The spastic thumb. Current concepts.

The spastic thumb is frequently positioned in the palm (thumb-in-palm deformity), impeding hand function and in severe cases affecting hygiene. It usually results from intrinsic muscle spasticity and weakness of thumb retropulsion and extension although other possible causes, as a spastic flexor pollicis longus, may be associated. Correction of the thumb deformity provides substantial functional and aesthetic improvement in affected individuals, including the functional and nonfunctional hand. The surgical strategy depends on a thorough physical examination and the goal must be set specifically for each patient. Surgical options may include release or lengthening of the spastic muscles, imbrication or tendon transfers to augment the weak extensors and abductors, joint procedures when needed and neurectomies in selected cases. Most patients improve with the surgical treatment and both patients and caregivers are satisfied with the outcomes. Alleviating the thumb-in-palm deformity would enhance hand function; however, accomplishing this task is difficult and requires attention to detail.