This study is a retrospective review from South Korea on the results of a modified Bilhaut-Cloquet procedure for Wassel type II and III polydactylies of the thumb. Over a six year period, seven thumbs underwent this procedure at an average age of 30 months (range, 7-66 months). The inclusion criteria included a symmetric bifid thumb with a nail size less than 2/3 of that of the normal contralateral thumb or smaller than the index fingernail in patients with bilateral involvement. The surgical procedure involves making use of the entire DIP joint including its physis and the majority of the distal phalanx with its overlying nail bed of the thumb with the greater range of interphalangeal motion combined with essentially a fillet flap containing the minor part of the distal phalanx, supporting nail bed and collateral ligament attachment to the proximal phalanx. The nail bed is repaired with an 8-0 nylon suture under slight tension, Kirschner wire for stabilization of the DIP joint, and an osteotomy of the proximal phalanx in a Wassel III if the distal interphalangeal joint has an angular deformity greater than 20 degrees.
At final follow up, all patients and their parents were satisfied with the cosmetic and functional results and reportedly would undergo the procedure again. The width of the nail was nearly the same as the contralateral thumb, but the length was slightly shorter. No nail plate deformitites or grooves developed. There was no evidence of physeal injury or growth arrest in any patient, although one patient with a type III deformity gradually developed an angular deviation deformity at the DIP joint of 18 degrees but did not request surgical treatment.
The use of the modified Bilhaut-Cloquet procedure for many hand surgeons has become somewhat historical. However, many patients treated with amputation of the smaller digit with repair of the collateral ligament and possible osteotomy and pinning often have a smaller digit that is stiffer. Previous studies on the use of the Bilhaut-Cloquet procedure have documented a high rate of secondary deformities, limited motion, fusion of the interphalangeal joint, and nail plate irregularity. This procedure making use of predominantly one articular DIP joint, but components of the nail bed from two allow for less deformity and improved motion limiting the risk of growth arrest or fusion. It may be a viable consideration in notably smaller thumb polydactyly.
Thumb, Duplication, Polydactyly, Wassel, Bilhaut