The hallucal distal phalanx and transverse convexity of the nail plate: the relationship

• Published in: Foot (Edinburgh, Scotland) Vol. 10; no. 2; pp. 59 - 65
• Main Authors: Mahon, D.J., Holland, D.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2000
• ISSN: 0958-2592; 1532-2963
• DOI: 10.1054/foot.2000.0606

It has been suggested that the distal phalanx is responsible for determining the shape of the nail plate. A pilot study (n =10) was undertaken to analyse the cross-sectional profile of the hallux and identify possible relationship between the distal phalanx and nail plate. The study involved 5 halluces presenting with nails of normal transverse convexity and 5 with overcurvature, taken from 10 cadavers. Transverse cross-sections were analysed at 5 points through each distal phalanx using magnified photographs (×4) and a mathematical formula as a measurement tool. Results suggest that the phalanx plays less of a role in determining nail plate convexity than was previously thought, with high variation between the cross-sections within one digit, and from one digit to the next. This suggests that transverse convexity of the nail plate appears not to be determined simply by the convexity of the underlying phalanx, but rather by other changes stemming from within the individual matrix, subungual dermis or surrounding anatomical structures.