removing calcium from storage in bones produces 2 hormones that regulate blood calcium body manages phosphorus Primay hyperparathyroidism extremely rare usually tumor Pseudohyperparathyroidism occurs when there is an imbalance of Ca:P in the body due to either: - renal disease - kidney unable to excrete phosphorus - improper diet dairy cow pasture must be seeded with Ca rich plants Pseudohyperparathyroidism clinical signs pathological fracture "rubber jaw" - mandible decalcifies quickly - literally can flex mandible Pseudohyperparathyroidism diagnosis chemistry radiographs - bone looks mottled or thin, not thick (white) Pseudohyperparathyroidism treatment correct underlying disease - parathyroid tumor - renal disease - binders - drugs to help lay down bone again improve the diet - fat & muscle meat (table scraps) are phosphorus laden Osteomyelitis see more in cats than dogs as there are more penetrating (to bone) wounds in front legs (not necessarily fractured) bones lie deep in body; relatively well protected from infection infection of the bone secondary to contaminated wounds - eg bite wounds open fractures non-sterile fracture repair hematogenous spread - to bone through blood - eg brucellosis very difficult to treat draining tracts that don't heal keeps bone from healing Osteomyelitis clinical signs lameness swelling drainage (fistula) - probe wound w/ hematocrit - will go into bone fever - deep in body as immune system is working hard Osteomyelitis diagnosis clinical signs x-rays: - can see degradation of bone - culture & sensitivity to figure out exactly what's growing -- if it's sensitive to clindamycin than can treat as closed wound (also no sequestrum) Sequestrum a piece of dead bone separated from the sound bone in necrosis. Osteomyelitis treatment debridement - open surgically sequestrum removal bone stabilization - external antibiotic therapy - clindamycin (antirobe - brand) up to 8 weeks -- can cause GI tract upset -- best bone pentration; only one that gets into bone readily - may need to lavage with antibiotics if clindamycin not effective amputation - may recover sooner and be more functional Osteomyelitis prognosis fair won't die

Author darlene.m.nelson ID 137702 Card Set vet-tech-animal-diseases-2-musculoskeletal-diseases-part-2 Description vet tech animal diseases 2 musculoskeletal diseases part 2 set Updated 2012-02-26T01:19:44Z Show Answers