Nonunion and Malunion — MCQs
Nonunion is most common in fracture of the:
The malunion of a supracondylar fracture of the humerus most commonly leads to:
McMurray's osteotomy is done for
Elephant foot deformity is indicative of:
Which of the following fractures is least likely associated with vascular injury?
The commonest complication of fracture of clavicle is :
Which of the following is false regarding clavicle?
Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-
Treatment of choice for displaced fracture neck femur in a 40 years old female
Which of the following bone defects offers the best chance for bone fill?
Nonunion and Malunion Indian Medical PG Practice Questions and MCQs
Question 1: Nonunion is most common in fracture of the:
- A. Talus
- B. Neck femur (Correct Answer)
- C. Scapula
- D. None of the options
Explanation: ***Neck femur*** - Fractures of the **femoral neck** are highly prone to **nonunion** due to the precarious and often-disrupted blood supply to the femoral head, particularly the **retinacular arteries**. - The high biomechanical stress and difficulty in achieving stable fixation in this region further contribute to the increased risk of nonunion. *Talus* - While talar fractures, especially those of the **talar neck**, can have a high incidence of complications like **avascular necrosis** due to limited blood supply, nonunion is less common than in femoral neck fractures. - The talus has a complex vascular network that, while vulnerable, often allows for healing. *Scapula* - **Scapular fractures** are generally uncommon and, when they occur, typically heal well without surgical intervention. - Due to the surrounding musculature and rich vascular supply, nonunion of the scapula is extremely rare. *None of the options* - This option is incorrect because **nonunion is indeed a significant problem** in specific fractures, particularly those of the femoral neck, making it a viable answer.
Question 2: The malunion of a supracondylar fracture of the humerus most commonly leads to:
- A. Cubitus varus (Correct Answer)
- B. Cubitus valgus
- C. Extension deformity
- D. Flexion deformity
Explanation: ***Cubitus varus*** - A **supracondylar fracture** malunion often results in posterior and medial displacement of the distal fragment, leading to a **loss of the carrying angle** or even its reversal, known as **cubitus varus** or **gunstock deformity**. - This characteristic deformity is the most common and recognizable long-term complication of improperly healed supracondylar humerus fractures. *Flexion deformity* - While some limitation of extension can occur, a pure **flexion deformity** is not the most common or defining malunion pattern for supracondylar fractures. - The primary angular deformity is typically in the coronal plane (varus) rather than the sagittal plane (flexion/extension). *Cubitus valgus* - **Cubitus valgus** is an increased carrying angle, where the forearm deviates laterally, and is relatively rare after supracondylar fracture malunion. - It is more commonly associated with **lateral condyle fractures** or physeal injuries. *Extension deformity* - An **extension deformity** would imply an increase in the normal extension of the elbow, which is not a common consequence of supracondylar fracture malunion. - The typical angular malunion involves either varus or, less commonly, some degree of flexion contracture.
Question 3: McMurray's osteotomy is done for
- A. Malunited intertrochanteric fracture of femur
- B. Malunited supracondylar fracture of humerus
- C. Nonunion lateral condyle fracture of humerus
- D. Nonunion transcervical neck fracture of femur (Correct Answer)
Explanation: ***Nonunion transcervical neck fracture of femur*** - **McMurray's osteotomy** was historically performed for **nonunion of femoral neck fractures**, particularly transcervical, to improve blood supply and encourage healing. - The procedure involves an **intertrochanteric osteotomy** which changes the biomechanics of the hip, promoting compression at the fracture site. *Malunited intertrochanteric fracture of femur* - This osteotomy is not typically indicated for **malunited intertrochanteric fractures**, as these usually heal well and subsequent malunion is managed differently if symptomatic. - Intertrochanteric fractures often have an **excellent blood supply**, making nonunion less common than in transcervical fractures. *Malunited supracondylar fracture of humerus* - **Malunited supracondylar fractures of the humerus** are managed according to the deformity, often with corrective osteotomies specific to the humerus, not McMurray's osteotomy. - McMurray's osteotomy is a procedure designed for the **femur** and hip joint biomechanics. *Nonunion lateral condyle fracture of humerus* - **Nonunion of lateral condyle fractures of the humerus** is a problem of the elbow joint and is treated with local procedures such as open reduction and internal fixation with bone grafting. - This fracture type is in the **upper limb** and has no relation to the hip-focused McMurray's osteotomy.
Question 4: Elephant foot deformity is indicative of:
- A. Unilateral Le Fort I fracture of maxilla
- B. Non-union of fractured edentulous mandible (Correct Answer)
- C. Diplopia
- D. Skeletal Class II malocclusion
Explanation: ***Non-union of fractured edentulous mandible*** - An **elephant foot deformity** is a characteristic radiographic finding in the non-union of a fracture, particularly in the context of an **edentulous mandible**. - It describes the appearance of **sclerotic, hypertrophic bone ends** at the fracture site, resembling the thick, club-like foot of an elephant, due to persistent movement and attempted callus formation. *Diplopia* - **Diplopia** refers to the perception of two images from a single object, often caused by ophthalmological or neurological issues affecting eye movement. - It is a symptom related to vision and has no association with bone deformities or fracture healing patterns. *Skeletal Class II malocclusion* - **Skeletal Class II malocclusion** describes a condition where the mandible is retrognathic (set back) relative to the maxilla, resulting in an "overbite." - This is a developmental craniofacial anomaly related to jaw position, not a characteristic sign of fracture non-union. *Unilateral Le Fort I fracture of maxilla* - A **unilateral Le Fort I fracture of the maxilla** is a midfacial fracture that separates the maxilla from the pterygoid plates and nasal septum, usually involving a horizontal fracture line above the maxillary teeth. - While it is a type of facial fracture, it does not typically result in an "elephant foot deformity," which is specific to hypertrophic non-unions, especially in the mandible.
Question 5: Which of the following fractures is least likely associated with vascular injury?
- A. Fracture supracondylar femur
- B. Fracture supracondylar humerus
- C. Fracture shaft of femur
- D. Fracture shaft of humerus (Correct Answer)
Explanation: ***Fracture shaft of humerus*** - While any fracture can theoretically cause vascular injury, **mid-shaft humeral fractures** are less commonly associated with significant **vascular compromise** compared to those around major joints or near critical neurovascular bundles. - The **brachial artery** and its branches are often sufficiently mobile and protected by surrounding musculature in the mid-shaft region, reducing the incidence of direct laceration or entrapment. *Fracture supracondylar femur* - **Supracondylar femur fractures** are in close proximity to the **femoral artery** and its branches in the popliteal fossa. - Displacement of these fractures can easily **lacerate or compress** these vital vessels, leading to high rates of vascular injury. *Fracture supracondylar humerus* - **Supracondylar humerus fractures** in children are notoriously associated with **brachial artery injury** due to the artery's close proximity and fixated position over the joint. - The acute angulation and displacement often seen in these fractures put the artery at significant risk of **kinking, compression, or transection**. *Fracture shaft of femur* - **Femoral shaft fractures** can be associated with significant vascular injury, particularly from **large displaced fragments** or high-energy trauma. - The **superficial femoral artery** and its perforating branches can be torn, leading to substantial hemorrhage or arterial compromise.
Question 6: The commonest complication of fracture of clavicle is :
- A. non union
- B. avascular necrosis
- C. Neurovascular injury
- D. malunion (Correct Answer)
Explanation: ***malunion*** - **Malunion** is the most frequent complication following a clavicle fracture, meaning the bone heals in an anatomically incorrect or deformed position. - This often results in a palpable bump or cosmetic deformity, and can occasionally cause functional impairment. *non union* - **Non-union** occurs when the fracture fails to heal completely, leaving a persistent gap between the bone fragments. - While possible, it is less common than malunion in clavicle fractures, especially with appropriate management. *avascular necrosis* - **Avascular necrosis** is rare in clavicle fractures because the clavicle has a rich blood supply. - It typically affects bones with precarious blood supply, such as the femoral head or scaphoid. *Neurovascular injury* - **Neurovascular injury** involving the subclavian vessels or brachial plexus is a serious but relatively rare complication of clavicle fractures. - While possible, especially with displaced fractures, it is not the most common adverse outcome.
Question 7: Which of the following is false regarding clavicle?
- A. First bone to ossify
- B. Membranous ossification
- C. Fracture can be treated with figure of 8 bandage
- D. Non-union is the commonest complication of clavicle fractures (Correct Answer)
Explanation: ***Non-union is the commonest complication of clavicle fractures*** - While clavicle fractures are relatively common, **malunion** (healing in an imperfect position) is more frequent than non-union. - **Non-union** typically occurs in less than 5% of all clavicle fractures, making it a rare complication rather than the commonest. *First bone to ossify* - The clavicle is indeed the **first bone to ossify** in the human embryo, beginning around the 5th to 6th week of gestation. - This characteristic highlights its unique developmental pathway compared to most other bones. *Membranous ossification* - The clavicle develops primarily through **intramembranous ossification**, which involves direct ossification of mesenchymal tissue without a cartilaginous precursor. - It's one of the few bones in the body, along with some bones of the skull, that ossifies this way. *Fracture can be treated with figure of 8 bandage* - A **figure-of-eight bandage** was historically used for clavicle fractures to provide reduction and immobilization. - However, current evidence suggests that a **simple sling** is equally effective and often more comfortable, with less risk of complications like neurovascular compression.
Question 8: Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-
- A. Distal 1/3
- B. Proximal 1/3 (Correct Answer)
- C. Scaphoid Tubercle fracture
- D. Middle 1/3
Explanation: ***Proximal 1/3*** - The **proximal pole of the scaphoid** has a precarious blood supply, primarily from retrograde extraosseous vessels entering distally. A fracture in this region can compromise this supply, leading to **avascular necrosis (AVN)**. - Due to the limited blood flow to the proximal fragment, healing is often impaired, increasing the risk of **non-union** and **malunion**. *Distal 1/3* - Fractures in the **distal 1/3 (distal pole)** of the scaphoid typically have a better prognosis. - This area has a more robust blood supply, reducing the risk of AVN and promoting faster healing. *Scaphoid Tubercle fracture* - Fractures of the **scaphoid tubercle** are usually considered stable and intra-articular, with a good blood supply. - These fractures generally heal well with conservative treatment and have a very low incidence of AVN or non-union. *Middle 1/3* - Fractures in the **middle 1/3 (waist)** of the scaphoid are the most common but still pose a significant risk of non-union. - While the risk of AVN is lower than for proximal pole fractures, it is still higher than for distal fractures, due to the critical vascular supply to both fragments.
Question 9: Treatment of choice for displaced fracture neck femur in a 40 years old female
- A. None of the options
- B. Bipolar hemiarthroplasty
- C. Multiple screw fixation (Correct Answer)
- D. THR
Explanation: ***Multiple screw fixation*** - For a **displaced femoral neck fracture** in a younger patient (40 years old), **internal fixation** with multiple screws is generally the preferred treatment to preserve the native **femoral head**. - This approach aims to achieve **anatomical reduction** and stable fixation, allowing for bone healing and a better long-term functional outcome in active individuals. *Bipolar hemiarthroplasty* - This procedure is typically reserved for older, less active patients with **displaced femoral neck fractures**, particularly those with pre-existing conditions that might limit their longevity or activity level. - While it replaces the femoral head, it does not preserve the native joint, which is a less desirable outcome in a 40-year-old. *THR* - **Total hip replacement** is usually considered for older patients, or younger patients with **pre-existing arthritis** or failed internal fixation, due to concerns about the prosthesis's longevity and potential future revisions. - In a 40-year-old, the goal is typically to preserve the native joint if possible, unless there are other complicating factors. *None of the options* - Internal fixation with multiple screws is a well-established and appropriate treatment for a displaced femoral neck fracture in a 40-year-old patient. - Therefore, one of the provided options is indeed the correct treatment choice for this specific scenario.
Question 10: Which of the following bone defects offers the best chance for bone fill?
- A. 3 Walled defect (Correct Answer)
- B. Hemisepta
- C. Osseous crater
- D. 2 Walled defect
Explanation: ***3 Walled defect*** - A **3-walled defect** provides the best prognosis for bone fill because it retains the most natural bone structure, enhancing the ability to contain bone graft material effectively. - The presence of three bony walls offers **excellent support and blood supply** for graft survival and successful bone regeneration. *Hemisepta* - A **hemisepta** refers to a one-walled defect, which offers very limited containment for graft materials. - It has a **poor prognosis** for bone fill due to insufficient support and rapid loss of grafting material. *Osseous crater* - An **osseous crater** is a two-walled defect where the buccal and lingual walls are present, but the interproximal walls are missing. - While better than a one-walled defect, it still presents challenges in graft containment and has a **less predictable outcome** compared to a 3-walled defect. *2 Walled defect* - A **2-walled defect** offers less containment and support for bone graft materials compared to a 3-walled defect. - The reduced number of walls means there is a **higher chance of graft material displacement** and a slower healing process.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free