A dynamic approach to the thumb-in palm deformity in cerebral palsy. Capsulodesis of the metacarpophalangeal joint of the thumb in children with cerebral palsy. Treatment of spastic thumb-in-palm deformity: a modified extensor pollicis longus tendon rerouting.
One hundred and sixty-five different surgical procedures were performed for the correction of thumb deformities in fifty-six patients with spastic cerebral palsy at Gillette Children's Hospital, St. Paul, Minnesota, between 1967 and 1975. The quality of voluntary muscle control and sensibility were the most important factors in predicting the success of operation. In the past, thumb deformities were classified on the basis of the static position of the thumb, but rational treatment decisions can be made only by a careful assessment of the patient's hand and thumb function. Using various combinations of releases, tendon transfers, and joint stabilizations, measurable and predictable improvement in function was achieved in all fifty-six patients whose records were analyzed. A deformity of hyperextension of the metacarpophalangeal joint of the thumb occurring in thirteen children with spastic cerebral palsy was corrected by capsulodesis of the joint. The technique involves shifting the metacarpal attachment of the volar plate more proximally in the metacarpal. When combined with selective release of the involved intrinsic muscles and selective transfer of the extrinsic motors, when indicated, the thumb is brough away from the palm and its function and appearance are improved. Moreover, there is not risk to growth of the thumb such as might follow arthrodesis in a growing child. Results were satisfactory except in two athetoid patients, in whom some of the intial correction was lost, but even their thumbs did not revert into hyperextension. In five patients, for reasons not entirely clear, the previously flexed interphalangeal joint had better extension postoperatively. This improved the function of the thumb, because the broad pulp of the thumb could then be used firmly against the side of the index finger. Fourteen patients (15 hands) with spastic thumb-in-palm deformities were treated with a modified technique of extensor pollicis longus tendon rerouting. Twelve patients obtained satisfactory correction of their deformities. Although functional improvement was not always anticipated, it was achieved to some degree in 12 patients. Extensor pollicis longus tendon rerouting can provide satisfactory correction of severe thumb-in-palm deformity especially when combined with other procedures such as metacarpophalangeal joint arthrodesis and thumb intrinsic muscle release. The modified rerouting technique can be done with a single incision and allows easy adjustment of tension.
Because the methodological quality of the studies is poor, it is impossible to provide a reliable judgement of the role of surgery for thumb-in-palm deformity. This review has demonstrated the need for randomized clinical trials or controlled clinical trials on the surgical treatment of thumb-in-palm deformity. Surgical reconstruction appears to improve hand function, to facilitate hygiene, and to improve the appearance and quality of life. For patient selection, a validated classification system should be developed to determine the type and extent of the cerebral palsied hand. The influence of age, intelligence, and voluntary muscle control still needs to be investigated. Investigators should focus on one particular surgical intervention or a specific group of interventions to find out which procedures produce the best functional improvement.