MSK & Sports Flashcards
Valgus of the knee
“knock kneed” and lower leg is abducted; can arise from MCL tear
Varus of the knee
“bow legged” and lower leg is adducted
ACL injury
anterior cruciate ligament; most commonly injured knee ligament; often a NONCONTACT athletic injury (running/jumping); classical senses a “pop” in knee
test for anterior drawer sign; resists anterior draw of the tibia
PCL injury
posterior cruciate ligament; often from trauma (force directed posteriorly at knee); classic cause “dashboard injury” where the knee goes into the dashboard in a MVC; test w the posterior drawer sign
MCL injury
medial collateral ligament; damaged by valgus stress; can be due to contact or non-contact; presents as an abnormal passive abduction; force from lateral side - push knee medial
Unhappy triad
injury common in contact sports; lateral force applied to a planted foot
ACL, MCL and medial meniscal tear
*more commonly the lateral meniscus in modern studies
LCL injury
lateral collateral ligament; very rare because you would have to get in-between the legs and apply medial force; presents as abnormal passive adduction
McMurray test
test for the meniscus tear; pt is supine with flexed (bent) knee and examiner coating the foot
internal rotation test for lateral meniscus (foot toward midline)
external rotation test for medial meniscus (foot away from midline)
Prepatellar Bursitis
inflammation of the pre patellar bursa; often caused by repeated kneeling “housemaid’s knee”; pain w activity; there will be swelling anterior to patella and warmth
Baker’s cyst
Popliteal cyst (behind the knee); popliteal fluid collection in gastrocnemius-semimembranous bursa commonly communicating w synovial space and related to chronic joint disease
Osgood-Schlatter Disease
tibial tuberosity avulsion; occurs in children; pain and swelling at tibial tubercle from overuse
*secondary ossification center of tibia; child that presents w pain and swelling just below the kneecaps; it is self limited
Patellar fracture
results from trauma to knee; swollen and painful knee that *cannot extend against gravity
dx w x-ray
3 bones that makeup the shoulder joint
scapula, clavicle and humerus
Rotator cuff
4 muscles: SItS (small “t” is for teres minor)
Supraspinatus (suprascapular n.) - most commonly injuried (impingement of tendon); “swimmers” and “throwers” assessed by “empty/full can” test
Infraspinatus (suprasca pular n) - pitching injury
teres minor (axillary n) - adducts and laterally rotates arm
Subscapularis (upper and lower subscapular n) - adducts and medially rotates arm
Empty/Full can test
Supraspinatus (suprascapular n.) - most commonly injuried (impingement of tendon); “swimmers” and “throwers” assessed by “empty/full can” test
Supraspinatus m initiates abduction for the first 15 degree but the main mover is the deltoid m (axillary n) that moves the shoulder up to 90degress
Shoulder dislocation
trauma; anterior dislocation of the humeral head; commonly from getting tackled while throwing a football
axillary n injury (loss of sensation of the deltoid and weak abduction)
Humerus fracture
common in elderly falls; often occurs in the PROXIMAL humerus; blood supply from the axillary artery and disruption may lead to avascular necrosis of head; axillary n injury leads to loss of arm abduction (deltoid m)
Lateral epicondylitis
tennis elbow; tenderness of lateral epicondyle and proximal wrist *extensors; elbow pain w resisted wrist extension
repetitive extension due to “backhand shots”
Medial epicondylitis
golfer’s elbow; tenderness of medial epicondyle; pain w resisted wrist *flexion
repetitive flexion due to “forehand shots”
Nursemaid’s Elbow
radial head subluxation; partial dislocation caused by “axial traction” on a pronated forearm (arm is pulled when extended at elbow)
*annular ligament slips over head of radius (trapped in radiohumeral joint)
Supracondylar Fracture
most common pediatric elbow fracture (fall on outstretched arm); brachial artery may be injured and median nerve (travel together); often both are injured
Axillary nerve lesion
deltoid m (abduction 15-90 degrees); sensation to area over the deltoid; proximal humerus fracture (elderly falls) or dislocated shoulder
Radial nerve lesion
extensors to arm, wrist and fingers; triceps m (weakness w high up injury); “wrist drop” and sensory loss on back of hand; “Saturday night palsy” and crutches
*runs in spiral/radial groove - vulnerable to compression
Musculocutaneous nerve
lateral cord of brachial plexus (C5, C6 and C7); innervates the biceps and provides sensation to lateral forearm; lesions here are rare
Upper trunk lesion
Erb’s palsy or Upper plexus injury (C5-C6); caused by excessive angle at neck/shoulder; classic cause is *birth trauma - shoulder dystocia
arm is straight at side; internally rotates (hand facing out) “waiter’s tip”
Lower trunk lesion
Klumpke palsy or Lower plexus injury (C8-T1); caused by excessive abduction of arm; classic cause is catching a tree branch while falling
affects the ulnar and median nerves; results in “clawed hand”
Thoracic Outlet Syndrome
compression of nerves/vessels leaving thorax; occurs above 1st rib and behind clavicle “thoracic outlet”
Causes: cervical rib - an extra rib from the 7th cervical vertebrae
Long Thoracic Nerve lesion
innervates serrates anterior muscle and presents w winging of scapula
Scaphoid bone injury
most commonly fractured carpal bone; palpable in anatomic snuff box; classically from FOOSH injury (falling on out-stretched hand); complications: avascular necrosis and nonunion (failure to heal)
Lunate bone injury
caused by trauma or fall; attached to radius; presents w a wrist is painful or swollen; can lead to carpal tunnel
carpal tunnel syndrome
transverse carpal ligament (flexor retinaculum) carpal bones are inferior along with the *median nerve
motor loss to thumb side and sensory loss on thumb side (thenar eminence and lateral 3 1/2 fingers)
hallmark: pain or paresthesia over median n distribution
carpal tunnel and acromegaly
GH excess in adults; enlarged jaw and coarse facial features; enlarged hands and feet (rings that no longer fit); 1/3 have carpal tunnel syndrome
Dialysis-related amyloidosis
amyloid deposits from B2 microglobulin (MHC I); complications of renal failure; dialysis does not effectively remove the B2 micro globulin and it deposits in bones, joints and tendons; can cause carpal tunnel syndrome
Guyon’s canal
ulnar canal; ABOVE the transverse carpal ligament (median n is below) passage of the ulnar nerve via the hook of the hamate (hamate bone injury); loss of abduction/adduction (interossei), motor/sensory loss of little finger (hypothenar muscles)
overuse of the wrist; commonly reported in bicyclists (direct pressure from handlebars)
Greenstick Fracture
pediatric fracture; bent bone from a fracture; fracture *does not extend through width of the bone; there is a bending force (from side) applied to bone
Torus fracture
pediatric fracture; “buckle fracture” caused by axial force trauma; occurs in distal metaphysis (most porous bone)
Lumbricals
originate from tendons of the *flexor digitorum profundus; flex MCP and extend IP (form L shape of hand); lesion takes form of claw fingers - partial based on which nerve is injuried
medial two lumbricals: ulnar n
lateral two lumbirical: median n
Flexor carpi radialis innervation
innervated by median nerve (a major flexor of the wrist) the flexor carpi ulnaris (ulnar n)
Median nerve lesions
“pope’s blessing” also called Hand of Benediction; ask pt to make a fist and thumb and lateral fingers cannot
at rest “ape hand”
Recurrent branch of the median nerve
motor innervation to thenar muscles (NO sensory); covers carpal tunnel and can be injured in *superficial laceration; immobilizes the thumb but sensation is NORMAL
iliohypogastric nerve
T12-L1; motor innervation to internal oblique and transversus abdominis and sensory to suprepubic region (below umbilicus and above pubic bone)
commonly injured in abdominal/pelvic surgery; radiates to suprapubic area
Genitofemoral nerve
L1-L2 provides motor innervation to cremasteric muscle (covers testis and spermatic cord)
genital branch - skin anterior scotum (males) and skin over mons pubis and labia majora (female)
femoral branch - skin upper anterior thigh
presents: absent cremasteric reflex (stroke inner thigh and scotum rises on I/p side); decreased sensation of anterior thigh
Lateral femoral cutaneous nerve
pure sensory from L2-L3; courses inguinal ligament into thigh; compressed by tight clothing, obesity, and pregnancy
*meralgia paresthetica
Sciatic nerve
L4-S3 largeness nerve in the body; branches into the common perineal and tibial
Herniated disc
most common cause of radiculopathy (compression of nerve root); occurs posteriorly due to weakness in the posterior longitudinal ligament; degeneration of the annulus fibrosis and bulging of the nucleus pulposus leading to unilateral nerve compression
Superior gluteal nerve injury
L4-S1 innervates gluteus minimus/medius which are the major hip abductors; often injured in intramuscular injections to buttocks (want to inject upper/outer quadrants to avoid injury); classic findings are Trendelenburg sign (pelvis tilts w walking)
Legg-Calve-Perthese Disease
idiopathic avascular necrosis that is the common in children (4-8 yrs); abnormal blood flow to femoral head; presents as hip pain and limping
Mitochondrial encephalomyopathy
characterized by ragged red fibers on muscle biopsy and a maternal inheritance pattern; *heteroplasmy or proportion of mitochondria w normal and mutant genomes will cause different presentations in affect family members
3rd pharyngeal pouch
thymus and inferior parathyroid glands arise from here; MG is associated w abnormalities of the thymus
Adalimumab
a recombinant human IgG that binds TNF-alpha; anti drug autoantibodies can develop against it that can block its integration w TNF-alpha preventing the drug from functioning and leading to more rapid drug clearance
TNF-alpha inhibitors and latent TB
TNF-alpha inhibitors impair cell-mediated immunity; all pts beginning tx should be evaluated for latent TB
IgA vasculitis (Henoch-Schonlein purpura)
an IgA-mediated small vessel vasculitis that manifests w palpable purpura on the LE, abdominal pain, arthralgia/arthritis and renal disease; renal involvement is primarily due to IgA deposition in the mesangium
Spondylolysis due to pars interarticularis fracture
fracture of the posterior vertebral arch often occurs at the pars interarticularis; b/l disruption of the pars interarticularis can lead to anterior displacement of the vertebral body
Myostitis ossificans
characterized by the formation of lamellar bone in extra skeletal tissues; often triggered by trauma; presents as a painful, firm, mobile mass within muscle; histology shows benign metaplastic bone and proliferating fibroblasts w/o mitotic atypia
McCune-Albright syndrome
characterized by the triad: fibrous dysplasia of the bone, endocrine abnormalities, and cafe-au-lait spots; condition results from an activating mut in the G protein/cAMP/AC pathway
Paget disease of bone
bone pain and elevated alkaline phosphatase level in elderly pt can occur w osteoclast metastases and Paget disease of bone; biopsy showing mosaic pattern of lamellar bone is diagnostic for PDB; initial phase is characterized by an increase in osteoclastic activity
osteosarcoma is the most common primary malignant bone tumor in children and young adults and typically arises near the metaphases of long bones causing progressive pain and soft tissue swelling X-ray reveals lytic and sclerotic bone lesion and histo shows malignant tumor cells that produce neoplastic osteoid and mineralized bone
Giant cell arteritis
characterized by granulomatous inflammation of the media and fragmentation of the internal elastic lamina most often affecting the medium and small branches of the carotid artery’s ischemic optic neuropathy w irreversible blindness is a potential complication therefore pts are required immediate glucocorticoid therapy
thoracic outlet syndrome question
most often caused by compression of the brachial plexus as it passes through the scalene triangle, the space bordered by the anterior and middle scalene muscles and the 1st rib; the presence of a cervical rib is a risk factor
Raloxifene: postmenopausal osteoporosis
raloxifene has estrogen agonist activity on bone which decreases bone resorption and improves bone density; it has an estrogen antagonist effect on breast tissue, decreasing the risk of breast cancer; also acts as antagonist in uterus and does not increase risk of endometrial cancer
Dermatomyositis
characterized by proximal muscle weakness resembling polymyositis w additional inflammatory features involving the skin; both dermatomyositis and polymyositis may occur alone or as separate paraneoplastic syndromes associated w an underlying adenocarcinoma (ex; ovary, lung, pancreas)
Golgi tendon organ (GTO)
the muscle spindle system is a feedback system that monitors and maintains muscle length while the Golgi tendon system is a feedback system that monitors and maintains muscle force; GTOs are sensitive to increases in muscle tension but are relatively insensitive to passive stretch
medications for osteoporosis
bisphosphonates inhibit osteoclast-mediated bone resorption; decrease osteoclast recruitment and induce osteoclast apoptosis
Enthesitis
inflammation at the bony insertions of tendons, ligaments and joint capsules; syndromes include achilles tendinitis, plantar fasciitis and dactylitis
osteopetrosis
defective osteoclast activity leading to increased bone density; infantile form mut in carbonic anhydrase type II (makes acid) - presents w renal tubular acidosis, seizures and intellectual disease
bones prone to break; excess bone in medullary cavity leads to loss of bone marrow = pancytopenia; excess bone in skull leads to compression of cranial nerves
curable w bone marrow transplant
Rickets
low calcium or Vitamin D intake leading to poor mineralization of osteoid; in children the growth
plate thickens
Labs: low Ca2+, low VitD, high PTH, low Phosphate and high bone alk phos (increased osteoblast activity)
tx w Vitamin D and Ca2+ supplementation
hallmark of Paget’s disease; mosaic pattern of lamellar bone; cement lines
Chalkstick fracture
classically seen in Paget’s disease
bone pain/fractures cheat sheet
Dual-energy X-ray absorptiometry (DXA) of -2.5 or lower is diagnostic for osteoporosis; recommended screening for women over 65 yrs
Osteosarcoma
malignant bone tumor of osteoblasts; histo- irregular osteoid formation
painful and enlarging mass on bone; typically occurs in metaphysics of long bone
X-ray: Codman triangle (tumor breaks through cortex) and Sunburst/Sunray sign (tiny bone fibers in periosteum)
Risk factor: *prior radiation and increased risk w Rb
Tx: surgery is not enough! ALWAYS add chemo
Ewing sarcoma
malignant bone tumor of *neuroectoderm cells; occurs in diaphysis (shaft) of long bones; bone cultures and tumor aspiration = sterile (unlike osteomyelitis)
genetic translocation of chr 11 and 22
X-ray: onion skin
Histo: sheets of small round cells (primitive neuroectoderm cells)
jersey finger
the flexor digitorum profundus tendon inserts onto the base of the distal phalanx and flexes the DIP joint; it is susceptible to rupture when an actively flexed DIP joint is forcefully hyperextended
parvovirus (B19) arthritis
Parvovirus B19 causes erythema infectious (fifth disease) in children and arthritis in adults; parvovirus arthritis can mimic rheumatoid arthritis but is usually self-resolving
lumbosacral radiculopathy
sciatica is a nonspecific term for back pain that radiates down the leg due to compression of the lumbosacral nerve roots; the S1 nerve root is commonly involved resulting in pain/sensory loss down the posterior thigh and calf to the lateral aspect of the foot; pts may also have weakness in thigh extension, knee flexion and foot plantar flexion w an absent Achilles reflex
radial neuropathy
injury of the radial nerve at the supinator muscle may occur due to repetitive pronation/supination of the forearm, direct trauma, or subluxation of the radius; pts typically have weakness during finger and thumb extension w/o wrist drop or sensory deficits
midshaft humeral fracture
the deep brachial (profunda brachii) artery and radial nerve run together along the posterior aspect of the humerus; midshaft fractures of the humerus risk injury to these structures
