Sunday, June 29, 2014

Cerebral Palsy, Thumb Deformity

Cerebral palsy (CP) is defined as a permanent limitation in physical function which does not change or get worse over time.  Most commonly, it is a disorder with spastic muscles and limitations in motion but kids can present in a variety of different ways.  I have not previously blogged on this topic and will start with the case as an example as it is an good example of the difficulty with cerebral palsy and the potential benefit of surgery in certain situations.  I will break this down further in a series of posts on cerebral palsy in general as well as other posts on specific joint issues.  More to come!

Today, I would like to share a case of an older adolescent with cerebral palsy involving all four limbs. Previously, due to a severe wrist flexion position, he had been treated with a wrist fusion.  That surgery had helped him overall but left his thumb in difficult position.    He has a very weak pinch with the thumb and also difficulty trying to hold bigger objects due to the position of the thumb.  Muscle overfiring and tightness, as commonly seen in cerebral palsy, combine to make this thumb position difficult.
Cerebral palsy thumb with marked deformity.

Attempted pinch in cerebral palsy thumb. 

Holding a spoon with cerebral palsy thumb deformity.

The thumb abnormal positioning has been classified by Dr House from Minnesota.  He practiced at Gillette Children's Hospital and was a great educator on cerebral palsy.  The classic article from 1981 House article described 4 types of possible thumb deformity, the explanation behind these deformities of the thumb, and treatment options.  This thumb is a type 3 cerebral palsy thumb most noted by the severe adduction contracture of the thumb metacarpal (thumb positioned next to index finger) and the notable hyperextension of the MCP joint.  Treatment considerations are somewhat different in this patient based on age but the reasoning behind the positioning of the thumb is well explained from this article on cerebral palsy thumb from more than 30 years ago.

Due to the challenges of the thumb position, we elected to proceed with a stabilization of the CMC joint- the carpometacarpal joint at the base of the thumb.  We were able to align the joint after muscle lengthenings and joint release.  We held this position with temporary pins.  Next, we fused (or made stiff) the MCP joint- the joint where the thumb meets the hand.  The pins are also temporary (6 weeks) but the joint will be stiff forever although in a very functional position.  
Improved thumb position in cerebral palsy after surgery.

Improved thumb position in cerebral palsy after surgery.

Improved thumb position in cerebral palsy after surgery.
Charles A. Goldfarb, MD
My Bio at Washington University
congenitalhand@wudosis.wustl.edu


2 comments:

  1. Great blog! I am physiotherapist and I work with children with neurological diseases every day and your posts are very interesting and helpful. Hands are so important in our daily life. Thanks!

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    Replies
    1. Alba,

      Thank you so much for both your post and your work with children.

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