A cadaver study on volume and surface area of the fingertip.

The volume of the volar soft tissue, dorsal soft tissue, and bone and the area of the dorsal and volar surfaces were estimated in 35 adult cadaver fingertips. The fingertip was defined as the part of the finger distal to the plane of the palmar skin crease and the major dorsal crease at the distal interphalangeal articulation. An impression molding technique, involving silicone rubber, was used to determine the volume, while dyed imprints of the dorsal and palmar surfaces were used to determine the surface area. In all digits, the mean volume of the volar soft tissue of the fingertip was found to be about 56%, the dorsal soft tissue about 26%, and the volume of bone about 18%. The volar soft tissue includes the skin and fascia (51% of the total fingertip volume), the flexor tendon and its sheath, and the volar plate and volar joint capsule (5% of the total). Power relationships for the total fingertip volume, the volume of volar soft tissue, and the volume of bone in terms of the length of the fingertip were noted. There was also a linear relationship found between the volume of the volar soft tissue and the volar surface area. This study provides data on the ratio of soft tissue to bone in the fingertip. The maintenance of the soft tissue-to-bone ratio, so as to regain fingertip form and function, may be of particular importance when designing flaps and coverage in the reconstruction of the fingertip.