2. Trauma MCQs

Discussion: Posterior partial articular tibial plateau fractures are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the lateral radiograph include maintenance of continuity between the anterior articular surface and tibial shaft along with subluxation of the knee joint with excessively anterior tibial station (the femoral condyles remain with the fractured posterior articular pieces while the remainder of the tibia subluxes anteriorly). 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. Attempting to visualize, reduce, and stabilize a posterior partial articular pattern in the supine position from an anterior approach is fraught with difficulties. Prone positioning is preferred for definitive fixation. Surgical approaches vary, but typically incorporate a posteromedial interval deep to the popliteus and soleus to provide buttress plating to the posterior column of the tibia.

Discussion: The radiographs show multiple carpometacarpal dislocations. Reduction is often obtainable but difficult to maintain. Internal fixation is required to maintain the reduction, preferably with Kirschner wires. Closed reduction and percutaneous pinning is preferred by some surgeons. Others recommend open reduction to remove irreconstructable osteochondral fragments from the individual joints and to ensure correct reduction of the carpometacarpal joints. Kirschner wires are removed at 6 to 8 weeks.

In children ages 3 to 5, who have sustained multiple trauma, the treatment priority is initially their more serious life-threatening injuries. Once other injuries are stabilized, then femoral fractures can be treated. External fixation is rarely needed in this age group, except in the multi-trauma patient with ipsilateral fractures or contralateral fractures. It is also useful in patients with head injuries, in open fractures, and when traction has not prevented significant shortening and angulation of the fracture.

Time to definitive fixation is not a modifiable risk factor concerning open fractures. The other factors are risk factors that have been studied in regards to infection, and all are more important than definitive fixation. Definitive fixation can wait until complete closure and/or coverage. When concerning management of open fractures, the most important factor is a thorough debridement. However, the quality of debridement is often not able to be quantified and thus, often not mentioned in studies. While early clinical and animal studies have shown that initial debridement should occur within 6 hours of injury, more recent clinical trials have not found a significant correlation within that urgent time frame, but rather recommend initial debridement as soon as possible within 24 hours. Time to antibiotic administration has been found to have a significant impact in lowering infection risk. Immediate administration in the emergency room is recommended. The ability to cover and/or close an open wound also has a significant impact on infection. Recent studies have recommended placing hardware after fasciotomy closure and have also demonstrated lower infection rates when flaps are placed within 72 hours of injury.

In osteopenic individuals, even those with excellent obtained or maintained balance, long instrumented fusions to the sacrum impart a high degree of strain, and the sacrum may fail in a transverse fracture or fracture-dislocation pattern. The risk of proximal functional kyphosis is unrelated to distal fixation as are coronal plane correction and rod contouring. Pubic ramus fractures have been shown to be associated with both fixation to the sacrum alone as well as to the ilium.

NPWT provides an excellent bolster for a skin graft and improves skin graft incorporation. It needs to be applied with nonadherent dressings to prevent adherence to the skin graft.

Chest injury (rib fracture, pneumothorax, hemothorax, contusion) is the most commonly associated injury in patients who have sustained a significant scapular injury. Chest injury becomes even more commonly found when the scapula has more than one zone of injury (ie, multiple fractures). Humeral fracture, clavicle fracture, and axillary nerve injury are not as common as chest injury.

DISCUSSION: The patient has sustained a Vancouver B2 periprosthetic femoral fracture (a femoral fracture that occurs around or just distal to a loose stem, with adequate proximal bone stock). The stem is no longer fixed to proximal bone; therefore, retention of the femoral component is not recommended. Nonsurgical management is contraindicated because of the high risk of nonunion and malunion with significant component settling in the distal fragment and leg shortening. Revision femoral arthroplasty must attain distal fixation in adequate host bone, which is usually successful with a porous-coated cylindrical stem.

DISCUSSION: The radiographic and clinical findings suggest a scapulothoracic dissociation with a widely displaced clavicular fracture and a laterally displaced scapula. These injuries have a high association with neurovascular injuries to the brachial plexus and subclavian artery. Emergent vascular evaluation with arteriography and possible vascular repair are indicated. This repair can be combined with open reduction and internal fixation of the clavicle to improve stability. Delay in treatment of these vascular injuries can be devastating.

Hill-Sachs impaction fracture from subluxationSalter-Harris type II fracture of the proximal humerus

DISCUSSION: Type 2A hangman’s fractures are thought to have a flexion mechanism rather than extension and axial loading. This allows them to rotate around the anterior longitudinal ligament into flexion. Anterior translation of greater than 3 mm and angulation distinguish type 2 fractures from type 1 fractures. Although there is an association between C1 ring fractures and C2 fractures, this does not factor into the classification. If a C2-3 facet dislocation exists in combination with a C2 pars fracture, it is considered a type 3 fracture.

DISCUSSION: The patient has a displaced lateral condyle fracture; therefore, simple immobilization for 3 to 8 weeks is likely to result in malunion or nonunion. Closed reduction of such injuries is rarely successful. The fracture is unstable, so fixation is required after open reduction. Because the fixation must cross the physis, smooth pins are indicated for the skeletally immature elbow. Open reduction with fixation has been shown to reduce the risk of delayed union and malunion.

Studies have shown that approximately 25% of diaphyseal fractures of the tibia with intact fibulae will go onto varus malunion if treated nonsurgically. Limb-lengthdiscrepancies are also common. Here the fibula acts as a strut, preventing valgus collapse but predisposing to varus collapse. Valgus and procurvatum is the typical deformity in proximal tibial fractures.

The Weber and Lauge-Hansen fracture classifications suggest that the interosseous membrane (IOM) is torn with certain fracture patterns. In a recent study that evaluated ankle fractures with MRI, Nielson and associates identified 30 patients with IOM tears. Ten of the tears did not correspond with the level of the fibular fracture. The authors concluded that stability of the syndesmosis should not be based on the level of the fibular fracture alone but should also include an intraoperative stress test. Transsyndesmotic fixation should be considered for those fractures where the intraoperative stress test demonstrates instability. A widened medial clear space may occur with a deltoid injury and distal fibular fracture in the absence of a significant tear of the interosseous membrane. Reference: Nielson JH, Sallis JG, Potter HG, et al: Correlation of interosseous membrane tears to the level of the fibular fracture. J Orthop Trauma 2004;18:68-74.

Female patients with natural red-hair may require higher dosages of post-operative analgesia compared to other hair types.Melanocortin-1-receptor (MC1R) is one of the key proteins involved in hair color and skin tone. Mutations of the MC1R alleles can render this protein non-functional, which results in a phenotype of red-hair and fair skin. Mutations of the MC1R have shown to modulate the pain response and opioid efficacy in these patients. Women aremore commonly affected and often require more anaesthetic and higher dosages of opioid to achieve comparable MAC level and pain-relief, respectively, as women with other hair types.Liem et al. showed that a greater concentration of induction and maintenance agents (sevoflurane and desflurane, respectively) were required to sustain comparable MAC levels in red-haired patients as dark haired patients.Fillingim et al. reviewed the affect of gender, sex and pain. They concluded there is a biopsychosocial element of pain that is perceived differently by men and women. In terms of postoperative and procedural pain, the outcome might be more severe in women than men.Delaney et al. looked at the involvement of the melanocortin-1 receptor in acute pain in mice. They found that while the MC1R is better known as a gene involved in mammalian hair colour, it was shown to be involved in the pain pathway of inflammatory but not neuropathic origin. Mutations of MC1R showed increased tolerance to noxious pain stimulus in mice.Figures A and B are AP and lateral radiographs of a left tibia. There is a low energy, distal third shaft fracture with no cortical apposition on the AP view.Incorrect Answers:

This patient has a closed midshaft clavicle fracture with significant displacement that has healed and remodeled nicely with nonsurgical treatment. Functional disability or nonunion after nonsurgical treatment of clavicle fractures in adolescents is rare. Schulz and associates showed no differences in pain, strength, range of motion, or subjective outcome scores between injured and uninjured limbs treated nonsurgically to address displaced, shortened midshaft clavicle fractures in adolescents. Bae and associates demonstrated that clavicle fracture malunions in adolescents do not cause loss of motion or strength.

The radiograph shows a subtrochanteric femoral shaft fracture in a skeletally immature patient. The proximal fragment is displaced into flexion, abduction, and external rotation. Flexion is attributable to the pull of the iliopsoas at the lesser trochanter. Abduction is attributable to the pull of the abductor muscles (gluteus medius and minimus) at the greater trochanter. External rotation is attributable to the pull of the small external rotators, including the piriformis. The majority of the adductor musculature originates on the symphysis pubis and bypasses the proximal femur, inserting further distally on the adductor tubercle. The hamstrings originate on the ischial tuberosity and also bypass the proximal fragment, inserting distally on the proximal tibia and fibula.(SBQ12TR.39) A 36-year-old male falls from a 10-ft scaffold and suffers the injuries shown in Figures A and B. The patient is placed in a spanning external fixator and brought back to the operating room once his soft tissues are amenable. Planning to use a dual-incision approach, what is the correct interval to use when approaching the medial side?Popliteus and pes anserineLateral head of the gastrocnemius and pes anserinePoliteus and lateral head of the gastrocnemiusIliotibial band and medial head of the gastrocnemiusPes anserine and medial head of the gastrocnemiusThe posteromedial approach to the tibial plateau is between the the pes anserine tendons and the medial head of the gastrocnemius.A dual-incision approach is often utilized to optimally place definitive fixation for bicondylar tibial plateau fractures. For fractures that require posterior or posteromedial fixation, the correct interval is between the pes anserine and the medial head of the gastrocnemius.Higgins et al. in a large cohort morphological review, noted a high incidence of a posteromedial fragment in bicondylar fractures. Occurring at a high frequency, theauthors recommended direct visualization and reduction via a dual approach rather than using indirect reduction techniques.Falker et al. describes a step-by-step approach to utilizing the posteromedial approach for the tibial plateau and placing an anti-glide plate.Figure A and B exhibit a bicondylar tibial plateau fracture with a posteromedial fragment noted on the lateral x-ray. Illustration A exhibits the surrounding anatomy and interval in between the medial head of the gastrocnemius and the pes anserine.Incorrect answers:

DISCUSSION: The patient is hemodynamically unstable, so any treatment should be aimed at stabilization. Airway, breathing, and circulation are the most important areas to control initially; the patient has been intubated and has adequate venous access. Despite fluid resuscitation, the child remains hypotensive, indicating continued blood loss. With an unstable pelvic fracture there can be significant hemorrhage. Decreasing the pelvic volume can decrease blood loss related to the pelvic fracture. This can be done in the emergency department by applying a pelvic sling. Other means of decreasing pelvic volume include a pelvic clamp, a simple anterior frame pelvic external fixator, or a simple sheet tied around the pelvis. These maneuvers may stabilize the patient so that further evaluation and treatment can be undertaken. All of the other choices will delay stabilization and should be postponed until the patient is stabilized.

DISCUSSION: Scapulothoracic dissociation is a rare, violent traumatic injury in which the scapula is torn away from the chest wall but the skin remains intact. Massive swelling and ecchymosis are common. Neurovascular injury is the rule with possible subclavian or axillary artery disruption and severe partial or complete brachial plexus paralysis. The diagnosis is made on a nonrotated chest radiograph that shows significant lateral displacement of the medial scapular border from the sternal notch. A right midshaft clavicular fracture is present but is not considered the most significant finding.

DISCUSSION: This intra-articular distal humerus fracture with displacement at the joint surface is best treated with surgical fixation. The most biomechanically sound construct is two plates applied to either column 180 degrees from one another. Elbow arthroplasty is most appropriate for low demand elderly patients.