Acquired malalignment: a complication of lateral longitudinal nail biopsy

We report the development of malalignment of the nail following lateral longitudinal biopsy of the nail unit in seven subjects. The lateral biopsies were in excess of the routine 3 mm diagnostic biopsy performed for investigation of a nail dystrophy, being indicated for excision of focal pathology. Deviation of the distal nail towards the side of excision might be accounted for by one or both of two mechanisms. First, the matrix might become skewed by the unilateral loss of a ligamentous structure extending from the lateral ligament of the distal interphalangeal joint. Second, there may be a reduction of embedding of nail in the lateral nail fold on the operative side in spite of a thorough lateral nail fold reconstruction. This reduction may result in an unopposed inward force from the remaining nail fold.