[CAN NATURAL SKIN CREASE PREDICT OUR PHALANX JOINT ALIGNMENT?]

Background: Proximal interphalangeal injury may result in malalignment of the phalanx axis of motion. In some instances, these fractures are treated with an external fixation method such as Suzuki-type fixation, during which the surgeon must perform X-rays to preserve the phalanx anatomical axis of motion.

Objectives: To assess the correlation between the palmar skin crease and the joint axis of the proximal interphalangeal joint (PIPJ) of the fingers opposing the thumb to improve the surgeons' perioperative planning procedure. Also, we aim to ascertain whether sex, age, and handedness have affected our findings.

Methods: We performed a single-center prospective study in which information on 144 digits from 18 patients was gathered. Radiopaque stainless-steel wire was used to mark the palmar skin crease of the PIPJ and a series of X-rays were performed to assess the actual axis of the PIPJ correlating to the marked skin crease.

Results: Our study shows a positive correlation between Cobb angle finger 2 and 5 (r = .468, p < .05). Also, a positive correlation between Cobb angle finger 3 and finger 4 (r = .474, p < .05). No significant differences were found between age groups, and right and left hands. Finger 2 Cobb angle was significantly higher in females (F = 2.27, M = 1.49), p = .048.

Conclusions: The study results support the hypothesis that the palmar proximal interphalangeal skin crease is positively correlated with the joint line axis measurement from which the axis of motion is formed. Our findings show homogeneity across age and hand-sidedness.