The treatment of a severe traction injury resulting in complete, posttraumatic brachial plexus palsy remains a daunting challenge to the upper extremity surgeon. Operative intervention must address painful glenohumeral instability while optimizing functional rehabilitation. Glenohumeral arthrodesis has been shown to reliably alleviate pain from shoulder instability and place the extremity in a functional position for activities of daily living. An above the elbow amputation has also been advocated to remove the flail insensate extremity and create a stable stump for prosthetic training and rehabilitation. We describe the technique of a combined glenohumeral arthrodesis and above elbow amputation to address the flail insensate limb following a severe posttraumatic brachial plexus injury. In our clinical experience, the combination of procedures results in an improved pain level, enhances shoulder stability, encourages functional rehabilitation via prosthetic fitting, and is associated with high patient satisfaction.