Tuesday, November 20, 2012

Unusual Combination

We have come a long way in understanding congenital hand and upper extremity abnormalities.  Dr Swanson, more than 40 years ago, published a classification system that was adopted by most of us who treat patients with birth anomalies.  This classification system was based purely on appearance of the extremity but allowed us to communicate better as well as advancing the field through research.  Recently, Drs Oberg, Tonkin and Manske suggested another classification system still based on appearance but a bit more refined and improved through the last 40 years of research.  Eventually we will have a system based not on appearance (phenotype) but based on the genetics (genotype).  We have a ways to go.

Our research has allowed us to better understand the origin of many anomalies, but certainly not all.  The more we learn, the more we can give good advice to families on 1) associated conditions to look for in their child http://congenitalhand.wustl.edu/2012/04/diagnosis-and-evaluation.html 2) the risk to future children and 3) the risk to the affected child's future children.  We also want to give rest to mothers' (and fathers) fears that they caused the problem: in almost all cases, this is simply not the case.  The more I learn about how limb forms, the more amazed I am that it ever happens "correctly."  There are so many signals and responses and molecules and proteins- simply amazing.

Combination of cleft hand and forearm synostosis

another X-ray of cleft hand and synostosis

I present only one example in this post.  This is a very rare combination of a cleft hand http://congenitalhand.wustl.edu/2012/01/central-deficiency.html and a forearm synostosis http://congenitalhand.wustl.edu/search/label/Synostosisin an otherwise healthy child.  The child has been evaluated by genetics on several occasions without identification of any know syndrome or abnormality.  The cleft hand appears as a thumb and pinky only.  The other hand is normal.  The forearm does not rotate as bone unites the proximal portion of the radius and ulna.  Why do these 2 anomalies happen together?  It is unclear.  The cleft hand usually only affects the hand plate.  The forearm synostosis often happens in isolation.  I believe it is safe to say that the two anomalies happened together for 1 of 2 reasons.  First, it may simply have been timing.  The forearm bones may have been separating at the same time the central digits were forming- one insult at that critical time caused both.  Alternatively, a key signal may not have happened affecting both areas and thus causing both problems.  At this point, the error is not clear and we know formation is complex. http://congenitalhand.wustl.edu/2012/10/limb-formation.html One day it might be.  I should also point out that these unusual combinations often teach us a great deal because it is unlikely to be coincidence.  Unlikely to be lightning striking twice in one unfortunate arm.

Wednesday, November 14, 2012

Carpenter Syndrome

Carpenter Syndrome is one rare type of acrocephalopolysyndactyly, Type 2.  It is closely related to acrocephalosyndactyly, with the most notable type of this group of disorders being Apert syndrome.  These syndrome all have craniosynostosis (premature fusion of the suture lines of the skull) and syndactyly, with or without polydactyly as well.  Carpenter syndrome has been further described at the Online Mendalian Inheritance in Man- http://www.omim.org/entry/201000  and http://www.carpentersyndrome.com/links.html

I have not cared for a child with Carpenter Syndrome but have had the recent pleasure of meeting and caring for a delightful young adult.  This patient had previous surgeries to address the polydactyly and syndactyly with primary current complaints of deformity of the fingers and the thumb and a narrow first web space of the thumb.  The finger deformities affected the long and ring fingers, the site of the previous syndactyly (likely bony or complex syndactyly), previously treated at a young age.

Narrow first web space in Carpenter Syndrome.

Finger appearance in Carpenter Syndrome appearance after syndactyly reconstruction in the past.  Note especially the deformity of the ring finger.  The long finger is also angled but more difficult to see in this picture.

Carpenter Syndrome xrays.  Not that the middle phalanx bones are not rectangular- leading to deformity.

The thumb in Carpenter Syndrome.

At the patient and family's request, surgery was done to 1) straighten the long and ring fingers (clinodactyly deformity) 2) straighten the thumb (fusion of the thumb IP joint) and 3 deepen the thumb- index web space.  Surgery was successful in meeting these goals.  Below are pictures immediately after surgery.
Clinodactyly correction in Carpenters syndrome.  The finger alignment is markedly improved but there is still some deviation in the long finger.

Lateral xray (side view) showing improved alignment after clinodactyly correction in Carpenters Syndrome

Clinical photograph after surgery focusing on the deepened web space.

View from palm after Carpenter's syndrome correction.

Demonstration of straighter fingers after clinodactyly correction in Carpenters Syndrome.

Friday, November 2, 2012

Clavicle Pseudoarthrosis

Clavicle pseudoarthrosis (meaning fake joint) is a rare condition.  It occurs when the normal growth centers of the clavicle do not join (fuse) during development.  It is almost always right sided, a fact which is may be related to pressure from the subclavian artery.  Clavicle pseudoarthrosis is generally painless but it causes a large prominence in the center aspect of the clavicle- it can be functionally limiting.
Clavicle pseudoarthrosis.  Note the prominence on the left side compared to right.
Another view of clavicle pseudoarthrosis
The x- ray in clavicle pseudoarthrosis shows a "joint" or separation in the midportion of the clavicle.

Two x- rays showing clavicle pseudoarthrosis

Treatment for clavicle pseudoarthrosis is based purely on symptoms.  If the bump does not interfere with function (complaints may be related to backpack straps or sports), then observation is reasonable.  If the bump is causing a problem or if painful, operative intervention can be considered.  Surgery removes the interval between the bone ends (i.e., the fake joint) and the bone ends are approximated and held in place with a plate and screws. The bone typically heals uneventfully.  Pain and deformity can reliably be treated.  Complications with surgery are rare.

X- ray demonstrating clavicle plating in pseudoarthrosis

After reconstruction for clavicle pseudoarthrosis
Another view after reconstruction for clavicle pseudoarthrosis