Arthroplasty

Arthroplasty Indian Medical PG Question 1: During abutment preparation of natural teeth for overdenture, which of the following is more preferable?

• A. Short copings
• B. Long copings
• C. Bare root surface (Correct Answer)
• D. None of the above options are ideal.

Arthroplasty Explanation: ***Bare root surface*** - A **bare root surface** is often preferred as it allows for optimal placement of the overdenture framework directly over the root without significant bulk. - This approach minimizes tooth reduction and maintains more of the natural tooth structure, which helps preserve the **periodontal health** surrounding the abutment. *Short copings* - While short copings can provide some protection to the abutment, they add vertical height to the restored tooth. - This added height can make it challenging to achieve proper occlusal clearance and may compromise the stability of the **overdenture**. *Long copings* - **Long copings** require more extensive tooth reduction, potentially weakening the abutment tooth. - They can also increase the leverage on the abutment, increasing the risk of dislodgement and reducing the **longevity** of the overdenture. *None of the above options are ideal.* - This statement is incorrect because a **bare root surface** is a viable and often preferred option for overdenture abutment preparation. - The decision depends on individual patient factors and the specific design of the **overdenture**, but a bare root surface is often optimal.

Arthroplasty Indian Medical PG Question 2: 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

Arthroplasty 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.

Arthroplasty Indian Medical PG Question 3: A 45-year-old was given steroids after renal transplant. After 2 years he had difficulty in walking and pain in both hips. Which one of the following is most likely cause?

• A. Tuberculosis
• B. Primary Osteoarthritis
• C. Aluminum toxicity
• D. Avascular necrosis (Correct Answer)

Arthroplasty Explanation: ***Avascular necrosis*** - Chronic **steroid use**, especially after organ transplantation, is a major risk factor for avascular necrosis (AVN) due to impaired blood supply to bone, particularly in the femoral head. - **Hip pain** and **difficulty walking** are classic symptoms of AVN, which can lead to collapse of the femoral head if untreated. *Tuberculosis* - While tuberculosis can affect bones and joints (**Pott's disease**), it typically presents with more systemic symptoms like fever, weight loss, and night sweats, which are not mentioned. - Skeletal TB often affects the spine more commonly and usually presents with granulomatous inflammation and bone destruction rather than isolated joint pain in the hips *Primary Osteoarthritis* - Primary osteoarthritis is typically an **age-related degenerative joint disease** occurring in older individuals, and while it causes hip pain, it is not directly linked to steroid use in a 45-year-old. - The onset of pain in this scenario, following long-term steroid use, strongly points away from primary osteoarthritis as the primary driving factor. *Aluminum toxicity* - Aluminum toxicity can occur in patients with **renal failure** and can cause **osteomalacia** or **dialysis encephalopathy**. - Its presentation typically involves bone pain, fractures, and neurological symptoms, but it does not specifically cause avascular necrosis of the femoral head as seen with steroid use.

Arthroplasty Indian Medical PG Question 4: A 55-year-old male, known smoker, complains of calf pain while walking. He experiences calf pain while walking but can continue walking with effort. Which grade of claudication does this patient fall under?

• A. Grade I (Mild claudication)
• B. Grade II (Moderate claudication) (Correct Answer)
• C. Grade III (Severe claudication)
• D. Grade IV (Ischemic rest pain)

Arthroplasty Explanation: ***Grade II (Moderate claudication)*** - **Grade II claudication** is characterized by **intermittent claudication** where the patient experiences pain while walking but can **continue walking with effort**. - This level of claudication reflects a moderate degree of peripheral arterial disease, where blood flow is sufficiently compromised to cause pain with exertion but not severe enough to force immediate cessation of activity. - The patient in this scenario can continue ambulation despite discomfort, which is the defining feature of this grade. *Grade I (Mild claudication)* - **Grade I claudication** involves discomfort or pain that the patient can **tolerate without significantly altering their gait or pace**. - In this stage, the pain is minimal, and the patient may perceive it as a dull ache or mild fatigue rather than true pain. - Walking can continue without significant effort or limitation. *Grade III (Severe claudication)* - **Grade III claudication** is marked by pain that is **severe enough to stop the patient from walking within a short distance** (typically less than 200 meters). - The pain forces the patient to rest and recover before they can resume walking. - This represents significant functional limitation in daily activities. *Grade IV (Ischemic rest pain)* - **Grade IV**, also known as **critical limb ischemia**, involves **pain even at rest**, especially in the feet or toes, often worsening at night when the limb is elevated. - This stage indicates severe arterial obstruction and is frequently associated with **ulcers, non-healing wounds, or gangrene**. - This represents advanced peripheral arterial disease requiring urgent intervention. **Note:** This grading system is a simplified clinical classification. The standard medical classifications for peripheral arterial disease are the **Fontaine classification** (Stages I-IV) and **Rutherford classification** (Categories 0-6).

Arthroplasty Indian Medical PG Question 5: Nickel-titanium alloy has increased flexibility over stainless steel. How does the modulus of elasticity for nickel-titanium alloy compare to that of stainless steel?

• A. One-fourth to one-fifth that of stainless steel (Correct Answer)
• B. Similar to stainless steel
• C. 2 to 3 times that of stainless steel
• D. Half that of stainless steel

Arthroplasty Explanation: ***One-fourth to one-fifth that of stainless steel*** - **Nickel-titanium (NiTi) alloys** are known for their exceptional **superelasticity** and **shape memory properties**, which are directly related to their low modulus of elasticity. - This significantly lower modulus allows NiTi wires to undergo large elastic deformations without permanent deformation, providing increased flexibility and lighter, more continuous forces in orthodontics. *Similar to stainless steel* - This statement is incorrect because NiTi alloys were developed precisely to overcome the limitations of stainless steel, particularly its high stiffness. - If their moduli were similar, NiTi would not offer the clinical advantages of increased flexibility and lower force application. *2 to 3 times that of stainless steel* - This is incorrect as a higher modulus of elasticity would mean increased stiffness and reduced flexibility, which is contrary to the known properties and clinical applications of NiTi alloys. - Materials with higher moduli require greater force to deform and would be less suitable for applications requiring gentle, continuous forces like initial orthodontic tooth movement. *Half that of stainless steel* - While NiTi has a lower modulus than stainless steel, "half" is not an accurate approximation of the difference; the actual reduction is significantly greater, typically in the range of one-fourth to one-fifth. - This difference is crucial for explaining the unique clinical benefits of NiTi, such as its ability to be bent significantly without permanent deformation.

Arthroplasty Indian Medical PG Question 6: The rephrased question is:What is the most common complication of a fractured talus?

• A. Avascular necrosis (AVN) (Correct Answer)
• B. Osteoarthritis of the subtalar joint
• C. Nonunion of the talus
• D. Osteoarthritis of the ankle joint

Arthroplasty Explanation: ***Avascular necrosis (AVN)*** - The talus has a **precarious blood supply**, with arterial branches entering at multiple points but often centrally, making it vulnerable to **ischemia** after fracture. - Fractures, especially neck fractures, can disrupt these delicate vessels, leading to **osteonecrosis** and collapse of the bone. *Nonunion of the talus* - While possible, talar nonunion is **less common** than AVN due to the talus's dense cortical bone and limited muscle attachments. - Nonunion is more frequently seen with fractures of other bones, such as the **scaphoid**. *Osteoarthritis of the subtalar joint* - **Subtalar osteoarthritis** can occur post-talar fracture, often as a **secondary complication** of disrupted articular surfaces or AVN. - However, the **initial and most common direct complication** stemming from the blood supply disruption is AVN. *Osteoarthritis of the ankle joint* - **Ankle osteoarthritis** can also develop after certain talar fractures, particularly those involving the talar dome or leading to incongruity of the ankle joint. - Similar to subtalar arthritis, it is often a **later or secondary sequela**, rather than the immediate and most frequent direct complication like AVN.

Arthroplasty Indian Medical PG Question 7: ASA classification is done for – a) Status of patient b) Risk c) Pain d) Lung disease

• A. ac
• B. a
• C. ab (Correct Answer)
• D. bc

Arthroplasty Explanation: ***ab*** - The **American Society of Anesthesiologists (ASA) Physical Status Classification System** is used to assess a patient's **overall health (status)** before surgery. - This classification helps in determining the **anesthetic risk** and guides anesthetic management. *ac* - While patient status is assessed, ASA classification does not primarily classify **pain** or pain management strategies. - **Lung disease** can influence a patient's ASA status, but it's not the sole or primary factor being classified independently. *a* - The ASA classification evaluates the patient's **overall health or status** but significantly aims to assess the **risk** associated with anesthesia and surgery. - Without considering risk, the classification loses its primary purpose in surgical planning. *bc* - The ASA system is indeed used to stratify **risk** for anesthesia and surgery, but it primarily does this by categorizing the patient's **overall physical status**. - It does not directly classify **pain** as an independent variable; patient conditions causing pain would contribute to their overall status.

Arthroplasty Indian Medical PG Question 8: What is the best treatment for a 60-year-old man with intracapsular femoral neck fracture?

• A. Hemiarthroplasty (Correct Answer)
• B. Total hip replacement
• C. Internal fixation
• D. Casting

Arthroplasty Explanation: **Hemiarthroplasty** * **Hemiarthroplasty** is generally preferred in older patients with **displaced intracapsular femoral neck fractures** due to the high risk of **avascular necrosis** and non-union with internal fixation. * In a 60-year-old, a hemiarthroplasty provides a good balance between **mobility** and avoiding the complexities of a total hip replacement, especially if the patient has lower functional demands or comorbidities. *Total hip replacement* * **Total hip replacement** might be considered for younger, more active patients with minimal comorbidities, or older patients with pre-existing **hip arthritis**, as it offers better long-term function and pain relief. * However, it's a more extensive procedure with a higher risk of complications like **dislocation** and necessitates careful selection based on the patient's physiological age and functional expectations. *Internal fixation* * **Internal fixation** is primarily used for **non-displaced** or minimally displaced intracapsular femoral neck fractures in active patients, or displaced fractures in younger patients (usually <60 years old) to preserve their native femoral head. * In a 60-year-old with a displaced fracture, the risk of **avascular necrosis** of the femoral head and **non-union** is significantly higher with internal fixation, making it a less preferred option. *Casting* * **Casting** is not an appropriate treatment for a femoral neck fracture. * Femoral neck fractures are **intra-articular** and require surgical stabilization to achieve stability and allow for early mobilization.

Arthroplasty Indian Medical PG Question 9: All of the following factors affect osseointegration EXCEPT:

• A. Biocompatibility of implant material.
• B. Implant design.
• C. Patient's blood type (Correct Answer)
• D. Status of the host bed.

Arthroplasty Explanation: ***Patient's blood type*** - A patient's **blood type** (e.g., A, B, AB, O) is determined by antigens present on red blood cells and plays no direct role in the biological processes of bone healing or the integration of a dental implant with bone. - While systemic factors can influence osseointegration, blood type itself does not affect the cellular and molecular mechanisms required for direct bone-to-implant contact. *Biocompatibility of implant material* - The **biocompatibility** of the implant material (e.g., **titanium**) is crucial for osseointegration, as it must not elicit adverse reactions and must permit host bone growth on its surface. - Materials that are cytotoxic or inflammatory will prevent bone apposition and lead to fibrous encapsulation rather than direct bone contact. *Implant design* - **Implant design**, including features like **surface roughness**, thread pitch, and macro-geometry, significantly influences the initial stability and long-term success of osseointegration. - A greater surface area and appropriate surface treatments can enhance bone cell attachment and differentiation, promoting faster and stronger bone integration. *Status of the host bed* - The **status of the host bone bed** refers to its quality and quantity (e.g., bone density, vascularity), which are critical for the biological processes of osseointegration. - Adequate bone volume and good bone quality provide a stable foundation and sufficient blood supply for bone regeneration around the implant.

Arthroplasty Indian Medical PG Question 10: 79 yrs old lady had fall, the following X-ray was taken. Which of the following is treatment?

• A. Hip spica
• B. Nailing
• C. Hemiahroplasty (Correct Answer)
• D. Total Hip Replacement

Arthroplasty Explanation: ***Hemiarthroplasty*** - The X-ray shows a **displaced femoral neck fracture** in an elderly patient, which typically has a high risk of **avascular necrosis** of the femoral head due to disruption of blood supply. - Hemiarthroplasty involves replacing only the **femoral head and neck** with a prosthetic component, leaving the acetabulum intact, which is suitable for elderly patients with good acetabular cartilage and less active lifestyles. *Hip spica* - A hip spica cast is primarily used for **pediatric femur fractures** or certain types of hip dislocations in children, not for displaced femoral neck fractures in elderly adults. - This method would not provide stable fixation or address the high risk of **avascular necrosis** associated with these fractures in older patients. *Nailing* - Nailing (intramedullary nailing) is typically used for **intertrochanteric fractures** or subtrochanteric fractures, where the fracture line is distal to the femoral neck. - For displaced femoral neck fractures, nailing alone may not provide adequate stability and carries a higher risk of **non-union** or **avascular necrosis** compared to arthroplasty in elderly patients. *Total Hip Replacement* - Total hip replacement involves replacing both the **femoral head and the acetabulum** with prosthetic components. - While an option for femoral neck fractures, it is generally reserved for younger, more active patients or those with pre-existing **acetabular pathology** like arthritis, as it is a more extensive and complex procedure than hemiarthroplasty.

Arthroplasty Flashcard 1 of 3

Question: Patients with metal on metal implants have high levels of _____ and chromium in serum, erythrocytes, and urine.

Answer: cobalt

Arthroplasty Flashcard 2 of 3

Question: Which muscle is used for girdlestone arthroplasty?_____

Answer: Vastus lateralis

Arthroplasty Flashcard 3 of 3

Question: Girdlestone arthroplasty preserves the hip joint _____.

Answer: mobility