Examqo › Examqo library › Physical medicine and rehabilitation › Amputation, prosthetics, orthoses and mobility aids
Lower limb amputation — levels, residual limb care and functional K-levels
The higher the amputation level, the slower and more energy-costly walking becomes — so preserving the knee joint is the most important goal in amputation, and rehabilitation starts before the prosthesis with contracture prevention and residual limb shaping.
Why it matters in the exam
The common cause of lower limb amputation in developed countries is vascular disease, usually with diabetes; in young people — trauma. Main levels: partial foot amputations (transmetatarsal, Lisfranc, Chopart), Syme (ankle disarticulation keeping the heel pad), transtibial, knee disarticulation, transfemoral and hip disarticulation. After a Chopart amputation the foot tends to an equinus deformity because the Achilles tendon pulls unopposed. In a Syme amputation the residual limb bears weight at its end, but the heel pad can migrate, and the prosthesis is wide at the ankle with little room for a prosthetic foot.
Energy cost of walking rises with amputation level, and is higher after vascular than after traumatic amputation; a transfemoral amputee walks more slowly than a transtibial amputee and spends more energy. After surgery: a rigid removable dressing or a compression dressing to reduce oedema and shape the limb. Contracture prevention: after transtibial amputation — no pillow under the knee (knee flexion contracture); after transfemoral amputation — lying prone and preventing hip flexion and abduction.
Phantom sensation (the feeling that the limb is present) occurs in almost all amputees and is not a problem; phantom pain is common and is treated with mirror therapy, gabapentin or pregabalin and tricyclic antidepressants. Pain in the residual limb itself is sometimes due to a neuroma (a tender spot with an electric sensation), a bone spur or a poorly fitting socket. The Medicare functional levels (K0–K4) decide which components are appropriate: K0 — does not walk and a prosthesis will not improve function; K1 — household walking at a fixed cadence; K2 — limited community walking crossing low-level barriers (kerbs, stairs, uneven surfaces); K3 — community walking at variable cadence; K4 — beyond ordinary demands (athlete, active child).
Key points
- Preserving the knee is the goal.
- Energy cost rises with level and with vascular amputation.
- Contracture prevention: no pillow under the knee; prone lying.
- Phantom sensation is common; phantom pain is treated.
- K0–K4 decide the components.
Summary table
| K-level | Description | Suitable foot |
|---|---|---|
| K0 | Does not walk; a prosthesis will not improve function | No walking prosthesis |
| K1 | Household walking at a fixed cadence | SACH or single axis |
| K2 | Limited community, low-level barriers | Flexible keel or multiaxial |
| K3 | Community at variable cadence | Energy-storing (dynamic response) foot |
| K4 | Beyond ordinary demands, high-intensity activity | Components for sport and high load |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Physical medicine and rehabilitation.
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- VA/DoD Clinical Practice Guideline for Rehabilitation of Individuals with Lower Limb Amputation, 2017 — Pre-prosthetic care, residual limb management and K-levels
- Braddom's Physical Medicine and Rehabilitation, 6th edition (2021) — Lower Limb Amputation and Gait
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.