Spontaneous Resolution of Congenital Insufficiency of the Extensor Tendon Central Slip.

Background: The congenital insufficiency of the extensor tendon central slip of the fingers is a relatively rare condition, with only a few reported cases in pediatric patients, as described in 2 clinical series. In this study, we aimed to present the natural history of a significant number of untreated patients with this deformity.

Methods: This study has received institutional review board approval, and parents provided informed consent following the Declaration of Helsinki guidelines for biomedical research involving humans. A retrospective analysis of children with this deformity, ranging from June 2008 to July 2021, was collected by 1 surgeon. The inclusion criteria included children with a supple PIP flexion deformity, characterized by MP hyperextension and PIP extension lag, which had been present since birth. Complete passive PIP extension and the absence of volar skin webbing differentiated this condition from camptodactyly.

Results: The mean age of 24 children with 57 involved digits at diagnosis was 7 months (range, 1 to 17) and the mean follow-up was 6 years to 9 months (2 yr to 1 mo to 13 yr). Six patients had an incorrect previous diagnosis of camptodactyly.Active PIP extension recovered progressively. At the final follow-up, complete PIP extension occurred in all except 4 cases in which a residual 10° extension lag. The mean time for a complete active PIP extension was 2 years to 7 months (20 mo to 3 yr to 9 mo). Nineteen cases (79%) showed a mild FDS contracture of the involved digits at the final follow-up.The deformity was bilateral in 15 children (62.5%) and involved only 1 finger (unilaterally or bilaterally) in 15 cases (62.5%), and 2 fingers in 6 (25%). Little and ring fingers were most commonly involved. In 7 cases, there was a family history of finger deformity.

Conclusions: Congenital insufficiency of the extensor tendon central slip typically resolves spontaneously within the first 4 years of life. Literature suggests that splinting can expedite the correction of the deformity and thus, if possible, it can be used. In most cases, a residual, clinically insignificant FDS contracture may be present. This condition is often misdiagnosed as camptodactyly.

Level of evidence: IV.