To present the outcomes after one-bone forearm (OBF) surgery for chronic posttraumatic forearm and distal radioulnar joint instability. We conducted a retrospective chart review to study patients who underwent OBF surgery because of a traumatic etiology. We collected patient demographics, surgical technique, preoperative and postoperative range of motion, final grip strength, and complications from the medical records. Patients were asked to complete the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire, a 0- to 10-point pain scale, and a 0- to 10-point treatment satisfaction scale. There were 5 male and 5 female patients, with a mean age of 32 years at the time of OBF surgery (range, 17-44 y). The mean number of procedures before OBF surgery was 3.6 (range, 2-7); 4 patients had undergone a Darrach procedure and 3 patients had undergone a Sauvé-Kapandji procedure. The median clinical follow-up duration was 6 years (range, 1-17 y). Wrist and elbow range of motion did not change remarkably before and after surgery. Of 8 primary OBF surgeries, 3 resulted in nonunion. Of 10 patients, 4 experienced painful impingement of the remaining proximal radius on adjacent bone and soft tissue and required a total of 7 procedures after OBF surgery. The median follow-up duration for patient-rated outcomes was 10 years (range, 5-21 y; n = 7). The median Quick Disabilities of the Arm, Shoulder, and Hand questionnaire score was 77, the median pain score was 7, and the median satisfaction score was 7. In our experience, complications after OBF surgery are common. Although wrist and elbow range of motion were spared, pain persisted and functional outcomes were poor. One-bone forearm surgery is our last resort for a chronically painful and unstable forearm. Therapeutic IV.