Wednesday, January 1, 2014

Macrodactyly/ Large digits

Macrodactyly, which literally means large digit, is an uncommon condition that affects the fingers more commonly than the toes.  Macrodactyly almost always affects only one extremity, often multiple digits. The index finger and long finger are affected most commonly, followed by the thumb.  In some cases, the enlargement that is present at birth stays proportionally the same (static) while in other cases the enlargement continues to worsen with time (progressive).

An increased nerve or blood supply most commonly lead to the overgrowth, either of the digits (macrodactyly) or the entire limb.  In most cases, macrodactyly is spontaneous and not a genetic condition.  However, macrodactyly or limb overgrowth (also called hemihypertrophy) may be associated with a variety of syndromes.  When we do not know the etiology of hemihypertrophy, a series of ultrasounds are often used to assure that the patient does not have a Wilms tumor.  http://www.stjude.org/stjude/v/index.jsp?vgnextoid=5ceb061585f70110VgnVCM1000001e0215acRCRD

What follows is a partial listing of syndromes with a link for additional information:

Proteus syndrome  http://ghr.nlm.nih.gov/condition/proteus-syndrome
Olliers disease (cartilage tumors) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1592482/
Beckwith- Wiedemann syndrome http://ghr.nlm.nih.gov/condition/beckwith-wiedemann-syndrome
Klippel- Trenaunay syndrome (port wine stains)  http://ghr.nlm.nih.gov/condition/klippel-trenaunay-syndrome
Neurofibromatosis http://www.nlm.nih.gov/medlineplus/neurofibromatosis.html

Surgery in Macrodactyly
The decision for surgery in macrodactyly and the decision of which surgery should be performed are both a challenge.  In cases with nerve overgrowth, nerve decompression may become necessary as the large nerve becomes compressed causing symptoms similar to carpal tunnel syndrome (pain, loss of dexterity, numbness, etc).  Vascular masses and bony overgrowth (Olliers) may require surgical debulking.

The most common macrodactyly situation in my experience is an enlarged digit with angulation, decreased motion, and an abnormal appearance.  The best time for surgery is not obvious in most of these cases.  One important goal is to avoid the scenario in which we perform one surgery after another over many years- essentially subjecting the child to numerous surgeries (with accompanying stress).  To avoid this situation, very difficult decisions may be required including the possibility of excising the entire digit (or ray) when one or two digits are markedly enlarged- not an easy choice but often better than surgery after surgery.

If the digit is not terribly large, debulking the digit (often removing excess fat and skin) is a reasonable choice.  Also we can slow the growth of the digit (at least one of the bones) and correct angulation with an osteotomy (cutting and angling the bone).

Examples
Macrodactyly of the left thumb and index fingers.
Palm view of same patient with macrodactyly.


Long finger macrodactyly
Another long finger macrodactyly by x- ray.  Not the size difference of the bones- both length and width.

Recent patient below.


Macrodactyly affecting only the index finger.  The primary complaints are angulation, decreased motion, and enlargement.

Another view of the enlarged index finger in macrodactyly.  The patient had surgery several years ago and there is a tight scar band on the inside (ulnar side) of the index finger contributing to the deformity.

Palmar view of the macrodactyly.
This macrodactyly patient was observed and found to be worsening with time.  She was taken to the operating room for treatment of the scar band (with a z- plasty or skin re- arrangement), debulking, and osteotomy of the bone to align it.


Charles A. Goldfarb, MD
Washington University School of Medicine
http://www.ortho.wustl.edu/content/Patient-Care/2637/FIND-A-PHYSICIAN/Physician-Directory/Charles-Goldfarb-MD/Bio.aspx

4 comments:

  1. Hello. I have a question about amputation with ray resection in the case of Macrodactyly. You mentioned in person that this would involve a metal plate in the hand. Does this mean that you would be splicing the metacarpals together as opposed to simply removing the metacarpal from the middle finger? Is there a reference where I can see what is involved in the ray resection surgery? Thanks. (Macrodactyly "victim")

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    1. Don. Thank you for the question. Most often, a ray resection is an excision of the entire, enlarged ray (finger including metacarpal in the palm). Sometimes, if the digit is angulated, an osteotomy can be performed to straighten the bone- the newly positioned bone is often held with a plate for the healing process. Occasionally, we will shift a metacarpal in one direction or another and "splice" the bone but that is less common in this condition compared to others (such as with cleft hand). This review article may be helpful: http://www.ncbi.nlm.nih.gov/pubmed/26050204. Good luck.

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    2. Thanks for the answer. I've been researching procedures (you know - I read about them on the internet, so I an an *expert* - grin), and I came across an article that describes a "ray transfer" technique as an alternative to the simple excision of the entire affected ray. The following is a link to an article describing it. http://emedicine.medscape.com/article/1238395-technique#d9 Look at the second and third figures in the article to see them compared visually. Have you heard of this technique? I have been told by a family friend that specializes in joint replacements that the transfer technique would likely result in a stronger grip upon completion of the process - but I can't find much literature on the subject. Is this a possibility or an older technique that is no longer done?

      Thanks again for commenting. My ability to do unbiased research is a little low due to personal involvement!

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    3. Don,
      As shown in the picture, we typically use the "ray transfer" or, as I call it, the 'transposition" after trauma or sometimes with a tumor. It could be considered in macrodactyly but may not be helpful. The downsides of the procedure are several but mainly that it narrows the hand which can affect function and strength. It will not increase strength. The positives are improved appearance and a generally great outcome.

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