2. Trauma MCQs

DISCUSSION: In a recent analysis of 200 patients with tibial fractures, Bhandari and associates attempted to identify variables that were predictive of reoperation. The variables in the study were type of injury (fracture pattern), degree of open injury, mechanism of injury, cortical bone contact, postoperative complications, polytrauma, anti-inflammatory drug use, nail insertion technique (reamed versus nonreamed), smoking history, alcohol use, diabetes mellitus, peripheral vascular disease, age, disability status pre-injury, gender, surgeon, time to surgery, steroid use, phenytoin use, antibiotic use, anticoagulant use, and type of fixation used. Three variables were statistically significant predictors of reoperation to achieve bone union in the first postinjury year: transverse fracture pattern, open fracture, and cortical contact of 50% or less. Using these three variables, four reoperation risk groups were identified based on the number of these three variables present: 0, 1, 2, or 3. The risk for reoperation was 0%, 18%, 47%, and 94%, respectively. The authors concluded that these statistics can provide prognostic information to patients and help identify those high-risk patients where early intervention to achieve union is indicated. In addition, the data highlights the significance of achieving cortical contact at the time of initial fixation. REFERENCE: Bhandari M, Tornetta P III, Sprague S, et al: Predictors of reoperation following operative management of fractures of the tibial shaft. J Orthop Trauma 2003;17:353-361.

DISCUSSION: The patient is at risk for a pelvic vascular injury and major hemorrhage. This type of complication of pelvic trauma is highest in motorcyclists. Once it is recognized that the pelvic ring has opened, it is important to close that ring to tamponade any venous bleeding with a pelvic binder and to add a skeletal traction pin to the limb on the involved side. This will correct any translational displacement. The noninvasive pelvic binders or sheets are easy to apply and are very effective. They do not compromise future care and allow the surgeons access to the abdomen. External fixation or pelvic resuscitation clamps require a certain amount of skill to apply and are not always available. If the pelvic stabilization does not improve the hemodynamic parameters in 10 to 15 minutes, angiography is necessary.

When the lesser trochanter (LT) profile is larger than the uninjured side, the proximal fragment is externally rotated. This leads to an overall internal rotation (IR) malalignment of the distal fragment. Malalignment is described based on the distal fragment relative to the proximal fragment. For more proximal femoral fractures, the proximal fragment tends to be flexed and externally rotated due to the iliopsoas. Matching rotation requires external rotation of the distal fragment when the patient is supine on a fracture table.Rotational malalignment is the most common complication of intramedullary nailing of a comminuted diaphyseal femoral fracture. The rotational profile of the lesser trochanter can be used to evaluate rotational alignment. The proximal femur is rotated until a neutral position is obtained as judged by the radiographic profile of the lesser trochanter. If the AP image shows a smaller lesser trochanter, there is IR of the LT. A larger LT indicates external rotation (ER) of the LT.Jaarsma et al. describe CT imaging in determining rotational alignment. They note that the incidence of post-nailing malalignment > 10 ° is 40%, > 15 ° is 20-30%, and> 20 ° is 16%. They also note that patients with ER deformities have more symptoms than those with IR deformities, and that small deformities <15 ° give rise to less complaints. This is because ER deformities lead to compensation with hip retroversion, which causes more symptoms than hip anteversion when compensating for IR deformities.Incorrect Answers:(SBQ12TR.37) A 44-year-old male presents with the isolated injury seen in Figure A after a motor vehicle accident and underwent the operative treatment seen in Figure B within 8 hours from the time of incident. Which of the following complications is this patient at highest risk of developing?Pulmonary embolusPeriprosthetic fractureContralateral hip fractureOsteonecrosisInfectionThis young male patient has sustained a displaced femoral neck fracture and underwent open reduction internal fixation with 3 cannulated screws. Based on the available options, the patient is most at risk of developing osteonecrosis of the femoral head.Femoral neck fractures in young patients typically are the result of a high-energy trauma. Fracture displacement has been shown to disrupt vascular supply to the femoral head by interrupting retinacular vessels and ligament teres vascularization, as well as increasing intracapsular pressure, producing a tamponade effect. The incidence of osteonecrosis in patients younger than 60 years with displaced femoral neck fractures has been shown to be between 15-30%. Quality of reduction is one key factor that has been shown to influence outcomes postoperatively.Loizou et al. prospectively studied 1,023 patients who sustained an intracapsular hip fracture that was treated with internal fixation using standard fixation modalities. They showed that osteonecrosis was less common for undisplaced (4.0%) than for displaced fractures (9.5%). The population at greatest risk were women younger than the age of 60 with displaced fractures.Barnes et al. review subcapital hip fractures. They found that late segmental collapse was more common in displaced fractures in women younger than age 75 years than in those older than age 75 years treated with internal fixation.Figure A shows a displaced, Garden 3/Pauwels I hip fracture. Figure B shows anatomical fixation with 3 cannulated screws.Incorrect Answers:

The CT scan shows a stress fracture of the olecranon. This injury is the result of repetitive abutment of the olecranon into the olecranon fossa, traction from triceps activity during the deceleration phase of the throwing motion, and impaction of the medial olecranon onto the olecranon fossa from valgus forces. Fractures may be either transverse or oblique in orientation. Initial treatment consists of rest and temporary splinting. Electrical bone stimulation may also be considered. Open fixation with a large compression screw is recommended when nonsurgical management has failed to provide relief.

DISCUSSION: Reverse oblique intertrochanteric femoral fractures account for 5% of all intertrochanteric or subtrochanteric fractures. They are uncommon but not rare and will be encountered in practice. The sliding hip screw is associated with the most problems because of its design. When reverse oblique fractures are fixed with a sliding hip screw, the action of the construct causes medial displacement of the distal fragment rather than compression of the proximal and distal fragments. All of the other implants prevent medial displacement of the distal segment. It should not be assumed that simply using one of the other implants is reason for success. There is a significant failure rate for each of these implants with reverse oblique fractures. The implant must be ideally placed and the fracture must be reduced. REFERENCES: Haidukewych GJ, Israel TA, Berry DB: Reverse obliquity fractures of the intertrochanteric region of the femur. J Bone Joint Surg Am 2001;83:643-650. Sanders RW, Regazzoni P: Treatment of subtrochanteric femur fractures using the dynamic condylar screw. J Orthop Trauma 1989;3:206-213. Baumgaertner MR, Chrostowski JH, Levy RN: Intertrochanteric hip fracture, in Browner BD, Jupiter JP, Levine AM, Trafton P (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 1833-1881.

A high index of suspicion should exist for an arterial injury after any knee dislocation. Due to collateral circulation around the knee, pulses may still be present, as well as normal capillary refill. Though angiography is the gold standard for assessment of both major and minor (intimal) injury to the arterial system, it is invasive and not always readily available. Assessment of the ABI can be done without specialized equipment and personnel. When the ABI (systolic BP distal to injury/systolic BP of uninjured upper extremity) is less than 0.9, consideration of invasive testing or surgical exploration is recommended.

DISCUSSION: This cuboid compression fracture (“nutcracker” injury) is associated with subtle injury to the Lisfranc complex. This diagnosis must be made to ensure proper treatment. REFERENCE: Early JS: Fractures and dislocations of the midfoot and forefoot, in Bucholz R, Heckman JD, Court-Brown CM (eds): Rockwood and Green’s Fractures in Adults. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp 2337-2400.

DISCUSSION: The patient has several indications that he is not ready for definitive fixation of the femoral shaft fracture at this point. He is cold with a core temperature of 93 degrees F, and hypothermia of less than 95 degrees F (35 degrees C) has been shown to be associated with an increased mortality rate in trauma patients. The patient has also not been resuscitated based on his increasing lactate levels and although controversial, it has been shown that temporary external fixation leads to a lower incidence of multiple organ failure and acute respiratory distress syndrome.

DISCUSSION: The etiology of hip fractures in the elderly is multifactorial. Events leading to hip fracture from a fall include fall initiation, fall descent, impact, and the structural capacity of the femur. Hayes and Myers noted that striking the ground in a stiff state with the trunk muscles contracted actually increased the peak impact force, whereas falling in a relaxed state reduced peak impact force. Direction of the fall was important; falls to the side, not forward, were associated with an increased risk of hip fracture. Increased muscle activity about the hip is thought to be associated with spontaneous fractures of the hip and may account for up to 25% of hip fractures; however, it is not related to fractures resulting from a fall.

DISCUSSION: Measurable anterior cruciate ligament laxity, while frequently seen after tibial eminence fractures, usually does not cause symptoms. It is found even in patients whose fractures have been anatomically reduced and fixed, leading to speculation that it is due to stretching of the ligament at the time of injury.

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.

DISCUSSION: The patient has sustained a low-velocity, low-caliber gunshot wound to the foot. Because the injury occurred within a period of 8 hours, this is classified as a type I wound. Several studies support the use of surface debridement, cleansing, and sterile dressings as the treatment of choice. More aggressive measures are reserved for high-velocity injuries and shotgun injuries. REFERENCES: Brettler D, Sedlin ED, Mendes DG: Conservative treatment of low velocity gunshot wounds. Clin Orthop 1979;140:26-31. Hampton OD: The indications for debridement of gunshot bullet wounds of the extremities in civilian practice. J Trauma 1961;1:368-372. Marcus NA, Blair WF, Shuck JM, Omer GE Jr: Low-velocity gunshot wounds to extremities. J Trauma 1980;20:1061-1064.

DISCUSSION: The patient has a Vancouver type B2 periprosthetic femoral fracture with a loose, cementless femoral component. Radiographs show subsidence of the femoral component and the patient reports pain in the thigh for several years prior to the fall. When the femoral component is loose, revision is mandated to treat both the loose component and the fracture. Nonsurgical management is associated with a high risk of medical complications related to extended recumbency as well as a high rate of malunion and nonunion. Cementless femoral component revision has been shown to fare better than cemented femoral components, particularly for treating periprosthetic fractures of the femur. REFERENCES: Masri BA, Meek RM, Duncan CP: Periprosthetic fractures evaluation and treatment. Clin Orthop Relat Res 2004;420:80-95. Springer BD, Berry DJ, Lewallen DB: Treatment of periprosthetic femoral fractures following total hip arthroplasty with femoral component revision. J Bone Joint Surg Am 2003;85:2156-2162.

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.

Several studies have shown worse functional results in patients older than 40 or 50 years of age compared to younger patients after open reduction and internal fixation of tibial plateau fractures. Two studies showed that older patients with less severe fractures performed less favorably than younger patients with more severe injuries. Only 35% of patients older than 50 years were satisfied with their results independent of fracture type.

DISCUSSION: In 1977, Perren and Cordey penned a German manuscript that first described an interpretation of mechanical influences on tissue differentiation. This became known as the Strain Theory of Perren. By remembering that low strain generally leads to bone formation and healing, it is possible to manipulate this fraction intraoperatively to achieve success. When a simple fracture pattern is anatomically reduced and compressed, then the total resting distance between fragments after stabilization approaches 0. This means the numerator must be near 0 to achieve a low-strain environment. This is what occurs in absolute stability (no motion between fracture fragments under physiologic load) and primary bone healing occurs. In the case of a transverse humeral shaft fracture between two stiff joints, the construct is relatively stiff, leading to low strain.

DISCUSSION: The lateral sacral view is used to place percutaneous iliosacral screws. Sacral alar morphology has been shown to be variable from patient to patient. Therefore, intraoperative fluoroscopy is recommended. During placement of the screws, the L5 nerve root is at risk. Routt et al (1997) examined the sacral slope and sacral alar anatomy in cadavers and a series of patients. They determined that the pelvic outlet and lateral sacral plain films provide the best plain radiographic view of the sacral ala. They recommended routine usage of these views intraoperatively to guide screw placement. Routt et al (2000) reported on the early complications of percutaneous placement of iliosacral screws for treatment of posterior pelvic ring disruptions. While technically challenging, this technique leads to less blood loss and lower rates of infection compared to traditional open techniques. Barei et al described methods of anterior and posterior pelvic ring disruptions. They determined that successful placement depends on accurate closed reduction, excellent intraoperative fluoroscopic imaging, and detailed preoperative planning. Early treatment decreased hemorrhage, provides patient comfort, and allows early mobilization.

(3786) Q2-7568:Which of the following treatment methods is used for the majority of patients with a stress fracture:

DISCUSSION: The radiographs reveal a displaced olecranon fracture. To maximize joint congruity of this intra-articular injury, open reduction and internal fixation is the treatment of choice. A tension band plate will assist with maintenance of the reduction and may aid in early range of motion because injuries to the elbow are prone to stiffness. The oblique fracture line is particularly well suited to plate fixation. Percutaneous pin fixation is unlikely to achieve anatomic joint reduction that can be obtained with open means. External immobilization will not accomplish joint reduction and will most likely lead to a nonunion. REFERENCES: Hotchkiss RN: Fractures and dislocations of the elbow, in Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD (eds): Rockwood and Green’s Fractures in Adults, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, pp 929-1024. Murphy DF, Greene WB, Gilbert JA, Dameron TB Jr: Displaced olecranon fractures in adults: Biomechanical analysis of fixation methods. Clin Orthop 1987;224:210-214. Hume MC, Wiss DA: Olecranon fractures: A clinical and radiographic comparison of tension band wiring and plate fixation. Clin Orthop 1992;285:229-235.

DISCUSSION: The most common complication following acetabular or pelvic ring injury is deep venous thrombosis (DVT). Without prophylaxis, rates of DVT are as high as 70% to 80%. With prophylaxis, the rates are around 10%. Infection rates in surgical repair of acetabular fractures are relatively low but a history of diabetes mellitus and a significant Morel-Lavalle lesion certainly increase the risk. However, even with these two complicating factors, the rates of infection are still lower than 10%. Sciatic nerve palsy rates from the injury alone approach 20% and iatrogenic injury is usually less than 2%. Degenerative changes to the hip following this injury approach 20% to 25%, even with an anatomic reduction. REFERENCES: Geerts WH, Code KI, Jay RM, et al: A prospective study of venous thromboembolism after major trauma. N Engl J Med 1994;331:1601-1606. Steele N, Dodenhoff RM, Ward AJ, et al: Thromboprophylaxis in pelvic and acetabular trauma surgery: The role of early treatment with low-molecular-weight heparin. J Bone Joint Surg Br 2005;87:209-212.