MSK Flashcards
Osteoclast Formation
*Marrow pre-cursor produces multinucleated osteoclast
*M-CSF induces myeloid precursors to differentiate into osteoclast precursors that express RANK
- RANK –> NK-kB –> RANK-L triggers osteoclast precursors
Hyaline Cartilage Model
- What type of division?
- What type of Growth?
*Chondrocyte Division
*Growth: Appositional (diameter) growth via addition of matrix to peripheral surface cartilage
Periosteum Formation
- What do chondroblasts develop>
New chondroblasts develop on the perichondrium
Bony Collar Formation
- Where do osteoblasts secrete?
- Provide support for what?
*Osteoblasts secrete osteoid against shaft of cartilage model
*Collar acts as support for the developing bone
Matrix Calcification
Growth of chondrocytes w/in the primary ossification
- Begin secreting alkaline phophatase which is needed for mineral deposition
- Death of the chondrocytes leads to cavitation in middle of bone
Chondrocytes secrete
*Alkaline Phophatase
*VEGF
Secondary Ossification
*Where does it appear?
*When does the epiphyseal plate form?
*Appears at epiphysis of long bones
*Mesenchyme + blood vessels carried in via periosteal buds
*Epiphyseal plate forms once primary + secondary ossification centers meet
Osteoporosis
*Main Cause?
*Other causes?
*Presentation
*Diagnosis
*Tx:
*Due to age-related drops in estrogen
- Estrogen decreases = bone resorption increases & bone density decreases
- Estrogen usually blocks bone resorption via blocking IL-6
*ETOH, Hyperparathyroidism, Multiple Myeloma, Hyperthyroidism (thyroid induces osteoclasts)
*Presentation:
- Non-trauma related fractures
- Vertebral Compression fracture
*Dx: DEXA Scan, Fragility fracture
*Tx:
- Lifestyle modifications (smoking cessation, alcohol cessation, calcium/vitamin D, exercises)
- Bisphosphonates: ends in “-dronates”: promote osteoclast apoptosis
- Can’t tolerate bisphosphonates: try Teriparatide OR SERM’s (Raloxifene)
Osteomalacia / Rickets
*What happens in children?
*Inheritance
*Mutation
*Presentation
*Manage
*Rickets happens in children
*Inheritance: X-linked dominant
*Mutation of PHEX gene, PHEX usually provides instructions needed for proper bone/teeth development
- Regulates phosphate in body
*Presentation:
- Bowing of legs
- Craniotabes
- Wrist/Ankle Thickening
*Manage: Vitamin D + Ca2+
Scurvy
*Cause?
*Presentation:
*Cause: Vitamin C Deficiency
- Vitamin C needed for collagen hydroxylation
*Presentation: Bleeding gums, bleeding from hair follicles, easy bruising
Osteitis Deformans (Paget’s Disease)
*Cause
*Presentation
*Dx & Tx
*Cause: Increased osteoclastic activity w/ abnormal deposition of lamellar bone interspersed w/ woven bone
- Osteoclasts = sensitive to vitamin D
*Presentation:
- Intranuclear inclusions
- Bone pain that worsens w/ activity
- Bony Deformity (sclerotic lesions)
- Broken Bones
- Elevated alkaline phosphatase levels
- Normal serum Ca2+ & phosphorus levels
*Dx & Tx:
- Dx: Sclerotic Lesions
- Tx: (Nitrogen containing) Bisphosphanates – Zoledronate, Pamidronate, Risedronate, Alendronate
Pyogenic Osteomyelitis
*What?
*Organism?
- Organism associated w/ sickle cell patients? IV drug users?
*Who?
*Where?
*Presentation:
*Dx
*Tx
*Bone infection
*Caused by Staph Aureus, aerobic gram-neg. bacilli &/or coagulase negative staph species
*Sickle cell patients: salmonella
*IV drug users: pseudomonas
*Who?: Affects kids
*Where: Long bones
*Gradually worsening
*Bone Pain
*Swelling, warmth, tenderness
*Dx: Inflammation + Osteonecrosis + Periosteal elevation thickening + MRI
*Tx: Staph: Naficillin, Oxacillin,
(Inhibit peptidoglycan subunits in cell wall)
Cefazolin (inhibit cell wall synthesis by binding to penicillin-binding proteins & inhibit peptidoglycan synthesis)
Osteochondroma
*What?
*Where?
*Who?
*Presentation
*What?: Most common benign bone tumor
*Where?: Found most commonly at the distal femur / proximal tibia
*Males < 25 y/o
*Presentation:
- Painless lesion near join
- Pain worsens w/ activity
- Paresthesias if on or near a nerve
Giant Cell Tumor
*What?
*Where?
*Who?
*Presentation
*Dx
*Histology
*Tx
*Metastasize?
*What?
*Where?: Long Bones
*Who?: 20 - 40 y/o females
*Presentation:
- Pain, swelling, inflammation
- Limited ROM at joint
*Dx:
- Bone scans
- X-Ray: Soap Bubble Sign
- CT = cortical thinning + penetration better than x-ray
- MRI helps identify if surrounding tissues are affected
*Histology:
- Multinucleated giant cells
*Tx: Surgical excision
*Metastasis: To lungs
Osteosarcoma
*What?
*Where?
*Who?
*Presentation
*Dx
*Histology
*Tx
*Metastasize?
*What?: Primary Bone Tumor
- Can develop after radiation therapy for childhood cancres
*Where?: Distal femur, proximal tibia
*Who?: Males 10-20 yr & > 65 years
*Presentation: Pain lasting several months w/o systemic sx’s
*Dx:
- Elevated Alkaline Phosphatase
- Elevated Lactate Dehydrogenase
- Elevated ESR
- X-Ray
(1) destruction of normal bony pattern
(2) Indistinct bony margins
(3) Mix of radiolucent/radiodense areeas
CODMAN’S TRIANGLE
*Histology
*Tx: Surgery, Chemo
Ewing’s Sarcoma
*What? / Translocation?
*Where?
*Who?
*Presentation
*Dx
*Histology
*Tx
*What?: Tumor can occur post-traumatic event
- Translocation: t(11;22)
*Where?: Tibia, fibula, femur, humerus
*Who?: Children 10 - 20 y/o
*Presentation:
- Localized pain/swelling for several weeks & months
*Dx
- X-ray: Shows onion skinning
*Histology
*Tx:
Chemo:
- Doxorubicin: Cardiomyopathy (adverse effect)
- Cyclophosphamide / Ifosfamide: Hemorrhagic Cystitis, toxic metabolite that causes hemorrhagic cystitis = acrolein, treatment of acrolein: Mesna
Rheumatoid arthritis
*What? / Which HLA is it associated with?
*Where?
*Who?
*Presentation
*Dx
*Tx
*What?: Chronic inflammatory joint disorder, involves synovial joints
- Associated w/ HLADR4
*Where?:
- Proximal Interphalangeal joints
- MCP’s
- In toes: metatarsol joints
*Who?: Females
*Presentation:
- Symmetrical
- Morning stiffness, improves as day progresses
- Pain, swelling of affected joints
- Myalgia, stiffness, depression, chronic fatigue
- Ulnar Deviation, Swan neck deformity
- Pannus formation
*Dx:
- Anti IgG antibody (IgG antibody)
-Anti Citrullinated peptide antibody
*Tx:
- Inflammatory cytokines: TNF-alpha ; IL-1
- Manage w/ NSAIDs, systemic glucocorticoids, DMARD: Methotrexate (Inhibits DHFR enzyme)
Osteoarthritis
*What?
*Where?
*Who?
*Presentation
*Dx
- Inflammatory markers?
*Tx
*What? : Degenerative arthritis, “wear & tear arthritis”
*Where?: Involves hands, feet, knees, hips, spine
*Who?
*Presentation: Heberden’s Nodes (DIP), Bouchard (Proximal-PIP)
- Asymmetric distribution
- Weight bearing joints
- Worse at the end of the day (RA worse in the morning)
*Dx:
- No inflammatory markers
- Synovial fluid = negative
- Imaging = joint space narrowing & bone spurs (from bone rubbing on bone)
*Tx:
- Acetaminophen
- NSAIDs
- Steroids
- Surgery
Psoriatic Arthritis
*What? / HLA Association
*Where?
*Who?
*Presentation
*Dx
- Inflammatory markers?
*Tx
*What?: Affects DIP + Psoriatic findings
- Dermatologic findings before arthritic findings
- HLAB27
*Where?
*Who?
*Presentation:
- Dermatologic findings before arthritic findings
- Dermatologic findings: on scalp, nails, intergluteal region
- Nail pitting
-Arthritic findings = Asymmetric
- Visual disturbances: uveitis, conjunctivitis
*Dx
- Imaging: Erosive changes + new bone formation
- Pencil in cup deformity (DIP)
*Tx:
- NSAIDs
- DMARDs
- UV Light
Systemic Lupus Erythematosus (SLE)
*Main Heart causes
*Mnemonic
*Can cause Limbann-Sacks endocarditis (mitral valve vegetations) OR inflammation of the pericardial sac
*Mnemonic:
RASH OR PAIN
- R: Rash (discoid)
- A: Arthritis
- S: Serositis
- H: Hematologic disorders
- O: Oral / pharyngeal disorders
- R: Renal Causes
- P: Photosensitivity
- A: ANA prescence
- I: Immuno (anti- dsDNA–specific, Anti-nuclear–specific, anti- Smith, Anti-cardiolipin antibody)
- N: Neuro Disorders
What are the antibodies found in SLE?
(1) Anti-nuclear Ab
(2) Anti ds-DNA Ab
(3) Anti-smith
(4) Anticardiolipin antibody (antiphospholipid ab)
What is falsely elevated in SLE?
*PTT
*VDRL & RPR
Tx SLE
*NSAIDs
* Steroids
*Hydroxychloroquine
What antibody helps to differentiate between drug induced vs. non-drug induced lupus?
What drugs cause drug-induced lupus?
*Anti-histone antibody
*Drug-induced Lupus:
(1) Procainamide
(2) Hydralazine
(3) Penicillamine
(4) Isoniazid
(5) Diltiazem
(6) Minocycline
(7) Quinidine
(8) Methyldopa
(9) Chlorpromazine
(10) Infliximab
(11) Etanercept
Sjogren’s
*What? / HLA Association
*Presentation (triad)
*Dx
- Ab associations
- Histology
*Tx
*Autoimmune condition against lacrimal and salivary glands
- HLA-DR3
*Presentation:
(1) keratoconjunctivitis
(2) xerostomia (dry mouth)
(3) arthritis
*Dx:
- Ab associations: Anti-RO/SSA, Anti-La/SSB, anti-nuclear antibodies
- Histology: tons of lymphocytes
*Tx: Pilocarpine, methotrexate, hydroxychloroquine
Behcet’s Disease
*What? / HLA Association
*Presentation
*Dx
*Tx
*What? / HLA Association:
- Vascular inflammatory disease that affects a variety of systems throughout the body
- Associated w/ genital + oral disorders
- HLAB51
*Presentation:
- Pseudofolliculitis
- Acneiform lesions
- Pustular eruptions
- Erythema Nodosum
- Visual disturbances: anterir uveitis, retinal vasculitis
*Tx:
- Steroids
- Infliximab (anti-TNF) w/ uveitis
Spondyloarthropathies are associated w/ what haplotype?
Associated w/ HLA B27
Ankylosing Spondylitis
*What? / HLA Association
*Presentation
*Dx
- What does diagnosis require?
- Inflamm. markers
*Tx
*What? / HLA Association:
- Chronic spinal inflammatory disease
- HLAB27
*Presentation:
- Sacroiliitis
- Chronic back pain, neck pain, gluteal pain, Limited mobility, Pain and mobility improve w/ exercise but not rest
- Nighttime pain usually seen
- Cardiovascular findings
- Visual disturbances
- Inflammatory bowel disease
- Pulmonary disturbances (limited chest expansion)
*Dx
- Diagnosis requires sacroillitis
- Inflammatory markers: Non-specific–ESR, CRP
- Narrowing joint space
- Fusion of vertebrae (bamboo spine)
*Tx
- Exercises to strengthen + loosen up
Reactive Arthritis
*What?
*Presentation
*Dx
*Tx
*What?: Arthritis in response to an organism
*Presentation: Arthritis, Conjunctivitis, Urethritis
- “can’t see, can’t pee, can’t climb a tree”
- Arthritis usually affects more than 1 joint
- Keratoderma Blennorhagica (lesions on palms + soles)
- Circinate Balanitis: Inflamm. around glans penis
*Dx
- Organisms: Salmonella, Shigella, Campylobacter, Yersinia, Chlamydia trachomatis, E. Coli, C. Difficile
- Sx’s develop days to weeks following infection
*Tx: Treat w/ organism specific medication
Scleroderma
*What?
*Presentation
- What is CREST Syndrome
*Dx
*Tx
*What?: Systemic autoimmune disease characterized by (1) vasculopathy (2) Fibrosis of skin & other organs
*Presentation:
- Ulcers on fingers
- Telangiectasias
- Pitting (fingertips)
-Depigmentation/hyperpigmentation)
- C: Calcinosis
- R: Raynoud Phenomenon (lack of blood flow to finger tips)
- E: Esophageal dysmotility
- S: Sclerodactylyl
- T: Telangiectasias (small dilated blood vessels)
*Dx
- Anti-centromere ab
- Anti Scl-70 ab
- ANA
*Tx
- Methotrexate
Sarcoidosis
*What?
*Presentation
*Dx
*Tx
*What? : Multi-system disorder
- Non-caseating granulomas
- Caused by dysregulated cell-mediated immune response
(Non-caseating granulomas formed by: Th1 CD4+ helper T cells –> secrete IL-2 –> interferon Gamma)
*Who?:
- People 20 - 60 y/o
- More common in black females
*Presentation:
- Affects lungs –> interstital fibrosis –> restrictive lung disease
*Dx
- ^ ACE levels
- Hypercalcemia (due from ^ 1,23-dihydroxy vitamin D levels from increased 1-alpha hydroxylase enzyme activity)
- Dec. PTH secretion
- Bilateral hilar adenopathy on imaging
*Tx:
- Glucocorticoids
Mixed Connective Tissues Disease
- Easy or Hard to diagnose?
- Who get it?
- Antibody?
- Hard to diagnose b/c combines SLE, sclerosis, polymyositis
- Females in their 20’s
- Associated w/ anti-U1 RNP ab
Polymyalgia Rheumatica
*What?
*Presentation / Where?
*Who
*Dx
*Tx
*What?: Pain in multiple areas: poly
*Presentation / Where?:
- Pain in multiple areas
- Pain in shoulders, neck, torso (pain & stiffness):
- Morning stiffness lasting @ least 30 min.
- Pain in muscles used to wave goodbye, dressing, brushing hair
*Who?: > 50 yrs of age
*Dx:
- ^ ESR & CRP
- MRI: synovial inflammation
- Morning stiffness at least 30 minutes for at least 2 weeks
*Tx:
- Low dose steroids
Fibromyalgia
*What?
*who?
*Presentation
*Where?
*Dx
*Tx
*What?:
- Widespread musculoskeletal pain + fatigue
- Can be associated w/ psychiatric / cognitive sx’s
*Who?: Females 20 - 50 y/o
*Presentation
*Where?
- 11/18 areas
*Dx:
- Pain in 11/18 areas for 3 months
*Tx
- Exercise + Higher quality rest
- Duloxetine (SNRI)
- Amitryptiline
- Pregabalin
- Milnacipran
Polymyositis & Dermatomyositis
*What?
*Presentation
*Dx
*Tx
*What? : Proximal muscle weakness , dermatomyositis = skin eruptions
*Presentation:
- Skin eruptions affects flexors of neck, deltoids, hip flexors
- Gottron’s Papules: discolored/erythematous papules on finger joints
- Gottron’s sign
- Facial erythema
- Upper eyelid swelling
- Areas of hyper/hypo-pigmentation
- Epidermal atrophy and telangiectasias
*Dx
*Tx
Gout
*What?
*Presentation
- Where does it most commonly affect?
- What does it make?
*Dx
*Tx
*What? : Monoarticular arthritis from overproduction or under excretion of uric acid
*Presentation:
- Most commonly affects big toe (podagra)
- Uric acid under the skin = tophus (tophus: caused by uric acid crystals in joint space–precipitated by red meats, alcohol ETOH)
*Dx:
- Crystals = needle shaped + negative birefringent
*Tx:
- Acutely: NSAID’s, Colchicine
- Glucocorticoids
- Allopurinol
Pseudogout
*What?
*Where does it most commonly affect?
*Dx
*Tx
*What?: Crystals composed of Ca2+ Pyrophosphate
*Presentation:
- Affects knee
*Dx:
- Rhomboid shaped crystals
- Positively birefringent
*Tx:
- NSAIDs, Colchicine, Glucocorticoidss
- Long term treatment: Colchicine
Septic Arthritis
*What most commonly causes this?
*Presentation
*Where is this most seen in IV drug users?
*Dx
*Tx
*N. Gonorrhea
- Most commonly causes this
*Presentation:
- Fever, chills, IV drug users
*Where in IV drug users?: Sternoclavicular joint, sternomandibular joint, endocarditis
*Dx:
- Joint aspiration to identify organism
- Check for crystals
- Check WBCs
*Tx:
- 3rd generation cephalosporin for gonorrheal infection (ceftriaxone or ceflotaxine)
- Vancomycin
Distal radial fracture can happen in… how?
- Youth
- Older people
- Falling?
- Youth from playing sports
- Older population w/ osteoporosis
- Fall on outstretched hand
Smith fracture
Can occur from fall on flexed wrist or blunt trauma to posterior aspect of wrist
Ulnar fracture
- Cause
Dx:
Require:
Cause: Blunt trauma from medial aspect of forearm
Dx: Xray
Require: immobilization w/ cast
Scaphoid Fracture
*Cause?
*Pain where signals this?
- Borders of this region:
>Roof:
>Floor:
>Medial Border:
>Lateral Border:
>Proximal Border:
*Next step
*Worrisome complication:
*What does scaphoid articulate with?
*Cause: Falling on outstretched hand (FOOSH)
*Pain in snuff box signals scaphoid fracture
- Snuffbox borders:
>Roof: Skin of hand
>Floor: Scaphoid & Trapezium
>Medial Border: Tendon of extensor pollicus longus
>Lateral Border: tendon of abductor pollicus longus & extensor pollicus brevis
>Proximal Border: styloid process of radius
*Next step: X-RAY
*Worrisome complication: avascular necrosis
*Scaphoid articulates w/ radius
What is the vascular supply of the scaphoid bone?
Radial artery
Mnemonic for bones in hand
So long to pinky here comes the thumb!
Lunate Dislocation
*Cause?
*How is it distinguished from scaphoid fracture?
*Caused by falling on an outstretched hand
*Distinguished from scaphoid by presence of paresthesias from median nerve impingement
Carpal Tunnel
*Cause
*Pain where? (Location of pain?)
*Borders of carpal tunnel
- Superiorly
- Inferiorly
*Dx
*Tx
*Cause: increased pressure in carpal tunnel
*Pain & paresthesias in the
distribution of median nerve
*Location: thumb, index, middle, lateral half of ring
*Carpal tunnel borders:
- Superiorly: flexor retinaculum (transverse carpal ligament)
- Inferiorly: carpal bones
*Dx: Positive tinel sign & positive phalen test
*Tx: (1) conservative
(2) splint– keeping wrist in slight extension
(3) glucocorticoids
(4) Surgical decompression
Rotator Cuff Injury
- What are the muscles? What do they do?
- Cause of injury?
- Common Sx’s
- Dx
- Tx
*SITS
- Supraspinatus: Abducts arm 0 - 15 degrees
- Infraspinatus: lateral/external rotation
- Teres minor: ADducts & external rotates arm
- Subscapularis: ADducts & medial/internal rotation of arm
*Cause: Repetitive throwing
*Sx’s
- Tendon becomes impinged between acromion + head of humerus
- Pain upon abduction
- Dec. ROM (mainly internal rotaiton)
- Crepitations felt over humeral head
*Dx:
- Neer test, can confirm diagnosis
(forcibly elevate arm post pronation)
–pain = Neer sign
*Tx:
- Resting arm
- NSAID’s/Steroid injections
- Arthroscopic surgery
Shoulder Dislocation
*Cause?
*What is subluxation?
*Most Common shoulder dislocation
*What nerve is most likely affected?
*Physical findings
*Dx
*Cause: dislocation = displacement of humeral head from glenoid fossa
- Forceful external rotation & abduction of arm at shoulder = most responsible for dislocations
*Subluxation: translocation of humeral head relative to glenoid articular surface
*Most common shoulder dislocation: Anterior (Subcoracoid dislocation)
*Axillary nerve wraps around hueral head & at risk of injury with shoulder dislocation = loss of sensation of lateral arm + shoulder
*Physical findings:
- Flattened deltoid prominence
- Protruding acromion
- Anterior axillary fullness
- Sensory loss of skin over deltoid + lateral arm
- Pain immobility
*Dx: X-ray
Elbow Injuries
*Lateral Epicondylitis due from repetitive – motions; most commonly occurs in (this sport)
*Medial Epicondylitis due from repetitive – motions; most commonly occurs in (this sport)
*Lateral Epicondylitis due from repetitive extension motions; most commonly occurs in tennis
*Medial Epicondylitis due from repetitive flexion motions; most commonly occurs in baseball or golf
Quadriceps
- What muscles make it up?
- Action?
- Innervation?
- Blood Supply
- Muscles:
(1) Rectus femoris
(2) Vastus Lateralis
(3) Vastus Intermedius
(4) Vastus Medialis - Action: extension of leg at the knee
- Innervation: Femoral Nerve
- Blood supply: femoral artery + branches of deep femoral artery
Hamstring
- What muscles make it up?
- Action?
- Innervation?
- Blood Supply
- Muscles:
(1) Semitendinosus
(2) Semimembranosus
(3) Biceps femoris - Long head
- Action:
Extend at hip + flex at knee - Innervation:
Tibial division of sciatic nerve - Blood supply:
Deep femoral artery
Hip Flexors (5)
(1) Sartorious
(2) Rectus Femoris
(3) Pectineus
(4) Psoas
(5) Iliacus
Anterior Compartment of leg
- Muscles
- Blood Supply
- Major Action
- Nerve
- Tibialis Anterior
- Extensor Digitorum Longus (EDL)
- Extensor Hallucis Longus
- Fibularis tertius
(peroneus tertius)
*muscle belly often fused w/ EDL
*but tendon inserts in diff. location
*4 muscles
*Blood Supply:
*Ant. Tibial artery
Major action:
*ext. of toes &/or dorsiflexion of foot at ankle
Nerve:
*Deep fibular n.
Lateral Compartment
- Muscles
- Blood Supply
- Major Action
- Nerve
- Fibularis (peroneus) longus
- Inserts on plantar surface of foot
- 1st metatarsal & medial cuneiform - Fibularis (peroneus) brevis
- Inserts on dorsum of 5th metatarsal
*2 muscles
both pass posterior to lateral malleolus at ankle
- Tendons bound down by sup./inf. Retinacula
Blood:
- Fibular artery
(branch of posterior tibial)
Action:
- Eversion of the foot
(turn plantar surface laterally)
- Weak plantarflexion at ankle (tilting foot inferiorly at the ankle)
Innervation:
- Superficial fibular
Posterior Compartment Superficial
- Muscles
- Blood Supply
- Major Action
- Nerve
*3 muscles, superficially
transverse intermuscular septum divides posterior compartment of leg into a superficial/deep group
- Gastrocnemius
- lateral/medial head - Soleus
- tendon of gastrocnemius & soleus unite inf. To form the calcaneal tendon
(Achilles tendon)
*some consider gastrocnemius/soleus: triceps surae
- Plantaris
- Small weak muscle w/ long tendon
- Like palmaris longus in upper limb
Blood:
- Post. Tibial artery
- Fibular artery
Action:
- Plantarflexion at ankle
(gastrocnemius flexes at knee)
“Foot in pond”
Innervation:
- Tibial Nerve
Posterior Compartment Deep
- Muscles
- Blood Supply
- Major Action
- Nerve
*4 muscles, deep
1. Flexor hallucis longus
- Flexor digitorum longus
- Tibialis posterior
- Inverts food (turns plantar surface medially) - Popliteus
- Crosses the knee
○ Only muscle in post. compartment - Only muscle that does not cross the ankle
- Crosses the knee
Blood:
- Posterior tibial artery
(branch of posterior tibial)
- Fibular artery
Action:
for all muscles except popliteus
- Flexion of toes
- Plantarflexion at ankle
(gastrocnemius flexes at knee)
Innervation:
- Tibial Nerve
○ Gives off medial sural cutaneous n.
§ Then passes deep to arch of soleus
□ Ends as medial / lateral plantar nerve
What ligament is most likely injured in an ankle sprain?
Anterior talofibular ligament
What nerve travels around lateral condyle in the leg?
(1) Describe it’s course
(2) Injury
(3) Branches
Common Fibular Nerve (Peroneal Nerve)
(1) Courses laterally around neck of fibula around lateral condyle
(2) Susceptible to trauma from lateral blows to knee, tight casts
- Foot drop
- Peroneal neuropathy: ext. bedrest, knee hyperflexion
- Peripheral neuropathy: obstetric stirrups, ballet dancers, crossing the legs
(3) Superficial fibular nerve + deep fibular branches
- Fibular n : supplies muscles of lateral compartment of leg
- Deep fibular n: supplies muscles of anterior compartment of leg–dorsiflexion of foot/extension of toes
Trendelenburg gait
- What?
- What side is affected?
- What?: Abnormal gait caused by weakness of abductor muscles of lower limb, gluteus medius, gluteus minimus
- What side is affect?: Contralateral side (injured side opposite of pelvic sag, patient picks up foot off the ground, pelvis sags on opposite side of injury)
Sciatica
(AKA sciatic neuropathy)
*What?
*Cause
*Signs & Sx’s
*Dx
*Tx
*What?: Result of irritation of the sciatic nerve or one of its roots
- Due to injury at L5 or S1
*Cause:
- Herniation
- Spinal canal stenosis
- Bone spurs
- Piriformis syndrome (inflammed piriformis)
*Signs & Sx’s:
- Weakness of posterior thigh
- Weakness of muscles distal to the knee
- Shooting pain from posterior thigh/leg to foot
- Post. thigh pain and/or sensory diminishment
- Pain or loss of sensation in calk
- Loss of sensation on plantar surface of foot
- Diminished ankle reflex due to S1 nerve root (weakened plantar flexion
*Dx:
- Physical exam
- Neurologic exam
- Imaging if needed
*Tx:
- Muscle relaxants &/or opioids
- Long-term management w/ NSAIDs, Acetaminophen
Hip Dislocation
- What type of dislocation?
- Injures what nerve?
- Dx
- Most likely posterior dislocation (affected side appears shortened & internally rotated)
- Anterior dislocation (affected side: not shortened, externally rotated)
*Dx:
- X-Ray
- Neurologic examination
- Immediate reduction under sedation
- May req. open reduction
- Post. dislocation
- Pt’s should avoid weight bearing activity for a min. of 3 weeks
Femoral Neck Fracture
- What caused it?
- Sx’s
- What nerve is at risk & what is a compliation?
*What caused it:
- Older pt’s suffering from osteoporosis
*Sx’s: Severe hip/groin pain upon movement
(leg usually externally rotated on presentation)
*Nerve at risk: medial femoral circumflex artery
- Complication: avascular necrosis of femoral head (may be associated w/ sickle cell disease, SLE, steroid therapy, alcoholism)
Anterior Cruciate Ligament (ACL)
- Where does it attach?
- What does it help do?
- Who are ACL tears more common in?
- Cause?
- Sx’s?
- Dx
- Tx
*Ant. aspect of tibia
*Helps to stabilize the knee during extension
*ACL tears are more common in women due from muscular imbalance between ant. & post. muscles of the thigh
- Athletes
*Cause:
- Landing on stiff leg
- Rapid deceleration followed by acute directional changes ^ risk of injury
*Sx’s
- Pain & Swelling
- Non-stability in knee
- Popping sound on injury
*Dx:
- Anterior drawer sign (90 degrees)
- Lachman test (30 degrees)
- MRI
*Tx: Surgery
Posterior Cruciate Ligament
*Attachment
*Purpose
*Cause
*Dx
*Attaches to posterior aspect of intercondylar area of tibia
*Purpose:
- Prevents post. movement of femur relative to tibia, when knee flexes
*Cause: dashboard injury
*Dx: posterior drawer test
Medial Collateral Ligament
*Is this the most commonly injured collateral ligament?
*Cause
*YES!
*Cause: direct blow to lateral aspect of knee
Unhappy triad
(1) ACL
(2) Medial Collateral
(3) Medial meniscus
Mnemonic to remember which is more medial: tibia or fibula?
Tibia = towards the middle
Meniscal Tears
*Who?
*Cause?
*Sx’s
*Who?: Most commonly in older people w/ joint degeneration
*Cause?: Planted foot and rapid change in direction
*Sx’s: knee unsteadiness, pain, swelling, clicking, locking during mostion
Bursitis
*What?
*Cause?
*What? Inflammation of fluid filled bursa (counteracts joint friction)
*Cause:
- Associated w/ constant repetitive motion, maintaining long-term positions such as kneeling
Baker’s Cyst
*What?
*Cause?
*Which specific bursa is affected?
*What?: Cyst formation in popliteal fossa
*Cause?: Knee injuries, inflammatory arthritis, degenerative disease
*Specific bursa affected:
- Gastrocnemius semimembranosus bursa–lies between 2 muscles on medial side of fossa
Orbital blowout fracture
*Cause?
*What is it called when surrounding bones are affected?
*Cause?: Blunt trauma to face
- increase pressure posteriorly in orbit causes weakest bones to fracture
*LeFort Fracture: Maxillary bones + surrounding structure
Basilar Skull fracture
*What?
*Most commonly due to?
*Clinical Signs
*What?: trauma to at least 1 of 5 bones that make up base of skull (sphenoid , occipital cribiform plate of ethmoid bone, orbital plate of frontal pone, petrous or squamous portion of temporal bone)
*Temporal Bone Injury
*Signs:
- Battle’s sign: bruising of mastoid bone – posterior auricular artery = branch of carotid a.
- Periorbital Ecchymosis, Raccoon Eye
- CSF rhinorrhea
- Hemotympanum (blood behind tympanic membrane)
Type-1 Muscle Fibers
*What are they used for?
*What type of respiration?
*What color are they?
*Used for a long-term, sustained work
*Aerobic Respiration. Rich in mitochondria, have little energy
*Dark, b/c very rich in mitochondria
Type 2 Fast twitch
*What are they used for?
*What types, how fast to they fatigue?
*What color are they?
*What are they used for?: Rapid, forceful movements for short period of time
*Different types:
- Type 2a: moderately fast, fairly resistant to fatigue, tons of mitochondria
- Type 2x: faster than 2a, fatigue faster than 2a, mid-range mitochondria
- Type 2b: fastest contraction speed, fatigue rapidly, low amount of mitochondria
*What color are they?: lighter
What gives striated appearance to muscles?
*Sarcomeres
*Cardiac Muscle
- Does it have sarcomeres?
- Does it use intracellular Ca2+?
- Does it have syncytial and autonomic activity?
- Does it contain gap junctions?
- Does it have sarcomeres?: Yes
- Does it use intracellular Ca2+? Yes, uses extracellular calcium to trigger intracellular release, extracellular ca2+ flows into T-tubules
- Does it have syncytial and autonomic activity?
- complete syncytial & autonomic activity
- Does it contain gap junctions?: Yes
*Does smooth muscle have striations?
- What is the job of intracellular & extracellular Ca2+
- Does it have autonomics? And syncytial activity?
- Does it contain troponin?
*Smooth muscle does not have striations because no sarcomeres.
- Intracellular Ca2+ needed for contraction,
- Extracellular Ca2+ needed to stimulate 2nd messenger system
*Has full autonomics and syncytial activity
*Does NOT contain troponin
What is rigor mortis?
Rigor Mortis: without ATP myosin head remains bound to actin filaments
What does a smooth muscle contraction use?
- Ca2+?
- What complex?
*Uses two sources of calcium
*Uses calmodulin (calcium binding protein) & myosin light chain kinase
Golgi Tendon Organ
- Where is it located?
- Role?
- Pathway?
*Located in the muscle
*Role: Watch tesnion w/in muscle
- Allows for maximal muscle contraction only for 1 second
*Pathway:
1. Golgi tendon organ will detect tension applied to the tendon
2. Sensory neurons send signal to spine
3. Sensory neurons synapse with inhibitory interneurons
(synapse w/ alpha motor neurons)
4. Alpha motor neuron inhibition leads to muscle relaxation and relief of tension
Muscle Strain
- Tx
Overstretching of muscle
- Tx: NSAIDS &/or muscle relaxants (baclofen, cyclobensaprine)
Muscle Sprain
- Tx Mnemonic
Tearing of a tendon via XS stretching results in muscular sprain
- Tx: RICE: rest, ice, compression, elevation
What causes malignant hypertheria?
Defects in ryanodine receptor, associated w/anesthetics (ex. succinylcholine)
