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

Sunday, June 26, 2016

Thumb Deformity

The thumb is vital for high level hand function.  The concept of the opposable thumb- the thumb that can meet the fingers for pinch and other high level function- has been said to separate man from at least some of our primate 'relatives'.  In the growing child, the thumb is key for exploring the world and, most notably at school age, for fine motor manipulation with pens, pencils, scissors, and other tools.

As a surgeon, our job is to assess thumb function and thumb alignment and, when necessary, offer intervention to assure each child can obtain maximal function.  For some children, therapy can help with strength and help the child and family understand how to best function.  For others, surgery can provide better alignment, rotation, or stability in an effort to allow the thumb ideal interaction with the fingers and with the world.  Thumb stability is key to function but a lack of stability is not something that kids complain about (or know how to complain about).  But pinch is affected and the surgeon should look for this issue as it is correctable with good results.

Thumb stability is most commonly compromised in two situations.  First, the underdeveloped or hypoplastic thumb.  I have previously blogged about the hypoplastic thumb HERE, among other blog posts.  A typical hypoplastic thumb is small, has poor muscle and has an unstable joint.  Surgery can address the instability and the lack of muscle support.
Hypoplastic thumb.  Not the rotated position of the smaller thumb.

And second, thumb polydactyly, or extra thumb, can be associated with instability.  The most common scenario of instability in thumb polydactyly is after removal of the extra thumb.  That is, the patient has surgery to remove the extra thumb and a lack of stability or a zig-zag deformity becomes a problem several years later.

Triphalangeal thumb, or a thumb with three bones rather than two, is often associated with polydactyly (extra thumb).  Early surgery may be offered to remove the extra thumb and often the third bone in the primary thumb is initially watched to confirm whether or not that bone will cause problems.  I have previously blogged about the problematic triphalangeal thumb HERE.

This is another example.  This child had an extra thumb removed and there is deformity of the remaining thumb which is affecting function including pinch.  There is a lack of pinch strength related to both a lack of stability and the deformity.  In addition, the fact that the thumb has an extra joint (an extra area to bend) can change the way the thumb works.  Adults have shared that this extra joint is not a good thing for function.
Triphalangeal thumb.  The thumb is small and crooked compared to the normal thumb.

Another view of the deformity of the triphalangeal thumb.

Palm view of the triphalangeal thumb with visible scar from previous extra thumb excision.

Triphalangeal thumb with small middle bone (middle phalanx)

Triphalangeal thumb with small middle bone (middle phalanx).  The angulation of the thumb is clear.
Thumb stability is key to function.  This child will benefit from stability and correction of deformity.

Charles A. Goldfarb, MD
My Bio at Washington University

Thursday, June 16, 2016

Bent Finger: Surgery for Camptodactyly

I have blogged several times on camptodactyly as it is a common finger anomaly and I have received regular requests for information on the topic.  Those posts can be found HERE and HERE and HERE and HERE.    The popularity of the topic camptodactyly can be seen with the large number of comments and questions on the last link.

The medical literature tends to assess outcomes and causes of camptodactyly- neither of which is easy to do.  There are many reported causes including unusual tendons, tight tendons and an imbalance between tendons that bend (too strong) and straighten the finger.  There is also much information about associated conditions and syndromes (arthrogryposis, for example).  A Google search on camptodactyly returns 86, 500 results with many of the first page results from hospitals, Wikipedia, and other information sites.

My general philosophy in treating camptodactyly is therapy first which includes splinting and stretching.  Most kids will respond to therapy and, even if not perfect, the finger becomes fully functional and surgery is avoided.  Some kids, unfortunately either fail therapy (therapy is attempted but not successful) or can never really try it because the deformity is too severe to allow effective splinting.  Those kids may benefit from surgery although families should know that surgery is unlikely to provide a fully mobile finger.

I wanted to share early outcomes of one child with camptodactyly.  He had an isolated ring finger flexion deformity without associated syndrome or other anomalies.
Camptodactyly, bent finger deformity, resting posture.

Camptodactyly, bent finger deformity, resting posture.

Camptodactyly, bent finger deformity, resting posture.  Attempted extension demonstrates a nearly 90 degree contracture.

This child was sent to therapy but ultimately, the degree of deformity contributed to a failure of splinting and stretching.  Surgical release of the tight structures in this camptodactyly was performed with straightening of the finger.  In addition, once such fingers are released, there is often a skin deficit.  We have been using a rotation flap to cover this deficit and avoid bigger flaps or skin grafts.

Camptodactyly 1 week after surgery.  The pin is still in place (removed that day).  Note the triangular flap which was rotated to cover the deficit.

Camptodactyly 5 weeks after surgery.  Note how the patient can straighten the finger and the flap is healed nicely.

Camptodactyly 5 weeks after surgery.  Flexion of the finger continues to improve.

This patient is doing well and both bending and straightening the finger should improve with time and therapy.  The lack of full flexion (bending) as demonstrated above does demonstrate a key point in the treatment of kids with camptodactyly- we need to be careful to avoid loosing finger flexion and work on flexion and extension (straightening) after surgery.

Camptodactyly is a common birth difference of the upper extremity which thankfully often responds to splinting and surgery can be avoided.  While surgery is never a perfect solution, it can be very helpful in the right children.

Charles A. Goldfarb, MD
My Bio at Washington University

Monday, June 6, 2016

Clasped Thumb.

Clasped thumb is an uncommon diagnosis in which the thumb is held in the palm.  While there are several potential reasons for this positioning, in many cases it is simply due to a delay in muscle development of the thumb extensors.  Over time, those muscles (EPB and EPL) can (but may not) strengthen sufficiently to allow normal function.  Our job during the interval between diagnosis and recovery is to keep the thumb flexible so that if the muscles do develop, the thumb can straighten.  This mainly entails therapy to straighten the thumb to stretch it and sometimes we use splints to do the same.  Occasionally, a soft Benik Splint can help place the thumb in a better position to allow function.

Often clasped thumb affects both sides but the recovery may not be equal.  In the patient below, the right side was worse from early childhood.

Clasped thumb with the fingers straightened.

Over time, in this patient, the left side recovery but the right side did not.
Continued clasped thumb in a 2 year old.

This video demonstrates that the left thumb has recovered nicely but the right still has notable limitations.  We will continue to discuss surgery while giving this clasped thumb a bit longer to recover on its own.

I have previously blogged about congenital clasped thumb- see HERE.  I hope this video sheds light on the diagnosis.  

A couple of further thoughts on congenital clasped thumb.
1)  Surgery can be helpful.  If the patient fails to gain the strength to straighten the thumb, surgery can improve function.  Typically we rearrange tendons to add another muscle unit to help the straightening process.  We do want to allow sufficient time for the thumb to gain strength and recover on its own, but this does not always occur.
2) Generally the diagnosis of clasped thumb is clear but not always.  Other diagnoses must be considered including an association with syndromes or even things like cerebral palsy (CP).  CP can have a thumb in palm deformity but it is related to tight muscles (spastic muscles) rather than weak extensor muscles.

Clasped thumb is a diagnosis that can have a very favorable outcome with or without surgery.  

Charles A. Goldfarb, MD
My Bio at Washington University

Saturday, May 28, 2016

Finger Flexion Deformity

I have previously posted several times on camptodactyly, a condition with a stiff, bent finger.  Those posts can be viewed HERE.  Camptodactyly is relatively common compared to other birth differences of the hand and upper extremity as it can be seen in isolation (i.e., not associated with any other conditions) or in association with cleft hand, ulnar deficiency, arthrogryposis, or other syndromes.  It can involve one finger, or several.

Thankfully, many kids with camptodactyly do well with stretching and without surgery as the bent finger position does not affect function.  Surgery is reserved for kids with significant bend of the finger that has failed therapy with splinting and interferes with function.

One reader posted about her young child with a flexible camptodactyly.  That is, a bent posture of the PIP joint that can be passively straightened (i.e., by mom) but is not able to be straightened actively by the child.  In my experience, this is far less common than the more typical, stiff or fixed, camptodactyly.  Here are a few photos of a 13 month old child (similar in age to the child mentioned above).
Flexed position of the PIP joint of the patient's right index finger.  This has the appearance of camptodactyly.

In this picture, I am demonstrating that the finger can be fully straightened at the PIP joint- thus not a typical camptodactyly.

Live action shot (sorry, a bit blurry) demonstrating that the child cannot straighten the finger on his own.

This is similar to a clasped thumb, a condition in which the child's thumb is in the palm and the child cannot straighten it.  I have previously blogged about it HERE.  As in clasped thumb, we will give the child above time to develop muscle strength to straighten the thumb.  In clasped thumb, the strength issue is generally thought to be the EPB muscle (forearm based) whereas in the child above, a weakness of the intrinsic muscles of the hand are to blame.  Either way, with time, we hope that the muscles will develop and the straightening power will appear.  Our job, while we wait, is to assure that the finger (or thumb) do not get stiff in the the bent position.

Charles A. Goldfarb, MD
My Bio at Washington University