Principles of conservative management for a non-orthotic tenodesis grip in tetraplegics.

The effectiveness of a tenodesis grip is determined by the passive properties of the hand. An effective tenodesis grip can be achieved by encouraging a decrease in the resting length (i.e., adaptive shortening) of the flexor digitorum profundus and the flexor digitorum superficialis so that the fingers flex when the wrist is extended. Also, adaptive shortening of the flexor pollicis longus needs to be encouraged so that the thumb approximates the flexed fingers when the wrist is extended. The length of the adductor pollicis will in part dictate where along the radial side of the index finger the thumb will contact. Development of an effective tenodesis grip also requires that excessive metacarpophalangeal and interphalangeal joint stiffness of the fingers be prevented and that the interphalangeal joint of the thumb become stiff in extension. Careful management of the tetraplegic hand can ensure the development of the musculoskeletal changes necessary for an effective tenodesis grip.