(A) Type I
(B) Type II
(C) Type IIIA
(D) Type IIIB
(E) Type IIIC
2. Six weeks after open reduction and internal fixation of a talar neck fracture, an anteroposterior radiograph of the ankle reveals a lucency deep to the subchondral surface of the talar dome. This indicates:
(A) Malreduction of the fracture
(B) Osteonecrosis of the talus
(C) Collapse of the dome of the talus
(D) Associated tibial plafond impaction
(E) Revascularization of the talus
(A) Supination
(B) Pronation
(C) Dorsiflexion
(D) External rotation
(E) Internal rotation
4. In performing a lateral approach to the calcaneus for open reduction, internal fixation, the structure at risk is:
a) Lateral plantar artery
b) Lateral plantar nerve
c) Dorsalis pedism artery
d) Sural nerve
e) Superficial peroneal nerve
5. An 18-year-old woman arrives in your office 3 years after sustaining a comminuted right femur fracture treated with intramedullary (IM) nail fixation. She is complaining of moderate low back pain. On physical examination, you note that she has an 8-cm leg length discrepancy, and radiographs confirm that the right femur has healed 8 cm short. The most appropriate treatment at this point is:
A) Shoe lift on the right
B) Limb lengthening of the right femur
C) Limb shortening of the left femur
D) Observation
E) Left leg epiphysiodesis
6. Union rates of the femur after antegrade or retrograde reamed intramedullary nailing are:
A) Higher for antegrade nailing
B) Higher for retrograde nailing
C) Identical
D) Dependent on location in the bone
E) None of the above
7. A 39-year-old man sustained a grade II open diaphyseal tibia fracture that was treated with irrigation and debridement, external fixation, and delayed wound closure 12 weeks ago. At 9 weeks, the patient's weight bearing status was increased to partial weight bearing and the patient has since reported slight leg pain. Radiographs indicated a comminuted diaphyseal fracture of the tibia with no signs of callus formation. The radiographs also show no signs of loosening of the external fixator pins. Treatment at this point should include:
A) Removal of external fixator and placement of a patellar tendon bearing (PTB) cast, and progression to weight bearing as tolerated
B) Irrigation and debridement
C) Removal of external fixation and intramedullary nailing
D) Autogenous bone grafting
E) Placement of coralline hydroxyapatite into the fracture site
a) A distal third oblique fracture
b) A proximal third metaphyseal fracture
c) A comminuted midshaft fracture
d) A transverse midshaft fracture
e) An open transverse fracture with a large butterfly fragment
9. The most important factor in predicting cutout of an implant to repair intertrochanteric fractures of the hip is:
a) Size of the chosen screw
b) Posterior/inferior placement
c) Tip/apex distance
d) Pitch of the chosen screw
e) Angle of the plate
10. The optimal number of screws to repair displaced fractures of the femoral neck is:
A) Three
B) Five
C) Two
D) Four
E) Six
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1. C
Explanation:
Open fractures must be graded after the first debridement. Preoperative classification of open fractures often underestimates the degree of bone and soft tissue compromise. The Gustillo-Anderson classification divides open fractures into 5 groups:
• Type I fractures have an open wound less than 1 cm in length.
• Type II wounds measure greater than 1 cm but less than 10 cm without contamination, and the wounds can be closed without flap coverage.
• Type IIIA fractures have an open wound greater than 10 cm that can be closed with delayed primary techniques. Segmental fractures and gunshot injuries are also graded IIIA.
• Type IIIB fractures require rotational of free flap wound coverage.
• Type IIIC fractures are any open fractures with an associated vascular injury that requires repair.
2. E
Explanation:
The talus is composed of 7 articular surfaces covering 60% of the bony surface. Vascular access to the bone is limited to the nonarticular areas. An anastomotic sling of vessels provides the blood supply to the body of the talus that include: laterally, the artery of the tarsal sinus; medially, the artery of the tarsal canal, and additional arteries that enter dorsally through the neck and on the medial surface of the body.
The likelihood of talar body osteonecrosis increases with the severity of the injury. The diagnosis of osteonecrosis is routinely made radiographically by the absence of a Hawkin sign. This lucency deep to the subchondral surface of the dome of the talar dome on an anteroposterior radiograph of the ankle obtained 6 to 8 weeks after injury is an indication of revascularization.
3.
Answer: D
Explanation:
Tillaux originally described a special fracture occurring in older adolescents. The mechanism of injury is an external rotational force with stress placed on the anterior tibiofibular ligament, causing avulsion of the distal tibial physis anterolaterally. This occurs after the medial part of the physis has closed but before the lateral part closes. The resultant fracture through the physis runs across the epiphysis and distally into the joint, creating a Salter-Harris type III or IV fracture. Open reduction and internal fixation are indicated if the fracture is displaced. If left untreated, nonunions may result.
4.
Answer: D
Explanation: The sural nerve is the most likely structure to be at risk when performing a lateral approach to the calcaneus to perform an open reduction and internal fixation. Care must be taken to protect the small saphenous vein and sural nerve lying immediately posterior to the incision.
5.
Answer: B
Explanation:
The patient in question is at skeletal maturity. The approach to leg length discrepancies (LLD) depends on the length difference between the limbs. Discrepancies of more than 4 cm to 5 cm are treated with lengthening. Distraction is usually at the rate of 1 mm/day and is achieved by using Ilizarov principles, including metaphyseal corticotomy (preservation of the medullary canal and blood supply) and gradual lengthening. Lengthening over an IM nail may decrease the time in a distraction device.
- A shoe lift is reserved for differences less than 2 cm.
- The patient is at skeletal maturity so epiphysiodesis is not an option.
- Limb shortening of the unaffected limb is reserved for limb discrepancies of 2 cm to 5 cm.
- Observation is unlikely to change the patient's symptoms.
6.
Answer: C
Explanation:
Several studies have compared antegrade with retrograde nailing. When controlled for canal fit and degree of reaming, the biological effects of antegrade and retrograde nailing on union are identical. The entry portal is irrelevant to union of the fracture.
7.
Answer: D
Explanation: In this patient, the soft tissue has healed from his open wound. The patient is progressing toward a delayed nonunion due to lack of callus formation. The next step should include autogenous bone grafting. The progression of his weight bearing status will lead to loosening of his external fixator pins.
8.
Answer: B
Explanation: Fractures of the proximal third of the tibial shaft do not appear to respond as favorably to intramedullary nailing as do fractures in the distal two-thirds of the tibia. Valgus, apex anterior angulation, and residual displacement at the fracture site are common after nailing. Surgical errors of a medialized nail entry point and a posteriorly and laterally directed nail insertion angle contributed to malalignment. Based on their findings, the authors have limited the use of intramedullary nailing for proximal third tibial shaft fractures and consider alternate forms of fixation (plate or external fixation). An alternative technique is the use of blocking screws.
9.
Answer: C
Explanation: The most important factor in predicting cutout of an implant is the tip/apex distance. Screw design is a consideration but is limited by the anatomy of the proximal femur. Posterior/inferior placement was a factor used with old devices that did not purchase adequately in the femoral head.
10.
Answer: A
Explanation: Studies show that the optimal treatment for displaced fractures of the femoral neck is three parallel screws in a tripod configuration. Adding a fourth or fifth screw does not improve fixation, adds to technical difficulties, and theoretically, more vascular damage to femoral head can occur.
