High Yield Topics

Fracture, Humeral Shaft

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Fracture, Humeral Shaft
Julie J. Chuan
Basics
  • Direct trauma from a fall
  • Direct blow to the upper arm
  • Fall on elbow or outstretched arm
  • Motor vehicle or industrial accident
  • Pitching a ball (torque causes a spiral fracture)
  • Bone malignancy (pathologic fracture) (1)[B]
Description
  • Transverse fractures occur from a bending force.
  • Spiral fractures occur from torsion.
  • Oblique fractures occur from bending and torsion and may have an associated butterfly fragment.
  • Proximal or distal comminuted fractures occur from compressive forces.
Pediatric Considerations
Spiral fractures in children are concerning for child abuse.
Epidemiology
  • Bimodal distribution in the 3rd and 7th decades
  • 3rd decade male predominance owing to sports and vehicular trauma
  • 7th decade female predominance owing to simple falls (1)[B]
  • Types:
    • Midshaft: 60%
    • Proximal shaft: 25%
    • Distal shaft: 10% (1)[B]
Diagnosis
  • History and physical examination with special attention to a thorough neurovascular and skin examination
  • Consider associated injuries such as ipsilateral shoulder, elbow, wrist, or hand fractures or dislocations.
  • Diagnosis is confirmed by x-ray.
Pre Hospital
  • Immobilize with sling and swath for transport.
  • Evaluate for open fracture.
  • Evaluate for distal neurologic and vascular deficit.
  • Rapid transport in presence of neurologic or vascular deficits
History
  • History of fall: Simple trip and fall, a low-impact force, is often associated with older (70+ yrs), osteoporotic women.
  • Collision or direct blow: Higher impact, occurring more commonly in younger men
  • Pain after throwing or pitching
  • History of malignancy
  • Consider as pathologic fractures any humerus fracture produced by low-energy mechanism; the humerus can be a common site of metastatic disease.
Pediatric Considerations
  • “Falls” in toddlers or infants are concerning for abuse
  • Check for other bruises and injuries suggesting abuse.
  • Examine the elbow in children who are guarding their arm.
  • Elbow dislocations are more common in toddlers (nursemaid's elbow).
  • Supracondylar fractures are more common in children when they sustain a fall.
Physical Exam
  • Pain and swelling over the area of the humeral shaft
  • Shortening, deformity, or decreased mobility
  • Crepitus on gentle passive range of motion (ROM)
  • Neurologic deficit (2)[C],(3)[B]:
    • Radial nerve is most commonly injured, occurring in 15% of humeral shaft fractures:
      • It is tethered down and emerges through the intermuscular septum at the middle to distal shaft.
      • Injury will affect active extension in the wrist, hand, and fingers.
      • Occurs most frequently in middle and distal shaft fractures and spiral fractures
      • Usually a neurapraxia or axonotmesis (perineurium and epineurium intact)
    • Ulnar nerve injury will affect finger abduction (spreading the fingers apart).
    • Median nerve injury will affect thumb opposition (thumb and small finger pinch).
  • Vascular injury: Presenting as decreased pulse, slow distal capillary refill, or a cool extremity:
    • Brachial artery
    • Cephalic and basilic veins
  • Open fracture: If the skin is disrupted over the site of the fracture, there is a high risk of infection and need for surgical evaluation.
Diagnostic Tests & Interpretation
  • Anteroposterior (AP) and lateral views of the entire humerus are mandatory to assess for fracture pattern.
    • Displacement, including angulation and shortening type of fracture: Transverse, spiral, oblique
    • Location of the fracture on the humeral shaft in relation to muscle attachments
    • Number of fracture segments (butterfly fragments) and comminution
  • Include shoulder and elbow views to exclude associated joint involvement.

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Imaging
The AO/ASIF system defines humeral shaft fractures as follows (3)[B]:
  • Type A: Simple fractures:
    • A1: Simple spiral
    • A2: Simple short oblique
    • A3: Simple transverse
  • Type B: Wedge fractures:
    • B1: Spiral wedge
    • B2: Bending wedge
    • B3: Fragmented wedge
  • Type C: Complex pattern fractures:
    • C1: Complex spiral
    • C2: Segmental fracture
    • C3: Irregular comminuted fracture
Pathological Findings
Pathologic fractures of the humeral shaft are associated with the following malignancies (1)[B]:
  • Women:
    • Breast 40%
    • Myeloma 23%
    • Lung 9%
    • Kidney 9%
  • Men:
    • Prostate 33%
    • Kidney 25%
    • Myeloma 8%
    • Lung 8%
Differential Diagnosis
  • Bone contusion
  • Muscle contusion: Primarily the biceps, triceps, or deltoid
  • Hematoma
  • Tendon rupture: Primarily the biceps
  • Neurapraxia: Primarily the radial nerve
  • Abscess
Treatment
  • These fractures usually do not require elaborate reduction or immobilization.
  • Fractures without neurovascular compromise can be treated conservatively; see immobilization options below.
  • Immobilize for 4–6 wks until clinically and radiographically healed.
Pre-Hospital
  • With the introduction of functional (Sarmiento) bracing, conservative treatment has become more popular and can be managed in the office.
  • Conservative care can be undertaken with 90% healing rates for adults with low to moderate functional demands. The degree of displacement accepted in these studies was up to 20 degrees and 2 cm of shortening.
    • Fractures can displace further after injury owing to contraction of the surrounding muscles (see below).
    • No randomized, controlled trials support these recommendations, so they are class C recommendations.
  • Open fractures or fractures associated with neurovascular compromise require immediate orthopedic consultation.
  • Children remodel well and usually are able to compensate with overgrowth for fractures up to 1.5 cm shortening and 20 degrees of angulation.
  • Anyone with high functional demands such as elite athletes, mechanics, and carpenters should be considered for surgical fixation for optimal anatomic alignment.
  • Of the nonunions, 90% ultimately heal with surgical intervention.
  • The carrying angle (valgus angle at the elbow when the arm is fully extended) is most often affected in displaced humeral shaft fractures (4)[C].
ED Treatment
Specific injuries will warrant further surgical intervention and should be referred immediately to the ED if seen in the office (5)[B].
  • Radial nerve palsy at any evaluation
  • Multisite trauma
  • Open or segmental fractures
  • Floating elbow: Occurs when there is a fracture above and below the elbow and is considered an “unstable” injury
  • Ipsilateral arm injuries
  • Vascular injury: Refer for urgent vascular surgery evaluation.
Medication
  • Immobilization: Immobilize to limit movement at the site of the fracture, which is one of the most effective methods of pain control.
  • Ice: Icing the fracture site intermittently (15 min q.i.d.) for the first few days will reduce swelling and help to control pain.
  • Elevation: After immobilization, try to elevate the arm above the level of the heart as much as possible to minimize swelling.
  • Analgesic medications:
    • Narcotic analgesics: Initially may be needed for adequate pain control
    • Nonnarcotic analgesics: After the fracture stabilizes (about 1 wk), NSAIDs and/or acetaminophen should provide sufficient pain relief.
Additional Treatment
Consider displacing forces of the contracted muscles around the site of fracture when immobilizing the injury:
  • Supraspinatus, infraspinatus, and teres minor externally rotate the humeral head.
  • Subscapularis internally rotates the humeral head.
  • Pectoralis pulls fragments toward the chest (medially) and forward (anteriorly).
  • Latissimus and teres major pull fragments inward toward the chest.
  • Deltoid displaces the fracture outward (abducts) away from the chest.

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Referral
Surgical indications (4)[B]:
  • Unacceptable alignment after closed reduction
  • Radial nerve palsy at any evaluation, including after closed reduction
  • Multisite trauma
  • Open or segmental fractures
  • Floating elbow: Occurs when there is a fracture above and below the elbow and is considered an “unstable” injury
  • Ipsilateral arm injuries
  • Pathologic fractures
  • Fracture with significant gap between segments usually represents muscle or fat separating the bone fragments and is unlikely to heal.
  • Vascular injury: Refer for urgent vascular surgery evaluation.
Surgery/Other Procedures
  • Surgical options:
    • Intermedullary nailing
    • External fixation
    • Plate fixation
  • Immobilization options for conservative management (3)[B],(3)[C]:
    • Sling immobilization: Best for nondisplaced fractures that do not need distraction but can predispose to further shortening
    • Sugar-tong, coaptation, or U-shaped splint: Best for limitation of transverse fracture displacement; limits shoulder and elbow motion, predisposing to stiffness after prolonged immobilization
    • Hanging cast: Better for displaced or comminuted fractures needing distraction:
      • Needs closer follow-up after injury to evaluate for signs of compartment syndrome
      • Cannot keep arm elevated to minimize swelling because gravity aids with distraction of the fracture
    • Functional bracing: Allows for elbow mobility and earlier ROM; applied after initial swelling subsides and fracture starts to stabilize, usually 2 wks after injury
    • Always repeat the vascular and neurologic examination after splint or cast application.
  • Surgical treatment:
    • Benefits:
      • More predictable alignment
      • Immediate stability
    • Risks:
      • Infection
      • Nerve and vascular injury
      • Nonunion
      • Anesthesia risks
  • Conservative treatment (5)[B]:
    • Benefits:
      • Functional bracing usually allows for full or nearly full shoulder and elbow mobility.
      • Less infection and neurovascular injury risk
    • Risks:
      • Skin breakdown
      • Angular or translational malalignment/deformity
      • Nonunion (higher in simple fractures or type 1)
      • Shoulder or elbow stiffness
In-Patient Considerations
Initial Stabilization
  • Pain control with NSAIDs or narcotic analgesics
  • Immobilization with sling and swath or shoulder immobilizer pending definitive diagnosis
  • Application of ice to limit swelling
  • Open humerus fractures require covering with a sterile dressing, tetanus prophylaxis, and parenteral prophylactic antibiotics.
Admission Criteria
  • Open fractures
  • Associated neurovascular compromise
  • Multisite trauma
Discharge Criteria
  • Uncomplicated humeral shaft fractures should be referred to an orthopedic surgeon for follow-up.
  • Orthopedic consultation in the ED is required for patients with grossly displaced or comminuted fractures.
Ongoing Care
  • Immobilize until clinical healing pain-free with bony callus on radiographs, usually 4–6 wks.
  • Start passive ROM after 2 wks to minimize shoulder and elbow stiffness.
  • Nonunion is most common with proximal shaft fractures, with overall nonunion rate of about 6%.
  • Radial nerve injury is most common in distal shaft fractures.
  • Varus angulation is most common in transverse fractures.
Follow-Up Recommendations
Nonunion risk factors:
  • Open fracture
  • Segmental (more than 2 fragments)
  • Transverse (tend to displace into varus owing to displacing forces)
  • Highly comminuted (unable to hold alignment)
  • Associations: Smoking, use of NSAIDs
  • Comorbidities: Diabetes, hypothyroid, infection, metabolic bone disease (2)[C]

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Patient Monitoring
  • Weekly follow-up: Initially, every week to assess for displacement of the fracture
  • Every other week: Once the fracture is stable on consecutive radiographs (usually 2–3 wks after injury). follow every 2 wks.
    • Once callus is noted on radiograph and no pain on examination, splint can be removed, and shoulder and elbow should be mobilized with gentle ROM exercises.
    • Continue to follow clinically until ROM is restored and healing noted on radiographs (usually 8–12 wks).
  • At 12–14 wks, if union is not complete clinically and radiographically, consider referral to surgery for intervention.
Patient Education
  • Compartment syndrome signs and symptoms if casted
  • Monitor for new neurologic deficit.
  • Monitor for new vascular deficit.
  • Encourage wrist, hand, and shoulder ROM exercises.
  • Sleep upright (recliner) if in a hanging cast until fracture is stable to minimize displacement.
Complications
Compartment syndrome:
  • Pressure increases in a contained space with the potential for severe nerve and soft tissue injury (muscle ischemia and necrosis).
  • Present with:
    • Pain out of proportion to the injury
    • Paresthesias or numbness
    • Pulselessness (decreased pulse distally, slow capillary refill time, cool extremity), loss of motion distally (hand or fingers)
    • Pain worse with passive ROM
    • Distally continued swelling
    • Pallor
References
1. Ekholm R, Adami J, Tidermark J, et al. Fractures of the shaft of the humerus. An epidemiological study of 401 fractures. J Bone Joint Surg Br. 2006;88:1469–1473.
2. Anglen JO, Archdeacon MT, Cannada LK, et al. Avoiding complications in the treatment of humeral fractures. Instr Course Lect. 2009;58:3–11.
3. Papasoulis E, Drosos GI, Ververidis AN, et al. Functional bracing of humeral shaft fractures. A review of clinical studies. Injury. 2009.
4. Ekholm R, Tidermark J, Törnkvist H, et al. Outcome after closed functional treatment of humeral shaft fractures. J Orthop Trauma. 2006;20:591–596.
5. Jawa A, McCarty P, Doornberg J, et al. Extra-articular distal-third diaphyseal fractures of the humerus. A comparison of functional bracing and plate fixation. J Bone Joint Surg Am. 2006;88:2343–2347.
Additional Reading
Magnusson AR. Humerus and elbow. In: Rosen P, et al., eds. Emergency medicine: concepts and clinical practice. 4th ed. St. Louis: CV Mosby, 1998.
Simon R, Koenigskhecht S. Emergency orthopedics, the extremities. 3rd ed. Norwalk, CT: Appleton & Lange, 1993.
Zuckerman J, Koval K. Fractures of the shaft of the humerus. In: Rockwood CA, Green DP, eds. Rockwood and Green fractures in adults. 4th ed. Philadelphia: Lippincott-Raven, 1996.
Codes
ICD9
  • 812.21 Fracture of shaft of humerus, closed
  • 812.31 Fracture of shaft of humerus, open
Clinical Pearls
  • Radial nerve injury is the most common neurovascular injury, occurring in about 15% of humeral shaft fractures.
  • 10–20 degrees of angulation and 1–2 cm of shortening generally are well tolerated owing to compensated overgrowth and the surrounding muscles.
  • Contraction of the muscles around the humerus can displace the fracture after the initial injury and should be considered when immobilizing the fracture.
  • Consider close weekly follow-up after immobilization to monitor for fracture displacement.


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