Radial Longitudinal Deficiency.

Radial longitudinal deficiency (RLD) is the most common congenital longitudinal deficiency of the upper limb. Established principles of reconstruction dictate a staged approach to address the primary components of the deformity: radial wrist deviation and/or thumb deficiency. Severe RLD remains one of the most challenging conditions to manage, and no technique has yet achieved reliably durable correction. The goals of surgery are to create a stable carpal platform, achieve tension-free correction of soft tissue contractures, and restore a functional pinch mechanism. Surgical options for wrist stabilization may include soft tissue rearrangement and tendon transfer, centralization, free fibula flap, and radialization/ulnarization. Recently, adjunctive techniques such as soft tissue distraction and ulnar cuff osteotomy have been employed to facilitate correction and may benefit ulnar growth. Special considerations are described for thumb hypoplasia and limb length discrepancy. Outcomes are generally favorable for functional use, although long-term objective results remain suboptimal relative to normal function, and recurrence of angular deformity remains a significant challenge, underscoring the need for continued research. In this chapter, we outline the etiology, classification, surgical management, and outcomes of RLD.