Radial Longitudinal Deficiency New Perspectives on an Enduring Challenge

Radial longitudinal deficiency (RLD) is a multidimensional congenital hand difference encompassing skeletal, musculotendinous, and joint components. Managing RLD remains challenging, with numerous surgical procedures over the past century failing to achieve a stable, mobile, growing wrist without recurrence of the deformity. This review investigates new therapeutic approaches for RLD, delving into genetic, embryological, and histological aspects, including proximal muscle involvement and causes of recurrence. A notable association between RLD and preaxial polydactyly, linked to aberrations in the Sonic Hedgehog signaling pathway, is highlighted, suggesting a common embryonic origin. Experimental evidence indicates that ectopic Sonic Hedgehog signaling can result in radial aplasia and preaxial polydactyly. Histopathological studies revealed significant muscle abnormalities in RLD, contributing to deformities and recurrences. Techniques such as preoperative soft tissue distraction show promise, but recurrence rates persist. Alternative surgical procedures, such as vascularized second metatarsophalangeal joint transfer and ulna cuff osteotomy, offer potential improvements by minimizing recurrence and optimizing limb length. Despite advancements, effective management of RLD requires further research into the interplay between genetic factors, muscle abnormalities, and surgical outcomes. This review underscores the importance of early detection, genetic counseling, and a multidisciplinary approach to enhance long-term functional and aesthetic results for RLD patients.