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2. Trauma MCQs

Practice Set 190 of 640

This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 3781

Topic: 2. Trauma

A patient presents to the emergency department with the injury seen in Figure A. Which of the following is true about radial nerve palsies associated with isolated humeral shaft fractures after low velocity gunshot wounds?

. The initial treatment involves debridement, irrigation, nerve exploration, and osteosynthesis.
. The radial nerve palsy is often a result of neurotmesis.
. Initial treatment involves splinting and observation for return of neurologic function.
. Electrophysiologic testing for radial nerve palsies is indicated after 2-3 weeks without improvement.
. The radial nerve palsy will not resolve regardless of attempted interventions.

Correct Answer & Explanation

. The initial treatment involves debridement, irrigation, nerve exploration, and osteosynthesis.

Explanation

When a patient sustains an isolated humeral shaft fracture and radial nerve palsy from a GSW, the initial treatment involves splinting with observation.The majority of humeral shaft fractures are treated initially with a coaptation splint and then transitioned to a functional brace. Absolute surgical indications for operative management include: open fracture, brachial plexus injury, compartment syndrome, floating elbow, or vascular injury. A radial nerve palsy is not an indication for surgical management of an isolated humeral shaft fracture. Radial nerve injury from a low-velocity GSW is similar to that of blunt force trauma and thus, immediate exploration is not necessary. Instead, nerve function should be observed. Seventy percent of these nerve injuries will resolve spontaneously. Additionally, the patient should receive a short course of antibiotics as any low velocity GSW would be treated.Guo et al retrospectively reviewed the electrophysiologic data for 40 radial nerve palsies caused by GSWs and blunt trauma. After characterizing the palsies by level of injury, completeness of nerve injury, and other associated nerves injured, they found there to be no difference in any of these variables between GSW induced radial nerve palsies and blunt trauma induced palsies.Vaidya et al retrospectively reviewed the outcomes of 54 patients with humeral shaft fractures resulting from low velocity GSWs comparing operative and non-operative treatments. They found that patients receiving non-operative management did well and that 70% of radial nerve palsies in the non-operative treatment group resolved ontheir own. They recommended non-operative treatment for the majority of isolated humeral shaft fractures resulting from civilian gunshot wounds.Figure A is a radiograph of a humeral shaft fracture after a GSW. Illustration A is a radiograph of a humeral shaft fracture with a coaptation in place. Illustration B is an example of a functional brace.Incorrect answers:

Question 3782

Topic: 2. Trauma

Radiographs of a 7-year-old child show mid-diaphyseal fractures of the radius and ulna. Closed reduction with sedation in the emergency department is performed. Postreduction radiographs demonstrate 18 degrees angulation, 30% translation, and what appears to be 20 degrees of rotational malalignment. Based on these findings, what is the next most appropriate step in management? Review Topic

. Another attempt at closed reduction in the operating room
. Open reduction with plating of the radius only
. Open reduction with plating of the ulna only
. Open reduction with plating of both the radius and ulna
. Close monitoring with follow-up radiographs in 1 week

Correct Answer & Explanation

. Another attempt at closed reduction in the operating room

Explanation

In children younger than 8 years of age, acceptable reduction parameters for fractures of the forearm are less than 20 degrees of angulation, 100% translation, and less than 45 degrees of malrotation. Weekly monitoring for loss of reduction and unstable fractures requiring further intervention is needed. When acceptable alignment can be maintained, good outcomes can be expected in this age group. In patients older than 10 years, angulation of less than 10 degrees, full translation, and malrotation of 30 degrees can be accepted. When surgical treatment is indicated, plating of one or both bones is acceptable. However, in this patient, the reduction is acceptable so a repeat closed reduction attempt and surgical treatment are not needed.(SBQ13PE.17) A 14 year-old girl falls from the monkey bars, sustaining the injury shown in Figures A and B. This is a closed injury and she is neurovascularly intact. When deciding on optimal treatment, what are the acceptable parameters for angulation, malrotation, and bayonet apposition, respectively, in this patient?ReviewTopic10 degrees, 30 degrees, Yes, allowed10 degrees, 0 degrees, Yes, allowed0 degrees, 0 degrees, None0 degrees, 10 degress, None10 degrees, 15 degrees, NoneBoth bone fractures that occur in adolescents, especially in patients close to skeletal maturity, have very little potential for remodeling, and therefore, require anatomic restoration of the deformity.As patients get older and closer to skeletal maturity, closed reduction alone typically is not sufficient to obtain and maintain anatomic reduction. Often, operative intervention is required via either intramedullary nailing (IMN) or plating.Hertel et al. retrospectively reviewed diaphyseal plating of over 160 both bone forearm fractures in a wide age range of patients, which included adolescent patients (16 years old). The authors reported over a 96% union rate, low overall complication rate, and near zero refracture rate following subsequent hardware removal. The authors determined internal fixation with 3.5mm low contact dynamic compression plates sufficient for optimal results.Baldwin et al, in this systematic review and meta-analysis compared the use of IMN and plate osteosynthesis for the treatment of pediatric both bone fractures. A total of 12 studies were included for analysis. The authors noted excellent union and outcome results for both treatment modalities, although although there was a significantly higher rate of hardware removal (94% vs. 49%) in IMNs. While there was a slight trend toward increased rates of non-union with IMN, it was not statistically significant.Figures A and B show AP and lateral radiographs of a both bones forearm fracture in a near skeletally mature individual. Despite minimal angulation on the lateral, the deformity present in the coronal plane is unacceptable. Illustration A depicts the recommended parameters suggested by Baldwin et al. JOT 2014 for angulation, malrotation and bayonet apposition.Incorrect answers:

Question 3783

Topic: 2. Trauma

03 Which of the following findings is the best indication for the use of temporary external fixation of a femoral shaft fracture?

. Type IIIA open fracture
. back to this question next question
. Hemodynamic instability
. Segmental fracture
. Distal one third fracture
. Ipsilateral tibial shaft fracture 33.03

Correct Answer & Explanation

. Type IIIA open fracture

Explanation

These days, femoral shaft fractures at Tulane / Charity are commonly encountered by orthopaedic residents on the night-float team.Despite the presence of a well-rested 4th year surgeon, definitive orthopaedic fixation is not always the correct answer for each trauma patient.Tulane defines “Orthopaedic Tunnel Vision” as a condition commonly associated with a young MD at the Bulldog without a properwing-man, trying to make advances on the wrong patron due to his relatively easy 80-hour work week schedule and a few too many refined hops.Skeletal Trauma (p. 1967) describes “Orthopaedic Tunnel Vision” as looking at the orthopaedic injury without considering thepatient’s injury in general. Femoral shaft fractures are typically high energy injuries which often do not occur in isolation. In these fractures, it is particularly important to not have tunnel vision.Indications for temporary bridging external fixation includes hemodynamic instability(ans. 2), acidosis, hypothermjia, hypoxemia, coagulopathy, sepsis or severely contaminated soft tissues that cannot be adequately debrided. Definitive fixation is performed after the general surgical and medical issues have resolved.The other answer choices, including the type IIIA open fracture are not contraindications to definitive fixation in themselves (typically IM nailing—antegrade or retrograde).

Question 3784

Topic: 2. Trauma

A 33-year-old male suffers a gunshot to the right forearm as seen in figure A. There is a 2 cm radial-sided wound with exposed bone. What is the most appropriate treatment?

. Irrigation and debridement with open reduction and internal fixation of the radius and ulna with 3.5-mm LC-DCP bridge plate
. Closed reduction and sugartong splint with ORIF within 2 weeks
. Irrigation and debridement with open reduction and internal fixation of the radius and ulna with 4.5-mm LC-DCP compression plate
. Irrigation and debridement with open reduction and internal fixation of the radius and ulna with 4.5-mm LC-DCP bridge plate
. Irrigation and debridement definitive external fixationCorrent answer: 1The patient has a comminuted, relatively high-energy open fracture of the right radius and ulna, which is best treated with irrigation and debridement of the gunshot wounds followed by early internal fixation if possible using a 3.5 mm LC-DCP plate placed with a bridging technique.Diaphyseal forearm fractures are best treated with open reduction and internal fixation to restore anatomic alignment and absolute stability. Typically this is achieved by the use of 3.5 mm plates, placed in such a manner to produce interfragmentary compression. Due to the comminution in this case, bridge plating will provide a superior outcome as it will minimize interfragmentary strain and preserve the local bone biology. Multiple studies have demonstrated that open reduction and internal fixation at the initial encounter is appropriate, even if there is comminution, bone loss, or an open injury requiring multiple debridements.Anderson et al. performed a retrospective study of 87 patients with 129 diaphyseal forearm fractures treated with dynamic compression plates. Open fractures were fixed primarily and the overall union rate was 98%. Refracture occurred in 2 patients after removal of 4.5 mm plates, whereas there were no refractures after removal of the 3.5 mm plates.Moed et al. reviewed 57 patients that underwent immediate internal fixation of a diaphyseal forearm fracture. Functional results were good to excellent in 85% of patients and there were 2 deep infections and 6 non-unions overall.The authors conclude immediate plate fixation is an appropriate treatment method for open diaphyseal forearm fractures and recommend autogenous grafting at the time of wound closure.Jones et al. analyzed a retrospective case series of 18 patients with grade 3 open diaphyseal forearm fractures treated with irrigation and debridement and immediate open reduction and internal fixation followed by aggressive soft tissue management over the following weeks. Their treatment protocol provided good to excellent results in 66% of patients, indicating immediate reduction and fixation may be an acceptable treatment for some patients.Figure A demonstrates comminuted radius and ulna shaft fractures with retained bullet fragments.Incorrect answers:

Correct Answer & Explanation

. Irrigation and debridement with open reduction and internal fixation of the radius and ulna with 3.5-mm LC-DCP bridge plate

Explanation

OrthoCash 2020

Question 3785

Topic: 2. Trauma
Figure 56 is the radiograph of an otherwise healthy 3-year-old boy who fell and sustained the isolated injury shown. What is the best treatment modality?
. Elastic intramedullary nailing
. Submuscular plating
. Early hip spica casting
. Traction as definitive treatment

Correct Answer & Explanation

. Early hip spica casting

Explanation

DISCUSSION: At 3 years of age, children do well with nonsurgical treatment with early spica casting and early mobilization. There is no indication to perform surgical stabilization in such a closed isolated injury. The fracture is not shortened unacceptably according to clinical practice guidelines, and traction for this fracture is unnecessary. Traction also may be problematic for the family and healthcare system.

Question 3786

Topic: 2. Trauma
A 45-year-old man reports severe discomfort following a twisting injury to his right ankle and foot. Plain radiographs are negative; however, the CT scans shown in Figures 39a and 39b reveal a fracture. Management should consist of
. open reduction and internal fixation.
. percutaneous pin fixation.
. excision of the fracture fragment.
. primary calcaneocuboid joint arthrodesis.
. a walking cast or removable cast boot.

Correct Answer & Explanation

. a walking cast or removable cast boot.

Explanation

DISCUSSION: The CT scans show a fracture of the anterior process of the calcaneus that involves less than 25% of the joint surface with minimal to no displacement. The preferred treatment is external immobilization in either a walking cast or, more typically, a removable cast boot. For larger fractures that involve more than 25% of the articular surface with joint incongruity, open reduction and internal fixation may be indicated. Primary calcaneocuboid joint arthrodesis is not warranted because symptoms are rare in most patients. Delayed excision of the fragment is a late reconstructive option if painful nonunion develops. Percutaneous pin fixation is not indicated because there tends to be inherent stability in this fracture.

Question 3787

Topic: 2. Trauma
A 28-year-old man who sustained the injury shown in Figure 31 is hemodynamically unstable. In addition to fluid resuscitation, the next most appropriate step in management should include
. angiography and embolization.
. an emergent exploratory laparotomy.
. external pelvic stabilization.
. open reduction and internal fixation.
. closed reduction and percutaneous screw fixation.

Correct Answer & Explanation

. external pelvic stabilization.

Explanation

The radiograph shows us a pelvic inlet view of an APC II or III pelvic ring injury with syndesmotic disruption greater than 5cm, and a right SI joint disruption as well. APC (and some VS) injuries are associated with increases in pelvic volume allowing occult blood loss. All of the responses are viable options, but on a spectrum of timing. ORIF and CRPSF are both more elective options that require appropriate pre-operative planning and a stable patient, not to be undertaken in a hemodynamically unstable patient. The article referenced from JBJS 2002 reviewed 150 patients with pelvis fractures and the use of angiography for the management of hemorrhage. They concluded/recommended skeletal stabilization as the first line of treatment, followed by possible laparotomy and packing of pelvic retroperitoneum as a second line of treatment, with pelvic angiography and embolization only in those patients that were unresponsive to both previous interventions. They based their recommendations also on anatomical studies that suggested that the surfaces of the fracture and veins, rather than arteries, were the major sources of bleeding in these patients. External pelvic stabilization in their study included external fixators, pneumatic anti-shock garments, and pelvic clamps.

Question 3788

Topic: 2. Trauma

Which of the following would be associated with the spinal deformity shown in Figures 79a and 79b? Review Topic

. Improved gait
. Deformity progression
. Delayed satiety
. No further risk of fracture
. Improved lung function

Correct Answer & Explanation

. Improved gait

Explanation

The images delineate progressive osteoporotic collapse. As outlined by Kado and associates, Schlaich and associates, and Gold and associates, the progression of spinal deformity and the functional consequences of vertebral compression fractures are persistent even in those patients who are pain free. Vertebral compression fractures are associated with deteriorating gait, early satiety, further future fracture risk, and deteriorating lung function.

Question 3789

Topic: 2. Trauma

An active, right-handed 71-year-old woman fell on her left shoulder and sustained the injury shown in the radiographs in 52a and 52b and the CT scan in 52c. Management should consist of

. hemiarthroplasty
. open reduction and internal fixation
. closed reduction and percutaneous pinning
. a sling and early pedulum exercises
. a sling and swathe for 6 weeks, followed by shoulder rehabilitation

Correct Answer & Explanation

. hemiarthroplasty

Explanation

Prosthetic hemiarthroplasty is the accepted form of treatment for badly displaced fractures and fracture dislocations, including 4-part fractures, head splitting fractures and fractures with impression defects involving more than 45 % of the humeral head. Displacement is classified as >1cm or angulated > 45 degrees. About 15% of all shoulder fx’s are considered displaced.

Question 3790

Topic: 2. Trauma
Figures 31a and 31b show the T1- and T2-weighted MRI scans of a patient’s knee joint. What is the most likely diagnosis?
. Torn anterior cruciate ligament
. Torn medial meniscus
. Staphylococcus infection
. Rheumatoid arthritis
. Tibial plateau fracture

Correct Answer & Explanation

. Tibial plateau fracture

Explanation

The scans show a lipohemarthrosis. There is the characteristic layering of a superior zone containing fat (high signal intensity), a central zone containing serum (low signal intensity), and an inferior zone that contains red blood cells (low signal intensity). The most common cause of a lipohemarthrosis is an intra-articular fracture with leakage of marrow fat into the joint.

Question 3791

Topic: 2. Trauma

Osteoporotic vertebral compression fractures are associated with Review Topic

. neurologic deterioration in 33% of patients.
. osteomalacia in 50% of patients.
. a further fracture risk rate of 20%.
. chronic pain in 75% of patients.
. a 2-year mortality rate that is less than that associated with hip fractures.

Correct Answer & Explanation

. neurologic deterioration in 33% of patients.

Explanation

Osteoporotic vertebral compression fractures are associated with neurologic complications in less than 1% of patients. After the initial fracture however, patients have a 20% risk of further fractures. The mortality rate of patients with vertebral fractures exceeds that of patients with hip fractures when they are followed beyond 6 months.

Question 3792

Topic: 2. Trauma
An adult with a distal humeral fracture underwent open reduction and internal fixation. What is the most common postoperative complication?
. Loss of elbow range of motion
. Nonunion
. Malunion
. Infection
. Ulnar nerve dysfunction

Correct Answer & Explanation

. Loss of elbow range of motion

Explanation

DISCUSSION: Most patients lose elbow range of motion after open reduction and internal fixation of a distal humeral fracture. Ulnar nerve dysfunction, nonunion, and infection all occur less commonly. REFERENCES: Webb LX: Distal humerus fractures in adults. J Am Acad Orthop Surg 1996;4:336-344. McKee MD, Wilson TL, Winston L, et al: Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. J Bone Joint Surg Am 2000;82:1701-1707.

Question 3793

Topic: 2. Trauma
Which examination finding points toward a brachial plexus injury rather than root avulsion?
. Winging of the scapula
. Intact rhomboid function
. A biceps with 0/5 strength
. An ipsilateral clavicle fracture

Correct Answer & Explanation

. Intact rhomboid function

Explanation

EXPLANATION: A brachial plexus injury distal to the root level should leave the rhomboid muscle with intact function. Root avulsions of C5-6 will cause weakness of the rhomboids. The branching of the dorsal scapular nerve is proximal and often spared with upper brachial plexus injuries. Winging and biceps weakness may occur with either injury, and an ipsilateral fracture does not differentiate an avulsion from a brachial plexus injury.

Question 3794

Topic: 2. Trauma

Limited weight bearing usually is recommended following open reduction and internal fixation of intra-articular lower extremity fractures. A bone graft, or bone graft substitute is often placed in the metaphyseal void beneath the reduced articular fragments. Which of the following bone grafts or bone graft substitutes will most likely permit earlier weight bearing without subsidence of the articular reduction?

. Autogenous iliac crest bone graft
. Calcium phosphate
. Calcium sulfate
. Tricalcium phosphate
. Coralline hydroxyapatite blocks

Correct Answer & Explanation

. Autogenous iliac crest bone graft

Explanation

Most bone graft substitutes have a low compressive strength, similar to cancellous bone. Calcium phosphate cements, when hardened, have a much higher compressive strength compared to any of the other bone grafts or bone graft substitutes. In a study of 26 patients undergoing open reduction and internal fixation of displaced tibial plateau fractures, calcium phosphate was found to produce good outcomes. Because of the high mechanical strength of the cement, the authors allowed early weight bearing after a mean postoperative period of 4.5 weeks, with a range from 1 to 6 weeks. Despite early weight bearing, only two patients in this series had a partial loss of reduction. In biomechanical studies of displaced tibial plateau fractures, calcium phosphate compared favorably to cancellous bone graft. In one clinical series of patients undergoing open reduction and internal fixation for a calcaneus fracture, those patients whose reductions were supported with calcium phosphate were allowed to begin full weight bearing at 3 weeks and displayed no radiographic evidence of reduction loss. The effectiveness of calcium phosphate to resist deformation with cyclical loading in simulated calcaneal fractures has been confirmed in a biomechanical study.

Question 3795

Topic: 2. Trauma

A 68-year-old patient undergoes total knee arthroplasty for end-stage degenerative joint disease. Two years later, she trips and falls at home and sustains a fracture seen in Figures A and B. Before her fall, she was a community ambulator and had no knee pain. The component is determined to be stable and the surgeon decides to treat this fracture with closed reduction and retrograde intramedullary fixation with a supracondylar nail. Which of the following statements is true?

. The starting point tends to be more posterior than usual, resulting in hyperextension at the fracture site.
. An arthrotomy is not necessary
. A high-speed carbide burr is usually necessary to enlarge the box for nail entry.
. The backup plan should include devices that allow multiple points of fixation in the distal segment, such as dynamic condylar screw and fixed angle blade plate.
. The backup plan should include devices that resist varus collapse, such as condylar buttress plates.

Correct Answer & Explanation

. The starting point tends to be more posterior than usual, resulting in hyperextension at the fracture site.

Explanation

The patient has a cruciate-retaining (CR) prosthesis. The starting point for nail entry is more posterior than normal because of the femoral component. This leads to hyperextension at the fracture site.Periprosthetic femur fractures above total knee implants occur in 2% of patients. It is important to note: (1) pre-injury function, to determine if the prosthesis was loose, (2) the type of implant (CR vs posterior stabilized, PS) as a PS implant with a closed box would make retrograde intramedullary nailing more difficult (the surgeon has to consider the size of the box vs size of the nail, and if the box is smaller than the nail,must be prepared to enlarge the box with a metal-cutting burr, which has inherent problems of introducing wear debris into the joint), (3) pre-fracture radiographs help determine the position of the implants (flexion-extension, varus-valgus). These fractures can be treated with non-locking condylar buttress plates (not recommended today), fixed angle devices and intramedullary nailing.McLaren et al. describe 7 osteopenic patients (mean age, 61yrs, range 47-84yrs) treated with retrograde supracondylar nailing. They suggest not reaming, and placing 2-3 screws in the distal fragment. This may require leaving the nail protruding by 1cm. They then suggest removing the protruding segment with a burr at the end of the procedure.Haidukewych et al. debate plating vs nailing in a 80yr old osteopenic patient. It may be difficult to introduce retrograde intramedullary nails through the same incision if dense scar tissue is present. On the other hand, most plates require extensive dissection and do not respect the soft tissues and fracture biology, except for LISS plates and nails.Figures A and B show a displaced Lewis and Rorabeck type II periprosthetic fracture. Illustration A shows the technique of retrograde supracondylar nailing. With the knee flexed, the fracture is reduced and the entry point is in the intercondylar notch. Illustration B shows a comparison between PS and CR implants. Note the "box" in the PS implant. This is absent in the CR implant. Illustration C shows the Lewis and Rorabeck classification.Incorrect Answers:1 (at most 2) point of fixation in the distal segment. Answer 5: The backup plan should include devices that resist varus collapse (especially in cases with medial comminution), such as angle-stable devices (ABP, DCS and locking plates). Non-locking condylar buttress plates will not resist varus collapse.

Question 3796

Topic: Upper Extremity Trauma
Figure 7 shows the radiograph of an 18-year-old hockey player who sustained a shoulder injury during a fall into the side boards. Examination reveals a significant prominence at the acromioclavicular joint. Management should consist of
. a figure-of-8 clavicle strap.
. a sling for comfort, followed by early range-of-motion and strengthening exercises.
. open reduction and stabilization.
. immobilization in a spica cast.
. resection of the distal clavicle.

Correct Answer & Explanation

. open reduction and stabilization.

Explanation

The radiograph shows a type V acromioclavicular separation with greater than 100% superior elevation of the clavicle. This finding implies detachment of the deltoid and trapezius from the distal clavicle. Because of severe compromise of function and potential compromise to the overlying skin, surgery is the treatment of choice for type V acromioclavicular separations. During reduction and repair, meticulous repair of the deltotrapezial fascia will also aid in securing the repair.

Question 3797

Topic: 2. Trauma

Figure 1 is the MR image of a 55-year-old man who sustained an acute traumatic injury to his right shoulder with loss of active range of motion. He was initially evaluated by his primary care physician and treated with physical therapy without success. He was referred to an orthopaedist for surgical consultation 8 weeks after sustaining the injury. The orthopaedic surgeon performs a successful arthroscopic repair but notes poor tendon quality at the repair site. The treating surgeon keeps the patient in a sling full time for 6 weeks without formal therapy. One year after surgery, in comparison to early therapy, this rehabilitation program will likely result in

. no difference in terminal range of motion.
. a lower functional outcome score.
. a clinically significant reduction in passive forward flexion and external rotation.
. a higher retear rate of the rotator cuff repair.Historically, orthopaedic surgeons considered early range-of-motion programs following rotator cuff surgery secondary to concerns about potential postsurgical stiffness. Although this may have been a concern with primary open repair, arthroscopic surgery appears to substantially decrease this risk. More recently, investigators are reporting similar results in terms of range of motion, retear rate, and functional outcome scores among patients who undergo early versus delayed rehabilitation programs.

Correct Answer & Explanation

. no difference in terminal range of motion.

Explanation

Stemless shoulder arthroplasty prostheses have recently been suggested as an alternative to traditional stemmed replacement. Advantages of the stemless surgical technique would includeA. better glenoid exposure than with stemmed prostheses.B. reliable use in four-part proximal humerus fracture reconstruction.C. use in proximal humeral malunion without the need for an osteotomy.D. improved long-term survivorship profile.

Question 3798

Topic: 2. Trauma
What is the most common type of malalignment after intramedullary nailing of distal 1/3 tibia fractures?
. Varus
. Valgus
. Translational
. Rotational
. Apex anterior

Correct Answer & Explanation

. Rotational

Explanation

DISCUSSION: Puloski et al determined the incidence and severity of tibial malrotation following reamed intramedullary nail fixation as measured by computerized tomography. Malrotation was defined as an internal/external rotation deformity greater than 10 degrees. They found that 5 (22%) of the tibia were malrotated greater than 10 degrees, and of those 5 tibia, 4 were distal 1/3 fractures.

Question 3799

Topic: 2. Trauma

A 17-year-old football player is tackled with an opposing player's helmet hitting him hard in the abdomen. He is knocked backwards and suffers a diaphyseal femur fracture. He denies any loss of consciousness. Vital signs reveal a heart rate of 118, mean arterial pressure (MAP) of 68, and a respiration rate of 32 per minute. A FAST ultrasound study shows trace free fluid in the perisplenic space. A CBC taken prior to bolus IV fluids reveals a hematocrit of 48%, and a blood gas shows a lactate level of 1.8 and a base excess of -2.0. Which of the follow statements regarding the patient's hemodynamic status is correct?

. A well-placed and well-calibrated arterial line would be the most helpful clinical tool for determining when this patient is out of shock
. The hematocrit well within normal limits means the patient is not in hemodynamic shock
. A combination of heart rate greater than 120 and MAP less than 65 equates to poor tissue perfusion levels
. Normal lactate levels and base excess are markers of adequate tissue perfusion
. His orthopaedic injury alone cannot explain his vital sign derangements and an exploratory laparotomy is indicated

Correct Answer & Explanation

. A well-placed and well-calibrated arterial line would be the most helpful clinical tool for determining when this patient is out of shock

Explanation

Normal lactate levels or base excess indicate adequate tissue perfusion.Hypovolemic shock leads to poor tissue perfusion due to inadequate flow or oxygenation. If a patient is in compensated shock (i.e. normal vital signs), there may be ongoing inadequate perfusion of some end-organs. Elevated lactate or a base deficit are markers of poor end-organ perfusion, thus when normalized indicate appropriate end-organ perfusion even if vital sign derangements persist.Rossaint et al. wrote a comprehensive review article in 2006 in which they discuss principles of fluid management, coagulopathy, hypothermia and tissue oxygenation in hypovolemic shock. In addition to prolonged elevated lactate levels correlating to mortality, lactate levels (or base deficits) can be used to evaluate for compensated shock in the setting of normal hemodynamic status.Illustration A shows the classification of hypovolemic shock. Note the percent of blood loss required for vital sign abnormalities.Incorrect Answers:setting of massive blood loss. The hematocrit only changes once the patient has physiologic or iatrogenic fluid shifts in response to the blood loss. Answer 3: Vital sign derangements indicate uncompensated shock, but do not directly measure tissue perfusion or end-organ damage Answer 5: Though uncommon, bleeding from isolated femur fractures can lead to Class II shock (blood loss 15-30%)

Question 3800

Topic: 2. Trauma
Figure 42 shows the radiograph of a 70-year-old woman who has had a painful near ankylosis of her dominant elbow for 1 year. Treatment should consist of
. total elbow replacement.
. hardware removal and joint release.
. medial and lateral column humerus plating and a bone graft.
. distal humerus replacement.
. resection arthroplasty.

Correct Answer & Explanation

. total elbow replacement.

Explanation

The patient has arthritis and supracondylar nonunion of the elbow. Total elbow replacement has been shown to give almost immediate return of function as it can be performed while leaving the triceps intact and resecting the distal humerus fragment. Attempts at osteosynthesis are indicated in younger individuals with good joint surface. Resection arthroplasty yields poor function and is reserved as a salvage procedure.

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