Question 1

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.

Question

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

Prosthetics and Orthotics — MCQs

Prosthetics and Orthotics — MCQs

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