What is Hypoplastic Thumb?
The thumb provides more than 60 percent of function for the hand. When it is absent or underdeveloped, the hand’s ability to function normally is drastically reduced. Thumb hypoplasia, also called hypoplastic thumb, means that the thumb is unusually small or underdeveloped. Thumb aplasia means that the thumb is missing altogether.
The thumb provides more than 60 percent of function for the hand. When it is absent or underdeveloped, the hand’s ability to function normally is drastically reduced. Thumb hypoplasia, also called hypoplastic thumb, means that the thumb is unusually small or underdeveloped. Thumb aplasia means that the thumb is missing altogether.
In general, there are five types of thumb hypoplasia or aplasia:
- Type I: thumb is slightly smaller than normal, but all structures — the bones, tendons, ligaments, muscles and joints — are normal.
- Type II: thumb is small and there are often minor abnormalities in the tendons and muscles within the thumb. The middle joint of the thumb is unstable, causing the thumb to wobble. The web space between the thumb and index finger is tight and restricts movement. The bones of the thumb are abnormally small.
- Type III: there are abnormalities in many of the thumb’s muscles and tendons along with a range of problems in the joints of the thumb. An abnormally tight web space between the thumb and index finger is also present.
- Type IIIA: the critical joint at the base of the thumb is underdeveloped but adequately attached.
- Type IIIB: the critical joint at the base of the thumb is severely underdeveloped and lacks a firm connection, making it unstable for normal use.
- Type IV: thumb is “floating” with no bony support and is attached to the hand by only skin and soft tissue.
- Type V: thumb is completely absent.
Surgical correction of a hypoplastic thumb is highly variable. For Types I-IIIA, surgery can include deepening of the first webspace, joint stabilization, and/or tendon transfers (redirecting tendons from other parts of the hand). For Types IIIB-V, the gold standard for reconstruction is index finger pollicization. This is a process whereby the index finger is moved into the thumb position to provide vital pinch and grasp functions. Although the resulting hand will have usually four fingers, the overall function of the hand is vastly improved. Timing for correction of a hypoplastic thumb can begin as early as 6 months of age. As with other hand deformities, early correction affords improved function over a lifetime.
Why choose Dr Panossian
- He received his medical education at Tufts University School of Medicine.
- Graduated at the top of his class at UCLA, receiving Phi Beta Kappa and Summa Cum Laude honors.
- Was accepted into an elite combined general surgery and plastic surgery residency at the Keck School of Medicine of USC.
- Completed subspecialty training in craniofacial surgery at the Hospital for Sick Children in Toronto and Harvard Medical School.
- Was mentored by Dr. Ron Zuker in the practice of facial paralysis reconstruction. This prestigious fellowship position was available to only one surgeon in the United States.
- Is affiliated with various charitable and educational organizations, including Operation Smile and Mending Kids.
- Is a member of the American Society of Plastic Surgeons and the highly selective American Association of Plastic Surgeons, reserved for only a select group of individuals nationally who have demonstrated excellence in academic plastic surgery.
- Holds memberships in several other professional societies including the American College of Surgeons and the American Society of Reconstructive Microsurgery.
- He serves on the Board of Directors for Mending Kids and the Gondobay Manga Foundation, a non-profit organization dedicated to the improvement of lives in Sierra Leone.
- Has been nominated by his peers annually since 2012 as a “Super Doctor.”
- Served as an expert medical consultant and appeared on The Doctors, Grey’s Anatomy, and Nip/Tuck.
- Has been featured as “Top Doctor” in US News and World Report, Pasadena Magazine, and Los Angeles Magazine.
Last modified by Dr. Andre Panossian
