Purpose: To assess the clinical and radiographic outcomes of coronoid process fractures surgically managed with buttress plate fixation via a medial approach. Methods: A retrospective review of all coronoid fractures surgically fixed in our institution using a buttress plate technique via a medial approach between June 2012 and April 2015 by the senior author was performed. These fractures were all sizeable fractures contributing to persistent elbow instability in terrible triad or varus posteromedial rotatory instability injury patts. A prospective telephone ques-tionnaire was conducted to assess patient outcomes using the disabilities of the arm, shoulder and hand (DASH) score and Mayo hlbow performance score (MEPS). Results: Twelve patients were included in the study, comprising 10 males and 2 females with an average age of 39 years (range, 19-72 years). Mean follow-up was 16 months (range, 4-18 months). The average time to radiographic union was 4 months (range, 3-7 months). Range of motion measurements at final follow-up were obtained in 11 out of 12 patients, with one patient defaulting follow-up. All 11 patients displayed a functional elbow range of motion of at least 30°-130°, with an average arc of motion of 130° (range, 110° -140°), mean elbow flexion of 134° (range, 110° -140°) and mean flexion contracture of 3° (range, 0° -20°). The mean DASH score was 16 (range, 2.5-43.8) and the mean MEPS was 75 (range, 65-100). Complications observed included one patient with a superficial wound infection which resolved with a course of oral antibiotics and one patient with radiographic evidence of heterotopic ossification which was conservatively managed. No residual elbow instability was observed and no reoperations were performed. Conclusion: Buttress plate fixation via a medial approach of coronoid process fractures that contribute to persistent elbow instability represents a reliable method of treatment that produces satisfactory and predictable outcomes.