Sunday, July 17, 2016

Rebuilding the Mirror Hand

Mirror hand is an incredibly rare birth difference of the hand and upper extremity.  I have previously blogged about this diagnosis, specifically regarding how limbs form and how birth differences come to be- find the post HERE.  But I have not previously written about the reconstruction or rebuilding of the mirror hand.  And there is very little to be found on a Google search or in the medical literature.

The term mirror hand reflects the appearance of the hand and the duplication of the ulnar half (the non- thumb half) of the hand (such that it can look like a mirror image).  Typically there are 7 or 8 fingers without a thumb.  There can also be a duplication of the wrist bones and the forearm bones (in which case there are two ulna bones without a radius).  I will share more about the forearm and elbow in another post.

What follows is the case of Evan, a young boy with mirror hand.

Mirror hand with 7 fingers. 
Mirror hand with 7 fingers from the palm view.

Mirror hand with 7 fingers from the palm view.
When a child with mirror hand is examined, the use of the hand is important to understand.  The basic reconstruction/ rebuilding strategy is to pollicize (turn a finger into the thumb- see previous blogs on the pollicization HERE, recognizing that these are radial deficiency hands) one of the fingers- the question is- which finger is best to be the thumb?  Sometimes the strategy that makes the most sense is to use the fourth finger which means the hand will have, after reconstruction, 3 fingers and a thumb (which might seem crazy given the child started with 7 or 8 fingers).  In other cases, we can create a 4 finger and thumb hand in the mirror hand reconstruction.  The decision is based on quality of the fingers (size, mobility, and child's use).  This video is instructive as Evan uses the space between the 4th and 5th fingers for function which makes the concept of a 4 finger and thumb hand appropriate.

Once we have decided how to proceed with reconstruction, two procedures are performed.  A pollicization is the most challenging but we also perform a procedure to help the wrist straighten or extend.  The wrist tends to flex because of a lack of the wrist extensor muscles (which is explained by the muscles)- surgery can strengthen the wrist extensors.  We also temporarily pin the wrist to allow healing.  Here are a series of images after the surgery while still in the operating room.

Mirror hand post pollicization.

Mirror hand post pollicization.

Mirror hand post pollicization.

We were very pleased with the pollicization and wrist reconstruction procedure for Evan. The later pictures are even more helpful in understanding Evan's improving function.

Here is Evan shortly after surgery with his friend Owyn.  The kids share the diagnosis of mirror hand and the families have helped one another through the diagnosis and treatment at the St. Louis Shriners Hospital.

Evan and I shortly after surgery.  Note the tape on Evan's new thumb which helps for positioning soon after surgery.

Evan showing off his new thumb after mirror hand reconstruction, approximately 7 weeks after surgery.  Note the pinch with the new thumb.

In this video taken approximately 3 months after surgery, Evan is using the new thumb for pinching the large metal balls.  

In this final video, also taken 3 months after surgery, Evan uses the new thumb for smaller object pinch.

Evan and his family traveled a long distance to come to St. Louis for the care of his mirror hand and he has, thankfully, done wonderfully.  The function (and appearance) of his hand are much improved.  We will follow his elbow (specifically the flexion of the elbow) for possible later reconstruction.  Evan's mom agreed to allow me to post the images and videos in part to allow others with this rare condition to understand treatment options.

Charles A. Goldfarb, MD
My Bio at Washington University

Monday, July 4, 2016

Cerebral Palsy Article Link

I recently wrote (with help) an article for Hand Clinics on Cerebral Palsy treatment.  While I generally write scientific papers (that review patients to help with future care), occasionally I will write a review that summarizes our knowledge- that is this chapter regarding tendon transfers.  Thank you to my coauthors of this manuscript, Anchal Bansal and Lindley Wall, MD (my partner).  Elsevier provides temporary free access as noted below.

"To help you access and share your article, we are providing you with the following personal article link, which will provide free access to your article, and is valid for 50 days, until August 23, 2016."

I hope this is a helpful review.

Charles A. Goldfarb, MD
My Bio at Washington University

Saturday, July 2, 2016

Fingernail Bump

As a hand surgeon, I am often asked questions about fingernails- whether related to irregularity (bumps, pain, swelling) of the nails or pain.  Most of these are minor or temporary issues and there are several excellent reviews on the internet including bundoomedscape, and others.  Most of the issues on this list are infections including paronychia, felon, and herpetic whitlow.  This matches my experience with patients.

Paronychia of the thumb.  Note the redness suggestive of infection.

One somewhat less common anomaly is the osteochondroma (bone and cartilage growth) from the distal phalanx which appears beneath the nail.  This so- called subungual (meaning literally beneath the nail) osteochondroma is benign meaning it does not spread and typically does not come back when removed surgically.  I have previously blogged a number of times about osteochondromas- typically in the setting of multiple osteochondromatosis, a hereditary condition with osteochondromas in numerous areas throughout the body- see posts HERE, HERE, HERE, and HERE.    Osteochondromas beneath the fingernails may be associated with multiple osteochondromatosis or can be isolated without any other lesion.

Patients with a subungual osteochondroma complain about several issues.  First, the patient notice a deformity of the nail.  The reason for this nail change is that the layer above the bone receives pressure from the growing osteochondroma and the nail matrix (or nail bed) is altered.  When the nail matrix is changed, the nail becomes abnormal.  The second complaint may be a visible deformity of the nail with a bump.  And lastly, there may be pain but this is not always the primary complaint.

Basic nail anatomy. Photo from Wikipedia.

Importantly, this diagnosis overlaps with the subungual exostosis as described on Wikipedia.  In short, subungual osteochondromas are one type of exostosis but not all exostoses are osteochondromas.  Importantly, while I primarily see and treat these in the fingers, they more commonly happen affecting the toenails.
Wikipedia pictures of big toe with subungual exostosis.

Here is a case of a subungual osteochondroma of the index finger causing nail irregularity and pain.  Surgical treatment involves nail removal, excision of the osteochondroma, and repair of the nailbed. The nail grows back over time.
Subungual osteochondroma causing nail irregularity

Subungual osteochondroma causing nail irregularity

Subungual osteochondroma causing nail irregularity

x-ray of subungual osteochondroma causing nail irregularity.  Note the bump on the top of the distal phalanx (beneath nail which is not visible on the xray).

x-ray of subungual osteochondroma causing nail irregularity.  The osteochondroma is more difficult to see here.

Charles A. Goldfarb, MD
My Bio at Washington University