Large Animal Sx- Pathophysiology of Joint Dz 2

wilsbach's version from 2015-11-04 18:52

osteochondrosis, OCD, Subchondral bone cyst

Question Answer
OSTEOCHONDROSIS is what kinda problem?Development Orthopedic Disease
Development Orthopedic Disease--> list 5Osteochondrosis**, Cervical vertebral malformation, Juvenile OA, Flexural limb deformities, Angular limb deformities
osteochondrosis can be due to problems in either of what two areas?Epiphyseal cartilage, or Metaphyseal growth plate (physitis)
definition of Development Orthopedic Disease?A general term used to describe orthopedic conditions seen in the foal during musculoskeletal development
what is osteochondrosis?failure of normal endochondral ossification
two types of osteochondrosis?Dyschondroplasia, Osteochondritis Dissecans (OCD)
what is Endochondral Ossification, and what does it do?this is a HIGHLY ORGANIZED process where the cartilage precursors of immature bones are replaced with bone, which results in longitudinal and circumfrential bone growth.
what are the two primary places of endochondral ossification in normal healthy bone?(1) metaphyseal side of the physis (‘the’ growth plate) (2) the epiphyseal growth plate (future subchondral bone).
what are the zones of the growth plate?Resting chondrocytes, Proliferative zone, Zone of hypertrophy, Zone of calcification, Primary spongiosa
what are the Epiphyseal Manifestations of osteochondrosis? (which disorders- 3)Osteochondrosis of epiphyseal cartilage, Cervical vertebral malformation/stenosis, Juvenile osteoarthritis
what are the Metaphyseal Manifestations of osteochondrosis? (4)Osteochondrosis of metaphyseal growth plate, Cervical vertebral malformation/stenosis, Flexural limb deformities, Angular limb deformities
Osteochondrosis dissicans (OCD) aka?flap lesion
OCD can lead to what two problems?Subchondral Bone Cyst, Juvenile OA
Proposed causes of osteochondrosis (dissicans)?Rapid growth, Genetic predisposition, Nutrition, Trauma, Endocrine imbalances
how does rapid growth play a role as a risk factor to osteochondrosis (dissicans)? (reasons why rapid growth happens)High energy diet, Large body size, Genetic predisposition to rapid growth
is osteochondrosis genetic?Inheritance not fully determined, but Some OCD locations heritable
which nutritonal problems can lead to OCD/osteochondrosis?High energy diets (prominent problem), Excessive protein, Mineral imbalances (Calcium, Phosphorus, Zinc, Copper)
an imbalance in certian minerals can lead to OCD...which minerals?Calcium, Phosphorus, Zinc, Copper
two types of trauma which might lead to osteochondrosis dissicans?(1) Primary – initiating injury (2) Secondary – damage to abnormal tissues
which two endocrine imbalances can lead to osteochondrosis dissicans?Low thyroxine, High glucocorticoids
what are the two morphological type of OCD?(1) flaps (2) cysts
what is osteochondrosis dissecans?A condition of articular-epiphyseal cartilage where a dissecting lesion develops and flaps visibly detach from the underlying bone
is this normal to see? NO...the probe should not sink in, the surface should be firm like a carrot. This is a dissecting lesion of OCD before the flap has formed
clinical signs of OCD?Joint affected determines clinical signs, but there will be Joint effusion (synovitis) and there is MAYBE lameness.
at what age does OCD usually develop?4 months to 2 years of age (young!)
what would conservative tx for OCD be?rest, balanced diet (restrict caloric intake- might get better), NSAID’s, intra-articular medication
what are the surgical options for tx OCD?(1) arthroscopy ( (2) arthrotomy- we really don't do this anymore) (3) can try to place pins through the flap into the subchondral bone to hold it down and see if it will heal
what is Subchondral bone cyst?(related to osteochondrosis!!) Manifestation of osteochondrosis where articular cartilage becomes infolded resulting in development of a cyst-like lesion in the underlying subchondral bone.
which type of surfaces do subchondral bone cysts usually develop on?Occur predominantly on weight bearing surfaces
clinical signs of a subchondral bone cyst? (what AGE do you see these signs?)Between 6 months and 2 years of age.(ocd was 4mo to 2years of age), intermittent lameness (common history), joint effusion (depends on joint and communication of cyst with joint)
*if you see a horse with INTERMITTANT LAMENESS what are you thinking?subchondral bone cyst
*subchondral bone cysts can develop from what two problems?osteochondrosis (young horses) OR secondary to osteoarthritis in older horses
***most common place for horses to get subchondral cysts?medial femoral chondyle of the stifle
what is the conservative treatment for subchondral bone cysts?rest, controlled exercise, intra-articular medication
what are the surgical tx options for subchondral bone cysts?Arthroscopy (debride cyst, inject stem cells), Corticosteroid injection (he says: one of the few times steroids help in horses)
what might you be able to do to help guide your theraputic injection into the subchondral bone cyst?guide with ultrasound
what is intracameral?inject steroids right in the cyst
4 most common sites of OCD in the hock?(1) ****Distal intermediate ridge of tibia (DIRT LESION!- most common!!) (2) Lateral trochlea (3) Medial trochlea (4) Medial malleolus
where is the "dirt" lesion?Distal intermediate ridge of tibia
which trochlea of the hock has a hook?LATERAL (lateral looks like gonzo's nose)
where is the medial/lateral trochlea of the talus (and why do we care? how can we tell them apart?)common site of OCD in the hock-- the lateral trochlea is more hooked than the R
why do we care about the medial malleolus of the tibia? where is it?one of the common sites of OCD in the hock
juvenile OCD can eventually turn osteoarthritis
Common sites of OCD in Stifle Joint?Lateral trochlea of femur, Medial trochlea of femur, Articular surface of Patella
where are the L and M trochlea of the femur, and why do we care about these locations?common sites of OCD in the stifle.
Common sites OCD Fetlock?Plantar proximal aspect of proximal phalanx, Dorsal aspect of sagittal ridge
where is the fetlock sagital ridge (of which bone is this)? why do we care?sagital ridge of the cannon (MC3) where it is common to get OCD in the fetlock here.
what kinda signs does a DIRT lesion usually cause?(distal intermediate ridge of the tibia) usually cause a lot of swelling, but not as much lameness-- so if you see a DIRT lesion on a really lame horse, be sure to check elsewhere for causes of lameness also

Treatment of Joint PAIN

Question Answer
what are some methods of physical therapy to treat joint pain?HEAT, COLD, MASSAGE, BANDAGES, STRETCHING, POULTICES, SWIMMING, CHIROPRACTIC, ACUPUNCTURE
Non-steroidal antiinflammatory drugs--> how do they work?Inhibit cyclo-oxygenase (COX) which is an enzyme that stimulates production of prostaglandins. Prostaglandins regulate inflammation and some normal organ functions
what does COX-1 do?regulates organ function
what does COX-2 do?amplifies inflammation
what is Arachidonic acid?the enzymes COX 1 and COX 2 convert AAcid into the prostaglandins which then mediate organ function and inflammation
organs which are regulated by COX-1/prostaglandins?intestines, stomach, kidney
Most common NSAIDs used in horses inhibit... (COX 1, COX 2, or both?) AND WHAT ARE THEY? both-- drugs are Phenylbutazone ("bute") and Banamine
what are the newer NSAIDs which only inhibit COX-2?Carprofen ("Rimadyl"), Etodolac ("Etogesic"), and Firocoxib ("Equioxx")
what is the COX-2 specific inhibitor available for horses?Firocoxib ("Equioxx")
pros and cons of Intraarticular steroid injections?PRO: anti-inflammatory you can put right into where the problem is. CON: suppress chondrocytes (less regeneration)
(said in class) which steroid do you want to inject into a high motion joint? low motion?high motion joint- triamcinolone. Low motion- depo medrol
why are corticosteroids awesome to put in inflamed joints?Decreases synovitis, Inhibits migration of inflammatory cells to the joint, Provides good pain relief for many diseases, Inexpensive compared to HA and PSGAG’s
what are the downsides to putting corticosteroids into inflamed joints?Deleterious effects on cartilage may occur (chondrocyte suppression), Deleterious effects likely dose related, May hasten (quicken) cartilage deterioration in joints with osteoarthritis
how do corticostroids affect chondrocytes?usually, suppress chondrocytes which means less regeneration capability. However, at low doses MIGHT be chondroprotective, because it dec synovitis, and the imflammatory mediators released by inflamed synovial tissues are bad for chondrocytes too-- so dec this might help them out
when are corticosteroids contraindicated for joints?Contraindicated in infected joints, joints with fractures and when damaged cartilage needs to be rested-- might inc risk of postoperative infections :(
what is Hyaluronic Acid (Hyaluronan)?Normal constituent of joints which Lubricates joint, reduces influx of inflammatory cells, and protects cartilage. thus, it is the BEST tx for synovitis
how can you admin hyaluronic acid to a joint?intraarticular, IV
PSGAGS stands for?Injectable polysulfated glycosaminoglycans
what do Injectable polysulfated glycosaminoglycans (PSGAGS) do? what is the primary component of it?Protects cartilage and enhances HA (Hyaluronic Acid ) production. Primary component is chondroitin sulfate
how can you admin Injectable polysulfated glycosaminoglycans (PSGAGS)?Carries increased risk of post injection infection when put given intraarticularly. Frequently given in the muscle
what is IRAP?Interleukin-1 Receptor Antagonist Protein
what does Interleukin-1Receptor Antagonist Protein (IRAP) do?IRAP blocks IL-1 receptors (IL-1 is an inflammatory protein).
what is PRP?Platelet Rich Plasma
what is Platelet Rich Plasma, why is it helpful?(Autologous PRP can be obtained with in practice with special equipment). Platelets rich in growth factors (IGF, PDGF, TGF-b) and these growth factors help with tendonitis, wound healing (more recently used in joint dz)
what are the 2 Autologous protein solutions?(1) ACS (autologous conditioned serum) (2) Pro-Stride Injection (autologous cellular therapy)
Regenerative Cell Medicine--> what cells are useful, how do we get these cells, when do we do this?Mesenchymal Stem Cells Harvested from various tissues (Fat, Bone Marrow, Blood, Skin, Teeth) and there is Selected use in joints (Severe OA, Extensive OCD lesions)
Oral Glycosaminoglycans Supplements--> when are these most useful? what might it help with?Most useful for early onset of osteoarthritis, May help with synovitis (Absorption from the gut is variable and not well documented in horses)-- it is Likely some benefit in horses with mild to moderate joint pain (products: Cosequin, J-Flex, PlatinumVet Joint Formula, Fluid Flex, Free Flex, etc)
Alternative joint therapy--> what is sarapin/what's it good for?plant alkaloid that desensitizes nerves.
Alternative joint therapy--> what is Ammonium sulfate/whats it good for?Dr Adam's says: DO NOT USE IT. some ppl do tho. DONT EVER USE IT! its a salt. injecting salt into a wound.
Alternative joint therapy--> list some various alternative joint therapy drugsSarapin, Ammonium sulfate (DO NOT USE), Snake venom, Silicone, Atropine, Autologous Synovial Fluid
summary of Medical treatment of joint pain (drugs)Nonsteroidal antiinflammatory drugs (phenylbutazone, Banamine, Ketofen), Hyaluronan (intraarticular and intravenous), Polysulfated glycosaminoglycans (PSGAGs) (Intramuscular and oral), Corticosteroids, Irap, PRP, stem cells
admin of PSGAGS? (polysulfated glycosaminoglycans)IM or oral
Surgical Treatment of Joint Disease- 3 major options?(1) Arthroscopy (2) Reconstruct ligaments (3) Surgical arthrodesis or facilitated ankylosis
what can you surgically do with arthroscopy? (4)Remove fragments of bone, Debride loose cartilage, Stabilize large fragments – compression, Remove foreign bodies