Dorsal scapholunate interosseous ligament: ultrasound evaluation between dominant and non-dominant wrist in young sports patients.

Abstract

The dorsal component of the scapholunate ligament, is the strongest component, in fact it has a maximum tensile strength of 300N and mainly controls flexion and extension. In a recent study, the thickness and length of the dorsal component of SLIL was measured using ultrasound image, the length of the dorsal scapholunate ligament was 7.5mm ± 1.4mm and the thickness of 1.8mm ± 0.4mm. We evaluate 60 wrists of 30 young athletic volunteers with ultra-sound image, comparing the thickness variations of the dorsal component of SLIL between the dominant and non-dominant wrist, to confirm our hypothesis that the dorsal component SLIL has proprioceptive activity and therefore the thickness of the ligament increases in following wrist activity. With a high-frequency ultrasound probe > 15MHz (Sonoscape X3 Pro) we evaluated 60 wrists of 30 young men (16 males and 14 females, 20-38years old) manual sports volunteers (10 tennis players, 8 padel players, 7 swimmers, 5 weight lifters) with no recent ligament injuries of the hand or wrist to participate in the study, we compared the dorsal component of SLIL between the dominant and non-dominant wrist. Dorsal SLIL was visualized in all 60 volunteers wrists. We measured an average scapholunate dorsal ligament length 7.7mm and average thickness of 2.3mm in the dominant wrist and average 7.2mm in length and average 1.9mm thickness in the non dominant wrist. The mean dorsal scapholunate interval was average 4.9mm and the mean central interval was average 2.1mm in the dominant wrist and 4.7mm and 1.8mm in the non dominant wrist, so that meas-urements remained unchanged with those reported by previous authors. In our study we ultrasonographically measured an average scapholunate dorsal ligament length 7.7mm and average thickness of 2.3mm in the dominant wrist and average 7.2mm in length and average 1.9mm thickness in the non dominant wrist. This confirms our hypothesis that there is a direct stimulus on the ligamentous component of the dor-sal SLIL in the dominant wrist following repeated uses and activities such as to cause an increase in thickness of the dorsal ligament to highlight the possibility of a proprioceptivity of the ligament if subjected to continuous training. IV.