MSK Injuries Flashcards
MSK injuries fall into what categories?
- Direct (contact) or indirect (non-contact)
- Muscle strain
- Ligamentous sprain
- Fracture
- Contusion/hematoma
Keys to approaching MSK injuries
- Rule out emergency
- Rule out fracture
- Manage conservatively
What is a muscle strain?
- Pulled muscle
- Injury involving the muscle or muscle-tendon unit
Where is a muscle strain mc?
- distal muscle tendon junction injury
- In muscles attached to 2 joints
MOA causing muscle strain
Forceful eccentric loading of the muscle
What is a ligament sprain?
Trauma to the ligaments that connect bones of a joint
Where are the most common ligament sprains?
- Ankle
- Knee
- Wrist during sports activities
MOA of ligament sprain
Joint overextended; ligament overstretched
Ligament sprains are uncommon in children and older adults. Why?
Children and older adults tend to have weaker bones than ligaments, leading to avulsion fractures rather than ligament sprains
Risk factors for strains and sprains
- Poor ergonomics
- Deconditioned or unstretched muscles
- Body habitus
- Environment
- Specific activities
- Fatigue
- Increased age with reduced physical activity
- Overuse
- Previous injury
History in strains and sprains
- Popping, snapping, or tearing sensation at time of event
- Followed by pain, swelling, stiffness
- Difficulty bearing weight/reduced ability to use the extremity involved
- Bruising and discoloration may appear within 24-48 hours
Physical exam findings for both strains and sprains
- Asymmetric swelling
- Tenderness
- Ecchymosis
Physical exam findings for muscle strain
- Visible and/or palpable defect may be seen/felt
- Pain with active and passive flexion of the muscle
- Loss of active muscle contraction to move joint –> complete rupture of the muscle
Physical exam findings with ligament sprain
- Pain with active and passive ROM
- Joint instability/laxity
- More common for higher grade (III) sprains
- Special tests may be beneficial to determine specific ligament
What is a grade 1 muscle strain?
Tear of a few muscle fibers (<10%); fascia intact
What is a grade 2 muscle strain?
- Tear of moderate amount of muscle fibers (10-50%), fascia intact
What is a grade 3 muscle strain?
- Tear of most or all fibers (50-100%), fascia intact
What is a grade 4 muscle strain?
Tear of all muscle fibers (100%), fascia disrupted
What is a grade 1 ligament sprain?
Mild; a tear of only a few fibers of the ligament; no joint instability
What is a grade 2 ligament sprain?
Moderate; partial tear of the ligament; some laxity with stress maneuvers
What is a grade 3 ligament sprain?
- Severe; complete tear of the ligament
- Joint laxity with stress maneuvers
Diagnosis of strains and sprains
- Most often clinical, labs and imaging not necessary
- X-ray utilized if high concern for fracture
- MRI to confirm or grade strains/sprains
Indications for X-ray in suspected strain/sprain
- Positive Ottawa Ankle Rules
- Worsening pain/swelling with appropriate management
- Persistent pain/swelling after 7-10 days of appropriate management
Ottawa ankle rules
Ankle Sprains:
* Pain at medial malleolus or along distal 6 cm of the posterior/medial tibia
* Pain at the lateral malleolus or along the distal 6 cm of the posterior fibula
* Inability to bear weight immediately and for four consecutive steps in the emergency department
Foot sprains:
* Pain in the midfoot and at the base of the fifth metatarsal
* Pain in the midfoot and at the navicular bone
* Inability to bear weight immediately and for four consecutive steps in the emergency department
Indications for MRI for strains and sprains
- Suspected rupture or severe sprain
- Surgical intervention is likely
Healing process of strains and sprains
- Phase 1: hemostasis
- Phase 2: inflammatory phase
- Phase 3: proliferative phase
- Phase 4: maturation phase
Pathophysiology of phase 1 of strains and sprains
- Hemostasis
- Platelets aggregate and release cytokines, chemokines, and hormones
- Vasoconstriction occurs to limit bleeding into affected area causing temporary skin blanching
- Clot formation occurs
Pathophysiology of phase 2 of strains/sprains
- Onset 0-72 hours post injury
- Inflammatory/Destruction phase
- Results from tearing of the myofibers, ligament fibers, and microvasculature
- Bleeding and necrosis of the soft tissue induces an inflammatory cascade
- Homeostasis of fluid balance is disrupted resulting in swelling
- Capillaries dilate and become more permeable –> increase in blood transmission into the extravascular space and increase in the concentration of local inflammatory mediators
Pathophysiology of phase 3 of strains and sprains?
- 72 hrs - 3 weeks
- Proliferative/reparative/fibroblastic phase
- Granulation tissue formed
- Collagen deposition occurs
- Neovascularization at the injury, supporting tissue healing
- Inflammatory mediators are reduced
Pathophysiology of phase 4 of strains and sprains
- 3 wks - 2 yrs
- Maturation/remodeling phase
- Collagen and myofibers increase in number, strength, and organization
Management of hemostasis/inflammatory phase (day 0-3)
- Protection/compression of the injured area and rest
- Control pain and swelling ICE
Management of reparative phase (day 3-week 3)
- Continued protection with pain and swelling control
- Full AROM
- Progressive muscular strength, endurance, and power
Management of maturation phase of strains and sprains (wk 3- 2 years)
- Maintenance of ROM and flexibility
- Increased muscular strength, endurance and power
- Increased speed and agility
What is indicated in inflammatory phase of healing
PRICE
* Protection: padding, slings, braces, ACE wraps, air splint
* Rest: no additional force should be applied; avoid weight bearing
* Ice: ASAP to reduce pain and swelling through vasoconstriction for 15-20 minutes every 2-3 hours for the first 48 hours
* Compression: compression bandages (ACE) to limit swelling
* Elevation: ideally above the heart
* Heat should be avoided during this phase
Contraindications to ice in the inflammatory phase
- Raynaud’s
- PVD
- Impaired sensation
- Cold allergy/hypersensitivity
- Severe cold induced urticaria
Treatment of complete tear of muscle, tendon, or ligament
- Surgical repair
- Refer if joint instability, failure of conservative therapy, neurovascular compromise
What can be used for pain management in strains/sprains?
- NSAIDs first line
- Opioids may be needed based on severity of pain/injury
What should be done following PRICE?
- Weight-bearing
- ROM exercise
- Strength training
- Start low and go slow
- Consider referral to physical therapy
What is overuse syndrome
Umbrella term encompassing diagnosis that results from overuse of a musculoskeletal component
MOA of overuse syndrome
- Repetitive motions, stresses, or sustained exertion of that body part
- Repetitive microtrauma to the muscle or tendon leading to an acute or chronic degenerative state
Who more likely gets overuse syndrome
- Very common with athletes
- Sport may lead to your diagnosis
Extrinsic factors causing overuse syndrome?
- Repetitive mechanical load
- Increased duration, frequency, intensity, technique errors
- Equipment problems: poor footwear, racquet size, running surface
What anatomic factors can cause overuse syndrome?
- Malalignment
- Inflexibility
- Muscle weakness
- Muscle imbalance
- Decreased vascularity
Age-related factors causing overuse syndrome
- Tendon degeneration
- Decreased healing response
- Increased tendon stiffness
Systemic factors causing overuse syndrome
- Inflammatory disorders
- Quinolone-induced tendinopathy
Presentation of overuse syndrome
- Pain
- Muscle fatigue
- Numbness
- Swelling
- Symptoms tend to develop and slowly progress over time
- Pain may be localized to the tendinous insertion and exacerbated by muscle stretch or contraction
Work up of overuse syndrome
- Thorough and complete H&P considering aggravating/alleviating factors, repetitive activities, work environments
- PE: muscle testing, ROM, and special testing if indicated
- Radiograph: calcification or spur formation of tendon at insertion site
- Bone scans and MRIs: stress fractures, osseous pathology
- NCS/EMGs: if neurologic s/s
Management of overuse syndrome
- Most are mild and will resolve spontaneously
- Avoidance of the activity that led to syndrome
- Patient education
- Pain management –> ice/heat, NSAIDs, corticosteroid injections
- PT: home exercise programs
- OT: workplace modifications
- Referral to ortho if conservative tx fails
What is the periosteum
- Thick outer layer
- Contains vessels, nerve endings and cells that repair fractures
What is the endosteum
- Inner lining of the marrow cavity
What is the epiphysis?
- Contains epiphyseal plate (growth plate/physis)
- Very vascular and prone to infection and fractures
- Present on child at end of growth plate and not on adult
What is metaphysis
- Spongy, cancellous bone
- Most susceptible to compression fractures
What is diaphysis
- Thick cortical bone
- Provides most of the structural support of the long b one
What is a fracture
Disruption in the continuity or structural integrity of a bone
MOA of fractures
- Stress applied to the bone greater than the bone’s intrinsic strength
- Can also occur pathologically
- All bones can fracture but extremities at highest risk
History in fractures
- Often hx of trauma
- Pain worsened by movement
- Localized tenderness
- +/- deformity
- +/- numbness/tingling
Physical exam in fractures
- Always inspect bones/joint above and below injury
Inspection - Edema, ecchymosis
- Deformity
- Skin integrity
Palpation
* Tenderness, crepitus
* Evaluate joint stability
* Assess NV status
Imaging for fractures
- First line: radiograph
- CT or MRI –> indicated if diagnosis needs confirmed or to further define a complex fracture prior to surgical repair
Components of describing a fracture
- Open vs closed
- Location
- Orientation/direction: communuted vs segmented, compression vs impaction
- Displacement: degree of angulation and direction
Gustilo and Anderson classification grade I
- Low energy injury with an open wound <1 cm in legnth and no evidence of contamination
Gustilo and Anderson classification grade II
- Moderate injury with comminution of the fracture and a 1- to 10 cm wound with some contamination
Gustilo and Anderson classification grade IIIA
High-energy fracture apttern with a wound >10 cm and gross contamination
Gustilo and Anderson classification grade IIIB
High energy fracture with a >10 cm contaminated wound with exposed bone
Grade IIIC gustilo and anderson classification
Similar to grade IIIB with vascular involvement
Fracture location description
- Diaphysis/shaft: location on bone shaft
- Distal or proximal metaphysis (end of adult bone or neck of child)
- Epiphysis/growth plate
- Anatomical name of the bone
Transverse fracture
Fracture perpendicular to the shaft of the bone
Oblique fracture
Angulated fracture line
Spiral fracture
Multiplanar and complex fracture line
Comminuted fracture
Fracture in which there are more than two fracture fragments
Segmental comminuted fracture
Type of comminuted fracture in which there are 2 fracture lines isolating a segment of bone
Avulsed fracture
A detached bone fragment that results from the excessive pulling of a ligament, tendon, or joint capsule from its point of attachment on a bone
Compression fracture
Common with osteoporosis type of impaction that occurs in the vertebrae
Intra-articular fracture
Crosses the articular cartilage and enters the joint
Non-displaced
Fragments are in anatomic alignment
Displaced
Fracture is no longer in anatomic alignment
How is severity of displaced fracture annotated?
in mm or % with regard to the direction the distal fragment is offset in relation to the proximal fragment
Angulated fracture displacement
- Bone fragments are misaligned
- Described as the degree and direction of deviation of the distal fragment
- Could be medial, ventral, lateral, dorsal
Bayoneted fracture displacement
Distal fragment longitudinally overlaps the proximal fragment
Distracted fracture displacement
Distal fragment is separated from the proximal fragment by a gap described by mm/cm
Rotational deformity displacement
- Degree the distal fragment is twisted on axis of normal bone
- Usually detected by physical exam
Make sure to look at the practice displacement questions to ensure you understand!
Okay fine!
What is a torus (buckle) fracture?
- Incomplete fracture along distal metaphysis where bone is most spongy
- MC in distal radius
- May be very subtle –> important to look at multiple views on x-ray
- Common in pediatrics
What is a greenstick fracture?
- Common in pediatrics
- Fracture that doesn’t extend through the entire periosteum
- Occurs in pediatric population due to soft bone
- Fracture on the tension side and buckle on the other side of the shaft of a long bone
Salter-Harris classification
- Used to describe fractures involving growth plate
When does growth plate closure usually occur?
- Depends on specific bone and age of patient
- Females average 12-14
- Males 14-16
Go back and look over Salter Harris classification!
Got it!
What can assist in detecting fractures in skeletally immature children?
Comparison of unaffected side
lack of ossification of epiphyses in young children can make fracture identification difficult
Salter harris classification mneumonic
- S: slipped (type I) - some people say straight across, through growth plate
- A: above (type II), does not affect joint, through growth plate and metaphysis
- L: lower (type III), affects the joint, through growth plate and epiphysis
- TE: through everything (type IV), through all three elements
- R: rammed (type V), crush injury of growth plate
What are the 3 phases of fracture healing?
- Stage 1: Inflammatory phase
- Stage 2: reparative phase
- Stage 3: remodeling phase
What are characteristics of the inflammatory phase of fracture healing?
- Immediately bleeding from the fracture site and surrounding tissue occurs
- Peaks after several days, bioactive cells migrate to fracture site hematoma leading to formation of granulation tissue
What are characteristics of reparative phase of fracture healing?
- Neovascularization promotes the healing process
- Necrotic debris is removed by phagocytes and fibroblasts begin to produce collagen
- Soft callus produced first
- Then mineralization begins to slowly convert woven/immature bone
What are characteristics of the remodeling phase of fracture healing?
- Overlaps with repair phase and can continue for several months
- Woven (immature) bone is replaced with more mature lamellar bone
- Typically around 6-10 weeks
Indications for immediate orthopedic consultation with fracture?
- Open fracture
- Displaced fracture
- Unstable fracture
- Irreducible fracture
- Fractures complicated by compartment syndrome
- Nerve or vascular injury in fracture
What guides closed fracture management?
- Bone involved
- Type of fracture
- Degree of displacement
- Open vs. Closed
What is management of axial fracture?
Bed rest and non-weight bearing
Hip, pelvis, spine
Management of closed extremity fracture
- Reduction if displaced or angulated
- Moderate-severe displacement/angulation requires surgical intervention with ORIF (open reduction and internal fixation with plates, screws, pins or intramedullar devices)
- Immobilization: splints, casting, slings
- Bed rest
- Elevation
- Avoidance of weight bearing
- Further evaluation by a specialist
Open fracture management
- Orthopedic emergency!! High risk of osteomyelitis, compartment syndrome, and neurovascular injury
- Require irrigation/debridement followed by sterile dressing
- NPO
- Pain medication
- Broad spectrum IV antibiotics
- Update Td if applicable
Type I and II open fracture IV antibiotics
- 1st generation cephalosporin: cefazolin
- If at risk for anaerobic infection, add metronidazole
Type III open fracture IV antibiotics
- 1st generation cephalosporin (cefazolin)
- +aminoglycoside (gentamicin)
- If at risk for anaerobic infection (ie farm injury or necrosis) add metronidazole
Factors that worsen prognosis of fractures
- Skeletal maturity
- Fractures of multiple bones in the extremity
- Intra-articular fractures
- Marked displacement of fractures
- Unstable vertebral factures
- Comminuted, oblique, and segmental fractures
Adverse outcomes from fractures
- Malunion
- Nonunion
- Stiffness, muscle atrophy: early PT can prevent
- Arthritis: associated with intra-articular fx
- Vascular or nerve injury
- Compartment syndrome
- Osteonecrosis
Malunion
- Inadequate alignment of fracture
- Results from inappropriate reduction, immobilization, or surgical error in alignment
Treatment of malunion
Osteotomy or bone cuts to restore anatomical alignment
Nonunion diagnostic criteria
- Lack of healing within 6 months of a injury
- No healing progress in 3 consecutive months
Factors that affects nonunion healing
- Smoking
- Indolent infection
- Inadequate immobilization
- Malnutrition
- NSAID use significant
- Soft tissue injury
Treatment options for nonunion fractures
- Surgical fixation
- Bone graft
- Electrical/US stimulation
What is a stress fracture?
Fracture in normal bone that has been subjected to repeated or continuous loads that in and of themselves are not sufficient to cause a fracture
Causes of stress fracture
- Small number of repetitions with a relatively large load
- Large number of repetitions with a usual load
- Common in athletes, especially runners
Risk factors for stress fracture
- Prior stress fracture
- Low level of fitness
- Increasing volume and intensity of physical activity
- Female gender, especially when combined with menstrual irregularity (+eating disorder = triad)
- Eating disorders (female athlete triad)
- Diets poor in calcium and vitamin D
- Poor bone health
- Poor biomechanics
History with stress fracture
- Gradual onset, localized pain
- Worse with significant activity initially
- Less activity can produce pain as fracture progresses
- Look at risk factors
Physical exam with stress fracture
Localized tenderness over injury site
Imaging in stress fracture
- If doubting diagnosis
- Plain radiographs should be obtained initially due to high specificity, may not appear on radiographs for weeks
- If suspicion high and diagnosis needs confirmed, MRI, CT, or bone scan
Management of stress fracture
- Based on fracture site
- Conservative management for low-risk fractures
- Surgery for high-risk fractures
What locations are considered low-risk fractures?
- Fx of 2nd-4th metatarsal shafts
- Posteromedial tibial shaft
- Fibula
- Proximal humerus or humeral shaft
- Ribs, sacrum, and pubic rami
Conservative therapy for stress fracture
- Acute pain control
- Reduced weight bearing or splinting
- Reduction or modification of activities
- Rehabilitative exercise to promote optimal biomechanics
- Reduce risk factors
High-risk stress fracture locations
- Pars interarticularis of lumbar spine
- Femoral head and neck
- Patella
- Anterior cortex of tibia
- Medial malleolus
- Talus, tarsal navicular
- Proximal 5th metatarsal shaft, great toes sesamoids, base of second metatarsal bone
When should referral to orthopedist for stress fracture be done immediately?
- High risk fractures
- Lengthy rehab program inappropriate
- Conservative treatment fails
Goals of splinting
- Reduce pain, bleeding, and swelling of injury site and surrounding areas
- Immobilize the injury
- Prevent further damage of the muscles, nerves and blood supply
- Prevent further laceration of the skin and contamination of an open wound
Indications for splinting
- Fractures
- Dislocations
- Severe sprains
Splinting instructions
- Remove clothing to fully inspect area
- Check NV status distal to injury before and after splint
- Clean all wounds and cover with dry, sterile dressing
- Immobilize above and below fracture bone
- Intra-articular fx immobilize above and below joint fracture
- Pad all rigid splints to prevent local injury
- While applying splint, minimize movement of the limb and support injury site until splint has set
- Attempt to reduce any severely deformed limb with constant gentle traction
- If resistance is encountered, splint in position of deformity
Splinting types
- Prefabricated plastic splints
- Air splints
- Fabric splints
- Metal splints
- Plaster and fiberglass splints
What is splint of choice when expected to remain in place for more than a few hours?
Plaster and fiberglass splints
Splinting materials
- Cast padding and stockinette
- Prefabricated plaster or fiberglass splints
- Rolls of plaster or fiberglass splinting material
- Elastic bandage
- Water
- Non-sterile gloves
Optimal timing for cast placement
- After swelling has resolved, 5-7 days after unless fracture is unstable
- Splints useful in meantime
Standard for closed, nondisplaced/reduced fractures
Casting
Materials needed for casting
- Stockinette
- Cast padding
- Fiberglass or plaster casting “tape”
Casting PEARLS
- Application similar to splinting
- Always note neurovascular status
- Follow up x-rays help document continued bone healing and union
- Important to tell patients to keep both splints and casts dry
- Patient’s must return to have cast removed
