Comparative Radiographic Analysis of the Width of the Lesser Digit Proximal Phalangeal Heads.

Background: Digital deformities represent a common presenting abnormality and target for surgical intervention in podiatric medicine and surgery. The objective of this investigation was to compare the radiographic width of the heads of the lesser digit proximal phalanges.

Methods: One hundred fifty consecutive feet with a diagnosis of digital deformity and performance of weightbearing radiographs were analyzed. The maximum width of the heads of the lesser digit proximal phalanges were recorded from the radiographs using computerized digital software.

Results: The mean ± standard deviation of the head of the second digit proximal phalanx was 9.74 ± 0.87 mm (range, 7.94-11.78 mm); the head of the third digit proximal phalanx, 9.00 ± 0.91 mm (range,7.27-10.94 mm); the head of the fourth digit proximal phalanx, 8.49 ± 1.01 mm (range, 5.57-10.73 mm); and the head of the fifth digit proximal phalanx, 8.67 ± 0.89 mm (range, 6.50-11.75 mm). The width of the head of the proximal phalanx decreased from the second digit to the third digit (P < .001), decreased from the third digit to the fourth digit (P < .001), and then increased from the fourth digit to the fifth digit (P = .032).

Conclusions: The results of this investigation provide evidence in support of an anatomical and structural contribution to digital deformities. The width of the heads of the lesser digit proximal phalanges decreased from the second to the third to the fourth toes, and then subsequently increased with the fifth proximal phalangeal head.