"At first, we thought there was nothing wrong with the right hand. We never expected that while bringing him in for the floating thumb on the left, doctors would also find developmental issues in the right hand." In the clinic, a mother couldn't help but express her surprise.
Because her baby's left thumb was "hanging" and immobile, she had done a lot of research online and made a special trip to Wuhan to explore thumb-preserving options. Unexpectedly, during the physical exam, it was discovered that the baby's right thumb also had developmental issues.
Left Floating Thumb
Why would the right thumb also be affected?
This baby is only 4 months old. The left hand shows Type IV thumb hypoplasia, commonly referred to as a floating thumb. The right hand has Type I thumb hypoplasia, which is comparatively milder.
In long-term clinical experience, we've observed that many babies with Type IV thumb hypoplasia also have some degree of developmental issues in the other thumb. This is often related to genetic regulation.
This family came to meet me mainly to address the floating thumb issue on the left hand. The parents came well-prepared, bringing a list full of questions that concerned the whole family.
This approach is commendable and worth promoting. Parents preparing their questions ahead of time helps ensure nothing important gets overlooked. The parents of this baby mainly focused on the following:
X-rays of Both Hands
When is the best time for surgery for a floating thumb?
Surgery for floating thumb depends on the development of the first metacarpal. Usually, around 18 months of age, surgery can be considered based on how the bone has grown.
Is the thumb bone preserved during surgery or removed and rebuilt?
If a metacarpal transfer is planned, part of the second metacarpal is transplanted to the first metacarpal while preserving the original thumb bone. This builds a solid framework, and a second surgery later can transfer tendons to enable thumb movement. Complete removal of the thumb bone is not necessary.
What is the best season for surgery?
Many parents worry that the summer heat will affect healing. However, babies' wounds are usually well-sealed, and external weather has little effect. So, there's no need to worry too much about seasonal timing.
Does the baby need to be weaned before surgery?
Not necessarily. The only difference lies in preoperative fasting times depending on feeding method:
Breastfeeding: stop 4 hours before surgery
Formula feeding: stop 6 hours before surgery
Older children eating solids: stop 8 hours before surgery
Will the thumb retain function after thumb-preserving surgery?
With consistent post-operative functional training, the thumb can regain significant function. Many tasks like holding a pen, writing, or using chopsticks can be learned with good rehabilitation - though parental support and guidance are key.
What's the best intervention for Type I thumb hypoplasia?
For the right hand, surgery is not currently needed. Type I thumb hypoplasia can often be improved through functional training, especially palm-to-palm activities that help improve thumb motion over time.
Right Hand - Type I Thumb Hypoplasia