2. Trauma MCQs

The strongest portion of the femoral neck is the posterior inferior neck in the region of the femoral calcar. The optimal biomechanical configuration includes an inverted triangle pattern with the single screw in the posterior inferior aspect of the femoral neck adjacent to the calcar.

The obturator artery lies closest to the transverse acetabular ligament. The femoral artery is closest to the anterior rim of the acetabulum. No named vessel lies within the substance of the gluteus minimus or superior to the piriformis tendon. The medial femoral circumflex artery lies medial or deep to the quadratus femoris muscle.

Fractures of the distal radius increase the relative risk of a subsequent hip fracture significantly more in men than in women. A previous spinal fracture has an equally important impact on the risk of a subsequent hip fracture in both genders.

DISCUSSION: The patient has a displaced intra-articular tibial tuberosity fracture; therefore, the treatment of choice is open reduction and internal fixation. Periosteum is often interposed between the fracture fragments and prevents satisfactory closed reduction.

DISCUSSION: Infantile tibia vara is a developmental condition characterized by a varus angulation of the proximal end of the tibia that is caused by a growth disturbance of the proximal medial physis. In a study of 42 affected extremities in 24 children younger than age 3 years, it was found that daytime ambulatory brace treatment favorably altered the natural history of tibia vara.

The patient has a displaced iliac wing and bilateral rami fractures with superior migration of the right hip. To prevent further deformity, the patient's right hip should be placed into skeletal traction. A pelvic binder may worsen the deformity because of the iliac wing fracture.

DISCUSSION: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment. Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making. Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair, but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

This view best reveals the posterior acetabular wall and the anterior column of the pelvis. This view is best taken by elevating the affected hip 45 degrees to the horizontal by means of a wedge and directing the beam through the hip joint with a 15 degree upward tilt. The inlet view best delineates posterior displacement of the hemipelvis. The outlet view best views the sacrum, the sacroiliac joints, and the sacral foramina, caudad and cephalad displacement as well. The standard AP radiograph is used in the initial trauma series as a screening tool. Ilial oblique views best view the anterior wall of the acetabulum and the posterior column of the pelvis.

A compartment syndrome of the deep posterior compartment causes symptoms related to structures running through that compartment. The deep posterior compartment includes the tibialis posterior, flexor hallucis longus, flexor digitorum longus, popliteus muscle, as well as the posterior tibial artery and the tibial nerve. Elevated pressures in this compartment would cause paresthesias in the distribution of the tibial nerve (plantar aspect of the foot) and would cause associated pain with passive stretch of the muscles in the compartment (great toe extension).

DISCUSSION: Copeland et al performed a retrospective analysis using their trauma registry data on consecutive blunt trauma patients with unilateral (800 patients) or bilateral (85 patients) femoral shaft fractures. Patients with bilateral femoral fractures had a significantly higher Injury Severity Score (30.2 versus 24.5, p < 0.05) and higher mortality rate (25.9 vs 11.7%, p < 0.014) than patients with unilateral femoral fractures. Bilateral fracture patients also had significantly more closed head injuries, open skull fractures, intraabdominal injuries requiring surgical intervention, and pelvic fractures. The rates of thoracic injury were similar. Regression analysis of variables evident on admission revealed a significant correlation between bilateral femoral fractures and death; however, other factors (shock, closed head injury, and thoracic injury) had much stronger correlations with mortality.

DISCUSSION: The patient has a posterior fracture-dislocation of the hip and following reduction, an incarcerated fragment of bone resulted in an incongruent reduction. Whereas expedient removal of the fragment is required to limit articular cartilage damage, this situation is not an emergency and the procedure may be performed when the appropriate surgical team is available and the patient is stabilized. Skeletal traction through either the femur or tibia may relieve some pressure on the joint and prevent articular damage. Nonsurgical care for incarcerated fragments is contraindicated. REFERENCES: Tile M, Olson SA: Decision making: Non operative and operative indications for acetabular fractures, in Tile M, Helfet DL, Kellam JF (eds): Fractures of the Pelvis and Acetabulum. Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 496-532. Letournel E, Judet R: Fractures of the Acetabulum, ed 2. Berlin, Germany, Springer Verlag, 1993, pp 337-339, p 507.

DISCUSSION: The patient has a fracture-dislocation of the radiocarpal joint. Attached to the large radial styloid fragment are the extrinsic wrist ligaments to the carpus. This injury should be treated with open reduction and internal fixation of the styloid fracture. Radiolunate fusion or extrinsic ligament repair is suggested when the extrinsic ligaments are ruptured, resulting in ulnar translocation of the carpus. REFERENCES: Dumontier C, Meyer ZU, Reckendorf G, et al: Radiocarpal dislocations: Classification and proposal for treatment: A review of twenty-seven cases. J Bone Joint Surg Am 2001;83:212. Bilos ZJ, Pankovich AM, Yelda S: Fracture-dislocation of the radiocarpal joint: A clinical study of five cases. J Bone Joint Surg Am 1977;59:198-203.

DISCUSSION: Persistent pain at the fracture site in the absence of infection is most likely due to a nonunion, best detected by CT. Walsh and DiGiovanni reported on a series of closed rotational fibular fractures in which nonunions were detected by CT in the absence of standard ankle radiographic findings. Repeat immobilization would not be appropriate at this late date. Pain management/sympathetic blocks would be considered if the patient displayed pain with light touch and disproportionate pain consistent with a complex regional pain syndrome. Acupuncture would be expected to be of limited benefit. REFERENCES: Walsh EF, DiGiovanni C: Fibular nonunion after closed rotational ankle fracture. Foot Ankle Int 2004;25:488-495. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003, pp 182-183.

DISCUSSION: Lateral condylar fractures are challenging to treat because of late displacement and development of a nonunion that may lead to valgus instability, pain, or tardy ulnar nerve palsy. Fractures such as this one with more than 2 mm of displacement on any radiographic view are prone to nonunion and should be stabilized. Fractures with less than 2 mm of displacement usually are stable and may be treated nonsurgically. In these patients, careful follow-up is recommended within several days of casting to check for fracture displacement. Arthrography or MRI may be helpful in these minimally displaced fractures. Fractures with an intact articular cartilage surface, such as noted on these studies, are unlikely to displace further.

DISCUSSION: The projection of the sacroiliac joint on the outer surface of the ilium should be well understood to avoid violation of the joint during bone graft harvesting and to help in insertion of the screw across the joint. The sacroiliac joint has superior and inferior limbs. The average lengths of the superior and inferior limbs are 4.4 cm and 5.6 cm, respectively. The average width of each limb is 2.0 cm. The average distance from the longitudinal axis of the superior limb to the posterior superior iliac spine is 5.5 cm. The average longitudinal axis of the inferior limb is 1.2 cm superior to the inferior margin of the posterior inferior iliac spine. The average angle between the two axes is 93 degrees. Figure 21c most closely shows the projection of the sacroiliac joint on the outer table of the ilium.

DISCUSSION: Femoral malrotation after intramedullary nailing is unfortunately a possibility with either antegrade or retrograde nailing techniques. According to a review by Hufner et al, malrotation (internal or external >15 degrees) was seen in 22% of their patients via CT scan after intramedullary nailing. There was a significant difference depending on the time of surgery, with significantly more malrotation during the night shift. Increased fracture comminution also significantly increased malrotation rates. No significant increases were seen with the other answers listed above.

In Figures 83a and 83b, a lateral split depression tibial plateau fracture is noted. This fracture is best treated with a lateral approach and lateral plate fixation to address the joint depression and split component.

Although management of femoral shaft fractures in patients with head injuries remains controversial, most practitioners agree that damage-control principles are appropriate for patients with evolving head injuries. This patient has a subarachnoid hemorrhage and a decreased GCS but is responding appropriately. The best treatment is a damage-control approach for the femur that will cause minimal blood loss and allow the brain injury (and swelling) to equilibrate. External fixation can be performed expeditiously and with minimal blood loss, which will reduce further injury to the brain. Special attention should be paid to maintaining cerebral perfusion pressure higher than 70 mmHg. Admission to the intensive care unit is recommended for monitoring of this injury. Knee immobilizers are not tolerated well by young muscular men with femur shaft fractures. A GCS score of 11 or higher can be observed without ICP monitoring.

The photograph shows the characteristic attitude of the hand when an anterior interosseous nerve palsy is present. The patient is unable to flex the interphalangeal joint to the joint of the thumb. Anterior interosseous nerve palsies are often misdiagnosed as tendon ruptures.(SBQ12TR.54) A 37-year-old male cashier is shot in the leg. He sustains the injury shown in Figures A and B, and is subsequently taken to the operating room for intramedullary nailing. Figure C shows a radiograph of the nail starting point (*). What complication is most likely to result?Varus malunionNonunionValgus malunionMalrotationSuperficial peroneal nerve injuryThis patient is presenting with a comminuted fracture of the proximal third of the tibia. He is appropriately undergoing intramedullary nail fixation, however, the start point illustrated in Figure C is too medial and often leads to a valgus malunion.Intramedullary nail fixation is more technically demanding in proximal tibial fractures than diaphyseal fractures. The valgus deformity is due to imbalanced muscle forces on the proximal fragment, which are then accentuated by a start point that is too medial. An apex anterior (procurvatum) deformity can also occur and results from the pull of the patellar tendon or a posteriorly directed nail that deflects off the posterior tibial cortex and rotates the proximal fragment. The ideal starting point for proximal tibial fractures is slightly lateral to the medial aspect of the lateral tibial spine on a true AP x-ray and very proximal and just anterior to the anterior margin of the articular surface.Nork et al. reported the results of intramedullary nailing of proximal tibial fractures with emphasis on techniques of reduction. Various techniques were found to be successful including attention to the proper starting point, the use of unicortical plates, and the use of a femoral distractor applied to the tibia.Lowe et al. describe surgical techniques for complex proximal tibial fractures. They describe the extended leg position, use of a femoral distractor, temporary plate fixation, blocking (Poller) screws, and use of percutaneous clamps as means to achieve reduction during fixation.Figure A and B show an AP and lateral radiograph of a comminuted extra-articular fracture through the proximal third of the tibia. Figure C demonstrates a start point that is too medial (represented by the asterisk) for intramedullary nail fixation. Illustration A and B show the ideal start point for intramedullary nail fixation of the tibia on AP and lateral radiographs.Incorrect Answers:Varus malunion is more likely to occur in midshaft tibia fractures with an intact fibula.Nonunion after a proximal tibial fracture treated with intramedullary nailing is less common than malunion.Malrotation occurs most commonly after IM nailing of fractures through the distal third of the tibia.The superficial peroneal nerve is at risk during distal screw fixation using a LISS plating technique for fracture fixation.

The patient has a nonunion of the distal fifth of the tibia. The nonunion appears to be oligotrophic, somewhere between atrophic and hypertrophic. Management requires stabilization and stimulation of the local biology, which can be accomplished with open reduction and internal fixation with bone grafting. Bracing or casting does not provide enough stability. Ultrasound bone stimulation has been shown to speed fresh fracture repair but is not indicated in nonunions. The distal segment is too short for intramedullary nailing. A fibular osteotomy alone would increase instability and, even with prolonged casting, would be unlikely to lead to successful repair.