Henry Ford Macomb Orthopaedic Surgery Residency
July 29, 2011
Answer Key for Quiz 2
1. PREFERRED RESPONSE: 4
DISCUSSION: Great toe fractures through the physis should be considered open fractures if there is bleeding at the nail fold. Treatment should include irrigation and debridement and appropriate antibiotics. Immobilization with a cast is usually sufficient for treatment of
the fracture.
2. PREFERRED RESPONSE: 5
DISCUSSION: Avulsion fractures of the tibial spine are rare injuries that result from rapid deceleration or hyperextension of the knee in skeletally immature individuals. This injury is the equivalent of ruptures of the anterior cruciate ligament in adults. These fractures are classified as types 1 through 3. Type 1 is a minimally displaced fracture, type 2 fractures have an intact posterior hinge, and type 3 fractures have complete separation. The radiograph demonstrates a completely displaced, or type III, tibial spine avulsion. Surgical reduction is indicated in type 2 fractures that fail to reduce with knee extension and in all type 3 fractures. Reduction may be arthroscopic or open, with fixation of the bony fragment using a method that maintains physeal integrity and prevents later growth arrest. Preferred techniques would be with suture or an intra-epiphyseal screw
3. PREFERRED RESPONSE: 4
DISCUSSION: Immediate spica casting is ideal for younger children with uncomplicated femoral fractures that are the result of relatively low-energy injury. Surgical stabilization of pediatric femoral fractures is most commonly performed in children who are older than age 6 years or in children with other factors associated with their femoral fracture, such as concomitant head injury, open fracture, floating knee, severe comminution, or vascular injury.
4. PREFERRED RESPONSE: 1
DISCUSSION: Assessment of the acutely injured patient follows the Advanced Trauma Life Support protocol. Cervical cord injury is often associated with a disruption in sympathetic outflow. Absent sympathetic input to the lower extremities leads to vasodilatation, decreased venous return to the heart, and subsequent hypotension. With hypotension, the physiologic response of tachycardia is not possible because of the unopposed vagal tone. This results in bradycardia. Patient positioning, fluid support, pressor agents, and atropine are used to treat neurogenic shock.
5. PREFERRED RESPONSE: 5
DISCUSSION: The radiographs reveal a fracture entering the 4-5 intermetatarsal articulation, consistent with a zone 2 injury. This classically is also referred to as a Jones fracture. The history and radiographic findings indicate this is an acute fracture, which guides management. A zone 1 fracture enters the fifth tarsometatarsal joint, and a zone 3 fracture is a proximal diaphyseal fracture distal to the 4-5 articulation. Initial management is usually nonsurgical and consists of non-weight-bearing in a short leg cast. This method has been shown to result in a better healing rate compared to weight bearing as tolerated.
6. PREFERRED RESPONSE: 1
DISCUSSION: Proximal tibial metaphyseal fractures may result in late genu valgum as a result of asymmetric growth of the proximal tibia. These patients are best treated with observation because the deformity is likely to remodel. Osteotomy is not indicated and potentially will lead to recurrence. Stapling of the medial tibial physis is appropriate in patients who have a severe and progressive deformity.
REFERENCES: Cozen L: Knock-knee deformity in children: Congenital and acquired. Clin Orthop 1990;258:191-203.
7. PREFERRED RESPONSE: 4
DISCUSSION: The incidence of vascular injury in supracondylar humeral fractures is directly related to the degree and direction of displacement. Significant posterior lateral displacement tends to result in brachial artery and median nerve injuries, and posterior medial displacement may lead to radial nerve injury. The brachial artery is always injured at the level of the fracture; therefore, angiography or MRA will not assist in locating the injury. The treatment of choice is surgical reduction and stabilization of the fracture, followed by reassessment of the vascular status. If the hand is pink and warm or pulses can be detected with doppler, it is reasonable to follow the extremity closely after surgery. If the arm becomes pulseless and white, immediate anterior exploration of the arm is indicated. The artery is often entrapped in the fracture and once extricated, will provide adequate blood flow. If the artery is injured, a primary repair or vein graft is needed.
8. PREFERRED RESPONSE: 1
DISCUSSION: Tillaux and triplane fractures occur in adolescents as the result of an external rotation injury of the ankle. As seen on the CT scan, the growth plate starts to close during adolescence; therefore, growth arrest resulting in limb-length discrepancy or angulation is less of a concern in this age group than achieving joint congruity. The joint should be surgically reduced if displacement is greater than 2 mm to minimize the chances of late arthrosis.
9. PREFERRED RESPONSE: 4
DISCUSSION: Acceptable alignment in both bone forearm fractures is related to age and location. In children younger than age 9 years, angulations of 15° and malrotation of 45° are acceptable. In children older than age 9 years, acceptable alignment is 10° of angulation and 30° of malrotation. Bayonet apposition is acceptable provided that the angular and rotational reductions are held within these guidelines. A long arm cast provides better control of deforming forces than a short arm cast.
10. PREFERRED RESPONSE: 3
DISCUSSION: Malunion of the talus is a devastating complication that leads to malpositioning of the foot and subsequent arthrosis of the subtalar joint complex. This is considered an avoidable complication in that accurate surgical reduction will minimize its development. Posttraumatic arthritis of the subtalar joint, osteonecrosis of the talus, posttraumatic arthritis of the ankle joint, and complex regional pain syndrome all may develop as a result of the initial traumatic event and may not be avoidable despite anatomic reduction.
11. PREFERRED RESPONSE: 4
DISCUSSION: Proximal humeral fractures in children are classified as metaphyseal or Salter-Harris type I or II fractures, and most of these fractures are treated with closed methods. Eighty percent of the growth of the humerus comes from the proximal physis; therefore, tremendous remodeling potential is present. Indications for open reduction include open fractures or severely displaced fractures in adolescents with minimal growth remaining. Acceptable limits of reduction in adolescent proximal humeral fractures include bayonet apposition and angulation of less than 35°. Common blocks to reduction in adolescents include the biceps tendon and periosteum. For this fracture, use of a shoulder sling without reduction will lead to healing and an excellent result as the proximal humerus remodels.
12. PREFERRED RESPONSE: 2
DISCUSSION: Monteggia fractures in children must be recognized. Early appropriate treatment is much easier than delayed reconstruction for a missed radial head dislocation. In younger children, attempts should be made to reduce the ulna fracture and radial head dislocation with traction and manual manipulation. Anterior Monteggia fractures are the most common, and in this variety the radius is much better stabilized in elbow flexion. Posterior Monteggia fractures are less common and may be managed in elbow extension. Closed reduction is much more successful in younger children; ulnar fixation with a rod or plate may be needed in older patients with unstable fractures. Annular ligament repair is rarely needed in the acute fracture.
13. PREFERRED RESPONSE: 3
DISCUSSION: Osteonecrosis of the femoral head is a known complication from the use of rigid intramedullary nails for femoral fractures in adolescents. When the nails are placed through the piriformis fossa, the lateral ascending vessels of the femoral neck may be injured, resulting in osteonecrosis of the femoral head in 1% to 2% of patients. Rigid reamed nails placed into the piriformis fossa are contraindicated in children with open growth plates because the physis is a barrier to blood supply and the ligamentum teres does not provide sufficient vascularity. Alternative fixation methods for femoral fractures in adolescents include external fixation and open reduction and internal fixation. Nailing through the tip of the trochanter may decrease the incidence of this serious complication.
14. PREFERRED RESPONSE: 4
DISCUSSION: The lateral radiograph shows 8 mm of atlantoaxial translation. In the absence of a bony injury, this represents rupture of the transverse atlantal ligament. The MRI scan reveals soft-tissue swelling posterior to the odontoid and a high intensity zone in the atlanto-dens interval consistent with acute injury. These injuries require arthrodesis because nonsurgical measures will not provide stability. Techniques for C1-2 fusion include Gallie, Brooks, or triple wiring. Transarticular screw fixation across the C1-2 articulation provides the most rigid means of fixation and the highest arthrodesis rates but is technically demanding. Anterior C2-3 arthrodesis will not address the level of instability. The normal atlanto-dens interval is 3 mm in an adult and 4 mm in a child.