Lecture 3: Misc MSK Injuries Flashcards
Essentials of diagnosis of Osteomyelitis
- Fever with bone pain and tenderness
- positive blood cultures
- Elevated ESR/CRP
- Early radiographs are typically negative, esp within 2 weeks
Trending ESR and CRP is much better than WBC due to chronicity
What are the causes of osteomyelitis?
- Hematogenous spread
- Contiguous spread
- Secondary infection d/t vascular insufficiency or neuropathy
Who is hematogenous osteomyelitis MC in? Where exactly?
Children, esp males, in their metaphysis in long bones
MC primary site of hematogenous osteomyelitis?
Urinary tract, skin/soft tissue, IV sites, endocardium, dentition
Staph
where is hematogenous spread MC in adults
vertebral column LS>TS>CS
Biggest RFs for hematogenous osteomyelitis in adults
- IVDU
- Diabetes
- IVs
in children - sickle cell, comp delivery, maternal infections, premature
Who is contiguous spread osteomyelitis MC in and how?
Adults, usually post fracture/open wound (diabetic ulcers)
Most commonly polymicrobial
How does osteomyelitis present?(4)
- Gradual onset of S/S
- Dull pain at site, fever and rigors
- Tenderness, warmth, erythema, swelling on exam
- Probing for bone is recommended if ulcer is present
How does vertebral involvement of osteomyelitis present?(4)
- Much slower onset
- Localized pain/tenderness
- Pain with percussion over affected area
- Neurologic symptoms in 1/3 of pts
Dx of osteomyelitis
- Early XR: maybe swelling, loss of tissue planes, periarticular demineralization of bones
- Later XR: Periosteal thickening or elevation, bone cortex irregularity
- Ideal: CT or MRI, which is highly sensitive
Children: 5-7d for changes
Adults: 10-14d for changes
When is CT/MRI indicated for osteomyelitis evaluation?
- Onset < 2 weeks at presentation
- XR neg but clinical presentation is suspicious
- positive neuro findings on exam
MRI is especially good for feet
Nuclear is alternative.
Who is bone biopsy indicated in for osteomyelitis?
Any patient with radiologic evidence without + blood cultures.
Do not delay biopsy due to abx use.
What would histology show for a positive bone biopsy for osteomyelitis?
Necrotic bone with extensive resorption adjacent to an inflammatory exudate
Must collect through an uninfected site if percutaneous.
Empiric ABX for osteomyelitis
MRSA and G- coverage: Vanco +3/4th gen cephalosporin
Typically only used in long-bone infections
ceftriaxone, ceftaz, cefepime
How long is staph osteomyelitis? what is the abx regimen used for this strain?
4 weeks
- IV cefazolin, nafcillin or oxacillin
- MRSA = vanc
If you want to transition a pt to PO abx for osteomyelitis, what is the combo?
After 2 weeks of IV agents at minimum, you can use Levofloxacin/ciprofloxacin + rifampin
can also use bactrim, doxy, or clinda
When is debridement indicated for osteomyelitis?
- Infection related to open fx or surgical hardware
- Extensive diseas involving multiple bony/ soft tissue layers
- Concomitant joint infection
- Recurrent/persistent infection
Persistent elevation of what labs over 2 weeks with appropriate ABX is suggestive of a persistent osteomyelitis infection?
ESR/CRP
What are the complications of osteomyelitis?
- Pathological fx
- Chronic
- Impaired bone growth
What is chronic osteomyelitis?
Bone infection over months-years resulting in the development of a sequestrum +/- sinus tract
what bone changes occur in chronic osteomyelitis
- increased intramedullary pressure causes rupture of periosteum and formation of cloaca (sinus tract)
- periosteal blood supply interruptions lead to necrosis
- necrotic bone leads to sequestrum
- new bone forms in areas where periosteum was damaged (involucrum)
What is involucrum?
Bone formation in areas where the periosteum was damaged
Where is chronic osteomyelitis MC in?
- Sternal
- Mandibular
- Feet
How does chronic osteomyelitis present?
- Pain, erythema, swelling
- +/- draining sinus tract
- fever usually not present
- bone palpation is positive
How do labs differ between chronic vs acute osteomyelitis?
Leukocytosis and ESR/CRP are rarely elevated in chronic.
What is a marjolin ulcer?
Epithelium of the sinus tract develops squamous cell carcinoma
Management of chronic osteomyelitis
- Debridement
- Obliteration of dead space
- Long-term ABX therapy
What is compartment syndrome?
Increased pressure within a limited space compromises the circulation and function of the muscles and nerves within that space
What are the 4 compartments of the lower leg?
- Anterior
- Lateral
- Superficial posterior
- Deep posterior
MC location for compartment is lower leg
What is normal compartment pressure and how long can we tolerate increased pressure?
- 10mm is normal, but we can tolerate up to 20 without damage.
- After around 8h, we start developing neuropathy.
- After around 12h, myocytes die and we develop contractures
Clinical presentation of compartment syndrome?
- Pain out of proportion
- Pain that worsens with passive stretching
- Paresthesias within 30min onset
- Tense to palpation
- Decreased sensation (use 2 point)
- Weak pulse in severe
Paralysis is late and pallor is rare
How do you measure compartment pressure?
- Two separate measurements within 5 cm of the site
- Pressures must be > 45 mm/Hg
- Must account for hypotensive patients, aka if DBP is within 30 of their compartment pressure. (DBP of 52 with pressure of 28 = compartment syndrome)
DO NOT USE in hands or feet
Management of compartment syndrome?
- Remove casts/dressings
- Elevate affected limb
- Surgical fasciotomy if patient has had it within 24h-48h
Essentials of rhabdomyolysis
- Crush injuries
- Serum elevations in CK and lyte abnormalities
- Release of myoglobin leads to renal toxicity
What is rhabdomyolysis?
- Acute skeletal muscle cell death leading to release of intracellular contents
- ATN will occur, leading to AKI
What causes ATN due to rhabdo?
Hypovolemia + myoglobin + uric acid crystals + decreased GFR + nephrotoxic ferrihemate (metabolite of myoglobin)
Clinical presentation of rhabdomyolysis
- Dark tea colored urine
- Myalgias and weakness
- Malaise, low-grade fever
- N/V, abd pain, and tachy if severe
Similar to a flu patient
swelling/tender of involved muscles. AMS d/t severe renal failure and urea-induced encephalopathy if severe!
Dx of rhabdo
- Elevated CK 5x ULN(Most sensitive)
- UA showing tea color when urine myoglobin is > 100
- A + blood on UA with negative RBC on microscopy = myoglobinuria
- CMP: Elevated phosphorus, uric acid, BUN/Cr, AST/ALT, K+. low calcium.
- CBC to monitor potential DIC
A UA cant differentiate blood and myoglobin
can see cardiac dysrhythmias on EKG d/t hyperkalemia or hypocalcemia
Management of Rhabdo
- IVF aggressively for first 72h early
- Monitor I&O to get goal of 200-300 urine output
- Urine alkalization via bicarb only if CK levels are higher than 5000, acidemia, dehydration or underlying renal disease
When would you treat hypocalcemia in rhabo?
Only if hyperkalemia is present
Discharge criteria for rhabdo
- Normal renal
- Normal lytes
- Alkaline urine
- Isolated cause of injury
- No uncontrolled comorbidities
Main complications of rhabdo
- AKI
- Compartment syndrome
- DIC
What is fibromyalgia?
Chronic condition characterized by multiple MSK pain with multiple tender points but no objective findings
MC demographic for fibromyalgia
20-55
Presentation of Fibromyalgia
- Chronic fatigue and generalized aching pain
- Depression
- Widespread soft tissue tenderness
- No joint involvement
How is fibromyalgia diagnosed?
ACR criteria:
- Widespread pain index (WPI) > 7 + symptom severity (SS) > 5 or WPI 3-6 with SS > 9
- 3months
- No other disorder
Dx of exclusion
Management of fibromyalgia
- Patient education
- CBT
- Exercise
- Wt loss if overweight
- Muscle relaxant: flexeril
- Antidepressants
- Neurontin/pregabalin
- Tramadol
Careful of tramadol addiction
Treatment protocol for fibromyalgia
**On average: start with cyclobenazeprine and amitriptyline QHS
What is neurogenic arthropathy/charcot joint?
Condition characterized by progressive destruction of bone and soft issues at weight bearing joints
What is the hallmark sign of neurogenic arthropathy?
Mid-foot collapse, described as a rocker-bottom foot
MC etiologies for neurogenic arthropathy
- DM (MC)
- Cerebral palsy
- Alcoholic neuropathy
- Spinal cord injury
- Syphilis
Where does neurogenic arthropathy occur most commonly?
- Foot
- Ankle
- Tarsometatarsal joint
- Ankle articulations
articulations are cuneonavicular, talonavicular and calcaneocuboid articulations
Presentation of neurogenic arthropathy
- Unilateral warmth, redness, and edema oer joint
- Hx of minor trauma
- Pain is present but low severity
- Loss of arch, bony protrusions
- 40% have concomitant ulcers
Dx imaging of neurogenic arthropathy
- XR with weight-bearing
- MRI if XR negative OR osteomyelitis is in DDx
What 3 things are key to look at for an XR for neurogenic arthropathy?
- Progressive decline of the yellow angle (calcaneal inclination)
- Equinus deformity (can’t dorsiflex)
- Destruction of TMT joint (red line)
Staging of neurogenic arthropathy
- Stage 0: early/inflammatory - localized swelling, erythema, warmth. little/no xray findings
- Stage 1: cont localized inflamm. Xray - fx, subluxation/dislocation, bony debris.
- Stage 2: coalescence with decreasing inflammation and healing of XR findings
- Stage 3: Remodeling with no inflammation, bony deformities, and mature fracture callus.
Tx for stage 0-2 neurogenic arthropathy
- Avoid weight-bearing via casting of foot
- CROW (charcot restraint orthotic walker) use
Tx for stage 3 or failed therapy neurogenic arthropathy
Discuss risk/benefit of surgery
What is Raynaud’s phenomenon?
- Syndrome of paroxysmal digital ischemia in cold or emotional stress.
- Vasoconstriction and then rapid vasodilation
MC in the fingers
What is primary Raynaud’s?
- NO vascular structural abnormalities
- MC in healthy females 15-30
- FMHx
MC type
What is secondary Raynaud’s?
- Underyling systemic condition leads to Raynaud’s
- MC in males > 40
- MC with rheumatologic conditions
- Frostbite, jackhammers
- More severe and higher risk of ulceration/gangrene
What are raynaud attacks?
- Sudden onset of cold digits with demaracation of skin pallor (white attack) or cyanosis (blue attack)
- Massive erythema when rewarming
- MC in the index, middle, and ring fingers
What do nailfold capillaries look like in raynaud’s?
Management of primary raynaud’s
Normal PE and nailfold capillaries
- Pt Ed
- Regular f/u
Management of secondary raynaud’s
Tx underlying
What is the patient education for Raynaud’s?
- Mittens and stockings
- Avoid vasoconstrictors
- Smoking cessation
First-line pharmacologic therapy for Raynaud’s
- CCBs (amlodipine)
- NTG or PDE5 inhibitors
Indicated if failure to control symptoms
If all fails, refer to vascular
What is Marfan’s syndrome?
Genetic disorder of CT tissue characterized by skeletal, ocular, and CV abnormalities
1 in 5000
Presentation of Marfan’s
- Tall, long arms, and digits (arachnodactylyl)
- Scoliosis
- Pectus Carinatum/excavatum
- Ecotopia lentis (eye lens displacement)
- Myopia (Near sighted)
- Retinal detachment
- MVP
- Aortic root dilation => aortic regurg or dissection
How is marfan’s confirmed?
Genetic testing showing a mutation in the fibrillin gene (FBN1) on chromosome 15
What criteria is used to score marfan syndrome?
Ghent criteria
No need to memorize criteria components
How do we manage Marfans?
- Annual Ophthalmology
- Annual Orthopedic
- Annual Echo/cardio
- Long term BBs (atenolol/metoprolol)
- Restriction from vigorous physical exertion
