Ankle Arthroplasty — MCQs
Severe disability in primary osteoarthritis of hip is best managed by -
Contraindications for skin traction: a) Dermatitis b) Vascularly compromised status of limb c) Abrasions d) Hypopigmentation (vitiligo) e) Bony deformity
What is the most common complication after total hip replacement?
Patellar tendon-bearing P.O.P. cast is indicated in the following fracture:
Surgery was performed as shown in the image below. What is the name of the procedure?
A 36-year-old man presents with an ankle injury sustained during a soccer match. What urgent intervention is required?
A 65-year-old presents with chronic knee pain, varus deformity, and medial joint space narrowing. BMI is 32. Best treatment option?
Which of the following is considered a fenestrated hip prosthesis?
A patient with an orthopaedic hip implant is to undergo dental extraction. What antibiotic prophylaxis is recommended?
Who is considered the father of joint replacement surgery?
Ankle Arthroplasty Indian Medical PG Practice Questions and MCQs
Question 1: Severe disability in primary osteoarthritis of hip is best managed by -
- A. Arthroplasty (Correct Answer)
- B. Arthrodesis
- C. Mc Murray's osteotomy
- D. Intra-articular hydrocortisone and physiotherapy
Explanation: ***Arthroplasty*** - **Total hip arthroplasty (THA)** is the most effective treatment for severe osteoarthritis of the hip, providing significant pain relief and functional improvement. - It involves replacing the damaged joint surfaces with **prosthetic components**, addressing advanced cartilage loss and structural damage. *Arthrodesis* - **Arthrodesis (joint fusion)** is an older technique that fixes the joint in a permanent position, eliminating pain but sacrificing all motion in that joint. - While it relieves pain, the severe loss of motion makes it generally less desirable than arthroplasty for the hip, especially in active patients. *Mc Murray's osteotomy* - **McMurray's osteotomy** is a surgical procedure primarily used for some types of **femoral neck fractures** or a specific type of **avascular necrosis** of the femoral head, not for severe osteoarthritis affecting the entire joint. - It involves cutting and realigning the bone, but it does not address advanced, widespread articular cartilage degeneration seen in severe osteoarthritis. *Intra-articular hydrocortisone and physiotherapy* - **Intra-articular hydrocortisone injections** and **physiotherapy** are conservative treatments used for mild to moderate hip osteoarthritis to manage pain and improve function. - These methods do not resolve severe structural damage and are typically insufficient for managing severe disability due to advanced osteoarthritis.
Question 2: Contraindications for skin traction: a) Dermatitis b) Vascularly compromised status of limb c) Abrasions d) Hypopigmentation (vitiligo) e) Bony deformity
- A. ab
- B. abc (Correct Answer)
- C. acd
- D. bcd
Explanation: ***ab*** - All conditions listed under 'a' and 'b' (Dermatitis, Vascularly compromised status of limb, Abrasions) are **absolute contraindications** for skin traction as they directly compromise skin integrity or circulation. - Applying skin traction in these situations can lead to **skin breakdown**, infection, or further **ischemic damage**, worsening the patient's condition. *ab* - While **dermatitis**, **vascular compromise**, and **abrasions** are indeed contraindications, the option for 'abc' implies there might be other correct choices included, which is not the case for this option. - This option is incomplete as it misses 'c' (Abrasions) which is also a significant contraindication. *acd* - This option incorrectly includes **hypopigmentation (vitiligo)** as a contraindication, which does not inherently prevent skin traction. - It also omits **vascularly compromised status of limb**, a critical contraindication, while including 'a', 'c', and 'd'. *bcd* - This option incorrectly includes **hypopigmentation (vitiligo)** as a contraindication for skin traction. - It also omits **dermatitis**, a key contraindication, while including 'b', 'c', and 'd'.
Question 3: What is the most common complication after total hip replacement?
- A. Dislocation
- B. DVT (Correct Answer)
- C. Infection
- D. Aseptic Loosening
Explanation: ***DVT*** - Deep vein thrombosis (DVT) is the **most common overall complication** following total hip replacement, with reported incidences as high as 40-60% without prophylaxis. - The risk of DVT is significant due to **venous stasis during surgery**, immobilization, and the inflammatory response to tissue injury. *Dislocation* - While a serious complication, **dislocation** of the prosthetic hip joint is less common than DVT, occurring in about 1-5% of primary total hip replacements. - It typically results from **improper joint positioning** or patient activities that push the hip beyond its normal range of motion. *Infection* - **Infection** is a severe but relatively rare complication, with rates for periprosthetic joint infection in total hip replacement typically ranging from 0.5% to 2%. - It can lead to significant morbidity and usually requires **further surgical intervention** for eradication. *Aseptic Loosening* - **Aseptic loosening** is a long-term complication, occurring years after the surgery, rather than an immediate post-operative complication. - This complication involves the **failure of the implant-bone interface** without evidence of infection, often due to particle disease or mechanical stress.
Question 4: Patellar tendon-bearing P.O.P. cast is indicated in the following fracture:
- A. Fracture of the tibia (Correct Answer)
- B. Fracture of the patella
- C. Fracture of the femur
- D. Fracture of the medial malleolus
Explanation: ***Fracture of the tibia*** - A **patellar tendon-bearing (PTB) cast** is specifically designed to bypass the knee joint and transfer weight from the patellar tendon to the cast, offloading the tibia. - This design is particularly useful for **stable, distal tibia fractures** where partial weight-bearing is desired to promote healing. *Fracture of the patella* - A PTB cast would place direct pressure on the **patella**, which is contraindicated in a patellar fracture. - Patellar fractures often require a **cylinder cast** or surgical fixation to immobilize the knee. *Fracture of the femur* - Femoral fractures are typically **more proximal** and require **traction**, **internal fixation**, or a **spica cast** for stabilization. - A PTB cast would not provide adequate immobilization or weight-bearing relief for a femoral fracture due to its design. *Fracture of the medial malleolus* - Medial malleolus fractures involve the **ankle joint**, which is distal to the area covered by a PTB cast. - These fractures typically require a **short leg cast** or surgical repair, focusing on ankle stabilization.
Question 5: Surgery was performed as shown in the image below. What is the name of the procedure?
- A. Below knee amputation
- B. Above knee amputation
- C. Lisfranc amputation
- D. Chopart amputation (Correct Answer)
Explanation: ***Chopart amputation*** - The image shows a disarticulation through the **talonavicular and calcaneocuboid joints**, which defines a **Chopart amputation**. - This procedure removes the distal foot while preserving the **calcaneus and talus**, forming a stump that allows for some ankle motion. *Below knee amputation* - A below-knee amputation involves transection of the tibia and fibula, preserving the knee joint, which is much more proximal than shown in the image. - This type of amputation removes a significant portion of the lower leg, with the foot entirely removed, unlike the partial foot amputation depicted. *Above knee amputation* - An above-knee amputation involves disarticulation or transection through the femur, completely removing the lower leg and knee joint. - This is a much more extensive amputation than what is illustrated, which is confined to the foot. *Lisfranc amputation* - A Lisfranc amputation is a disarticulation through the **tarsometatarsal joints**, removing the metatarsals and phalanges but preserving the tarsal bones. - The image clearly shows the incision more proximally, at the midtarsal level, specifically through the talonavicular and calcaneocuboid joints, not the tarsometatarsal joints.
Question 6: A 36-year-old man presents with an ankle injury sustained during a soccer match. What urgent intervention is required?
- A. Performing a CT scan to assess the injury
- B. Manipulation to restore alignment
- C. Immediate reduction of the dislocation
- D. Applying a splint to stabilize the injury (Correct Answer)
Explanation: ***Applying a splint to stabilize the injury*** - **Splinting** is a crucial urgent intervention for an ankle injury to **immobilize** the affected joint, reducing pain and preventing further damage to soft tissues or bone fragments. - It provides temporary stability until a definitive diagnosis and treatment plan can be established. *Performing a CT scan to assess the injury* - A **CT scan** is a diagnostic tool used to visualize complex fractures or soft tissue injuries in detail, but it is not an urgent intervention for initial management. - While important for diagnosis, it should typically follow initial stabilization and clinical assessment. *Immediate reduction of the dislocation* - **Reduction** is an urgent intervention for **dislocations**, but the question describes an "ankle injury," which could be a sprain, fracture, or dislocation. **Reduction** is only appropriate if a **dislocation** is confirmed. - Attempting to reduce a potential fracture without imaging can cause further trauma or pain. *Manipulation to restore alignment* - **Manipulation to restore alignment** is typically reserved for **dislocations** or certain types of **fractures** after proper imaging has been performed to understand the extent and type of injury. - Similar to reduction, it is not the universal first urgent intervention for an undiagnosed ankle injury.
Question 7: A 65-year-old presents with chronic knee pain, varus deformity, and medial joint space narrowing. BMI is 32. Best treatment option?
- A. Arthroscopic Debridement
- B. Unicompartmental Knee Replacement
- C. High Tibial Osteotomy
- D. Total Knee Replacement (Correct Answer)
Explanation: ***Total Knee Replacement*** - This is the most appropriate treatment for a 65-year-old with chronic knee pain, significant **varus deformity**, and **medial joint space narrowing**, indicative of advanced **osteoarthritis**. - A **high BMI (32)** is also a factor that often points towards the need for total joint replacement when conservative measures have failed, as it contributes to increased stress on the knee. *Arthroscopic Debridement* - This procedure is generally reserved for less severe osteoarthritis symptoms or mechanical symptoms like locking, and it is **not effective** for advanced joint degeneration with significant deformity. - It would provide little to no long-term benefit for the presented severe changes and chronic pain. *Unicompartmental Knee Replacement* - While suitable for isolated medial compartment osteoarthritis, a **varus deformity** indicates damage beyond a single compartment or significant malalignment that might not be fully corrected by a unicompartmental approach. - The chronicity, age, and likely degree of degeneration suggest a more comprehensive solution is needed. *High Tibial Osteotomy* - This procedure is typically performed in younger, more active patients with **varus malalignment** and early to moderate osteoarthritis to shift weight to a healthier compartment. - At 65 years old with chronic pain and advanced joint space narrowing, a **corrective osteotomy** is less likely to provide long-term relief and may delay a more definitive solution.
Question 8: Which of the following is considered a fenestrated hip prosthesis?
- A. Bipolar prosthesis
- B. Austin Moore prosthesis (Correct Answer)
- C. Thompson prosthesis
- D. All of the above
Explanation: **Explanation:** The correct answer is **Austin Moore prosthesis**. In orthopaedic surgery, a **fenestrated prosthesis** refers to an implant with "windows" or openings in its stem. These holes allow for bone to grow through the prosthesis (biological fixation), providing long-term stability. **1. Why Austin Moore is correct:** The Austin Moore prosthesis is a unipolar hemiarthroplasty implant used for femoral neck fractures. Its defining feature is a **fenestrated stem**. During surgery, bone chips are often packed into these fenestrations; over time, bone grows through these holes (osseointegration), anchoring the prosthesis to the femoral shaft without the need for bone cement. **2. Why the other options are incorrect:** * **Thompson prosthesis:** This is also a unipolar prosthesis, but it has a **solid (non-fenestrated) stem**. It is designed to be used with bone cement (Polymethylmethacrylate - PMMA) for fixation. * **Bipolar prosthesis:** This refers to an implant with two points of articulation (one at the acetabulum and one within the prosthetic head). While the stem design can vary, the term "bipolar" describes the head mechanism, not the presence of fenestrations. **High-Yield Clinical Pearls for NEET-PG:** * **Fixation:** Austin Moore = **Uncemented** (Press-fit/Biological); Thompson = **Cemented**. * **Indications:** Austin Moore is preferred in patients with good bone quality; Thompson is preferred in osteoporotic patients where cement provides immediate stability. * **Calcar:** The Austin Moore prosthesis has a collar that rests on the calcar femorale to prevent subsidence. * **Complication:** A common complication of unipolar prostheses (Moore/Thompson) is **acetabular erosion** (protrusio acetabuli) because the metal head rubs directly against the native cartilage.
Question 9: A patient with an orthopaedic hip implant is to undergo dental extraction. What antibiotic prophylaxis is recommended?
- A. Amoxicillin 3 times a day for 3 days before the procedure
- B. Amoxicillin 3 times a day for 1 day before the procedure
- C. Amoxicillin intravenously 1 hour before the procedure
- D. Antibiotic prophylaxis is not required (Correct Answer)
Explanation: **Explanation:** The correct answer is **D. Antibiotic prophylaxis is not required.** **1. Underlying Medical Concept:** Historically, it was believed that dental procedures could cause transient bacteremia leading to Late Prosthetic Joint Infection (PJI). However, current evidence-based guidelines from the **American Academy of Orthopaedic Surgeons (AAOS)** and the **American Dental Association (ADA)** state that there is no direct link between dental procedures and PJI. Routine antibiotic prophylaxis is **not recommended** for patients with prosthetic joint replacements undergoing dental procedures. The risks of antibiotic use (allergic reactions, *C. difficile* infection, and antimicrobial resistance) outweigh the unproven benefits of preventing joint infection. **2. Why Incorrect Options are Wrong:** * **Options A and B:** Prophylaxis is never administered for multiple days or a full day before a procedure. If prophylaxis were indicated (e.g., for infective endocarditis), it would be a single pre-operative dose. * **Option C:** While IV antibiotics are used for surgical prophylaxis (like during the arthroplasty itself), they are not indicated for dental work in patients with joint implants. **3. Clinical Pearls for NEET-PG:** * **Exception:** Prophylaxis may be considered only in **severely immunocompromised** patients (e.g., stage 3 AIDS, chemotherapy, or recent organ transplant) with poorly controlled oral infections, and even then, only after consultation between the dentist and the orthopedic surgeon. * **Timing:** If prophylaxis is deemed necessary for other reasons (like high-risk cardiac conditions), the standard dose is **2g Amoxicillin orally 30-60 minutes before** the procedure. * **High-Yield Fact:** The most common cause of Late PJI is hematogenous spread, but the source is usually skin or urinary tract infections, not dental flora.
Question 10: Who is considered the father of joint replacement surgery?
- A. Manning
- B. Gridlestone
- C. Charnley (Correct Answer)
- D. Ponseti
Explanation: **Explanation:** **Sir John Charnley** is universally recognized as the **"Father of Modern Joint Replacement"** for his pioneering work in Total Hip Arthroplasty (THA). In the early 1960s, he revolutionized the field by introducing the **Low Friction Arthroplasty (LFA)**. His three landmark contributions include: 1. The use of **Ultra-High-Molecular-Weight Polyethylene (UHMWPE)** for the socket. 2. The use of **Polymethylmethacrylate (PMMA)** bone cement for stable fixation. 3. The concept of a **small diameter femoral head (22.25 mm)** to reduce torque and wear. **Analysis of Incorrect Options:** * **Manning:** Not associated with the development of joint replacement; likely a distractor in the context of orthopedic history. * **Girdlestone:** Known for the **Girdlestone excision arthroplasty**, which involves removing the femoral head and neck without replacement. It is now primarily used as a salvage procedure for infected hip replacements. * **Ponseti:** Famous for the **Ponseti technique**, the gold standard non-operative treatment for Congenital Talipes Equinovarus (CTEV/Clubfoot) using serial casting. **High-Yield Clinical Pearls for NEET-PG:** * **Charnley’s Triad:** Low friction principle, Bone cement (PMMA), and UHMWPE. * **PMMA:** Acts as a grout (filler), not a glue. A common complication during its insertion is **Bone Cement Implantation Syndrome (BCIS)**, characterized by hypoxia and hypotension. * **Clean Air Rooms:** Charnley also pioneered the use of laminar airflow in operating theaters to reduce surgical site infections.
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