The capsular ligaments of the wrist: morphology, morphometry and clinical applications

Abstract

Variable wrist ligament descriptions and nomenclatures have been presented, but the dimensions of these ligaments have not yet been extensively investigated. To verify the numerous concepts advanced and to provide a better understanding of individual variations in carpal biomechanics, and the numerous pathomechanical concepts reported in the literature, this study aimed to determine capsular carpal ligament anatomy, their dimensions and variations. The origin, insertion, and number of fascicles of the capsular wrist ligaments were observed in precise dissection of 66 anatomic preparations. The dimensions of several capsular wrist ligaments were measured using a calliper: the parameters analysed being length and width at three levels each, from which mean length and width and approximate mean surface (product of mean length by mean width) were determined. The anatomy of the capsular ligaments of the wrist showed, besides relatively constant structures, considerable individual variations, particularly of the ulnocarpal and dorsal ligaments. The standard deviations of ligament lengths and widths were mostly less than 20% of the average value. Some measurements, however, showed larger variations, such as those associated with the dorsal scaphotriquetral and ulnocarpal ligaments. Ligament widths generally showed larger variations and less interdependency than did ligament lengths. The capsular wrist ligaments display morphologic and morphometric variations, which could explain the biomechanical variations reported in the literature, and the diversity of classifications and treatment methods proposed for carpal instability. Further studies, however, are needed to confirm this hypothesis.