The Peter Principle in orthopedics.

Original orthopedic devices that were developed, tested, and found useful, were subsequently modified and seemingly "improved" to a point of diminished usefulness--a manifestation of the Peter Principle applied to orthopedics. The authors describe seven examples: (1) the talar-tilt inversion apparatus; (2) the patellar-tendon-bearing, below-knee amputation prosthesis; (3) the patellar-tendon-bearing orthosis; (4) the Veterans Administration Prosthetic Center's lumbosacral orthosis; (5) the partial-foot prosthesis; (6) the ankle-foot orthosis; and (7) the occipito-zygomatic cervical orthosis.