a) In the presence of asymmetric pulses
b) In all cases
c) With absent pulses only
d) Does not need to be used as long as Doppler pulses are audible
e) Has been replaced by magnetic resonance image scanning
2. When using the lesser trochanteric profile to assess femoral rotation, a smaller lesser trochanter compared to the uninjured side indicates:
a) External rotation deformity of the distal fragment
b) Internal rotation deformity of the distal fragment
c) A prior injury of the lesser trochanter
d) A varus deformity of the proximal segment
e) A valgus deformity of the proximal segment
3. The safest distance below the knee for placement of external fixation wires is:
A) 5 mm
B) 9 mm
C) 14 mm
D) 19 mm
E) 25 mm
4. Which of the following is not required for use of the dynamic condylar screw (DCS) in a supracondylar femur fracture
A) 4 cm of intact distal femur or easily reconstructable distal femur
B) Intact medial condyle
C) Healthy, nonosteoporotic bone
D) Intact lateral soft tissue envelope
E) Fracture without intracondylar extension
5. Clinical variables associated with a poor outcome following calcaneal fractures include all of the following except:
a) Age older than 50 years
b) Increased body weight
c) History of heavy labor
d) On workers' compensation
e) Decreased body weight
6. Which of the following tibial plateau fractures is often associated with vascular injury:
a) Schatzker type I
b) Schatzker type II
c) Schatzker type III
d) Schatzker type IV
e) Bilateral fractures
7. Which of the following is an advantage of lateral positioning over supine positioning when performing antegrade intramedullary nailing of a subtrochanteric femur fracture with an intact lesser trochanter:
a) Provides improved pulmonary ventilation
b) Eliminates valgus sag at fracture site
c) Allows faster setup and positioning
d) Provides easier alignment of the distal segment to the flexed proximal segment
e) Provides more accurate rotational alignment
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Answers
1.
Answer: a
Explanation: Some controversy exists as to the role of angiography. It is clear that if pulses are not symmetric, angiography is indicated. By the time a Doppler study is needed, pulses are not palpable and angiography should be performed anyway. The need for angiography should not be determined by absent pulses, only asymmetric pulses.
2.
Answer: b
Explanation: Because the lesser trochanter is a posteromedial structure, a smaller profile indicates that the proximal segment is internally rotated compared to the knee. Rotation of the distal fragment is independent of the position of the proximal fragment as they are not connected. A smaller lesser trochanter means the proximal femur is internally rotated; the distal fragment can be either internally or externally rotated.
3.
Answer: C
Explanation: The joint capsule reflects 14 mm below the joint line. Pins placed less than 14 mm below the knee are at risk for articular penetration. Violation of the proximal tibio-fibular joint can also lead to knee sepsis.
4.
Answer: A
Explanation: To obtain adequate fixation using a DCS, at least 4 cm of intact distal femur or easily reconstructable intracondylar femur is necessary as well as an intact medial condyle. If the device is used percutaneously without medial soft tissue stripping, then medial bone grafting is not necessary. Dynamic condylar screws are ideal fixation devices in osteoporotic bone with the use of cement augmentation. The disadvantage to this plate is that the large shoulder can sometimes be prominent on the lateral aspect of the femur.
5.
Answer: e
Explanation: Paley and associates demonstrated the clinical variables associated with a poor outcome include age older than 50 years, increased body weight, history of heavy labor, and on workers' compensation.
6.
Answer: d
Explanation:A Schatzker type IV fracture is a fracture of the medial tibial plateau and may be a split or a split depression fracture. Many of these fractures represent a medial dislocation of the knee that has been reduced by the time the radiographs are taken. It is not the fracture of the medial plateau that gives this fracture its bad prognosis, but the associated injuries to the popliteal artery and peroneal nerve, as well as injuries to the collateral and cruciate ligaments. The arterial injury may be a rupture or only an intimal tear. Because of the frequence of associated popliteal artery injuries, whenever this lesion is recognized patients should be considered for an arteriogram to evaluate the artery and prevent and intraoperative or postoperative thrombosis.
7.
Answer: d
Explanation:
Subtrochanteric fractures can pose challenges in reduction due to the muscle attachments proximal and distal to the fragment. The gluteus medius and gluteus minimus attach to the greater trochanter and abduct the proximal fragment. The iliopsoas attaches to the lesser trochanter, flexing and externally rotating the proximal fragment. In the lateral position, it may be easier to align the distal fragment with the flexed proximal fragment. In the supine position, it may be necessary to place a Schantz pin in the proximal fragment to counteract the deforming forces acting on the proximal fragment.
Pulmonary ventilation is better in the supine position. In the lateral position, you must be careful to avoid valgus sag at the fracture site. Careful attention to correct rotational alignment is necessary in both the supine and lateral position.
