HKAFO consists of a hip joint and pelvic band in addition to a KAFO. The orthotic hip joint is positioned with the patient sitting upright at 90°, while the orthotic knee joint is centered over the medial femoral condyle. Pelvic bands complicate dressing after toileting unless the orthosis is worn under all clothing. Pelvic bands increase the energy demands for ambulation.
1. Bilateral pelvic band: This band is used more commonly with its posterior metal ends located anterior to the lateral midline of the pelvis and is interconnected by a flexible belt.
2. Unilateral pelvic band: This band rarely is used because most conditions requiring a HKAFO have bilateral involvement.
3. Pelvic girdle: The pelvic girdle is made of molded thermoplastic materials, providing a maximum degree of control in patients with bilateral involvement.
4. Silesian belt: This belt has no metal or rigid band and offers mild resistance to abduction and rotation of the hip. The Silesian belt attaches to the lateral upright and encircles the pelvis.
Hip joints and locks: The hip joint can prevent abduction and adduction as well as hip rotation.
1. Single axis hip joint with lock: This joint is the most common hip joint with flexion and extension. The single axis hip joint with lock may include an adjustable stop to control hyperextension.
2. Two-position lock hip joint: This hip joint can be locked at full extension and 90° of flexion and is used for hip spasticity control in a patient who has difficulty maintaining a seated position.
3. Double axis hip joint: This hip joint has a flexion-extension axis and abduction-adduction axis to control these motions.