The main postoperative threat to walking
After an above-knee amputation, the muscles that flex the hip are no longer balanced by the weight and leverage of the lower leg, and the client tends to keep the hip bent while sitting or lying with the residual limb raised. Over days, the hip flexor muscles and joint capsule shorten, producing a hip flexion contracture. A hip flexion contracture prevents the client from standing straight in a prosthesis, so preventing it is a key goal from the first days after surgery.
Why prone lying and no pillow
Prone lying for periods several times a day, as tolerated, stretches the hip flexors and keeps the hip fully extended. No pillow under the residual limb after the first 24 hours keeps the limb flat; a pillow lifts the limb and flexes the hip, which is exactly the position that leads to contracture. In the first 24 hours, the limb may be briefly elevated to reduce swelling, but by the third postoperative day elevation is no longer appropriate. Prolonged sitting and raising the head of the bed for long periods are also limited because both keep the hip flexed.
| Plan | Effect on the hip | Correct? |
|---|
| Prone periods, no pillow under the limb | Extended | Yes |
| Prone periods with a pillow under the limb | Partly flexed | No |
| Supine only with a pillow | Flexed | No |
| Sitting up most of the day | Flexed | No |
Why each distractor fails
The supine-only plan leaves out prone lying and adds a pillow, both of which favor contracture. Sitting up most of the day keeps the hip at about 90 degrees of flexion for hours. The plan with prone periods and a pillow under the limb has the right idea about prone lying but defeats it by raising the limb. Only the plan with prone lying and no pillow keeps the hip extended.
Other parts of residual limb care
Other measures include keeping the residual limb adducted, not abducted, which prevents an abduction contracture; avoiding a pillow between the thighs; doing range-of-motion and strengthening exercises; and shaping the limb with elastic wrapping or a shrinker for prosthetic fitting. Because of his peripheral arterial disease and diabetes, careful wound and skin inspection is also essential.
Exam takeaway
Key point After an above-knee amputation, prone lying several times a day and no pillow under the residual limb after 24 hours prevent hip flexion contracture.