Prosthetics and Orthotics Practice Questions

Q: At what level is a below-knee amputation typically performed?

10 cm below the tibial tuberosity. **Explanation:** The ideal level for a below-knee (transtibial) amputation is **10 cm below the tibial tuberosity** (or approximately 12.5–15 cm below the knee joint line). This level is considered the "gold standard" because it preserves a sufficient bony lever arm for efficient mobilization while ensuring adequate soft tissue coverage for prosthetic fitting. * **Why 10 cm is correct:** At this length, the stump is long enough to provide mechanical advantage for the quadriceps and hamstrings, yet short enough to allow for the bulky components of modern prosthetic sockets. It also ensures that the skin is well-vascularized, reducing the risk of flap necrosis. * **Why A (5 cm) is incorrect:** A stump shorter than 8–10 cm provides a very poor lever arm. The short segment often slips out of the prosthetic socket during flexion, making walking difficult and unstable. * **Why C & D (15–20 cm) are incorrect:** Amputations in the lower third of the leg are discouraged because the distal leg has poor vascularity and minimal muscle bulk. This leads to thin, fragile skin over the bone, frequent wound breakdown, and chronic pain due to inadequate padding. **High-Yield Clinical Pearls for NEET-PG:** * **Burgess Flap:** The standard technique uses a **long posterior myofascial flap** because the posterior calf skin has a better blood supply than the anterior skin. * **Nerve Management:** Nerves (like the tibial nerve) should be pulled distally, cut, and allowed to retract proximally to prevent the formation of painful **junctional neuromas**. * **Fibula Management:** The fibula is typically cut **1–2 cm shorter** than the tibia to prevent lateral pressure sores within the prosthesis. * **Ideal Stump Shape:** The final stump should be **conical** or cylindrical, never bulbous, to facilitate prosthetic use.

Q: What is the most common cause of amputation?

Peripheral vascular disease. **Explanation:** The correct answer is **Peripheral Vascular Disease (PVD)**. **1. Why Peripheral Vascular Disease is correct:** Globally and in modern clinical practice, PVD (often associated with **Diabetes Mellitus**) is the leading cause of limb amputations, accounting for nearly 80-90% of all cases in the elderly population. The underlying pathophysiology involves chronic ischemia, non-healing arterial ulcers, and subsequent gangrene. In diabetic patients, the combination of "angiopathy, neuropathy, and immunopathy" significantly increases the risk of lower-limb loss. **2. Why other options are incorrect:** * **Trauma:** While trauma is the leading cause of amputation in **young adults and children** (specifically machinery accidents or vehicular trauma), it ranks second to vascular diseases in the general population. * **Frostbite and Burns:** These are classified under thermal injuries. While they can lead to necrosis necessitating amputation, they represent a very small percentage of total cases compared to chronic systemic diseases. **3. NEET-PG High-Yield Pearls:** * **Most common cause overall:** Peripheral Vascular Disease (PVD). * **Most common cause in young adults:** Trauma. * **Most common site of amputation:** Lower limb (specifically the toe or transtibial/below-knee). * **Ideal Stump Shape:** Cylindrical (facilitates better prosthetic fitting). * **Myodesis vs. Myoplasty:** *Myodesis* (suturing muscle to bone) is preferred over *myoplasty* (suturing muscle to muscle) in major amputations to provide better distal muscle stabilization. * **Krukenberg Procedure:** A specialized amputation of the forearm that creates a "pincer" grip using the radius and ulna, indicated for bilateral hand loss in blind patients.

Q: The following splint substitutes for which paralyzed muscle action?

Lumbrical paralysis. ***Lumbrical paralysis*** - The **lumbrical substitution splint** (knuckle-bender splint) is specifically designed to compensate for **lumbrical muscle paralysis** in ulnar nerve injuries by assisting **MCP flexion** and **IP extension**. - This splint prevents the **paradoxical extension** at MCP joints that occurs when lumbricals are paralyzed, allowing proper finger function and grip strength. *Wrist extension* - **Wrist extension** is supported by a **cock-up splint**, not the knuckle-bender splint shown. - This function is lost in **radial nerve palsy** affecting **wrist extensors**, requiring different biomechanical support than lumbrical substitution. *Wrist drop* - **Wrist drop** is treated with a **cock-up splint** that supports the wrist in extension, not the knuckle-bender splint shown. - This condition results from **radial nerve palsy** affecting **wrist extensors**, requiring different biomechanical support than lumbrical substitution. *None of the above* - This option is incorrect as the splint shown has a **specific clinical indication** for lumbrical paralysis. - The **lumbrical substitution splint** is a well-recognized orthotic device used in **hand rehabilitation** and ulnar nerve palsy management.

Q: Taylor's Brace is used for which of the following?

Dorsolumbar immobilization. **Explanation:** **Taylor’s Brace** is a high-yield spinal orthosis in orthopaedics. It is a **thoraco-lumbo-sacral orthosis (TLSO)** designed specifically for **dorsolumbar immobilization**. The brace consists of two vertical posterior bars (paraspinal bars) and a pelvic band. It works on the principle of **three-point pressure**, providing hyperextension to the spine. By limiting flexion and rotation of the thoracolumbar junction, it stabilizes the spine, making it the gold standard for conditions like **Pott’s disease (Spinal TB)** and stable compression fractures of the lower thoracic or upper lumbar vertebrae. **Analysis of Options:** * **A. Cervical immobilization:** This requires a cervical collar (e.g., Philadelphia collar) or a Halo-vest. Taylor’s brace does not extend high enough to stabilize the neck. * **C. Scoliosis:** While some TLSOs are used for scoliosis, the specific brace of choice is usually the **Milwaukee brace** (for high curves) or the **Boston brace** (for lower curves). Taylor’s brace is for immobilization, not for corrective lateral forces. * **D. Fracture femur:** Femur fractures are managed with traction, intramedullary nails, or plates; orthotic management involves a Thomas splint or a Knee-Ankle-Foot Orthosis (KAFO), not a spinal brace. **Clinical Pearls for NEET-PG:** * **Ashman’s/Knight’s Brace:** Used for Lumbo-sacral immobilization (LSO). * **Milwaukee Brace:** A CTLSO used for Scoliosis with an apex above T8. * **Somersault/SOMI Brace:** Used for cervical spine injuries (C4-C5 level). * **Key Component:** Taylor’s brace specifically restricts **flexion and extension** of the dorsolumbar spine.

Question 1

At what level is a below-knee amputation typically performed?

Accepted Answer

10 cm below the tibial tuberosity

Answer

5 cm below the tibial tuberosity

Answer

15 cm below the tibial tuberosity

Answer

20 cm below the tibial tuberosity

Question 2

What is the most common cause of amputation?

Accepted Answer

Peripheral vascular disease

Answer

Trauma

Answer

Frostbite

Answer

Burns

Question 3

The Milwaukee brace is used in the treatment of which of the following conditions?

Accepted Answer

Scoliosis

Answer

Kyphosis

Answer

Cubitus varus

Answer

Genu varum

Question 4

The following splint substitutes for which paralyzed muscle action?

Accepted Answer

Lumbrical paralysis

Answer

Wrist extension

Answer

Wrist drop

Answer

None of the above

Question 5

Taylor's Brace is used for which of the following?

Accepted Answer

Dorsolumbar immobilization

Answer

Cervical immobilization

Answer

Scoliosis

Answer

Fracture femur

Prosthetics and Orthotics — MCQs

Prosthetics and Orthotics — MCQs

On this page

Practice by Chapter

Want unlimited practice?