A 45-year-old farmer undergoes right trans-femoral (above-knee) amputation after a farm machinery injury. He has good upper body strength and cardiovascular reserve. Which prosthetic knee component is most appropriate for a highly active user classified as K3 (MFCL — Medicare Functional Classification Level)?

• A Locked knee prosthesis (mechanical lock, safest for low-activity users)
• B Polycentric (4-bar) knee with manual knee lock
• C Microprocessor-controlled knee (C-Leg or equivalent) — variable cadence, stumble recovery ✓
• D Simple friction knee with no swing phase control

Explanation

The Medicare Functional Classification Level (MFCL/K-level) guides prosthetic prescription: K3 (community ambulator, variable cadence, obstacle avoidance) merits a microprocessor-controlled prosthetic knee (e.g., Ottobock C-Leg, Össur Rheo Knee). These devices use real-time sensor data (gyroscopes, load cells) to modulate knee resistance during swing and stance phases, enabling variable walking speed, stair descent, and stumble recovery — critical for an active 45-year-old. Locked knees are for K1 (household ambulator with fall risk). Polycentric knees suit K2 (limited community ambulation). Simple friction knees are single-cadence devices suitable only for K2 walkers.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.