Rosh MSK

Which MSK CA is most commonly associated w/ a “sunburst appearance” of the bone on radiographic imaging:

chordoma;

malignant fibrous histiocytoma;

chondrosarcoma;

Ewing sarcoma;

osteosarcoma

osteosarcoma—a type of malignant bone tumor that arises from osteoblasts (mesenchymal stem cells) in the periosteum

One of the MC primary bone CA.

dz: a type of malignant bone tumor that arises from osteoblasts (mesenchymal stem cells) in the periosteum

osteosarcoma

Where is osteosarcoma usually found?

metaphases of long bones such as femur or tibia

Dx of osteosarcoma

bx

Tx of osteosarcoma

surgery w/ adjuvant polychemotherapy

A 23-year-old woman presents to primary care with left lower leg pain for 3 weeks. She indicates the pain is in the posterior calf and heel and that it is worse with running but better with rest. She is currently training for a half marathon but has had to cut back on her running due to the pain. She reports no known injury and no prior issues with this leg. She has no significant medical history and takes no medications. Today, her vitals include a T of 98.6°F, BP of 118/78 mm Hg, RR of 12/min, HR of 72 bpm, and SpO2 of 100% on room air. On physical exam, she is tender to palpation over the posterior heel, but no tendon defects are noted. She has a negative Thompson test and Homan sign and maintains full range of motion of the ankle and foot. Which of the following is the most likely diagnosis:

Achilles tendinopathy;

plantar fasciitis;
lisfranc injury

Achilles tendinopathy—pain occurs in the posterior area, usually around the insertion of the tendon.

Typically the pain is worse w/ activity and better w/ rest.

Thompson test r/o Achilles tendon rupture.

Tx involves activity modification, anti-inflammatories, and gentle stretching as well as PT.

Lisfranc injury is a fx-dislocation of the midfoot involving injury to the Lisfranc ligament. This injury is due to trauma to foot.

Plantar fasciitis is a common overuse injury involving the plantar fascia.

What is the structure that connects the posterior calf muscles (gastrocnemius and soleus) to the calcaneus?

Achilles tendon

Name a posterior calf muscle.

gastrocnemius;

soleus

Which LE tendon is vulnerable to overuse injuries, especially in pts who do alot of running and jumping?

Achilles tendon

What is the Thompson test?

performed by squeezing the pt’s calf muscle and looking for a corresponding plantar flexion of the foot which will reveal an Achilles tendon rupture.

Tx of Achilles tendinopathy

activity modification: avoid aggravating activities and support Achilles w/ a heel lift or elastic bandage

PT;

gentle stretching;

anti-inflammatories

How long can sxs of plantar fasciitis take to resolve?

up to a year

RFs of plantar fasciitis

female sex;

obesity

A 48 y/o M sustains a closed tibial fx of the R leg after a fall from a ladder. The leg is splinted and he is discharged home w/ pain meds. The following day, he returns to the ED w/ persistent intolerable pain in his foot and calf. The splint is removed and on examination, the calf and foot are pale in comparison to the LE. There is severe pain w/ passive dorsiflexion of the foot and toes. Posterior tibial and dorsalis pedis pulses are weak. What is the tx for his suspected dx:

surgical fasciotomy;

surgical thrombectomy

surgical fasciotomy

dz: acute compartment syndrome

Closed tibial fxs are the MC fx associated w/ compartment syndrome. The tx is emergent fasciotomy.

Compartment pressures can be measured to confirm the dx, however, tx should not be delayed if there is high suspicion for the dx.

The 5 P’s (Pain out of proportion to exam; Pallor; Pulselessness; Paresthesias; Paralysis) are often late manifestations of the condition.

What is the MC fxs associated w/ compartment syndrome?

closed tibial fxs

Tx of compartment syndrome

fasciotomy

A 60 y/o F presents to the clinic to discuss her R knee pain, which started 6 months previously. The pain is described as sharp, worse with movement and improves with rest. The pt has noticed that her pain is worse in the afternoon compared to earlier in the day, though she does experience some pain for a few minutes when she steps out of bed each morning. It is limiting her daily evening walks. Her medical hx is significant for smoking 1 pack of cigs per day and a R medial meninscus repair 10 years ago. Vital signs are BP 110/70 mmHg, HR 96, RR 16, 02 98%, T 98.8, height 62 in and a BMI of 24. PE reveals mild edema of the R knee joint and TTP along medial joint line. Mild quadriceps wasting is also noted on the R-side. XRs of b/l knees shows joint space narrowing and bone spurs. Based on the pt’s presentation and XR findings, what is the most important RF for this condition:

age;

previous knee injury

Age —most important RF for OA

dz: OA

As adults age, the articular cartilage thins, making the joint more susceptible to inflammation. An XR of OA shows joint space narrowing, production of bone spurs, presence of cysts and subchondral sclerosis.

Previous knee injury can be a RF for development of OA, often occurring 10 years after initial injury. Age is thought to compound the issue, thus enforcing age as the most important RF.

Bone spur (aka osteophyte) is an abnormal bony growth that forms on the surface of a bone.

A 15 y/o gymnast presents w/ lower back pain worsened by lumbar hyperextension. Exam reveals localized tenderness and tight hamstrings. Neuro exam is normal. What is the most likely dx:

spondylosis;

lumbar disc herniation;

spinal osteomyelitis;

ankylosing spondylitis

spondylosis —common cause of low back pain in adolescent athletes, particularly those involved in sports requiring repetitive lumbar extension, such as gymnastics

Caused by a stress fx of the pars interarticularis, typically affecting L5 vertebral.

The pain is worsened by hyperextension and relieved w/ rest.

Dz: common cause of low back pain in adolescent athletes, particularly those involved in sports requiring repetitive lumbar extension, such as gymnastics

spondylosis

Dz: Caused by a stress fx of the pars interarticularis, typically affecting L5 vertebral.

spondylosis

Spondylosis pain is worsened by what?

hyperextension

Dx of spondylosis

lumbar x

Dz: XR shows a “Scotty dog” collar defect

spondylosis

Tx of spondylosis

rest;

PT;

activity modification

Dz: XR shows a break in the pars interarticularis

spondylosis

A 16 y/o M presents to your office w/ pain and swelling of his L thigh that has been slowly worsening over the past 3 months. He thinks it started after he was hit by another player in a football game. He is otherwise healthy. On PE, he has a firm, fixed, slightly tender, 12cm mass over the anterolateral distal thigh. He has FROM of his hip and knee. XRs of the femur show a poorly defined lesion of the distal metaphysis w/ a sunburst pattern of periosteal reaction, bone destruction and a soft tissue mass. What is the dx?

osteosarcoma

The pt has physical and XR findings suspicious for a malignant tumor of the distal femur.

Peak incidence of osteosarcoma is between 13-16 y/o which is at the time of adolescent growth spurt—Pt in this Q is 16 y/o.

Name the malignant bone tumors.

osteosarcoma;

Ewing sarcoma

What is osteoid?

immature bone

Dz: XRs show a destructive bone lesion w/ poorly defined margins and a periosteal reaction, often in a sunburst pattern or a Codman triangle.

osteosarcoma

Dz: Rapid growth of the tumor destroys bone, and the periosteum attempts to generate new bone which appears disorganized and amorphous.

osteosarcoma

periosteum—membrane of blood vessels and nerves that wrap around most bones

amorphous: w/o a clearly defined shape or form

What is periosteum?

membrane of blood vessels and nerves that wrap around most bones

What is spondylosis?

a general term for a variety of degenerative conditions that affect the spine

Which bone tumor has skip lesions meaning tumor is not contiguous w/ the primary lesion?

osteosarcoma

What is the role of neoadjuvant chemo?

often used to shrink the tumor prior to surgery

What does sunburst pattern signify in osteosarcoma?

periosteal reaction

T/F: Most primary chondrosarcomas are slow growing and arise in adults over age 50.

T

T/F: Osteochondroma is a benign tumor of bone and cartilage and does not result in periosteal reaction or bone destruction.

T

Dz: A benign bone tumor that often presents w/ pain, commonly night pain, that is relieved w/ NSAIDs

osteoid osteoma

Dz: XR shows cortical thickening around a lucent nidus w/o bone destruction

osteoid osteoma

What are some differences between secondary osteosarcomas in adults compared to those in children?

Secondary osteosarcomas are MC in adults, more resistant to tx and more likely to METS than those in children.

Dz: MC malignant bone tumor

osteosarcoma

Population that is affected by osteosarcomas

10-20 y/o OR

> 65 y/o

MC location of osteosarcoma

long bone metaphyses (located between epiphysis and diaphysis; trumpet-shaped region that’s wider than diaphysis and contains growth plate)

A 61 y/o M presents to the office reporting low back, pelvic and b/l upper thigh pain. He describes the pain as deep and aching and reports that it is worse at night. He does not have any radiating sharp pain, numbness or tingling in his legs. His PE is unremarkable. A XR of lumbar spine and pelvis shows focal osteolytic lesions w/ focal radiolucencies throughout the lumbar vertebrae, pelvis and b/l proximal femurs. What lab findings will help to establish a dx in this pt?

alkaline phosphatase

dx: Paget dz of the bone (osteitis deformans) —characterized by high bone turnover and disorganized bone formation.

A markedly elevated serum alkaline phosphatase and this can be normal if only one bone is involved; A bone-specific alkaline phosphatase should be ordered which would be from bone vs liver.

Dz: characterized by high bone turnover and disorganized bone formation

Paget dz of bone

Most commonly, does Paget dz of bone involve one bone or multiple bones?

multiple bones commonly

Dz: The affected bone will initially have increased osteoclast activity causing lytic lesions throughout and then increased osteoblastic activity occurs where bone is formed in a disorganized fashion

Paget dz of bone

What is the 2nd MC bone dz after osteoporosis?

Paget dz of bone

What population is affected by Paget dz of bone?

common in pts> 55 y/o

Dz: The high bone turnover results in highly vascular, weak and deformed bones

Paget dz of bone

What is the cause of Paget dz of bone?

unknown but a significant number of cases are genetic and passed on as an autosomal dominant trait

What is the first sx of Paget dz of bone?

aching, deep pain that is worse at night

Dz: D/t disorganized bone turnover, bones can be soft, leading to bowed tibias, kyphosis, and easy fxs w/ light trauma

Paget dz of bone

kyphosis—spinal deformity that causes the upper back to curve abnormally outward, giving appearance of a hump or hunchback

Mainstay of tx for Paget dz of bone

bisphosphonates w/ IV zoledronic acid

Why should pts w/ Paget dz of bone be monitored long-term w/ yearly serum alkaline phosphatase measurements?

relapse can occur

Where in the body is calcitonin produced?

thyroid gland

What substance works to block bone breakdown by inhibiting osteoclasts?

calcitonin

Calcitriol is a hormone produced from what substance?

vit D

What hormone functions to increase intestinal absorption of Ca and Phosphorus for proper bone health?

calcitriol

What are the common SEs of IV zoledronic acid?

(bisphosphonate)

fever;

fatigue;

myalgias;

bone pain;

abd pain;

ocular problems

Dz: Pts may report arthritic pain if the adj joints are involved;

Pts w/ skull involvement may report increased hat size, HAs or dilated scalp veins;

if temporal bone is involved, the cochlea can be damaged, leading to mixed sensorineural and conductive hearing loss, tinnitus and vertigo

Paget dz of bone

Dz: XR shows bone thickening & enlargement w/ thickened cortices;

Sxs include bone/joint pain; nerve impingement or hearing loss

Paget dz of bone

A 44 y/o M presents w/ insidious and atraumatic proximal lower leg pain. It is more tender during rest than exercise. It commonly occurs at night and doesn’t seem to improve w/ oral analgesics. Knee testing is negative for meniscal or ligamentous injury. A screening radiograph reveals no fx, but does show a non-speckled calcified lesion w/in the proximal tibia. A bone scan shows no spine or pelvic lytic lesions. What is the most likely dx?

chondrosarcoma—primary bone malignancy involving cells producing cartilages

Constant deep achy pain, especially in the nighttime hours and not relieved by rest, is the main sx of bone malignancy.

Dz: Primary bone malignancy involving cells producing cartilage

chondrosarcoma

What is the main sx of bone malignancy?

constant deep achy pain, especially in the nighttime hours and not relieved by rest

Dz: A childhood and teenage benign bone lesion, commonly associated w/ night pain that is relieved w/ NSAIDs

osteoid osteoma

Dz: A marrow malignancy, common in the 2nd decade, that causes lysis and osteomyelitis

Ewing sarcoma

Dz: Initial XR shows lytic lesions or intralesional calcifications (popcorn calcifications)

chondrosarcoma

Dx of chondrosarcoma

fine-needle aspiration or core bx

A 73 y/o F presents w/ R knee pain for the past several months that has been worse over the last 3 days. It is worse w/ walking and better w/ rest. She has not tried anything to alleviate the pain. PE findings reveal bony enlargement of the knee and joint line tenderness. An XR shows narrowed joint spaces and subarticular reactive sclerosis. She denies any injury or previous surgery on the knee. What is the best initial pharmacologic tx?

NSAID such as ibuprofen

dz: OA

Ibuprofen has the lowest SE profile w/ the most significant pain relief & is the initial analgesic of choice for OA.

In mild dz, topical NSAIDs are recommended prior to the initiation of oral NSAID use.

Why is acetaminophen no longer recommended as first-line therapy for OA?

d/t safety concerns associated w/ overuse and increased evidence of its negligible and non-clinically significant effects on pain.

MCC of acute compartment syndrome

tibia fx

When a fx occurs, edema accumulates around the area. The tibia is encased w/in a fascial structure that is unable to expand adequately to meet the demands of increased amount of fluid. B/c of this restriction, the amount of fluid w/in that compartmnet rises and venous outflow is reduced. A continuous rise in pressure leads to tissue ischemia while compressing blood vessels and nerves and therefore tissue loss.

Dz: occurs when there is elevated pressure w/in a muscular area that eventually compromises the circulation and fxn of the tissues w/in that area

compartment syndrome

How many compartments are there in the lower leg?

4

Which compartment of the lower leg is MC site for acute compartment syndrome?

anterior compartment

What are the 6 Ps of acute compartment syndrome & acute arterial occlusion?

Pain out of proportion (usually the first sx)

Paresthesia

Paralysis

Pallor

Pulselessness

Poikilothermia

What is normal compartment pressure?

0-10 mmHg

What is usually the first sx of compartment syndrome?

pain out of proportion

A soccer player presents to the ED after being kicked in the shin by his opponent. Upon presentation, he demonstrates pain out of proportion as well as extreme pain w/ passive ROM. You have a high suspicion for acute compartment syndrome. Which lab findings, if elevated, is most closely associated w/ this disorder:

CK;

CK-MB;

ESR

CK—marker of muscle injury and is elevated in rhabdomyolysis; commonly associated w/ acute compartment syndrome

In the case of acute compartment syndrome, the muscular compartment of the lower leg is under extreme pressure, which leads to muscle injury and eventually tissue ischemia.

ESR is an acute phase response; can help to assess kidney fxn and may elevate in cases of compartment syndrome d/t rhabdomyolysis but is a nonspecific indicator of injury and inflammation.

Name a marker of muscle injury.

CK

Which muscle has the highest concentration of CK compared to any other tissue?

skeletal muscle

What is the most sensitive lab indicator of an injury?

CK

What is the best lab marker to follow during the course of a muscular injury?

CK

Majority of CK-MB is found where in the body?

heart (cardiac tissue)

Which lab enzyme is typically elevated in cases of MI or stress to the heart muscle?

CK-MB

What is another acute phase reactant other than ESR that is elevated when there is an inflammatory or infectious process present?

CRP

Dz: PE findings include pain w/ passive muscle stretching, firm “wood-like” feeling of the area

acute compartment syndrome

Dz: occurs when tissue pressure w/in a closed area compromises perfusion and results in muscle and nerve ischemia

acute compartment syndrome

What is the MCC of acute compartment syndrome?

Fx

What PE findings are late findings of acute compartment syndrome?

motor deficits

Compartment syndrome can be a chronic condition for which population?

usually in athletes

What kind of compartment syndrome is MC: acute vs chronic

acute

What is the initial management of acute compartment syndrome?

remove any dressings, splints, or casts and

keeping the limb level w/ the torso

MC site of acute compartment syndrome

anterior compartment of the lower leg

One of the MC and earliest sx of acute compartment syndrome is?

pain out of proportion to the apparent injury

Complications of untreated acute compartment syndrome

muscle contractures;

sensory deficits;

paralysis;

infection

What is the normal pressure of a tissue compartment?

0-10 mmHg

Which bone fx is MC involved in acute compartment syndrome?

tibia

Why is the wound of a pt w/ acute compartment syndrome left open?

Delayed closure or skin grafting is performed after the edema has resolved

T/F: Clinical suspicion alone even w/o measured compartment pressures warrants surgical evaluation for fasciotomy of an acute compartment syndrome pt.

T