Ortho Surgery Wisdom Flashcards
Orthopedic Surgery Wisdom (31 cards)
Orthopedic urgencies
Require definitive care w/in 6 hours
- Hip dislocations/femoral head fractures (risk of avascular necrosis)
- Compartment syndrome (could lead to necrosis of muscle within and dysfunction of nerves that traverse compartment)
- Open fractures (risk of infection)
- Penetrating injury to joints (because synovial fluid is excellent bacterial growth medium)
- Necrotizing fasciitis
Necrotizing Fasciitis-Which organism?-Signs
Group A Streptococcus
Typically accompanied by gas production in soft tissue.
Can present as a compartment syndrome.
Orthopedic emergencies
Require initiation of definitive care within two hours of injury to prevent loss of life or limb.
- Fractures and dislocations associated with vascular injury constitute limb-threatening injuries
- Some types of pelvic ring injuries (because of risk of exanguinating hemorrhage)
Fractures in children
- Growth plate (epiphyseal) fractures(Salter-Harris classification)
- Buckle (or torus) fracture
- Greenstick fracture
- Spiral fractures (high suspicion of abuse)
What is the pathologic process in OSTEOarthitis?
Deterioration of cartilage and overgrowth of bone, often due to “wear and tear”.
What is the pathologic process/cause of rheumatoid arthitis?
AUTOIMMUNE inflammation of the synovial membranes, which lead to the destruction of the articular cartilage.
Which joints are preferentially affected in osteoarthitis?
Larger weight-bearing joints, such as hips and knees.
Think of the joints that bother abuela.
Which joints are preferentially affected in rheumatoid arthitis?
More often affects the smaller joints of the hands, wrists, and feet.
In contrasting osteoarthitis with rheumatoid arthritis, when is the pain worst for each conditions?
In osteoarthritis, the pain is often worse at the end of the day, when wear and tear builds up.
In rheumatoid arthritis, the STIFFNESS is worse after rest, such as first thing in the morning, and often lasts at least 30 min or more.
Of rheumatoid vs osteoarthritis, which has a gender predilection?
Rheumatoid arthritis is 3x more common in F vs M.
Most common mass of upper extremity
Ganglion cyst (fluid from normal joint moves into extraarticular space and forms collection).
Treat with AEIOU (double check this)
Aspirate Excise Inject (steroids) Observe Ultrasoud
Most common metastasis to upper extremity
BLT (breast, LUNG, thyroid)
PB - prostate, ? Bladder
Some are blastic, other are lytic.
Most common bone lesion of upper extremity
Osteochondroma - benign (noncancerous) tumor that develops during childhood or adolescence. It is abnormal growth forms on the surface of a bone near the growth plate.
Outgrowth of the growth plate and is made up of both bone and cartilage. As a child grows, the osteochondroma may grow larger as well, and will typically stop growing when the child reaches skeletalmaturity.
Can develop as a single tumor (osteocartilaginous exostosis) or as many tumors (multiple osteochondromatosis).
Most common cancer of upper extremity
Skin cancer - squamous cell carcinoma
Given the typical (degenerative) etiology of osteoarthritis, how then might a 20y old person have the condition?
The most likely cause of osteoarthitis in a young person is trauma.
However, while this is possible, it is not likely, and should be a diagnosis of exclusion.
How does trauma cause arthritis or degenerative joint disease (DJD)?
- DIRECT DAMAGE to the articular surface, which leads to breakdown.
- Chronic damage inflicted from loose ligaments. In loose joints, there is eccentric loading on small areas, and in those areas there will be increased pressure (where P = F/A), which leads to breakdown.
- Trauma can disrupt the blood supply to the bone and joint, and the arthritis may be from avascular necrosis (AVN).
If both rheumatoid arthritis and osteoarthritis can lead to end-stage destruction of the joint, why is it important to differentiate between the two?
The doctor has three jobs - identify diagnosis, state prognosis, and offer treatment. Therefore, the RA/OA difference holds three important distinctions.
- RA is a systemic disorder that can affect many organs of the body, therefore it is important to DIAGNOSE EXTRA-ARTICULAR disease.
- RA has a different prognosis, in terms of overall health/survival as well as joint specific.
- The diagnosis affects treatment: treatment for RA is not just symptomatic, and it also targets the root cause of the disease, immune abnormalities. This is accomplished with disease modifying anti-rheumatic drugs (DMARDs, such as methotrexate) and biologics (such as anti-TNFalpha/infliximab). The goal is not just palliation but STOP DISEASE PROGRESSION.
What is the role of body mass vis a vis osteoarthritis?
Excess body mass increases the load (force) placed on joints which increases the stress and accelerates the breakdown of cartilage.
However, OA may not be a pure mechanical phenomenon because being overweight has also been associated with higher rates of HAND OA - this suggests that a circulating systemic factor may also play a role.
Of note, basal thumb (C-MC) arthritis is more common among the obese; yet unless these people are doing a lot of handstands, this joint should not be excessively loaded by body mass.
Cardinal signs of osteoarthritis of the knee on plain radiographs?
- Asymmetrical joint narrowing (occurs as articular cartilage is lost in areas of abnormal load)
- Osteophytes (perhaps a reparative response, albeit a foolish/futile one, maybe because of abnormal loads stimulating bone).
- Subchondral sclerosis (deposition of bone under areas of stress - Wolff’s law - which makes the bone stiff and less compiant therefore more prone to further damage)
- Subchondral cysts (fluid seeps through the cracks in the cartilage and gets into bone. When fluid escapes into soft tissues, a Baker’s cyst may develop).
Why is osteoarthritis painful?
Not known with certainty.
Must be the bone and synovium transmitting pain, since cartilage is not innervate. May be due to joint “tipping”, soft tissue stretching around joint, fluid in knee under pressure causing pain by simple distension, and bone edema.
Also, could be due to a second disease presenting concurently.
What are the three tasks of bone? How can problems related to the two non-structural tasks lead to fracture?
- Skeletal homeostasis
- Mineral homeostasis (correct levels of Ca++, PO4-, Mg++, other ions)
- Hematopoesis
Define and contrast osteoporosis and osteomalacia
Osteoporosis = decreased bone mass with normal ratio of bone mineral to matrix (osteoid) as well as altered bone microarchitecture. Clinical features include fractures from minimal trauma, particularly the throracic and lumbar spine, wrist, and hip. Plan x-rays show decreased bone density but only once 30% of bone is loss. Use DEXA scan (reports bone density as T scores, representing deviation from mean of normal individuals, >2.5 is diagnostic).
Osteomalacia = decreased ratio of bone mineral to matrix. Characterized by diffuse bone pain, tenderness, and muscle weakness. X-rays commonly show decreased one density with thinning of cortex. Advanced disease can cause concavity of vertebral bodies (codfish vertebrae) and bowed legs. Labs may show low serum and urinary calcium, high serum alkPhos.
Suggest how a femoral shaft fracture can be lethal?
Bone is vascular, and fractures let marrow contents (fat especially) out into the circulation.
- FAT EMBOLI to the brain or lungs. The marrow contents are inflammatory in the lungs, and thus some patients develop ARDS after femoral shaft fracture.
- Marrow contents are TRHOMBOGENIC. patients with fx, especially if immobilized, can get extremity venous clots, and when a clot embolizes to the pulmonary artery, unhappiness is the result.
- Shock from SIGNIFICANT BLOOD LOSS and visceral injuries from the initial force that broke the bone.
Factors that regulate bone resorption
Vitamin D Serum Ca++ Growth hormone PTH (increases bone resorption) Calcitonin (increases bone formation)
