Learning Issues 1. Is there a correlation with clinical signs and small size of dog (i.e, are small dogs more prone to certain Musculoskeletal disorders?) For some conditions/diseases/malformations e.g. Legge-Perthes, medial luxations of patellaÉOften small animals are prone to obesity causing increased stress on joints and ligaments and predisposition to degenerative joint diseases. ItÕs not so much that small dogs are predisposed but that overweight dogs are and there is a high incidence of obese small dogs. 2. What clinical disorders can occur/reoccur months after initial trauma? Sprain, ligament tear re-injured, more tearing, actual regeneration of articular cartilage, patellar luxation problems, developmental or traumatic, contusions, strains, fractures, infection, circulatory disorders 3. Any types of trauma associated with small dogs? House injuriesÉjumping off of sofa,out of window seats, off beds, playing with large dogs, caught under owners feet, sudden movements or rotations of stifle joint while in 20-50% flexion. 4. Why didnÕt the antiinflammatory injection have an effect? Dose problem? Maybe infectious or autoimmune? Maybe b/c it was just once, maybe it did for short period and no one noticed (or part of chronicity), was it truly an antiinflammatory (acetaminophen), incorrect dosage. 5. Is there any correlation between allergies (sneezing) and the lameness (automimmune/infectious?) Borreliosis (Lyme Disease) but probably not the case here b/c common signs are pyrexia, inappetance and acute lameness with no history of trauma. 6. What is a Grade 3/4 lameness? Grade 3 luxations A. It varies from an occasional skip to a non weight bearing lameness B. Most patients exhibit a mild to moderate weight bearing lameness and minimal discomfort upon manipulation of the stifle joint. C. the patella is luxated during flexion and extension and can be manually posiitoned within the trochlear sulcus, but it reluxates with manipulation. 7. What is the significance of this being intermittent? Sometimes it stays in the groove and sometimes it doesnÕt but it doesnÕt pinpoint a diagnosis. 8.What is medial buttressing? Thickening of the joint capsule. 9. What does it mean if the patella is easily luxated to the medial side of the trochlear groove when the leg is in extension? Medially is common in toy breeds. 4 to 8 more times likely in a pomeranian. 10. Why does above occur only in extension? Muscles and ligaments that hold patella in place are less supportive in extension. 11. What kind of injury can occur from falling of bed? Sprains,strains, contusions, fractures. 12. Is this problem even related to prior injury? YesÉanimals with grade 1 more prone to trauma laterÉand animal with luxation places ligament under greater stress,traumatic arthritis can develop and later become osteoarthritis if repeated injury. Obesity accelerates this process. Collagen fibrils hyalinized and tensile strength of ligament reduced making ligaments more susceptiblw to damage from minimal trauma. 13. Are there degenerative or congenital changes that can occur unilaterally? Yes, not very often. OCD can occur in one joint but usually large breed dogs and giant, and usually in more than one joint. Hip dysplasia can happen in just one hip. Avascular necrosis of the femoral head (Legge Perthes) common in small breed and usually in one hip. Often due to sudden onset. Osteoarthritis secondray to meniscal or ligamnet damage. Synovial sarcomas possibility. Canine rheumaotid arthritis can be in more than one joint , in small distal joint, presents as shifting leg lameness and occurs in small toy breeds. 14. What is the importance of a negative cranial drawer? Does this only involve the ACL? Could the patellar ligament be torn if there is a negative cranial drawer? ShouldnÕt jump to conclusions b/c often show neg result and that doesnÕt rule out necessarily b/c animal may be tense with tight muscles and doesnÕt react well to test b/c they are painfulÉplus animal has medial buttressing which may be adding some support. Other factors that my diminish response chronicity, tenseness, partial tear, and the presence of a miniscal tearÉif patellar luxation should be reduced before examining Typically cranial drawer is to isolate the cranial cruc. Lig. Pat. Lig rupture is a rare injury if both meniscus and cruciate lig are torn the patellar ligament rises above the trochlea or proximal to it. 15. What can cause a luxated patella? In small it can be congenital (early in life and not assoc with trauma) May be considered genetic by some but itÕs actually the confirmation that is inherited and is a predisposing factor to the luxation problem. Or possible trauma 16. Can a luxated patella cause only intermittent lameness? Most definitely. 4 classes of lux: Neonates/older puppies, Young to mature with gait instabilities, older may be lame b/c of breakdown of tissues, tears, and traumas, dogs that are asymptomatic. Signs will vary. Intermittent or continuous, reluctance to jump may be noted. Signs may worsen with weight increase or if tear or rupture or hips luxated. 17. Is this a new injury or a reoccuring old injury? Could this be an old injury made worse (i.e, was a partial tear, now a total ligament tear?) Since fibrosi already (medial buttressing) sugeests that old injury was present whether new lameness due to additional trauma or exacerbation of the old will prob not be idÕd.until radiographs are taken if thenÉmost likely exploraotry surgery of the joint will demo the exact cause since cruciate and meniscal injuries are not evidenced on radiographs.Pain early-then seem to improve in 2-3 wks appear norm for sevÕl months and then gradual or sudden change in limb movement often b/c of secondary meniscal damage. 18. Can arthritis occur this early after an injury? Can arthritis cause intermittent lameness? Yes, degen changes of osteoarthritis are often present by this point. 19. After initial injury, dog was OK after 1 month- was this due to the antiinflammatory drug? If a long acting antiinflammatory is given- can it take that long to act? Improvement probably due to reasons presented in #17. Even if long acting antiinflammatory was given once you would expect improvement shortly after injection and then a decline after 7-15 days after antiinflamm wore off. 20. Why is there pain on the left side when has right hind lameness? Could this be compensatory? Pain on left due to couple of reasons possibly: 1.Due to inj to rt limb animal was limping for 1 moÉcaused increased force/stress on left leg leading to some pain. 2. 1 + predisposition to patellar deformities or stifle could lead to start of degenerative changes. In addition animal is overweight which leads to increased force on all joints. 21. What does pain elicited on dorsal flexion of tail indicate? Manipulation of the tail can be used to detect the presence of pain or any anomaly in the sacro- coccygeal. However this may not truly be a diagnostic indication especially given this dogÕs temperament and his reluctance to be examined. 22. Could this be from an old fracture that didnÕt heal properly? There are a number of potential problems associated with trt/fixation of fractures including poor reduciton, inadequate immobilization and excessive trauma, however the history for this dog does not support a previous fracture. 23. Are there any congenital abnormalities involved in ligament development? Medial luxation tendency/ occurrence can be congential. High incidence in toys.