Measurement and observation of the first web space based on morphology and clinical applications

Abstract

PurposeTo describe and evaluate the anatomical skin shape of the first web space in cadavers, and to guide flap design for this area. Methods12 cadavers (24 hands on both sides) were selected. Marker points were chosen based on the characteristics of the first web for morphological measurement and observation. The morphological characteristics of the first web under the radial or palmar abduction position of the thumb were measured and compared. The best morphologic feature and parameters of the first web repairing flap were obtained. ResultsWhen the thumb is in the palmar abduction position, the maximum distance a(p) is 6.78±0.72cm, and the skin area s(p) is 20.09±2.63cm2, both of which are significantly greater than the distance a(r) of 5.86±0.74cm and the skin area s(r) of 17.39±2.15cm2 when the thumb is in the radial abduction position (P<0.05). There was no significant difference in the length b(r) and b(p) of the long axis of the flap between two different abduction positions (P>0.05). It is found that the shape of the first web area is not a symmetrical spindle, but an irregular quadrilateral inclined to the index finger side. ConclusionThe flap design and measurement for the first web space covering should take the maximum palmar abduction position of the thumb as a reference. The asymmetric quadrilateral flap design is more in line with the anatomical and morphological characteristics of the region.