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Question 1

Type of Spondyloarthropathies

Answer 1

1. Ankylosing arthritis: long term inflammation of the spine, fused vertebrae
2. Reactive arthritis: inflammatory arthritis from an infection in another part of the body
3. Psoriatic arthritis: long term inflammatory arthritis caused by the autoimmune disease psoriasis, common to have distal interphalanges joint coloration
4. Enteropathic arthritis: long term arthritis with occurrence of inflammatory bowel disease

Question 2

Features of Spondyloarthropathies

Answer 2

1. Involvement of the axial skeleton, esp. sacroiliac joint
2. Peripheral arthritis: lower limbs more common than upper limbs, asymmetric
3. Enthesitis: inflammation of enthesis or where the ligament/tendon attaches to the bone
4. Uveitis of the eye and mucocutaneous probs

Male predominance and familial clustering, autosomal dominance with 20% penetrance

HLA-B27 association and absence of autoantibodies, Haida Indians and eskimos have high prevalence of HlA-B27 positive people, not cause but may impact way we react to bacteria especially those in the gut, overzealous reactions to bacteria may trigger systemic inflammation

Question 3

Inflammatory stuff for Spondyloarthropathies

Answer 3

Enthesitis: periosteal new bone formation, subchondral bone inflammation and resorption

Dactylitis: sausage digit, tendons and ligaments of the digit becomes inflammed and causes swelling, also seen in sarcoidosis and sickle cell

Uveitis: red painful eye

Urethritis or Cervicitis: from chlamydia or gonorrhea that triggers reactive arthritis, may have circinate balantis

Question 4

Schooner Test

Answer 4

Have limited ROM of flexion with spondyloarthropathies, mark lower back by L5, want to turn 10 cm line segment into 15 cm line segment by flexion

Question 5

Ankylosing spondylitis

Answer 5

Males more affected than females, normally 20-40 at diagnosis but there is juvenile AS

Diagnosis: inflammatory lower back/butt pain, peripheral arthritis
Uveitis, GI ulcers, lung disease or aortic valve insufficiency is rare

Question 6

Psoriatic Arthritis

Answer 6

Males and females affected equally, 20-40 at diagnosis, there’s a juvenile PsA

Diagnosis: skin and nail lesions, enthesitis, uveitis, axial and peripheral inflammatory arthritis, peripheral is oligo or polyarticular and involves DIP joints

Silvery plaques over elbows and umbilicus, onycholysis on nails

Question 7

Enteropathic Arthritis

Answer 7

Complication of inflammatory bowel disease, arthritis can be axial or peripheral

Clinical signs: pyoderma gangrenosum, symptomatic uveitis, oral ulcers,erythema nodosum

Question 8

Reactive Arthritis

Answer 8

Aseptic peripheral or axial arthritis occurring within a month of infection (GI, urethral, cervical or other)

Self limited or chronic, HLA-B27 positive increases risk of chronicity

Signs: Keratoderma blenorrhagicum (scaly pustules on feet), urethritis, cervicitis, vulvitis, circinate balinitis, inflammatory eye disease

Question 9

Radiographic findings of Spondyloarthropathies

Answer 9

Sacroilitis: unilateral or bilateral, has widening/irregularity of joint space, sclerosis, erosions

Lumbar spine: bridging syndesmophytes, bamboo spine, new bone forms along interosseous ligaments

Enthesitis: new bone and erosion where attach

Question 10

Treatment for Spondyloarthropathies

Answer 10

Intraarticular/topical steroids, PT, OT

Anti-TNF Agents are most effective for moderate to severe forms

NSAIDS then sulfasalazine and methotrexate (often ineffective for axial disease but work for peripheral) then anti-TNF agents

Question 11

Biomechanics of Fractures

Answer 11

1. Extrinsic Factors: magnitude, duration, and direction of force

Stress: load/area on which load acts

2. Intrinsic Factors: energy absorbing capacity, modulus of elasticity, fatigue strength

Bone is a two phase material with type I collagen and hydroxyapatite, strength of bone depends on density, mineral content, and amount of collagen

Question 12

Classifications of Fractures by Injury

Answer 12

1. Direct trauma-
   Nightstick fracture: small force over a small area, minimal soft tissue damage

Direct crush: large force over a large area, comminuted fracture, extensive soft tissue trauma

Penetrating fractures: large force over small area, gunshot, depends on velocity

2. Indirect trauma-
   Tension fracture: bone pulled apart, muscles and tendons, transverse fracture line

Compression fracture: short oblique fracture line, 45° shear strain, failure of cancellous in spine

Bending fractures: tension/compression, butterfly fragment on compression side

Rotational Fractures: spiral pattern, torsional stresses

Question 13

Fracture Clinical Evaluation and Care

Answer 13

Soft tissue care: primary goal to halt the continued trauma to the tissues, get pressure off soft tissue, may immobilize fracture with splint

Reduction: sooner is better, imperative in neurovascular injuries

Question 14

Pediatric Fractures

Answer 14

Thicker periosteum, more amenable to closer reduction and casts, more rapid healing

Physis-
Growth plate injury can be limb/life altering, leads to decreased growth

Nonphyseal-
Torus (buckle) fracture: More ductile so incomplete fracture, one side of bone/cortex broke

Greenstick fracture: bone bends but doesn’t break

Question 15

Apophysis

Answer 15

Small projection on a bone without an independent center of ossification

Can be tendon/bone interface, due to infused nature of structure when subject to high force, ischial tuberosity or ASIS

Question 16

Occult fracture

Answer 16

Often not easily seen on X-rays, hard to differentiate between and soft tissue injury

Present with pain/difficulty if weight bearing

Treat like fracture if think maybe, immobilize and re-examine (diagnosis is - if symptoms resolve)

Get MRI or other imaging if high stress area like femoral neck

Why a concern: can displace if at weight bearing joint, can violate blood supply, lead to nonunion or malunion

Question 17

Bone Fracture Treatment

Answer 17

1. Primary- rigid fixation
   Direct attempt by cortical bone to reestablish itself, need fracture fragments to be anatomically near each other, no callus

New osteoid on bone closes gals, cutting cones to allow new blood vessel entry

2. Secondary-
   Periosteum is important, enhanced by some motion and decreased by rigidity, endochondral/intramembranous, rapid, bridge lap gaps

Question 18

6 Stages of Secondary Bone Healing

Answer 18

1. Hematoma/Inflammation: direct bone formation via osteoprogenitor cells at periosteum (hard callus), Inflammatory Signaling
2. Angiogenesis/cartilage form: angiogenesis, mesenchymal Cells differentiate to chondrocytes to deposit cartilage
3. Cartilage calcification
4. Cartilage removal
5. Bone formation
6. Remodeling

Question 19

Fracture Fixation Stability

Answer 19

1. Cast/Splint- least stable
   Splints allow swelling and aren’t circumferential while casts are opposite, use for fractures with little displacement, limit motion, maintain alignment to limit soft tissue damage

More common in kids, secondary bone healing

2. External Fixation-
   Middle stable, temporary
   Open fractures, intrarticular fractures, fractures with soft tissue swelling and injury
3. Intermedullary Nails-
   Long bone fractures/diaphyseal (femur, tibia, humerus), closed reduction techniques, greater preservation of soft tissue compared to ORIF

Secondary bone healing, will see callus

4. Open Reduction Internal Fixation (ORIF)-
   Incision, realign bone/joint, plates and screws, middle stability

Plating method determines rigidity, can be 1° or 2° healing

5. Compression plating-
   Most stable, transverse or oblique fractures, compress bones to decrease gap bone must bridge which creates stability, need anatomic fixation

Bridge plating for comminution with proximal/distal fixation and little fixation in zone of injury, non-anatomic fixation, Secondary healing

Question 20

4 Sources of Blood Supply to Long Bones

Answer 20

1. Nutrient artery and branches: divide into multiple small branches when reach medullary cavity, some supply medullary cavity and others enter cortex to supply inner 2/3 via Haversian System, anastomoses with metaphyseal artery
2. Metaphyseal Artery: subdivide into numerous small branches,
3. Epiphyseal artery: pass through reserve zone of cartilage but no Capillaries, supply blood to proliferating zone of cartilage and the distal zones are less vascularized
4. Periosteal Artery

Question 21

Growing vs. Mature Bone Circulation

Answer 21

Blood doesn’t flow through physis and intramedullary vessels don’t reach epiphysis, direct epiphyseal artery is main blood supply to epiphysis (loses prominence when growth plate closes at skeletal maturity

Metaphyseal Blood Supply provides nutrients for active cells in enchondral ossification, doesn’t cross physis

Question 22

Disruption of Blood Supply to Bones

Answer 22

Medial circumflex humeral Artery is main blood supply to femoral head, branches transverse neck and may be torn by fracture, artery to the head of the femur is insufficient for blood supply when fractured so get avascular necrosis

Most nutrient arteries enter the neck of the talus, fracture can create osteonecrosis

Some people only have nutrient arteries on distal half of scaphoid, fracture of scaphoid makes osteonecrosis of proximal scaphoid

Common cause of secondary arthritis

Osteocytes disappear from lacunae

Revascularization extends inward from adjacent live bone

Dead bone is more opaque than live bone: new bone formation and collapse with old bone compression

Question 23

Osteonecrosis

Answer 23

Osteoclastic resorption: vessels approach and dead bone resorbed, articular surface weakens and a portion of it can collapse leading to degenerative arthritis

History/Physical: pain with activity, younger patient, limited joint ROM

Imaging: need MRI for early stage but radiographs work for later stages

Prevention and Treatment: restore Anatomy in fracture, total hip for end stage

Risk Factors: trauma, corticosteroid use, alcohol abuse, smoking, sickle cell, high cholesterol, organ transplant, Gaucher disease

Question 24

Osteonecrosis Etiology and Treatment

Answer 24

1. Etiology-
   Idiopathic is most common

Arterial compromise from fracture or heminoglobinpathies/arterial thrombosis

High intraosseous pressure: pressure in bone rises above capillary pressure from steroids, alcohol abuse, or Gaucher’s disease

2. Treatment-
   Early: core decompression

Later: bone grafting with vascularized fibula, osteotomy vs. total hip arthroplasty

Question 25

Osteonecrosis Stages

Answer 25

I: no X-ray changes but clinical symptoms are suspicious II: some bone remodeling, subchondral sclerosis, and cysts III: crescent sign on X-ray, subchondral fracture IV: narrowing, osteophyte development, deformation of bone (flattening of femoral head with normal joint space) V: narrowing of joint space, loss of articular cartilage on femoral head VI: arthritis involving femoral head and acetabular sides of the joint

Question 26

Osteochondrosis

Answer 26

Vascular insult to growing bone (osteonecrosis if to mature bone) Degenerative change in ossification center of epiphysis that goes on to avascular necrosis, perthes for femoral head, Freiberg on 2nd metatarsal involves flattening of the head Pathophysiology- Obliteration of the epiphyseal Blood Supply results in necrosis of the epiphysis 1. Cartilage cells deep in growth plate deprived of nutrients 2. Longitudinal growth stops 3. If collateral circulation not restored, growth plate closes

Question 27

Osteochondritis Dissecans

Answer 27

Damage at the articular cartilage due to blood deprivation of the subchondral bone, lose support for overlying articular cartilage Etiology can be traumatic (overuse) but is often idiopathic, could be underlying avascular necrosis Use plain radiographs or MRI Presents commonly in distal humerus, distal femur, and talus

Question 28

Osteochondritis Dissecans Stages

Answer 28

0. Normal X-ray and scintigraphically invisible 1. Bulge on medial femoral condyle due to partial separation of bone fragment, articular cartilage intact but show up on X-ray, no scintigraphically 2. Fragment demarcated by separation of articular cartilage, scintigraphically visible 3. Fragment of cartilage/bone completely separated, increased isotope uptake in lesion and femoral condyle 4. Increased uptake in adjacent tibial plateau

Question 29

Osteochondritis Dissecans Presentation and Treatment

Answer 29

1. Presentation- Mild aching to severe pain with joint effusion and sometimes a mechanical block 2. Treatment- depends on fragment status and child age Observation and stop activities, drilling, osteochondral allograft, mosaic plasty, ORIF

Question 30

Primary Survey for MSK Emergency

Answer 30

ABCDE A- airway Move air between mouth/nose to lungs, mechanical block or lost due to unconsciousness Treatment: endotracheal, nasotracheal, circothyroid intubation B-breathing Ability of lungs to exchange oxygen to the blood for transport to the tissues Impaired by hemothorax, pneumothorax, flail chest from multiple rib fxs, pulmonary contusions/pain Treatment: address specific injury, possible intubation with mechanical support C-circulation Assessing for shock when the body can’t deliver adequate oxygenated blood to tissues Evaluate for bleeding, cardiac tamponade, neurogenic shock from spinal cord injury Clinical signs: tachycardia, faint peripheral pulse, lower skin temp, sweating, loss of consciousness D-neurologic disability Give brief neuro exam E-exposure Remove all clothes to see all injuries

Question 31

Secondary Survey for MSK Emergencies

Answer 31

Systematic head to toe examination Immobilized on a spine board Rectal exam, Foley catheter, do every hole Do X-rays or act scans as needed

Question 32

Orthopedic Emergencies

Answer 32

Crush injuries Compartment syndrome Open fractures Bite wounds Pelvic/acetabulum fractures Dislocations

Question 33

Crush injuries

Answer 33

Earthquake, prolonged extremity compression, too much beer/drugs Continuous pressure on muscle causes cellular ischemia and death Cells leak K+ and myoglobin, while absorb Na/Ca/water, metabolic acidosis from hypotension and hyperkalemia/calcemia Renal failure as myoglobin precipitates in renal tubules, Metabolic abnormalities cause cardiac failure and arrhythmia Be wary of Compartment syndrome Treatment: prevention of renal failure, aggressive fluid resuscitation, sodium bicarbonate to prevent myoglobin precipitation, dialysis

Question 34

Pelvic and Acetabular Fractures

Answer 34

1. Pelvic fractures- Can injure multiple other areas, hemorrhage is leading cause of death and mainly comes from intra-abdominal source Manage hypotension: fluid resuscitation, evaluate chest/abs, sheet immobilization, angiography Fairly high mortality 2. Acetabular Fracture- High energy with associated injuries, not associated with ongoing blood loss, check for dislocation

Question 35

Compartment Syndrome

Answer 35

Increased pressure: ischemia, oxygen deprivation, damage to muscle and nerve tissue Extrinsic Factors: tight dressing/cast, burns, occlusive dressings Intrinsic factors: bleeding from injury or fracture, iatrogenic fluid infusion, swelling from tissue injury Often with closed Tibial shaft fractures, swelling can cause compression of muscles/neurovasculature Medical emergency, death of muscle and injury to nerves if untreated, can be reversible if release pressure

Question 36

Signs and Symptoms of Compartment Syndrome

Answer 36

Pain out of proportion Pallor Parathesia (late) Paralysis (progressive weakness) Pulselessness Others: elevated muscle compartment pressures, tense swollen area (porkiness), poikilothermia (cold)

Question 37

Open fractures

Answer 37

Emergency, infection increases greatly without prompt treatment, antibiotics help Generally high energy with multiple associated injuries like soft tissue loss and compartment syndrome Staph aureus most common, Cephalosporin for Grade I/II, add aminoglycosides (Gent) when Grade III, add penicillin if high contamination Thorough irrigation and debridement, skeletal stabilization

Question 38

Bite wound

Answer 38

Human: From punching, examine with hand in fist, Staph is common Cat bites have Pasteurella multocida Plan: local wound care, debridement open joints, antibiotics, rabies, tetanus

Question 39

Flexor tenosynovitis

Answer 39

Caused by puncture wound, very painful Staph aureus is most common, high index of suspicion, need prompt treatment Treatment- Prompt IV antibiotics, nonoperative Treatment should see improvement after 2 days but operate if not help after a day, can do closed continuous irrigation, open treatment

Question 40

Kanavel’s 4 Cardinal Signs of Flexor Tenosynovitis

Answer 40

1. Symmetric swelling of the entire digit 2. Exquisite tenderness along the sheath 3. Digit with semi-flexed posture 4. Pain with attempted passive extension

Question 41

Effusions

Answer 41

Abnormal collection of fluid in a joint, aspirate synovial fluid Immobilize, antibiotics, irrigate and debridement since infection damages cartilage History important and most effusions are benign Arthrocentesis: >50k WBC indicates infection, pain upon palpating and weight bearing

Question 42

Deep Vein Thrombosis

Answer 42

Diagnosis is clinically hard- Swelling, calf tenderness, Homan’s sign is unreliable, fever, elevated WBCs Can use Doppler ultrasound

Question 43

Virchow’s Triad

Answer 43

1. Hypercoagulable state- Malignancy, IBD, pregnancy or postpartum, oestrogen therapy, trauma of LE, sepsis, nephrotic syndrome 2. Vascular wall injury- Trauma or surgery, venipuncture, atherosclerosis, chemical irritation 3. Circulatory stasis- decreases blood flow rate Atrial fibrillation, immobility or paralysis, venous obstruction from tumor/obesity/pregnancy