Sunday, January 26, 2014

Radial Head Dislocation in Ulnar Deficiency

Ulnar longitudinal deficiency, or ulnar deficiency, is much less common than radial deficiency.  And, it less commonly requires surgery.  I have previously written about different aspects of surgery for ulnar deficiency hand surgery in ulnar deficiency .  Additionally, I have previously written about different aspects of more severe ulnar deficiency severe ulnar deficiency

There is a group of patients with ulnar deficiency who have a radial head dislocation at the elbow.  Here are the clinical pictures of one child
Ulnar deficiency with radial head dislocation

Another view of ulnar deficiency with radial head dislocation

The prominence at the elbow is the dislocation radial head.  These radiographs demonstrate the dislocated radial head with a completely absent ulna bone.

Ulnar deficiency with absent ulna and radial head dislocation.

Another view of ulnar deficiency with absent ulna and radial head dislocation at elbow.

In this case, there is no pain and very good elbow and hand function.  No intervention is planned.  The next case of ulnar deficiency is similar and I include x-rays.   Note the flexibility of the arm in almost all planes of motion.  Especially notice the elbow motion which, while not perfect, is functional.  There is no pain on examination.  Thanks to mom for allowing us to post these pictures.

Ulnar deficiency.  The arm is somewhat short but extends almost fully.

Excellent elbow flexion in ulnar deficiency
Again, good elbow flexion in ulnar deficiency.  There are 2 fingers and a thumb but good overall hand function.

Ulnar deficiency motion of the elbow and shoulder are excellent.
Again, ulnar deficiency with great overall motion. Note the shortness of the extremity.

These xrays will be very helpful in understanding this situation.  In both of these radiographs, we can see the very short ulna.  In reality, the distal 1/2 of the ulna is missing.  Therefore, the radius is relatively long.  Because of this length difference, the normal complex function of the two- bone forearm is affected.  Rotation is limited but most importantly, the length of the radius causes a problem.  The radius bends (should be almost straight) which we can see here. And, eventually, the radial head dislocates at the elbow- which we can see her also.  If painful, there are several options to improve alignment, function, and pain.  The most straightforward is to simply excise the prominent, painful part of the radial head.  That may be enough to resolve the symptoms.  Or, the radius and ulna can be fused together (one- bone forearm) which can be very helpful.  At this point, the family and the child are very happy with his function and he has no pain.  This issue is not unique to ulnar deficiency.  We can see it in any process with alters the length of the radius or ulna.  A common clinical situation is multiple hereditary exostosis with a short ulna.

Ulnar deficiency with radial head dislocation.

Ulnar deficiency with dislocated radial head.  Note how long the radius is compared to the short ulna.

Friday, January 24, 2014

The Hand in Arthrogryposis

Hand function is clearly vital for function.  As I have written about previously, the thumb is key for both fine manipulation (think picking up a coin) and large object grasp (soda can).  The fingers are key for grasp and strength in grasp.

Hand function in arthrogryposis can be a challenge.  First, in order to effectively use the hands, the arm has to be able to position the hand in an appropriate position.  We take that for granted but in the child with arthrogryposis, this is not so straightforward.  A stiff elbow and an internally rotated shoulder and a flexed wrist all make using and positioning the hand difficult.  So, before we specifically address the hand in children arthrogryposis, we have to correct the more proximal deformities.  This concept is especially important if there are severe hand issues because the more severe the issues, the more likely the child will need to use both hands to perform tasks (rather than being able to perform one handed tasks).  So, as I have previously written, we externally rotate the arms, we work to release the elbow, and we extend (or straighten the wrist).  

The wrist surgery probably should be discussed a bit more as it relates to finger function.  Many children with arthrogryposis have a flexed wrist position.  Sometimes this can be helpful for weight bearing as the child moves around but often, the flexed position only gets in the way.  To understand how difficult the bent wrist position can be, try this.   Bends your wrist down and try to make a fist with your fingers- it is really hard.  If we can bring the wrist up with surgery (splints rarely work), the fingers move better.

In my opinion, the finger are perhaps the most difficult aspect of the arthrogryposis upper extremity. There is often little we can do to make the fingers themselves work better.  However, if we can better position the arm and put the thumb and fingers in the best possible position, it can definitely help function.  The goals are to put the thumb in a position to allow larger object grasp and to remove it from a position that may block function of the fingers.  The thumb in arthrogryposis
If there is camptodactyly of the fingers, we straighten the fingers for the same reasons.  These surgeries are often a challenge as the skin may be insufficient (requiring skin grafts or flaps), the tendons may be short, and, as always, the muscles may be weak.  Here is a child with a markedly clasped thumb and with severe camptodactyly.

Here is the top of the hand in arthrogryposis with the ring and small fingers straighter.  You can't even see the thumb.

This is the palm sided view of the same arthrogrypotic hand.  Note the middle finger is markedly bent, as is the thumb.

Here we are trying to straighten those two digits, with little luck in this severe arthrogrypotic hand.

Here is an immediate after surgery picture.  We have lengthened tendons, moved skin, released joints and more.  We were very pleased with this early position in a difficult arthrogrypotic hand.

As always, please post questions if I can clarify further.  Thank you.

Charles Goldfarb, MD.

Tuesday, January 7, 2014

Amniotic Constriction Band

Amniotic constriction band is an uncommon condition about which I have previously blogged  ACB Blog Link .  There are numerous good general descriptions on the Internet including the following:

Shriners Link
Medline Plus

The difficulty is that there is little precise information on the upper extremity and hand finding in Amniotic Constriction Band.  There are numerous reasons for this.  First, there are a large number of names for this condition which can make searching for patients/ information difficult.  Alternatives include amniotic band syndrome, amniotic band sequence, constriction band syndrome, Streeters, and more.  I like Amniotic Constriction Band alone as I feel that it is descriptive and accurate.  It is not a syndrome.

The second issue is that almost no 2 patients with Amniotic Constriction Band are alike.  The fingers affected, the severity, the other limbs affected, the other findings...  all are different.  There are, however, some similarities.

  1. More than 1 extremity involved.  It is very uncommon to find a patient with only one limb or one hand involved.
  2. There are a few typical findings although, again, every patient is different and a patient may have 1 or all 3 of these:
  3. Constriction band on calf.
    1. Constriction bands or indentations.  These can be anywhere including fingers, toes, the lower leg, the arm.  If tight enough, this can cause a major problem past the band due to swelling.  These can also affect muscle quality and strength.
    2. Syndactyly.  This type of syndactyly is very different from other children with a developmental syndactyly. See my previous blogs on typical, congenital syndactyly.  Syndactyly Posts  Typically, in Amniotic Constriction Band, syndactyly is fenestrated (there is some space between the fingers).  Even if the fingers are not conjoined, there can be narrowing of the web space.
      Syndactyly and fingertip amputations, a classic appearance in Amniotic Constriction Band.
    3. Amputations.  This can involve the entire arm or leg but typically involves the fingers and most commonly the index, long, and ring fingers
Terry Light nicely summarized some of these findings in an article available online.  Light article

Below is a recent patient with Amniotic Constriction Band.  The patient has multiple extremities affected including feet (with syndactyly- fenestrated) and hand.  A first surgery more than one year ago separated the hand.   Here are preoperative images of the affected hand and foot.
Not the toe syndactyly.  There are spaces between the toes (fenestrations) that are consistent with the diagnosis of  Amniotic Constriction Band

Preoperative view of  the hand in Amniotic Constriction Band

Another preoperative view of the hand in Amniotic Constriction Band

Today the hand is in much better position and the primary issue is limited grasp due to short digits related to the amputations.  The patient is brought to the operating room to deepen the first webspace.  This area is critical to allow large object grasp.  There are many techniques but I favor a simply approach and we deepened using z- plasties which are skin rearrangements.

Amniotic Constriction Band with tight first webspace

Amniotic Constriction Band with tight first webspace

Amniotic Constriction Band with tight first webspace
After multiples z- plasties.  Note the deeper space which will allow larger object grasp.
Again, multiple z-plasties are visible.

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.

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

Proteus syndrome
Olliers disease (cartilage tumors)
Beckwith- Wiedemann syndrome
Klippel- Trenaunay syndrome (port wine stains)

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).

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