Miller-Trauma Flashcards
What is the classification of hemmoragic shock?
Class III/IV requires administration of blood products.
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Manifests as:
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Increases in heart rate and systemic vascular resistance
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Decreases in cardiac output, pulmonary capillary wedge pressure, central venous pressure, and mixed venous oxygen saturation
What is the mechanism of TXA?
Tranexamic acid is a synthetic analogue of lysine that can be used to prevent excessive bleeding. Its mechanism of action is competitive inhibition of plasminogen activation.
Define damage control orthopedics
Damage control orthopaedic principles involve staging the definitive care of the patient to avoid adding to the early overall physiologic insult
How does ultrasound help heal bone fractures?
Ultrasound—delivers small cumulative doses of ultrasound energy; thought to induce microfracture and healing response; 30 mW/cm2pulsed wave ultrasound has been shown effective for healing acute fractures.
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Electromagnetic—attempts to promote healing by directing integral ion flow at cellular level of bone
What antibiotics do you give for open fractures?
Antibiotics—usually started immediately. Antibiotic bead pouch with methylmethacrylate, tobramycin, and/or vancomycin may be used to initially manage highly contaminated wounds.
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Types I and II—first-generation cephalosporin (cefazolin) for 24 hours
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Type III—cephalosporin and aminoglycoside for 72 hours after injury or not more than 24 hours after each débridement or soft tissue coverage
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Heavily contaminated wounds and farm injuries—cephalosporin, aminoglycosides, and high-dose penicillin
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Freshwater wounds—fluoroquinolones (ciprofloxacin, levofloxacin) or third- or fourth-generation cephalosporin (ceftazidime)
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Saltwater wounds—doxycycline and ceftazidime or a fluoroquinolone
Tetanus prophylaxis
Tetanus is caused by the exotoxin of Clostridium tetani, which produces convulsion and severe muscle spasms with a 30%–40% mortality rate.
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Required tetanus prophylaxis treatment is based on the characteristics of the wound and the patient’s immunization status.
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Tetanus-prone wounds are more than 6 hours old, are more than 1 cm deep, have devitalized tissue, and are grossly contaminated.
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Patient with an unknown tetanus immunization status or who has received fewer than three tetanus immunizations and who has a tetanus-prone wound should receive tetanus and diphtheroid toxoid and human tetanus immunoglobulins (intramuscular injection of toxoid and immunoglobulin should occur at different sites).
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Patient with unknown tetanus immunization status or who has received fewer than three tetanus immunizations and who has a non–tetanus-prone wound should receive only tetanus toxoid.
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Fully immunized patient should receive tetanus toxoid if the wound is severe or is more than 24 hours old, or if the patient has not had a booster in the past 5 years.
osteomyelitis
Diagnosis
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Definitive diagnosis—by bone biopsy. Bone culture and microscopic pathology. Bone culture may have high false-negative rate. Microscopic pathology to evaluate for inflammatory changes consistent with infection.
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Other tests—may be used in combination with physical examination (draining wound, pain) to confirm diagnosis
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Chronic draining wounds can differentiate into squamous cell carcinoma and should undergo histologic analysis when excised.
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MRI—95% sensitive and 90% specific
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Technetium (Tc) 99m (99mTc) study—85% sensitive and 80% specific
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Indium (In) 111 study—95% sensitive and 85%–90% specific
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Treatment—based on grade and host type (Cierny/Mader classification)
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Grade
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Grade I—intramedullary; débridement by intramedullary reaming
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Grade II—superficial, involves cortex, often seen in diabetic wounds; curettage
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Grade III—localized, involves cortical lesion with extension into medullary canal; requires wide excision, bone grafting, and perhaps stabilization
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Grade IV—diffuse, indicates spread through cortex and along medullary canal; wide sequestrectomy, muscle flap, bone graft, and stabilization
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Host
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A—normal healthy patient
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B—locally compromised (vasculopathic)
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C—not considered a medical candidate for surgery; may require suppressive antibiotics
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LEAP study results
Multicenter prospective study of severe lower extremity trauma in the U.S. civilian population. Key findings and recommendations include:
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Injury severity scoring systems do not provide valid predictive value to guide amputation decision.
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Absence of plantar sensation on presentation is not predictive of extremity function or return of plantar sensation at 2-year follow-up.
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At 2- and 7-year follow-up, no difference in functional outcome between patients who underwent limb salvage surgery and those who underwent amputation
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Outcomes found to be affected more by patient’s economic, social, and personal resources than by the injury treatment method
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Patients with mangled extremity injuries have poor outcomes at 2 years. Outcomes continue to worsen between 2 and 7 years’ follow-up. Factors associated with poor outcome include older age, female gender, nonwhite race, lower level of education, current or prior smoking history, poor economic status, low self-efficacy, poor health status prior to injury, and involvement in legal system to obtain disability.
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Patients presenting with mangled lower extremity injuries are less agreeable and more likely to drink alcohol, to smoke, to be poor and uninsured, and to be neurotic and extroverted in comparison with population norms.
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Patients who undergo below-knee amputation function better than those who undergo above-knee amputation. Patients undergoing through-knee amputation have the poorest function.
Review the biomechanics of fracture healing
Stability and fracture healing
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Stability determines strain
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Absolute stability
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Relative stability
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Strain determines type of healing
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Strain is defined as change in fracture gap divided by the fracture gap (ΔL/L).
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Highest fracture site strain is seen in a simple fracture that is fixed with a gap (incompletely reduced).
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Strain less than 2% results in primary bone healing (endosteal healing).
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Strain 2%–10% results in secondary bone healing (enchondral ossification).
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Strain greater than 10% does not permit bone formation.
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Relative stability
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Micromotion at fracture site under physiologic load leads to callus formation.
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Strain decreases as callus matures, leading to increased stability.
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If there is too much motion, callus becomes hypertrophic as it tries to spread out force, and hypertrophic nonunion can result.
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Examples: casts, external fixators, IM nails, bridge plates
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Absolute stability
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No motion at fracture site under physiologic load
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Bone heals through direct healing (no callus).
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Strain is low or zero.
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Healing times are longer and more difficult to confirm by radiography.
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Implants must have longer fatigue life.
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Examples: oblique fractures fixed with lag screws and transverse fractures fixed with compression plating technique
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Healing in different bone types
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Diaphyseal (cortical)
Decreased blood supply leads to longer healing times.
Bone is more amenable to compression techniques (in short oblique/transverse fractures).
Strain is concentrated over a smaller surface area.
Cancellous (metaphyseal)
Larger surface area and better blood supply
Strain is lower as forces spread out over larger area.
Healing is more rapid.
However, joint surfaces tolerate very little malreduction (<2 mm), so there is often increased time to bear weight versus diaphyseal fractures.
Biomechanics of ORIF
Lag screws
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Provide rigid interfragmentary compression (absolute stability)
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Force is concentrated over a small area (around screw), so typically a plate is needed to protect/neutralize the deforming forces.
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Position screws
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Compress plate to bone but do not provide interfragmentary compression
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Friction between screw, plate, and bone resists pullout or bending.
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Plating
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Plate length matters more for bending stability than number of screws in plate.
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Torsional stability is more affected by position of screws (end hole must be filled).
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Longer plates spread the strain over more area (working length).
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To increase bending stiffness of a plate, decrease the working length by placing screws closer to the fracture site (a 10-hole plate centered at a fracture with screws in holes 1, 5, 6, and 10 has a higher bending stiffness than one with screws in holes 1, 3, 8, and 10).
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Plates are load bearing—will stress shield area they cover; important to protect area temporarily if plate removed after healing
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Compression plate function
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Plate design (oval holes) or use of compression device allows plate to apply compressive forces across fracture.
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Provides absolute stability when properly applied
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Relies on friction between plate and bone (needs at least some nonlocking screws)
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May need to be prebent to achieve compression of both near and far cortex
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Insertion order is neutral position, then compression on opposite side of fracture, then lag screw (if being placed through plate).
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Tight contact of plate to bone when initially applied causes decreased periosteal blood flow and temporary osteopenia.
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Bridge plate function
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Primarily for comminuted fracture patterns
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Plate “bridges” area of comminution with fixation above and below fracture.
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Allows some elastic deformation (relative stability)
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Use of screws very close to fracture should be avoided.
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Number and types of screws to insert are fracture dependent—no clear, widely accepted guidelines.
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Nonlocking screws compress plate to bone and can be used to lag in fragments; locking screws provide angular stability in short metaphyseal segments or in osteoporotic bone.
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Buttress plate function
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Plate provides support at 90-degree angle to fracture—typically in depressed metaphyseal/articular fractures that have been reduced.
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Can provide absolute stability to metaphyseal fragments
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Submuscular/percutaneous plating
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To preserve biology at fracture site, plate may be placed in submuscular plane by sliding through small incisions proximal or distal to fracture and avoiding exposure of fracture site.
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Typically used in bridge mode, although not exclusively
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Advantage: decreased soft tissue and biologic compromise
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Perfusion of both medulla and periosteum is better retained.
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Disadvantage: more prone to malreduction/malrotation
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Locked plating
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Screws have threads in head that lock into corresponding holes in plate
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Fail simultaneously rather than sequentially
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Stability does not depend on friction between plate and bone.
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Provides fixed-angle construct—similar to blade plate
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Most useful in unstable short-segment metaphyseal fractures and osteoporotic bone
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Fractures in which locking plate use is supported by data include
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Periprosthetic fractures
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Proximal humerus fracture
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Intraarticular distal femur and proximal tibia
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Humeral shaft nonunion in the elderly
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Unicortical locked screws
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Typically for metaphyseal bone
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Similar in pullout strength to bicortical locked screws in good-quality diaphyseal bone (but rare indications for use there)
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Weaker in torsion than bicortical screws
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Bicortical locked screws: biggest advantage is in osteoporotic diaphyseal bone
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Multiaxial screws
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May increase options for fixation in working around periprosthetic fractures
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No advantage in strength or pullout
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“Hybridization” describes the use of both locking and nonlocking screws in combination. This allows for both compression and fixed-angle support.
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IM nails
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Load-sharing devices—relative stability
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Stiffness depends on:
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Material
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Stainless is stiffer than titanium.
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Size
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Increased diameter leads to increased stiffness at a ratio of radius to the power of:
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3 in bending
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4 in torsion
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Wall thickness
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Larger = stiffer nail
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Radius of curvature of femoral nails is typically less than anatomic, improving frictional fixation.
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A large mismatch of curvature, however, results in difficult insertion, increased risk of intraoperative fracture, and malreduction in extension.
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Nails resist bending very well and require interlocks to resist torsion or compression loads.
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Working length is the portion of the nail that is unsupported by bone when loaded.
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Increased working length produces increased interfragmentary motion and may delay union.
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Advantage of intramedullary position is decreased lever arm for bending forces (especially useful in peritrochanteric fractures vs. plate-and-screw construct).
Key point on SC joint injuries
Sternoclavicular dislocation—“serendipity” view or CT scan reveals dislocation of sternoclavicular joint
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Anterior dislocation—more common, treated by closed reduction. The majority will remain unstable regardless of initial treatment modality, but these are typically asymptomatic.
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Posterior dislocation—more serious—30% associated with significant compression of posterior structures. May cause dysphagia or difficulty breathing and sensation of fullness in the throat. Treated by closed reduction with a towel clip in the operating room. A thoracic surgeon should be on standby.
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Chronic dislocation—treated by resection of the medial clavicle, with preservation and reconstruction of costoclavicular ligaments
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Pseudodislocation—medial clavicular epiphysis is the last to close, at a mean age of 25 years. In younger patients, sternoclavicular dislocation is often a Salter-Harris type I or II fracture.
Clavicle Fractures
classified by thirds
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Middle—80%
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Distal—15%
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Medial—5%
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Associated injuries—open clavicle fractures associated with high rates of pulmonary and closed-head injuries
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Treatment
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Nonoperative treatment: midthird fracture has traditionally been treated nonoperatively, in a sling.
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No difference in outcome between regular sling and figure-eight bandage
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Risk of nonunion after midshaft fracture is higher in female and elderly patients and with fractures that are displaced, shortened more than 2 cm, or comminuted.
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Lateral fractures have higher rates of nonunion compared with midshaft fractures.
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Operative treatment
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Middle third
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Have higher rates of nonunion and decreased shoulder strength and endurance (≈15%)
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Absolute surgical indications: open fracture, displaced fractures with skin compromise, associated neurovascular injury
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Relative surgical indications: floating shoulder (associated scapular neck fracture), shortening greater than 15–20 mm, complete displacement, comminution
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Prospective randomized study comparing operative with nonoperative treatment of displaced midthird clavicle fractures: operative treatment group had a 10-point improvement in Constant and DASH (Disabilities of the Arm, Shoulder, and Hand) scores at all time points, earlier time to union, and statistically fewer nonunions, symptomatic malunions, and complications than the nonoperative treatment group.
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Distal third
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Some recommend operative treatment of distal fractures that extend into the acromioclavicular joint, whereas others recommend a late Mumford procedure.
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Type II distal clavicle fractures, which involve displacement, have the highest nonunion incidence, but many nonunions are asymptomatic. Nonoperative and operative management approaches provide similar results. Operative decision based on amount of displacement and individual patient demands. For example, sling and early ROM are the best treatments for middle-aged woman with 100% displacement of a distal clavicle fracture.
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Fixation options
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Plate—typically dynamic compression plate; applied to superior aspect (better biomechanical strength but more prominent → hardware removal) or to anterior-inferior aspect (less hardware removal).
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IM rod and screw—may be inserted percutaneously; higher rates of hardware irritation and complication
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Avoid Steinmann pins, especially nonthreaded—can migrate.
AC joint dislocations
Classification and Treatment
Classification—classified by extent of involvement of the ligamentous support and direction and magnitude of displacement. Coracoclavicular (CC) and acromioclavicular (AC) ligaments may be ruptured.
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Type I—sprain of AC joint
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Type II—rupture of AC ligaments and sprain of CC ligaments
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Type III—rupture of both AC and CC ligaments
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Type IV—clavicle is buttonholed through trapezius posteriorly
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Type V—trapezius and deltoid detached
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Type VI—Clavicle is dislocated inferior to coracoid
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Treatment
Types I and II—always treated with brief immobilization in a sling
Type III—may be treated nonoperatively, but many advocate early operative treatment in patients who are heavy laborers and throwers. Weaver-Dunn procedure is the treatment of choice.
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Types IV to VI—usually treated operatively
What is a scapulothoracic dissociation?
result of significant trauma to chest wall, lung, and heart. Severe cases are treated essentially with a closed forequarter amputation.
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Associated with:
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Brachial plexus avulsion
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Subclavian or axillary artery injury
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AC dislocation, clavicle fracture, and sternoclavicular dislocation
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Mortality rate of 10%
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Diagnosis should be suspected when there is a neurologic and/or vascular deficit. More than 1 cm of lateral displacement of the scapula on a chest radiograph is also suggestive.
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Management
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Hemodynamically stable: angiography before surgery. Vascular injury may potentially be treated nonoperatively owing to the extensive collateral network around the shoulder.
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Hemodynamically unstable: high lateral thoracotomy or median sternotomy to control bleeding
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Musculoskeletal injury treatment is controversial but is often nonoperative if vascular repair is not undertaken.
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Functional outcome is based on severity of associated neurologic injury.
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Floating shoulder—fracture of the glenoid neck and clavicle
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Some recommend fixation when a clavicle fracture is associated with a displaced glenoid neck fracture, whereas others do not consider it necessary (depends on stability of superior shoulder suspensory complex [SSSC]).
Proximal Humerus Fractures:
Classification and Treatment
Neer classification (Neer defines “part” as displacement of >1 cm or angulation of >45 degrees); parts are articular surface, greater tuberosity, lesser tuberosity, and shaft
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One-part—nondisplaced or minimally displaced fracture (often of the humeral neck)
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Two-part—displacement of tuberosity of more than 1 cm; or surgical neck with head/shaft angled or displaced
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Three-part—displacement of the greater or lesser tuberosities and articular surface
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Four-part—displacement of shaft, articular surface, and both tuberosities.
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“Head splitting” is a variant, with split through the articular surface (usually requires replacement for treatment).
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Treatment
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One-part—sling for comfort and early mobilization
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Two-part—repair of the displaced tuberosity with sutures or tension band wiring; surgical neck fractures can normally be managed nonoperatively.
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Unstable, nonimpacted fractures may be treated with closed reduction with percutaneous pinning (CRPP), ORIF with locking plate fixation, or IM nailing
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Varying humeral nail designs. Straight nails are placed through a more central entry point (through superior articular cartilage) that can provide additional point of fixation. Nails with proximal bend are placed through an entry point just medial to the rotator cuff insertion.
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Immediate physical therapy during nonoperative management results in faster recovery.
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Greater tuberosity fractures are displaced superiorly and posteriorly owing to deforming pull of supraspinatus, infraspinatus, and teres minor. Healing in a displaced position would block abduction and external rotation.
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Surgery is indicated for displacement greater than 5 mm. In young patients with good bone, screws alone can be used, but nonabsorbable suture technique should be used in older patients.
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Three-part
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ORIF for young patients, with repair of the tuberosities or rotator cuff
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Screw cutout is the most common complication following ORIF with a periarticular locking plate.
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Hemiarthroplasty for older patients, with repair of the rotator cuff/tuberosities
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Four-part—same as for three-part
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Humeral height can be judged most reliably using the superior border of the pectoralis major insertion.
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Nonanatomic placement of the tuberosities leads to significant impairment in external rotation kinematics and an eightfold increase in torque requirements.
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Complications
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Avascular necrosis (AVN)
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Factors associated with humeral head ischemia (Hertel criteria):
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Disruption of the medial periosteal hinge
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Medial metadiaphyseal extension less than 8 mm
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Increasing fracture complexity
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Displacement greater than 10 mm
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Angulation greater than 45 degrees
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Neurovascular injury
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Axillary nerve injury
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Lateral pins placed during CRPP place the nerve most at risk.
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Anterior pins placed during CRPP risk the biceps tendon, cephalic vein, and musculocutaneous nerve.
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Hardware failure
The most common complication after locking plate fixation is screw cutout.
Nonunion
Most common after two-part fracture of surgical neck
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Nonunion of greater tuberosity following arthroplasty—loss of active shoulder elevation
Humeral Shaft Fractures:
Shaft fracture
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Classification by location and fracture pattern
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Treatment
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Nonoperative treatment: functional brace if there is less than 20 degrees of anterior angulation, less than 30 degrees of valgus/varus angulation, or less than 3 cm of shortening; contraindicated in patients with associated brachial plexus palsy
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Operative treatment: open fracture, floating elbow, polytrauma, pathologic fracture, associated brachial plexus injury
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ORIF
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Probably the gold standard
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Proximal two-thirds—anterolateral approach
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Distal half—posterior approach
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Need for radial nerve exploration—lateral approach
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Higher union rates and decreased secondary operations
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Weight bearing to tolerance is safe after plate fixation.
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IM nail
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Possibly better for segmental or shaft/proximal humerus combination as well as pathologic fracture
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Complication rate may be higher and may be associated with higher rates of reoperation than plate fixation.
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Distal locking screw risks
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Radial nerve with lateral-to-medial screw
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Musculocutaneous nerve with anteroposterior screw
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Complications
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Radial nerve palsy (5%–10%)
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When to observe:
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The vast majority (up to 92%) resolve with observation for 3 to 4 months.
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Brachioradialis followed by extensor carpi radialis longus (wrist extension in radial deviation) are the first to return, whereas extensor pollicis longus and extensor indicis proprius are last to return.
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When to explore
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Open fracture
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A higher likelihood of transection
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Perform ORIF of fracture at time of exploration.
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Controversial whether to observe or explore
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Secondary nerve palsy (i.e., after fracture manipulation)
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Spiral or oblique fracture of distal-third (Holstein-Lewis) fracture
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Management of palsy that does not recover is also controversial as to timing of electromyography, nerve exploration, and tendon transfers.
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Nonunion—treated with compression plate with bone graft if atrophic.
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Shoulder pain; some papers report a high incidence of shoulder pain, whereas others do not. Overall incidence is higher with IM nails.
Distal humerus
Single Column
Classification
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Classified as Milch types I and II lateral condyle fractures (more common) and types I and II medial condyle fractures.
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In type I lateral condyle fractures the lateral trochlear ridge is intact, and in type II lateral condyle fractures there is a fracture through lateral trochlear ridge (Fig. 11.4).
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Treatment—type I nondisplaced: immobilize in supination (lateral condyle fracture) or pronation (medial condyle fracture); otherwise, CRPP or ORIF
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Complications: cubitus valgus (lateral) or cubitus varus (medial), ulnar nerve injury, and degenerative joint disease (DJD)
Distal Humerus
Both Column fractures
Presentation: five major fragments identified
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Capitellum/lateral trochlea
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Lateral epicondyle
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Posterolateral epicondyle
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Posterior trochlea
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Medial trochlea/epicondyle
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Treatment (goal is early ROM with <3 weeks of immobilization)
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ORIF using a posterior approach with two plates applied to either column
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Biomechanical studies support both parallel placement (one plate medial, one plate lateral) and perpendicular placement (one plate medial, one plate posterolateral) configurations
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Used with olecranon osteotomy or triceps split/peel (final muscle strength similar with both)
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In an open fracture, ORIF by means of a triceps split through the defect should be used, producing better results than osteotomy.
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Very distal fractures are more difficult and frequently require reoperation (almost 50%) for stiffness
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No benefit from ulnar nerve transposition during ORIF
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“Bag-of-bones” technique—reasonable in patients with dementia and those who have severe medical comorbidities that prevent surgical treatment
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Total elbow arthroplasty—useful for comminuted fractures in patients with low functional demands older than 65 years, particularly those with osteoporosis or rheumatoid arthritis
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Complications
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Stiffness
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Most common complication
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Initially treated with static-progressive splinting
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Loss of elbow muscle strength of 25%
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Ulnar nerve injury
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Treated with anterior transposition
Heterotopic ossification (4%)
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Infection
Capitellar fractures
Treatment
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Type I (complete fracture)—if nondisplaced, splinted for 2 to 3 weeks and then allowed motion; if displaced more than 2 mm, ORIF.
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Type II (shear fracture of articular cartilage)—if nondisplaced, splinted for 2 to 3 weeks and then allowed motion; if displaced, fragment excision.
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Type III (comminuted fractures)—if displaced, fragment excision.
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Type IV (fracture involving capitellum and trochlea)—ORIF; lateral approach recommended
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Complications: nonunion (1%–11% with ORIF), olecranon osteotomy nonunion, ulnar nerve injury, heterotopic ossification (4% with ORIF), and AVN of capitellum
Olecranon Fractures
Treatment
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Less than 1–2 mm displaced—splinted at 60–90 degrees for 7–10 days, followed by gentle active ROM exercises.
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Tension band—stainless steel wire or braided cable, not braided suture material
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The wire loop should be dorsal to the midaxis of the ulna, thus transforming tensile forces at the fracture site into compressive forces at the articular surface.
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Kirschner wires are (K-wires) buried in anterior cortex for increased stability. Protrusion through the anterior cortex, however, is associated with reduced forearm rotation.
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Migration of K-wires and prominent or painful hardware occurs in 71%.
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Compared with K-wires that are positioned into the intramedullary canal, wires that penetrate the volar ulna cortex are associated with a higher potential risk of diminished forearm rotation.
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IM screw fixation—inadequate by itself, but a properly placed 7.3-mm partially threaded screw with tension band wiring works well.
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Plate fixation (dorsal or tension side)—preferred technique for oblique fractures that extend distal to the coronoid process; more stable than tension band wiring
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Excision with triceps advancement—used for nonreconstructible proximal olecranon fractures in elderly patients with low functional demands. Reattached close to the articular surface. Resection of more than 50% of the olecranon should be avoided.
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Complications: decreased ROM, DJD, nonunion, ulnar nerve neurapraxia, and instability
Coronoid Fractures
Classification
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Regan and Morrey classification
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Type I—fracture of the tip of the coronoid process
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Type II—fracture of 50% or less of coronoid
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Type III—of greater than 50% of coronoid
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O’Driscoll classification
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Tip
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Anteromedial process—caused by a varus posteromedial rotatory force and may be associated with posteromedial instability. Injury is at the attachment site of the anterior bundle of the medial collateral ligament.
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Basal
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Treatment
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Type I—associated with episodes of elbow instability. If instability persists, cerclage wire or No. 5 suture is applied through drill holes; if instability does not persist, no operation.
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Types II and III—ORIF helps restore elbow stability; stability must be confirmed before nonoperative treatment begins.
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Complications: instability (particularly medial) and DJD
Radial Head Fractures:
Classification and Treatment
Type I—nondisplaced
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Type II—partial articulation with displacement
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Type III—comminuted fractures involving the entire head of the radius
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Type IV—fractures associated with ligamentous injury or other associated fractures
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Treatment
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Type I—Splinted for no more than 7 days, and then allowed motion.
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Type II—nonsurgical treatment with analgesics and active ROM as symptoms resolve if elbow is stable and there is no block to motion with good reduction. Otherwise, ORIF. Surgery provides better results (90%–100% good or excellent).
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Type III—replacement of the radial head, usually with a metal implant. ORIF if fewer than three pieces. Excision only in elderly patients with low functional demands.
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Type IV—requires surgical repair: either ORIF or metallic radial head replacement must be used. Excision must not be done without addition of radial head implant.
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Safe zone for ORIF of radial head/neck is 110-degree arc (i.e., 25%) along lateral side, defined by radial styloid and Lister tubercle.
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Complications
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Loss of motion
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Posterior interosseous nerve (PIN) injury
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Arm is pronated to avoid injury.
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Radial shortening if Essex-Lopresti injury
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Synovitis if a silicone elastomer (e.g., Silastic) radial head implant is used
Young-Burgess Pelvic fracture classification
Lateral compression (LC)—all have anterior transverse pubic ramus fracture.
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LC I—sacral compression fracture
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LC II—posterior iliac wing fracture
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LC III—contralateral anteroposterior compression injury (windswept pelvis)
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Thought to be due to a rollover mechanism
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Anteroposterior compression (APC)—all have symphyseal diastasis.
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APC I—symphyseal diastasis less than 2.5 cm
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Stretching of anterior SI ligaments
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APC II—symphyseal diastasis greater than 2.5 cm with widening of SI joint anteriorly
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Rupture of sacrotuberous, sacrospinous, and anterior SI ligaments
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APC III—symphyseal diastasis greater than 2.5 cm with complete disruption of SI joint, both anteriorly and posteriorly. Highest transfusion requirements.
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Rupture of sacrotuberous, sacrospinous, and anterior and posterior SI ligaments
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Complete separation of hemipelvis from pelvic ring
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Vertical shear (VS)
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Usually due to a fall. Vertical displacement of hemipelvis commonly with complete disruption of the SI joint.
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Combined mechanism
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Stable types are lateral compression type I and anteroposterior compression type I
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APC II, APC III, LC III, and VS may involve stretching and tearing of veins and arteries causing hemorrhagic shock
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Associated injuries
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APC pattern has associated urethral and bladder injuries. Incidence of spleen, liver, bowel, and pelvic vascular injury increases from APC I to APC III categories.
LC I and LC II patterns have associated brain, lung, and abdominal injuries.
LC III pattern usually due to a crush injury to pelvis, sparing other organs from injury
Vertical shear mechanism fracture injury pattern and mortality similar to those for APC II and APC III patterns.
Combined mechanism pattern has organ injury pattern similar to lower-grade APC and LC patterns
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Cause of death in LC pattern is primarily brain injury, whereas in APC pattern, causes are primarily shock, sepsis, and ARDS.
Sacral Fracture Review
Diagnosis
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Mechanism of injury—high energy
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Radiographs—AP pelvis, inlet, outlet, and lateral views
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CT (usually required)
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Classification—Denis classification (Fig. 11.8) based on fracture location relative to foramen (zones I, II, and III)
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Treatment
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Nonoperative
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Indicated for stable and minimally displaced fractures
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Weight bearing as tolerated for incomplete fractures in which the ilium is contiguous with the intact sacrum (e.g., anterior impaction fractures from lateral compression mechanism or isolated sacral alar fractures)
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Touch-toe weight bearing for complete fractures
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Operative treatment
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Indicated for displaced fractures (>1 cm)
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Percutaneous iliosacral screws
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Appropriate fluoroscopic visualization of anatomic landmarks is mandatory before surgery.
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The pelvic outlet radiograph allows optimal visualization of the S1 neural foramina to avoid injury.
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The lateral sacral view identifies the sacral alar slope and minimizes risk to the L5 nerve root.
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High incidence of sacral dysmorphism (20%–44%). Sacralization of L5 or lumbarization of S1. Risk of anterior screw penetration causing neurologic injury is much higher with anterosuperior sacral concavity (Fig. 11.9).
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Radiographic signs of sacral dysmorphism best seen on outlet view: prominent mammillary processes, laterally downsloping sacral ala, residual vestigial disc space between S1 and S2, top of iliac wing at level of L5–S1 instead of at L4–5, noncircular S1 anterior neural tunnel
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Radiographic signs of sacral dysmorphism best seen on axial CT scan: peaked or prow-shaped sacral promontory, tongue-in-groove sacroiliac articulation, oblique and narrow S1 sacral ala, wider S2 alar channel
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Posterior plating
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Transiliac sacral bars
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Open foraminal decompression considered for neurologic injury associated with zone II fracture
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Complications
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Neurologic injury
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Highest incidence with displaced zone II fractures
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L5 nerve root usually involved with zone II fractures
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Cauda equina syndrome can be associated with zone III injuries.
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Chronic low back pain
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Malunion
Acetabular Fracture Classification review
A systematic evaluation can be used to classify most acetabular fractures using plain radiographs (see Fig. 11.10):
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Examine the iliopectineal and ilioischial lines.
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If both lines are intact:
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PW fracture
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If only one line disrupted:
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Iliopectineal line
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AW fracture
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AC fracture
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Ilioischial line
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PC fracture
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PC and PW fracture
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If both lines disrupted:
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Look at the obturator ring and determine whether it is intact.
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Obturator ring intact
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Transverse fracture
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Transverse/PW
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Obturator ring disrupted
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Look at iliac wing.
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Iliac wing intact
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T-type
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Iliac wing disrupted
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AC/PHT
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ABC fracture
□
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Typically used to evaluate posterior injuries, articular fragments, marginal impaction, and congruency of the hip joint
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Axial CT may be useful to aid in fracture classification.
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Vertical fracture line
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Transverse or T-shaped fracture
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If the wall can clearly be visualized, then AW or PW fracture
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Horizontal fracture line
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Column fracture
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Sequential axial CT cuts that demonstrate no intact support between the acetabular articular surface and axial skeleton through the sacroiliac joint indicate ABC fracture.
Review the cardinal lines of the pelvis
The six cardinal radiographic lines of the acetabulum. 1, Posterior wall; 2, anterior wall; 3, roof; 4, teardrop; 5, ilioischial line; 6, iliopectineal line.
SImple Type Acetabular Fractures
Simple types
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Posterior wall (PW)—most common simple type
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Posterior column (PC)
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Anterior wall (AW)
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Anterior column (AC)
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Transverse
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Involves both the anterior and posterior columns
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Associated types
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Posterior column/posterior wall (PC/PW)
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Transverse/posterior wall (TPW)
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T-type
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Transverse with vertical limbs through ischium
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Anterior column/posterior hemitransverse (AC/PHT)
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Least common type
Associated Pelvic Fractures
Posterior column/posterior wall (PC/PW)
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Transverse/posterior wall (TPW)
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T-type
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Transverse with vertical limbs through ischium
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Anterior column/posterior hemitransverse (AC/PHT)
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Least common type
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Associated both-column (ABC)
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Most common associated type
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Dissociation of acetabular dome from intact ilium
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Spur sign seen on obturator oblique view represents the posterior ilium that is undisplaced
Characterize the Spur Sign
pur sign. Obturator oblique radiograph (left) and drawing (right) of a both-column fracture. Note the medial translation of the dome of the acetabulum and the femoral head. The spur sign represents the intact portion of the iliac wing that remains in its anatomic position.
Characterize the obturator oblique image
Obturator oblique view of pelvis obtained with the patient tilted 45 degrees, with the unaffected hip down and adjacent to the x-ray cassette. The x-ray beam was centered over the affected hip. (B) Obturator oblique radiograph profiles the anterior column and the posterior wall of the acetabulum. (C) Obturator oblique–related landmarks.
Characterize the Illiac Oblique
Iliac oblique view of pelvis obtained with the patient tilted 45 degrees, with the affected hip down and adjacent to the x-ray cassette. The x-ray beam was centered over the affected hip. (B) Iliac oblique radiograph profiles the posterior column and the anterior wall of the acetabulum. (C) Iliac oblique–related landmarks.
What is Tip Apex Distance?
Tip-apex distance (TAD) should be less than 25 mm. Dotted line indicates apex of femoral head
Treatment plan for knee dislocation:
Schenck anatomic classification of knee dislocation (KD)
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KD I—dislocation with either anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) still intact (variable collateral involvement)
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KD II—torn ACL/PCL
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KD III—most common
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Torn ACL/PCL and either posterolateral corner (PLC–KD IIIL) or posteromedial corner (PMC–KD IIIM) injury
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KD IV—torn ACL/PCL/PLC/PMC
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KD V—fracture-dislocation
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More than 50% reduced at presentation (easily missed diagnosis)
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Vascular injury—rate 5%–15% in newer studies
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Selective arteriography with use of a physical examination (including ABI) rather than an immediate arteriogram is now the standard of care.
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Most common finding in patients with vascular injury is a diminished or absent pedal pulse.
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Significant soft tissue injuries
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Treatment
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Emergent reduction if patient did not present with fracture reduced
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Revascularization within 6 hours if there is significant arterial injury.
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Care for soft tissue injuries (open-knee dislocations)
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Ligament repair or reconstruction
•
Reconstruction with allograft becoming the most common
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Immediate reconstruction may be better than delayed reconstruction.
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Early motion rehabilitation
•
Possible role for hinged external fixator
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Complications
•
Vascular injury—highest with KD IV; ABI greater than 0.9 associated with an intact artery
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Neurologic injury—peroneal nerve injury common (≈25%), but up to 50% recover at least partially; may benefit from neurolysis.
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Stiffness/arthrofibrosis—most common complication (38%)
•
Ligamentous laxity also very common (37%)
How to place tibial blocking screws…
proximal tibia fractures
Tibial Plateau fractures:
Review
Type I—split
Type II—split depression
Type III—pure depression (rare)
Type IV—medial tibial (highest risk of associated vascular injury)
Type V—bicondylar with intact metaphysis
Type VI—bicondylar with metaphyseal/diaphyseal dissociation
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MRI changes treatment or classification in most cases.
Soft tissue injury is demonstrated (50%–90% incidence).
MCL and ACL injuries in 30%–50%
•
Meniscus tears in over 50% of cases
•
Lateral tears more common medial tears
•
Lateral meniscus tears most common in split depression (Schatzker type II) fractures
•
Peripheral tears most common type
•
Order of frequency—lateral greater than bicondylar greater than medial (think knee dislocation with medial plateau fractures)
•
The elderly osteoporotic patient is less likely to suffer associated ligamentous injury, because the bone fails before the ligament.
•
The lateral plateau is more convex and situated more proximal than the medial plateau, which is more concave.
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Treatment
•
Nonoperative treatment indicated in stable knees (<10 degrees coronal plane instability with the knee in full extension) with <3-mm articular step-off. Cast brace, early ROM, and delayed weight bearing for at least 4–6 weeks.
•
Operative treatment indicated with articular step-off more than 3 mm, condylar widening more than 5 mm, instability of the knee, and all medial and bicondylar plateau fractures.
•
The goal of treatment is restoration of normal alignment.
•
Maintenance of mechanical axis correlates most with a satisfactory clinical outcome.
•
Development of arthritis does not correlate with articular step-off.
•
ORIF
•
Plate fixation with early motion
•
Posteromedial coronal fragment may not be captured via a lateral plate. Usea separate posteromedial incision and posteromedial plate.
•
Use of bone void fillers
•
Calcium phosphate cement has highest compressive strength.
•
Lower rate of subsidence compared with autograft or allograft
•
Best treatment to prevent loss of articular reduction in a split-depression tibial plateau fracture consists of a lateral plate, rafting screws, and calcium phosphate cement.
•
External fixation—ring fixation useful for bicondylar fractures with severe soft tissue injuries. Small wires must be kept at least 15 mm from the joint to avoid a septic joint.
•
Spanning external fixators—used temporarily in selected high-energy injuries to allow for a reduction in soft tissue swelling before definitive fixation
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Complications: DJD, infection (surgical approach the most important factor), malunion (varus collapse with nonoperative or conventional plates in severe bicondylar fractures), ligament instability (left untreated, has an adverse impact on outcome), peroneal nerve injury
•
Compartment syndrome—increased risk with more proximal fractures. Anterior and lateral compartments are at highest risk.
Review Growth Plates
Introduction
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Fracture of the physis, or growth plate, is more likely than injury to attached ligaments; thus, a fracture of the physis should be assumed until evidence proves otherwise (young children rarely get sprains).
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Characteristics
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Although physeal fractures are classically thought to be through the zone of provisional calcification (within the zone of hypertrophy) of the growth plate, the fracture can be through many different layers.
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Blood supply of epiphysis is tenuous, and injuries can disrupt small physeal vessels supplying the growth center. This can lead to many complications associated with these injuries (e.g., LLD, malunion, bony bars).
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Most common physeal injuries occur in distal radius, followed by distal tibia
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Classification
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The Salter-Harris (SH) classification modified by Rang is the gold standard for physeal injuries (Fig. 11.21; Table 11.6).
•
It can be recalled using the mnemonic SALTR
•
I—slipped—separation physis
•
II—above—metaphysis and physis
•
III—lower—epiphysis and physis
•
IV—through—metaphysis, physis, epiphysis
•
V—ruined—crushed physis
•
SH I fracture is through the zone of hypertrophic cells of the physis.
▪
Treatment and results
□
Gentle reduction should be attempted initially for SH I and II fractures, sometimes with use of conscious sedation protocols. With reduction and immobilization, these fractures do well without a significant amount of growth arrest (except in the distal femur).
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SH III and IV fractures are intraarticular by definition and usually require ORIF. Follow-up radiographs are required for all physeal injuries.
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Remodeling is also common in pediatric fractures (up to 20 degrees), depending on the location of the fracture and the age of the patient.
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Harris-Park growth arrest lines (transverse radiodense lines) may be the only evidence of a physeal injury on follow-up radiographs.
▪
Partial growth arrest
□
Physeal bars or bridges occur from growth plate injuries that arrest a part of the physis and leave the uninjured physis to grow normally resulting in angular growth and deformity.
□
Physeal bridge resection with interposition of a fat graft or artificial material is reserved for patients with more than 2 cm of growth remaining and less than 50% physeal involvement.
□
Treatment of smaller peripheral bars in young patients has the highest success rate.
□
MRI and CT can help define the location and amount of physeal closure.
□
Arrest involving more than 50% of the physis should be treated with ipsilateral completion of the arrest and contralateral epiphysiodesis or ipsilateral limb lengthening.
Elbow Ossification
Secondary ossification centers in order of ossification can be recalled using the mnemonic Come Rub my Tree of Love, and age at ossification of these centers can be roughly estimated on the basis of odd numbers 1–11 (e.g., capitellum at 1 year):
•
Capitellum
•
Radial head
•
Medial epicondyle
•
Trochlea
•
Olecranon
•
Lateral epicondyle
•
Radial head, trochlea, and olecranon may appear as multiple ossification sites.
How to radiographically evaluate the pediatric elbow xray:
- Proximal radius should align with capitellum in all views.
- Long axis of ulna should align and be slightly medial to humerus on AP radiograph.
- Anterior humeral line should bisect capitellum on true lateral radiograph.
- Humeral-capitellar (Baumann) angle should be in valgus and fall between 9 and 26 degrees.
- Soft tissue shadows may demonstrate an anatomic anterior fat pad.
