Patient-Specific Instrumentation — MCQs
Most common bone for which nailing is done
Back examination of polytrauma patient is done by which method:-
Which one of the following is not a component of THORACOSCORE?
In immediate denture, why is clear acrylic stent or surgical template given soon after extraction?
Most reliable method to identify putrefied bodies with metallic implants?
Which prosthesis is shown below in the X-ray?
A 65-year-old lady presented with a swollen and painful knee. On examination, she was found to have grade III osteoarthritic changes. What is the best course of action?
What is the most effective management strategy for hemarthrosis?
In which of the following surgeries is monopolar cautery preferred over bipolar cautery?
Blood loss during major surgery is best estimated by:
Patient-Specific Instrumentation Indian Medical PG Practice Questions and MCQs
Question 1: Most common bone for which nailing is done
- A. Radius
- B. Ulna
- C. Tibia (Correct Answer)
- D. Humerus
Explanation: ***Tibia*** - The **tibia** is the most common long bone for which **intramedullary nailing** (IM nailing) is performed, particularly for fractures of the **tibial shaft**. - Its subcutaneous location and strong cortical bone make it amenable to this type of internal fixation, promoting stability and healing. *Radius* - Fractures of the **radius**, especially distal radial fractures, are more commonly treated with **plate and screw fixation** or external fixation, rather than intramedullary nailing. - While IM nailing can be used for some radial shaft fractures, it is not the most common bone for this procedure. *Ulna* - Like the radius, the **ulna** is less frequently fixed with intramedullary nails; **plate and screw fixation** is generally preferred for ulnar shaft fractures. - Its triangular cross-section and the presence of the interosseous membrane complicate IM nailing in some cases. *Humerus* - While **humeral shaft fractures** can be treated with intramedullary nailing, especially in comminuted or pathological fractures, it is overall less common than tibial nailing. - The risk of shoulder and elbow stiffness, as well as radial nerve injury, are considerations with humeral nailing.
Question 2: Back examination of polytrauma patient is done by which method:-
- A. Barrel roll
- B. Primary survey
- C. Logroll (Correct Answer)
- D. Chin lift
Explanation: ***Logroll*** - The **logroll technique** is used to safely turn a polytrauma patient onto their side to examine their back while maintaining spinal immobilization. - It requires multiple personnel (typically 3-5) to turn the patient as a single unit, preventing **unnecessary spinal movement** and potential injury. *Barrel roll* - This term is not a recognized medical technique for examining a polytrauma patient's back. - It might refer to a maneuver in aviation or gymnastics, unrelated to patient care. *Primary survey* - The **primary survey** is the initial rapid assessment of a trauma patient focusing on life-threatening injuries (ABCDE: Airway, Breathing, Circulation, Disability, Exposure). - While back examination is part of the "Exposure" component, the **logroll** is the *method* used for the examination, not the survey itself. *Chin lift* - The **chin lift** maneuver is used to open the airway in an unresponsive patient by lifting the chin upwards and supporting the jaw. - It is an airway management technique and does not involve assessing the patient's back.
Question 3: Which one of the following is not a component of THORACOSCORE?
- A. Performance status
- B. Complication of surgery (Correct Answer)
- C. Priority of surgery
- D. ASA grading
Explanation: ***Complication of surgery*** - THORACOSCORE is a **risk prediction model** for thoracic surgery used to estimate the *probability of mortality and significant morbidity*, but it does not account for the complications of surgery itself as a component. - The score uses **pre-operative patient characteristics** and co-morbidities to predict outcomes, not post-operative events. *Performance status* - **Performance status**, such as the **ECOG scale**, is a crucial component of THORACOSCORE, reflecting the patient's general health and functional capacity prior to surgery. - A lower performance status (indicating poorer functional ability) increases the predicted risk in THORACOSCORE. *Priority of surgery* - The **priority of surgery** (e.g., elective, urgent, emergency) is an important factor in THORACOSCORE, as emergency procedures generally carry a higher risk. - This variable helps to capture the urgency and associated physiological stress on the patient at the time of presentation for surgery. *ASA grading* - The **American Society of Anesthesiologists (ASA) physical status classification system** is a component of THORACOSCORE, assessing the patient's overall health status and anesthetic risk. - A higher ASA grade (indicating more severe systemic disease) contributes to a higher predicted risk in the THORACOSCORE model.
Question 4: In immediate denture, why is clear acrylic stent or surgical template given soon after extraction?
- A. For trimming jagged bone margins (Correct Answer)
- B. Condition tissues
- C. For impression taking
- D. Contain socket healing substances
Explanation: ***For trimming jagged bone margins*** - A clear acrylic stent aids in visualizing the underlying bone during surgery, allowing the clinician to **trim any sharp or jagged bone margins** post-extraction. - This process is crucial for creating a smooth, even ridge that will properly support the immediate denture and prevent **pressure sores** or discomfort. *Condition tissues* - Tissue conditioning is typically performed with a soft reline material placed inside an existing denture or a temporary base to improve the health of abused oral tissues. - A clear acrylic stent is a rigid device used during surgery and does not possess properties to condition tissues. *For impression taking* - Impressions for immediate dentures are taken *before* extractions to capture the existing dentition and soft tissue contours, which are then used to fabricate the denture. - A clear acrylic stent is used *during* the surgical phase, after extractions, to guide bone reshaping, not for taking an impression. *Contain socket healing substances* - While some materials can be placed in extraction sockets to aid healing, the primary purpose of a clear acrylic surgical template is mechanical guidance for bone reduction. - It itself does not typically contain or deliver healing substances to the socket.
Question 5: Most reliable method to identify putrefied bodies with metallic implants?
- A. Serial number matching (Correct Answer)
- B. X-ray superimposition
- C. Dental comparison
- D. DNA profiling
Explanation: ***Serial number matching*** - Metallic implants, such as orthopedic prostheses or pacemakers, often carry **unique serial numbers** that can be traced back to the manufacturer and patient records. - This method is highly reliable even in cases of severe **putrefaction** or fragmentation, as the implant itself is resistant to decomposition. *X-ray superimposition* - This method involves superimposing antemortem (before death) and postmortem (after death) X-rays to look for matching anatomical features. - While useful for bone and tooth identification, it is less reliable for specific identification with metallic implants compared to direct serial number matching, especially if the antemortem X-rays predate the implant. *Dental comparison* - **Dental comparison** involves comparing antemortem dental records (X-rays, charts) with postmortem dental findings. - This method is very effective for identification in general, but it does not directly utilize the metallic implant for identification and thus is not the *most reliable* method when an implant is present. *DNA profiling* - **DNA profiling** is highly effective for identification using biological samples, but it relies on obtaining viable DNA. - In cases of severe putrefaction, obtaining **high-quality, uncontaminated DNA** suitable for profiling can be very challenging or impossible from the remains themselves.
Question 6: Which prosthesis is shown below in the X-ray?
- A. Articular resurfacing
- B. Thompson prosthesis
- C. Austin Moore's prosthesis (Correct Answer)
- D. Birmingham hip replacement
Explanation: ***Austin Moore's prosthesis*** - The image clearly shows a **femoral stem with a long intramedullary component** and an **integrated prosthetic head** that articulates directly with the native acetabulum. This is characteristic of a hemiarthroplasty design, specifically resembling an Austin Moore prosthesis. - This type of prosthesis is commonly used for **femoral neck fractures** in older patients, replacing only the femoral head and neck rather than the entire hip joint. *Articular resurfacing* - **Articular resurfacing** involves capping the femoral head and lining the acetabulum with metallic implants, preserving more bone than a traditional total hip replacement. - The X-ray image does not show a cap on the femoral head or a separate acetabular component, which are features of resurfacing. *Thompson prosthesis* - The **Thompson prosthesis** is another type of hemiarthroplasty, but it typically has a **shorter, bulkier femoral stem** and a **relatively smaller head** compared to the Austin Moore prosthesis shown. - While both Thompson and Austin Moore prostheses are hemiarthroplasties, the specific shape and length of the stem in the X-ray are more consistent with an Austin Moore design. *Birmingham hip replacement* - The **Birmingham hip replacement** is a type of **hip resurfacing arthroplasty**, which, as explained earlier, involves capping the femoral head and is not depicted in this image. - It maintains more of the patient's original bone structure compared to conventional total hip replacement but still requires both femoral and acetabular components.
Question 7: A 65-year-old lady presented with a swollen and painful knee. On examination, she was found to have grade III osteoarthritic changes. What is the best course of action?
- A. Conservative management
- B. Total knee replacement (Correct Answer)
- C. Arthroscopic washing
- D. Partial knee replacement
Explanation: ***Total knee replacement*** - For **grade III osteoarthritis** in a 65-year-old, a total knee replacement is the most definitive and effective treatment to relieve pain and restore function in a severely damaged joint. - This procedure addresses widespread cartilage loss and structural changes typical of advanced osteoarthritis. *Conservative management* - This approach is typically favored for **mild to moderate osteoarthritis**, involving physical therapy, NSAIDs, and lifestyle modifications. - For **grade III changes** with significant pain and swelling, conservative measures are unlikely to provide sufficient relief or halt disease progression effectively. *Arthroscopic washing* - **Arthroscopic lavage** and debridement are rarely recommended for osteoarthritis as they have not shown sustained benefits for pain or function. - It is sometimes used for specific mechanical symptoms, but it does not address the underlying cartilage loss and structural damage in severe osteoarthritis. *Partial knee replacement* - A **partial knee replacement** is suitable when osteoarthritis is confined to a single compartment of the knee, and the other compartments are healthy. - Given the indication of "grade III osteoarthritic changes" without specifying a single compartment, a total knee replacement is generally more appropriate for widespread disease.
Question 8: What is the most effective management strategy for hemarthrosis?
- A. Immobilization with a P.O.P. cast
- B. Application of a compression bandage
- C. Needle aspiration to remove excess blood (Correct Answer)
- D. All of the options
Explanation: ***Needle aspiration to remove excess blood*** - **Aspirating the blood** from the joint effectively reduces intra-articular pressure, pain, and inflammation. - This procedure also helps prevent **synovial hypertrophy** and **cartilage damage** caused by the presence of blood in the joint. *Application of a compression bandage* - While helpful for reducing swelling and providing support, a **compression bandage alone** does not remove the accumulated blood. - It may alleviate some discomfort but does not address the underlying issue of **intra-articular blood accumulation**. *Immobilization with a P.O.P. cast* - **Immobilization** can help rest the joint and reduce pain, but it does not remove the blood from the joint space. - Prolonged immobilization can lead to **joint stiffness** and **muscle atrophy**, which are undesirable outcomes. *All of the options* - While compression and immobilization can be supportive measures, they are not the **most effective primary strategy** for managing hemarthrosis. - The direct removal of blood via **aspiration** is crucial for alleviating pressure and preventing long-term joint damage.
Question 9: In which of the following surgeries is monopolar cautery preferred over bipolar cautery?
- A. Surgery around Penis
- B. Surgery of the Hip (Correct Answer)
- C. Hand Surgery
- D. Surgery around the face
Explanation: ***Surgery of the Hip*** - **Monopolar cautery** is preferred in surgeries like hip surgery where a larger area needs to be coagulated, as it provides a wider field of effect and can be more efficient for **deep tissue coagulation**. - Its mechanism relies on the current passing through the patient to a large **dispersive electrode (grounding pad)**, making it suitable for extensive tissue work. *Hand Surgery* - In **hand surgery**, delicate structures like nerves and tendons are abundant, making **bipolar cautery** safer due to its localized current flow and reduced risk of inadvertent thermal spread. - **Bipolar cautery** limits the current to a small area between the two prongs of the instrument, thus minimizing damage to surrounding tissues. *Surgery around Penis* - **Bipolar cautery** is generally preferred in sensitive areas like the penis, due to its localized effect and reduced risk of thermal injury to adjacent delicate structures. - The avoidance of current passing through the body to a grounding pad in **bipolar modality** is especially important in areas with potential for nerve damage or scarring. *Surgery around the face* - Surgically around the face often involves delicate tissues and structures where **bipolar cautery** is favored to prevent widespread thermal damage and minimize scarring or nerve injury. - The confined current path of **bipolar cautery** makes it ideal for precision work in cosmetic or reconstructive facial surgery.
Question 10: Blood loss during major surgery is best estimated by:
- A. Transesophageal USG Doppler
- B. Visual assessment
- C. Suction bottles (Correct Answer)
- D. Cardiac output by thermodilution
Explanation: ***Suction bottles*** - Measuring the volume of fluid collected in **suction bottles** (after subtracting irrigating fluid) provides a direct and quantifiable estimate of blood loss. - This method is widely used in surgery due to its **simplicity and relative accuracy** for assessing blood collected from the surgical field. *Transesophageal USG Doppler* - This technique primarily assesses **cardiac function** and **blood flow dynamics**, not directly quantifying blood loss. - While it can indicate hypovolemia, it doesn't provide a precise measurement of the volume of blood lost. *Visual assessment* - **Visual estimation** of blood loss by surgical staff is notoriously inaccurate and can lead to significant underestimation or overestimation. - It is highly subjective and depends on factors like lighting, the color of the blood-soaked materials, and individual experience. *Cardiac output by thermodilution* - **Thermodilution** is used to measure cardiac output, which can reflect hemodynamic status and help guide fluid resuscitation. - It does not directly quantify the amount of blood lost but rather assesses the **body's response** to blood loss.
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