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2. Trauma MCQs

Practice Set 475 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 9481

Topic: 2. Trauma
Which of the following is considered a relative contraindication for antegrade intramedullary nailing of a proximal humeral shaft fracture?
. Open Gustilo-Anderson Type IIIA fracture.
. Severe shoulder stiffness or rotator cuff pathology.
. Associated ipsilateral forearm fracture.
. Medical comorbidities precluding general anesthesia.
. Polytrauma with head injury.

Correct Answer & Explanation

. Severe shoulder stiffness or rotator cuff pathology.

Explanation

Severe shoulder stiffness or pre-existing rotator cuff pathology (B) is a relative contraindication for antegrade humeral nailing. The entry portal for antegrade nails often traverses or impacts the rotator cuff (supraspinatus tendon), and prominent hardware can lead to impingement. In patients with pre-existing stiffness or cuff issues, this can significantly worsen shoulder function post-operatively. Open fractures (A) are often still nailed but with appropriate wound management. Ipsilateral forearm fractures (C) do not directly contraindicate a humeral nail. Medical comorbidities (D) contraindicate any surgery, not just nailing. Polytrauma (E) can make nailing the preferred choice for early mobilization.

Question 9482

Topic: 2. Trauma

In the setting of a humeral shaft nonunion treated with exchange intramedullary nailing, what is the primary purpose of over-reaming by 2mm beyond the initial nail diameter?

. A. To provide a tighter fit for the new nail.
. B. To stimulate biological activity and create space for bone graft.
. C. To facilitate removal of the previously failed nail.
. D. To reduce the risk of iatrogenic fracture during nail insertion.
. E. To allow for dynamic locking of the new nail.

Correct Answer & Explanation

. B. To stimulate biological activity and create space for bone graft.

Explanation

In exchange nailing for nonunion, over-reaming (typically by 2mm larger than the previous nail) serves to stimulate biological activity by disrupting the fibrous tissue at the nonunion site and promoting a new healing response. It also creates space for potential bone graft (if used) and allows for the insertion of a larger, stiffer nail to improve biomechanical stability. While removing the old nail (C) is part of the process, and preventing fracture (D) is generally desirable, the primary purpose of over-reaming in this context is biological stimulation and a larger implant for better fixation.

Question 9483

Topic: 2. Trauma

A patient undergoing antegrade femoral nailing develops a distal diaphyseal fracture during nail insertion. What is the most likely cause of this iatrogenic complication?

. A. Excessive reaming of the medullary canal.
. B. Use of an unreamed nail.
. C. Incorrect nail curvature not matching the femoral bow.
. D. Failure to achieve adequate reduction prior to nailing.
. E. Distal locking screws placed too early.

Correct Answer & Explanation

. C. Incorrect nail curvature not matching the femoral bow.

Explanation

An iatrogenic distal diaphyseal fracture during nail insertion is most commonly caused by an incorrect nail curvature that does not match the natural anterior bow of the femur. Forcing a straight nail into a bowed femur, or a nail with inappropriate curvature, creates excessive stress at the apex of the bow, leading to a fracture. Excessive reaming (A) might weaken the cortex but is less likely to cause a distinct fracture during insertion compared to a mismatch in curvature. Unreamed nails (B) are generally smaller and less likely to cause this. Poor reduction (D) or early locking (E) can cause other issues, but not typically a new fracture like this.

Question 9484

Topic: 2. Trauma

What is the primary advantage of a 'suprapatellar' approach for tibial intramedullary nailing compared to the traditional infrapatellar approach?

. A. Reduced risk of anterior knee pain post-operatively.
. B. Improved visualization of the proximal tibia and fracture site.
. C. Easier maintenance of reduction, especially for proximal tibial fractures.
. D. Decreased incidence of infrapatellar nerve injury.
. E. Allows for weight-bearing immediately after surgery.

Correct Answer & Explanation

. C. Easier maintenance of reduction, especially for proximal tibial fractures.

Explanation

The suprapatellar approach for tibial intramedullary nailing involves entering the knee joint just proximal to the patella and utilizing a sleeve to protect the joint. Its primary advantage is easier maintenance of reduction, especially for proximal tibial fractures, as the knee can be held in a more extended position. This often provides a more favorable entry angle, reduces anterior bowing, and can facilitate reduction by allowing greater control of the proximal fragment. While some studies suggest a reduced anterior knee pain (A) or nerve injury (D) compared to infrapatellar, the main biomechanical and technical advantage is the improved reduction capability. Visualization (B) is not necessarily improved. Weight-bearing (E) depends on fracture stability, not approach.

Question 9485

Topic: 2. Trauma

In the context of interlocking nail design, what is the main purpose of multiplanar locking options?

. A. To allow for earlier hardware removal.
. B. To accommodate different patient anatomies more easily.
. C. To improve rotational stability and resistance to pullout, especially in short bone segments or osteoporotic bone.
. D. To reduce the overall cost of the implant system.
. E. To facilitate dynamic locking.

Correct Answer & Explanation

. C. To improve rotational stability and resistance to pullout, especially in short bone segments or osteoporotic bone.

Explanation

Multiplanar locking options (e.g., screws inserted in different directions, such as oblique or transverse) are designed to improve rotational stability and resistance to screw pullout. This is particularly crucial in metaphyseal fractures where the bone segment is short and/or osteoporotic, and a single plane of locking may not provide sufficient purchase or stability against all deforming forces. It allows for a more robust capture of the bone fragment. It does not primarily affect hardware removal (A), cost (D), or dynamic locking (E).

Question 9486

Topic: 2. Trauma

A 22-year-old active duty soldier sustains a closed tibial shaft fracture (AO/OTA 42-A3) which is highly unstable. He is otherwise healthy. What is the most appropriate timeline for definitive intramedullary nailing to optimize outcomes and minimize complications?

. A. Within 6-12 hours of injury.
. B. Within 24 hours of injury.
. C. Between 3-7 days after injury, following soft tissue swelling reduction.
. D. After 2 weeks, once initial callus formation has begun.
. E. Electively, based on operating room availability.

Correct Answer & Explanation

. B. Within 24 hours of injury.

Explanation

For isolated, closed tibial shaft fractures in otherwise healthy individuals, definitive intramedullary nailing should ideally be performed within 24 hours (B) of injury, and often within the first 6-12 hours for high-energy fractures (A). This early intervention, often termed 'early total care,' has been shown to reduce complication rates (e.g., compartment syndrome, pulmonary complications), improve outcomes, and facilitate early mobilization. Delaying surgery for soft tissue swelling (C) is more common for open fractures or those with severe soft tissue damage, but for a closed, isolated fracture, early fixation is generally preferred. Waiting longer (D, E) significantly increases the risk of complications.

Question 9487

Topic: 2. Trauma

Which complication is uniquely associated with intramedullary nailing of the humerus via an antegrade approach compared to plating?

. A. Nonunion.
. B. Radial nerve palsy.
. C. Shoulder impingement syndrome.
. D. Infection.
. E. Malunion.

Correct Answer & Explanation

. C. Shoulder impingement syndrome.

Explanation

Shoulder impingement syndrome (C) is a specific complication associated with antegrade humeral intramedullary nailing. The proximal entry portal and any prominent hardware (nail end, locking screws) can irritate or impinge on the rotator cuff and subacromial bursa, leading to pain and restricted shoulder motion. While nonunion (A), radial nerve palsy (B - more common with plating), infection (D), and malunion (E) can occur with both methods, impingement is a distinct concern for antegrade nailing.

Question 9488

Topic: 2. Trauma

A patient with a closed femoral shaft fracture is brought to the operating room for intramedullary nailing. During positioning on the fracture table, which of the following maneuvers is most critical to prevent iatrogenic nerve injury?

. A. Ensuring the knee is fully extended.
. B. Padding all bony prominences, especially the peroneal nerve at the fibular head.
. C. Applying continuous traction until the fracture is reduced.
. D. Maintaining hip adduction and internal rotation.
. E. Avoiding any C-arm fluoroscopy prior to skin incision.

Correct Answer & Explanation

. B. Padding all bony prominences, especially the peroneal nerve at the fibular head.

Explanation

Padding all bony prominences, especially the common peroneal nerve at the fibular head (B), is critical to prevent iatrogenic nerve injury from pressure on the fracture table. Prolonged or excessive pressure on this nerve can lead to a peroneal neuropathy and subsequent foot drop. While positioning aims for reduction and stability (C, D), the specific concern for nerve injury relates to pressure points. Full knee extension (A) can increase sciatic nerve tension, not prevent injury. Fluoroscopy (E) is essential throughout the procedure.

Question 9489

Topic: 2. Trauma

For a comminuted distal tibial metaphyseal fracture (AO/OTA 43-A3), which of the following statements best describes the role of a solid, unreamed intramedullary nail?

. A. Provides absolute stability for primary bone healing.
. B. Is contraindicated due to the wide metaphyseal canal.
. C. Offers a load-sharing construct while minimizing soft tissue disruption and preserving periosteal blood supply.
. D. Is superior to reamed nailing for achieving rotational stability.
. E. Should always be combined with plate osteosynthesis for adequate fixation.

Correct Answer & Explanation

. C. Offers a load-sharing construct while minimizing soft tissue disruption and preserving periosteal blood supply.

Explanation

A solid, unreamed intramedullary nail offers a load-sharing construct that can be advantageous in distal tibial metaphyseal fractures, particularly when soft tissue compromise is a concern. Unreamed nails minimize additional disruption to the endosteal and periosteal blood supply and are less traumatic to the surrounding soft tissues, making them a biologically friendly option. They achieve relative stability for secondary bone healing, not absolute stability (A). While the canal is wide (B), locking screws and blocking screws can improve stability. Reamed nails often provide superior rotational stability (D) due to a larger diameter. Combining with plates (E) might be needed in some complex cases but is not a routine requirement for unreamed nails.

Question 9490

Topic: 2. Trauma
Which patient factor would most strongly favor an unreamed intramedullary nail over a reamed nail for a tibial shaft fracture?
. Segmental fracture pattern.
. Open Gustilo-Anderson Type IIIB fracture.
. Obese patient with a large medullary canal.
. Multiple ipsilateral fractures.
. Patient requiring early full weight-bearing.

Correct Answer & Explanation

. Open Gustilo-Anderson Type IIIB fracture.

Explanation

For an open Gustilo-Anderson Type IIIB tibial fracture (B), an unreamed intramedullary nail is often favored. The rationale is to minimize further iatrogenic soft tissue and endosteal damage, preserve local blood supply, and reduce the risk of infection by avoiding the introduction of reamer debris into a contaminated wound. While reamed nails generally provide stronger fixation, the biological compromise of severe open fractures often dictates a less invasive, unreamed approach initially. Segmental fractures (A) and the need for early weight-bearing (E) typically favor reamed nails for stronger constructs. Obesity (C) doesn't inherently favor unreamed, and multiple ipsilateral fractures (D) are managed based on specific fracture patterns.

Question 9491

Topic: 2. Trauma

What is the primary objective of a 'blocking screw' or 'Poller screw' when used in conjunction with an intramedullary nail for a proximal tibial shaft fracture with metaphyseal extension?

. A. To provide direct compression at the fracture site.
. B. To prevent the nail from backing out proximally.
. C. To guide the nail into the correct anatomical axis and prevent malalignment.
. D. To augment the nail's resistance to rotational forces.
. E. To allow for controlled shortening to promote healing.

Correct Answer & Explanation

. C. To guide the nail into the correct anatomical axis and prevent malalignment.

Explanation

Blocking screws (Poller screws) are placed in the medullary canal, adjacent to the fracture, but outside the path of the nail. Their primary objective is to restrict the motion of the nail, thereby guiding it into the correct anatomical axis and preventing malalignment (e.g., valgus/varus, procurvatum/recurvatum) in fractures with wide metaphyseal canals or severe comminution. They act as an 'internal splint' to center the nail and improve reduction. They do not provide direct compression (A), prevent backing out (B), primarily augment rotational stability (D), or allow for shortening (E).

Question 9492

Topic: 2. Trauma

Which type of nonunion is generally most amenable to treatment with exchange intramedullary nailing?

. A. Atrophic nonunion with significant bone loss.
. B. Hypertrophic nonunion with minimal deformity.
. C. Septic nonunion requiring debridement and antibiotic therapy.
. D. Nonunion with a large intercalary defect.
. E. Nonunion with extensive soft tissue scarring.

Correct Answer & Explanation

. B. Hypertrophic nonunion with minimal deformity.

Explanation

Exchange intramedullary nailing is most effective for hypertrophic or oligotrophic nonunions (B) where there is biological activity but inadequate mechanical stability. The reaming associated with exchange nailing stimulates bone healing, and a larger, stiffer nail provides improved mechanical stability. Atrophic nonunions (A) with bone loss typically require biological augmentation (e.g., bone grafting) in addition to mechanical stability, and may not respond to exchange nailing alone. Septic nonunions (C) require infection eradication first. Large defects (D) require bone transport or grafting. Extensive soft tissue scarring (E) makes any revision surgery more complex.

Question 9493

Topic: 2. Trauma

A 38-year-old male sustains a closed comminuted mid-shaft humerus fracture. During antegrade intramedullary nailing, a common intraoperative challenge is achieving and maintaining reduction. Which technique is often employed to assist with fracture reduction and control during nail insertion?

. A. Use of an external fixator for temporary stabilization.
. B. Application of a large cerclage wire around the fracture site.
. C. Insertion of a K-wire through the fracture fragments for provisional stabilization.
. D. Utilizing a fracture table with traction for continuous reduction.
. E. Performing an open reduction with clamps prior to nail insertion.

Correct Answer & Explanation

. C. Insertion of a K-wire through the fracture fragments for provisional stabilization.

Explanation

For comminuted humeral shaft fractures, achieving and maintaining reduction during antegrade nailing can be difficult due to muscle pull and fragment mobility. The use of a K-wire (or multiple K-wires) inserted percutaneously through the fracture fragments (often into the humeral head or distal fragment) for provisional stabilization (C) is a common and effective technique to control rotation and length, allowing for easier nail insertion and locking. External fixators (A) are generally not used for definitive humeral shaft fracture reduction in this context. Cerclage wires (B) are controversial with nails due to periosteal stripping. Fracture tables (D) are not typically used for humeral nailing. Open reduction (E) is often avoided if possible to maintain soft tissue integrity.

Question 9494

Topic: 2. Trauma

What is the primary reason for choosing a smaller diameter intramedullary nail in an unreamed technique?

. A. To allow for easier removal in the future.
. B. To preserve the endosteal blood supply.
. C. To reduce the cost of the implant.
. D. To provide greater rotational stability.
. E. To avoid damage to the periosteum.

Correct Answer & Explanation

. B. To preserve the endosteal blood supply.

Explanation

Unreamed intramedullary nailing utilizes a smaller diameter nail that can be inserted without reaming the medullary canal. The primary rationale is to preserve the endosteal blood supply, which is critical for bone healing, especially in open fractures or compromised patients. While it also causes less disruption to the local biology, the main advantage is blood supply preservation. A smaller nail generally provideslessrotational stability (D) and overall stiffness compared to a larger, reamed nail. It doesn't primarily affect cost (C) or ease of removal (A). Avoiding periosteal damage (E) is a general surgical principle, not specific to unreamed technique.

Question 9495

Topic: 2. Trauma

Which of the following is considered the most significant long-term complication unique to intramedullary nailing of the tibia?

. A. Nonunion.
. B. Malunion (angulation or rotation).
. C. Anterior knee pain.
. D. Infection.
. E. Hardware prominence requiring removal.

Correct Answer & Explanation

. C. Anterior knee pain.

Explanation

Anterior knee pain (C) is a very common and often persistent long-term complication after tibial intramedullary nailing, with reported incidences ranging from 10% to 70%. It is usually related to irritation of the patellar tendon by the proximal nail or locking screws, or damage to the infrapatellar branch of the saphenous nerve. While nonunion (A), malunion (B), infection (D), and hardware prominence (E) are common complications for many orthopedic surgeries, anterior knee pain is specifically prevalent and often troublesome after tibial nailing.

Question 9496

Topic: 2. Trauma

When performing intramedullary nailing of a distal third tibial fracture, what anatomical structure is most at risk during distal locking screw placement from a medial-to-lateral direction?

. A. Anterior tibial artery.
. B. Deep peroneal nerve.
. C. Saphenous nerve.
. D. Posterior tibial artery.
. E. Superficial peroneal nerve.

Correct Answer & Explanation

. C. Saphenous nerve.

Explanation

When placing distal locking screws in the tibia from a medial-to-lateral direction, the saphenous nerve (C) and saphenous vein are most at risk as they lie subcutaneously on the medial aspect of the distal tibia. The anterior tibial artery (A) and deep peroneal nerve (B) are in the anterior compartment, and the posterior tibial artery (D) is in the deep posterior compartment. The superficial peroneal nerve (E) is more lateral.

Question 9497

Topic: 2. Trauma

A 65-year-old male with a history of peripheral arterial disease presents with a closed distal femoral shaft fracture (AO/OTA 32-A3). Which type of intramedullary nail is generally preferred for this patient?

. A. Solid, unreamed nail.
. B. Cannulated, reamed nail.
. C. A long cephalomedullary nail.
. D. A short, static-locked nail.
. E. A flexible nail system.

Correct Answer & Explanation

. B. Cannulated, reamed nail.

Explanation

For distal femoral shaft fractures in patients with compromised vascularity (such as peripheral arterial disease), a cannulated, reamed intramedullary nail (B) is generally preferred. While solid, unreamed nails (A) minimize endosteal disruption, reamed nails allow for a larger diameter implant, providing superior mechanical stability which is crucial for distal femoral fractures that often involve shorter metaphyseal segments and may be osteoporotic. The risk of FES is lower in distal femoral nailing compared to diaphyseal, and the mechanical benefits of reaming typically outweigh the risks in this location, especially for fracture patterns like 32-A3. Cephalomedullary nails (C) are for proximal fractures. Short nails (D) are typically not used for shaft fractures. Flexible nails (E) are not standard for adult femoral shaft fractures.

Question 9498

Topic: 2. Trauma

In the management of a Gustilo-Anderson Type II open tibial shaft fracture with intramedullary nailing, what is the recommended timing for definitive wound closure?

. A. Primary closure at the time of initial nailing.
. B. Delayed primary closure at 5-7 days post-injury.
. C. Secondary intention healing.
. D. Closure only after hardware removal.
. E. Immediate skin grafting at the time of nailing.

Correct Answer & Explanation

. B. Delayed primary closure at 5-7 days post-injury.

Explanation

For Gustilo-Anderson Type II open tibial shaft fractures, delayed primary closure (B) at 5-7 days post-injury, after repeat debridement (if necessary) and assessment of wound viability, is generally recommended. This allows for adequate debridement, reduces bacterial load, and permits further assessment of soft tissue viability. Primary closure (A) carries a higher risk of infection. Secondary intention (C) is reserved for small wounds or those with significant tissue loss. Closure after hardware removal (D) is too late. Immediate skin grafting (E) is rarely appropriate for a Type II fracture and usually follows successful delayed closure.

Question 9499

Topic: 2. Trauma

Which of the following biomechanical features of an intramedullary nail is most crucial for preventing shortening in a comminuted femoral shaft fracture?

. A. The overall length of the nail.
. B. The ability to achieve static locking proximally and distally.
. C. The nail's bending stiffness.
. D. The reaming technique used.
. E. The material composition of the nail.

Correct Answer & Explanation

. B. The ability to achieve static locking proximally and distally.

Explanation

In comminuted fractures, where there is no cortical contact to resist axial loads, static locking (B) proximally and distally is absolutely crucial to prevent shortening. The locking screws convert the nail into a load-bearing construct that maintains length and rotation. While overall length (A), bending stiffness (C), reaming (D), and material (E) contribute to the nail's mechanical properties, static locking is the specific mechanism to prevent shortening in an axially unstable fracture.

Question 9500

Topic: 2. Trauma

What is the primary technical challenge when performing intramedullary nailing for a periprosthetic femoral fracture around a total hip arthroplasty stem (Vancouver B1 or B2)?

. A. Achieving an adequate distal lock in the femoral condyles.
. B. Determining the correct entry point through the greater trochanter.
. C. Bypassing the existing hip prosthesis without compromising its stability or alignment.
. D. Preventing fat embolism syndrome.
. E. Minimizing blood loss during reaming.

Correct Answer & Explanation

. C. Bypassing the existing hip prosthesis without compromising its stability or alignment.

Explanation

For periprosthetic femoral fractures around a total hip arthroplasty (THA) stem (Vancouver B1 or B2), the primary technical challenge is to bypass the existing hip prosthesis with the intramedullary nail without compromising the stability or alignment of the existing implant, or the fracture fixation. This often requires specialized nail designs (e.g., long nails, nails with specific bowing or offset entry options) and careful planning to ensure the nail can be inserted past the tip of the stem and provide adequate fixation proximally and distally. Distal locking (A) is a general challenge but secondary to bypassing the stem. Entry point (B) is critical but specific to the stem. FES (D) and blood loss (E) are general considerations.

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