Lecture 2: MSK Injuries Flashcards
What is a muscle strain?
- injury of muscle or muscle-tendon, usually distally
- MC in muscles with 2 joints
- MOA: Forceful eccentric loading
Eccentric = lengthening muscle while under load. (lowering coffee cup to a desk = eccentric loading of bicep)
What is a ligament sprain, MC locations, and MOI? (4)
- Trauma to ligaments that connect bones
- MC: ankle, knee, wrist
- MOI: Overextension of joint
- NOT COMMON IN CHILDREN OR OLDER ADULTS
Ligaments Link
How do strains/sprains usually present at time of injury?
- Popping, snapping, tearing sensation
- Pain, swelling, stiffness, difficulty bearing weight
- 24h-48h later: bruising/discoloration
Assessing what helps us determine the structures involved in a strain/sprain?
- SYMMETRY!! will see asymmetric swelling, tenderness and ecchymosis of injured area
- also point of maximal tenderness
How does a muscle strain present on PE?
- Visible/palpable defect maybe visible
- Pain with active and passive flexion
- If no contraction, complete rupture.
How does a ligament sprain present on PE?
- Pain with active and passive ROM
- Joint instability/laxity, esp in grade 3
- Special tests can be used, i.e. anterior drawer
How are muscle strains graded? (4)
- Grade 1: Tear of a few fibers < 10%, fascia intact
- Grade 2: Tear of more fibers < 50%, fascia intact
- Grade 3: Tear of most or all fibers, fascia intact
- Grade 4: Full tear, fascia disrupted
10, 50, 100, 100 + Fascia
How do you grade ligament sprains?
- Grade 1: Mild, few fibers torn, no instability.
- Grade 2: Moderate, partial tear, some laxity
- Grade 3: Severe, complete ligament tear, laxity
When is XR used for strain/sprain evaluation? (4)
- High concern for possible fracture
- Positive Ottawa ankle rules
- Worsening pain/swelling with appropriate management
- Persistent pain/swelling after 7-10d of appropriate management
What are the ottawa ankle rules for ankle sprains? (3)
- Pain at medial malleolus or along distal 6cm of posterior/medial tibia
- Pain at lateral malleolus or along distal 6cm of posterior fibula
- Inability to bear weight immediately and for four consecutive steps in the ED
What are the ottawa ankle rules for foot sprains? (3)
- Pain in midfoot + base of 5th metatarsal (pinky)
- Pain in midfoot + navicular bone
- Inability to bear weight immediately and for four consecutive steps in the ED
When is MRI utilized for strains/sprains?
- Confirming grade
- Indicated if suspected rupture or severe sprain
- Indicated if surgery is likely
What are the 4 phases of healing?
- Hemostasis
- Inflammatory
- Proliferative
- Maturation
What occurs on the skin during hemostasis in a strain/sprain? (1)
Management during this phase? (2)
- Platelets aggregate & release cytokines, chemokines, hormones. Vasoconstriction occurs to limit bleeding. This causes temporary skin blanching
- TX: Protection/compression of injured area
- Treat pain and swelling with ice
Immediately after injury
How does the inflammatory phase present for a strain/sprain? (2)
Management? (2)
- 0-72h post injury
- bleeding/necrosisinduces inflammatory cascade. swelling occurs. capillaries dilate and become more permeable which releases blood into the extravascular space (bruising).
- Protect/compress area
- Control pain and swelling via ice
How does the proliferative phase present in sprains/strains? (3)
Management? (2)
- 72h-3wks
- granulation tissue formed and Collagen deposition occurs. Neovascularization occurs at injury and inflamm mediators reduce
- Continue to protect area with pain and swelling control
- Full Assisted ROMs
How does the maturation phase present in strains/sprains? (2) Management? (2)
- 3wks - 2 years
- Collagen and myofibers increase in number/strength/organization
- Maintain ROM and flexibility
- Increase strength/endurance/power/speed/agility
What is PRICE?
- Protection (Padding, slings, braces, ACE, etc)
- Rest (Avoid weight bearing)
- Ice (ASAP, also avoid heat))
- Compression (ACE)
- Elevation (above heart)
Ice 15-20 minutes q2-3h for 48h. Avoid heat for 2-3d.
When is Ice contraindicated in strain/sprain management?
- Raynauds
- PVD
- Impaired sensation
- Cold allergy/HSR
- Severe cold induced urticaria
When is surgical repair indicated for strain/sprain?
- Complete tear
- Refer if unstable joint or failed therapy or neurovascular compromise
First line therapy for pain management in strains/sprains?
NSAIDs
What are the extrinsic and intrinsic factors for overuse syndrome?
- Extrinsic: Repetitive mechnical load or equipment problems
- Intrinsic: Anatomic weakness/imbalance, age, systemic
What medication class is known for tendinopathy?
Quinolones
Tendon rupture
How does overuse syndrome present? (3)
- Pain, fatigue, numbess, swelling
- Callous formation at tendinous insertion
- Exacerbated by stretching or contracting
When would radiograph be used for overuse syndrome?
- R/o fx
- Calfication or spur formation of tendon at insertion site
Management of overuse syndrome
- Resolves spontaneously if mild
- Avoid activity that led to it in the first place
- Pain management: ice/heat, NSAIDs, corticosteroid injections (ortho)
- PT/OT
What is the periosteum?
- Thick outer layer
- Containing vessels, nerve endings, repair cells
Pain comes from here. Painful periosteum
What is the endosteum?
Inner lining of marrow cavity
Which bone location is most susceptible to infection/fx?
Epiphysis, which has the growth plate and is found at the end of a bone in children
Which bone location is most susceptible to compression factures?
Metaphysis
What part of the bone is the main structural support?
Diaphysis
Define a fracture.
Disruption in continuity or structural integrity of a bone.
Hairline = fracture
What bones are most susceptible to fx?
Extremities
When is CT/MRI indicated for fx?
- Need to confirm Fx
- Further define complex fx prior to surgical repair
4 components of describing a fx
- Open vs closed
- Location
- Orientation/direction
- Displacement
How do you classify open vs closed fx?
- Grade 1: low energy with open wound < 1cm and no contamination
- Grade 2: moderate, comminution, 1-10cm wound with some contamination
- Grade 3A: high energy, > 10cm, gross contamination
- Grade 3B: 3A + exposed bone
- Grade 3C: 3B + vascular involvement
Gustilo and Anderson Classification
Assess need for ID and ortho
3B = see Bone
Describe this fracture location
Mid-shaft diaphyseal fx of the right tibia
Child
Describe this fracture location
- Distal diaphysis of the left radius
- Distal metaphysis of the left ulna
Two fractures.
Describe this fracture location
- Medial aspect of the distal tibial metaphysis
- Distal 1/3 of the fibular diaphysis
Two fractures
What are the types of orientation/direction for a fx? (6)
- Transverse/simple: perpendicular to shaft
- Oblique: angulated
- Spiral: multiplanar and complex
- Comminuted: 2+ fracture fragments
- Segmental: subtype of comminuted when it isolates a segment of bone
- Avulsed: Detached bone fx d/t excessive pulling of ligament, tendon, or joint capsule from attachment point.
Spiral fx may suggest child abuse
What condition is compression fx MC with?
Osteoporosis
What is an intra-articular fx?
Crossing articular cartilage into joint
Describe this fx location + orientation
Transverse fx of mid-shaft diaphysis of the humerus
Describe this fx location and orientation
Spiral fx of the mid-shaft diaphysis of the femur
Describe this fx location and orientation
Oblique fx of the diaphysis of the proximal phalanx of the 2nd digit
Describe this fx location and orientation
Compression fx of the 2nd lumbar vertebrae
Describe this fx location and orientation
Segmental fracture of the tibial diaphysis
Also a fibular fx
What does it mean when a fracture is displaced?
No longer in anatomic alignment.
We discuss in reference to the distal displaced fragment
Describe how an angulated or displaced fx is described
Degree and direction of deviation of the DISTAL fragment.
You can have angulation w/o displacement and vice versa
What is a bayoneted/shortened fx?
Distal fragment longitudinally overlaps proximal by mm/cm
What is a distracted fx?
Distal fragment is separated from proximal fragment by a gap in mm/cm
How is rotational deformity usually detected?
Upon PE
Describe the displacement of this fx
100% lateral displacement with 30deg medial angulation
Describe the displacement of this fx
25% ventral displacement without angulation
Describe this fx’s location, displacement, and orientation
- Transverse fx of the mid-shaft diaphysis of the femur.
- 100% medial displacement with shortening.
- No angulation
Describe this fx’s location, displacement, and orientation
- Oblique fx of distal 1/3 of diaphysis of radius
- 100% lateral displacement with shortening and 30deg of ventral/volar angulation
Describe this fx’s location, displacement, and orientation
- Comminuted tibial fx at the mid-diaphysis with 100% medial displacement without angulation.
- Oblique fibular fx at the mid-diaphysis with 100% medial displacement and 10deg of medial angulation
Features of a torus/buckle facture (3)
- Incomplete fx along distal metaphysis
- MC in distal radius
- May require multiple XRAY views due to how subtle it is
Metaphysis more spongy. MC in Children
Features of a greenstick fracture
- Fx with incomplete extension through periosteum
- MC in children
- Fracture on tension side and a buckle on other side of the shaft of a long bone.
What is salter-harris classification?
Describe fx involving the growth plates
Best done by comparing unaffected side
When do growth plates close?
- Females: 12-14
- Males: 14-16
Salter-harris mnemonic
- S (slipped type 1): Straight across
- A: (above type 2): Does not affect joint
- L (Lower type 3): Affects the joint
- TE (Through everything type 4)
- R (Rammed Type 5)
Salter-harris classification
Type 1
Slipped/straight across
Salter harris classification
Type 4
Through everything
Salter Harris classification
Type 3
Lower
Salter Harris classification
Type 2
Above
Salter Harris Classification
Type 5
Rammed
In the inflammatory phase of fx healing, when is it at its peak and what is happening?
Stage 1
Peaks after several days, forming granulation tissue at hematoma site.
What occurs in the reparative phase of fx healing? (4)
Stage 2
- Neovascularization
- Collagen production and debris cleanup
- Soft callus production
- Mineralization of soft callus into hard callus/immature bone
What occurs in the remodeling phase of fx healing? (2)
Stage 3
- Immature bone replace with mature, lamellar bone
- Occurs around weeks 6-10, overlapping with repair
Bone does not scar due to continuous remodeling. Only tissue that works like this.
When is emergent referral to ortho indicated for fx?
- Open
- Displaced
- Unstable
- Irreducible fx
- Compartment syndrome
- Vascular injury
What 4 factors guide closed fx management?
- Bone involved
- Type of fx
- Degree of displacement
- Open vs closed
Management of a closed axial fx (2)
- Bed rest
- Non-weight bearing
Hip, pelvis, spine
Management of closed extremity fx (6)
- Reduction of displacement or angulation
- Open reduction internal fixation (ORIF) if surgical needed
- Immobilization
- Bed rest
- Elevation
- Avoidance of weight-bearing
Management of open fracture (6)
- Emergent Ortho referral
- Risk of osteomyelitis, compartment syndrome, and/or NV injury
- Irrigation/debridement
- Sterile dressing
- NPO
- Pain meds
What empiric ABX is used for open fx grade 1 and 2?
Gustilo anderson classification
Cefazoline/Ancef 1g q6-12h
If risk of anaerobic, add metronidazole (farm injury, necrosis)
What empiric abx is used for a type 3 open fx?
Gustilo anderson classification
Cefazolin + gentamicin (aminoglycoside)
Add metro if risk of anaerobe
Type 3 = high energy damage pattern
What are the bad prognostic factors for a fx? (6)
- Skeletal maturity (older ppl cant remodel as well)
- Fx of multiple bones
- Intra-articular fx
- Marked displacement
- Unstable vertebral
- Comminuted, oblique, or segmental
What is a malunion and how is it treated?
- Inadequate alignment when healing a fx
- Requires osteotomy or bone cuts to restore alignment
What is considered nonuion and what is the tx? (3)
- Lack of healing within 6 months of an injury
- No healing progress within 3 consecutive months.
- Tx: surgical fixation, bone graft, electrical/US stimulation
What factors might result in nonunion of a fx? (6)
- Smoking
- Indolent infection
- Inadequate immobilization
- Malnutrition
- Excessive NSAID use
- Soft tissue injury
In what kind of fx is arthritis MC?
Intra-articular fx
Who is a stress fx MC in?
Runners
How do stress fractures present? (4)
- Little activity produces pain
- Localized tenderness over injury site
- Gradual onset
- No improvement with conservative therapy
Why is a stress fx hard to image?
- Tiny, so does not always show up on XRAY for weeks.
- CT/MRI is best if you have a high suspicion and need to confirm dx from XR
What are low-risk stress fx locations and management?
- 2nd-4th metatarsal shafts
- Posteromedial tibial shaft
- Fibula
- Proximal humerus or shaft
- Ribs, sacrum, pubic rami
- Conservative management
Where is a high risk stress fracture and management?
- Pars interarticularis of lumbar
- Femoral head or neck
- Patella
- Anterior cortex of tibia
- Medial malleolus
- Talus, tarsal or navicular
- Prox 5th metatarsal shaft, great toes sesamoids, base of 2nd metatarsal bone
- Surgery
Most of those are heavy weight bearing or used continuously
Indications for splinting
- Fx
- Dislocation
- Severe sprain
Prior to splinting, what should you assess? (2)
- Physical inspection of site
- Check sensation and pulses
When are plaster and fiberglass splints used?
Splint that must remain in place for more than a few hours.
When is casting indicated? (3)
- Closed
- Nondisplaced
- Reduced
Fx
When is a cast placed?
- After swelling resolves
- Probably 5-7 days post injury for a stable fx
Patient education pearls for casting
- Keep dry
- Return to have cast removed
