In this issue of Hand Clinics, guest editors Drs. Harvey Chim and Kevin Chung bring their considerable expertise to the topic of Advances in Microsurgical Reconstruction in the Upper Extremity. Top experts in the field discuss techniques, outcomes, and new developments such as perforator mapping, thin flaps, and functional muscle transfers, providing surgeons with expert guidance and resources in order to maximize function. Contains 14 relevant, practice-oriented topics including recent advances in upper extremity microsurgery: from traditional to perforator flaps; evolution and application of ultrasound for flap planning in upper extremity reconstruction; functional free muscle transfers for reconstruction of the paralytic limb; functional free muscle transfers for reconstruction of brachial plexus injuries; and more. Provides in-depth clinical reviews on advances in microsurgical reconstruction in the upper extremity, offering actionable insights for clinical practice. Presents the latest information on this timely, focused topic under the leadership of experienced editors in the field. Authors synthesize and distill the latest research and practice guidelines to create clinically significant, topic-based reviews.