Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

Which areas are MOST at risk when a patient with a below-the-knee amputation begins ambulating with a prosthesis?

1. Gluteal and quadricep areas

2. Patellar tendon and popliteal areas

3. Calf and ankle areas

4. Thigh and groin areas

The correct answer is: Patellar tendon and popliteal areas

When a patient with a below-the-knee amputation starts ambulating with a prosthesis, particular areas of the residual limb are at increased risk due to the nature of the prosthetic fitting and the dynamics of walking. The patellar tendon and popliteal areas are highly relevant in this context because these areas experience the most pressure and stress with weight-bearing activities. The patellar tendon, which is part of the musculotendinous unit for knee extension, directly engages in the function of supporting the prosthesis during ambulation. If the alignment or fitting of the prosthetic device is suboptimal, or if the residual limb has not sufficiently adjusted to the prosthetic use, there can be an increased risk of skin breakdown or pressure sores in the patellar tendon region. The popliteal area is similarly vulnerable, as it is a critical joint area that can be compressed during ambulation. Since the prosthetic limb alters gait mechanics, the additional forces acting on this area, combined with potential friction, can lead to complications. In contrast, the other areas mentioned, such as the gluteal and quadricep areas, the calf and ankle areas, and the thigh and groin areas, are less directly affected by the mechanics of a below