For more information about syndactyly, click here.
Hi, my name is Charles Goldfarb. I'm an Orthopedic Surgeon at Washington University in St. Louis. I see patients at the Orthopedic Center of Chesterfield, St. Louis Children's Hospital and the Shriner's Hospital for Children.
Kids born with hand and upper extremity abnormalities often come to these sites to see me for evaluation and treatment. Syndactyly is the abnormal joining of fingers. It can be one or more fingers that are joined together. Most commonly, it's between the long and the ring finger but it can involve any fingers. It can involve the thumb as well. Children are born with this abnormality but it is a problem that arises from development. In other words, all children have all the fingers and the thumb at one point in development fused together and through the normal processes, the web spaces develop and the fingers separate very early in utero.
During a normal pregnancy, the hand forms completely between 26 and 54 days of gestation so at 26 days, there's a small limb bud. It develops out towards the tip of the fingers and at one point, the fingers are all fused together. By 54 days of gestation, the fingers have separated giving us normal web spaces. If there's an abnormality in this process, the fingers may stay fused together. That can be a skin fusion or a bone fusion.
The problem this causes is somewhat functional. It causes a problem with large object grasp and depending on the fingers affected, can really be a functional issue especially if the thumb's involved and so while this is very uncommon, probably about 1 in every 1,000 children have this abnormality, it can be very debilitating for those children and therefore surgical intervention is considered.
Treatment for children born with syndactyly is provided at different ages based on the specific abnormality. If the thumb and index finger are fused together, that is typically treated before 6 months of age. If it involves the center digits, it's more of an elective procedure and is typically performed between 18 and 24 months. The surgery also depends specifically on what type of abnormality is there so if there's bony fusion, that's a more difficult treatment. If the syndactyly only comes to the PIP joint which is at this level, that's a more straightforward intervention. What we have to do is we have to bring new skin in to recover both fingers and so it's a complex series of skin flaps, sometimes skin grafts to resurface and recover both fingers and allow separation of the digits. However, having said that, it's a very successful surgery. Most kids only need one surgery and never need additional surgeries although, rarely, revision surgeries are required as a child ages.
Most of the time syndactyly is an isolated problem meaning it is only a joining of fingers together without associated problems. However, in some situations, they're much more a complex situation where the syndactyly is accompanied either A, by multiple digits being involved or B, by more generalized health issues which can include problems of the facial area, of skull development or even internal organs and so a comprehensive evaluation of patients is necessary.