251 Heterotopic ossification (HO) is a clinical condition where mature lamellar bone is formed in damaged tissues such as muscle, tendon, and fascia. 1 This clin- ical entity has been associated with genetic disorders (ie, fibrodysplasia ossificans progressive), traumatic injuries (ie, spinal cord injury, brain injury, ampu- tations, burns), and musculoskeletal surgeries (ie, elbow/acetabular fractures, hip arthroplasty). 2,3 HO may cause skin breakdown, significant soft tis- sue deformity or firmness, and chronic pain that reduce the rehabilitation outcome. For instance, HO can severely limit pressure garment compliance and prosthesis tolerance. Thus, this complication may affect not only the local function such as range of motion (ROM), but also activities of daily liv- ing and quality of life of trauma patients and their families. Several reports have highlighted that the HO incidence in some patient subgroups is considerably higher than previously recognized. Thus, approxi- mately 64% of major combat-related extremity wounds develop HO, and at least 19% of these cases require surgery for clinically relevant symptoms. 4–6 In burn patients, the incidence of HO varies between 0.2 and 4%, 1,7 and is more frequent in patients with burns >20% TBSA. This clinical study reviews the incidence of HO in our burn patients, the risk factors, clinical features, diagnostic methods, and therapeutic approaches including surgical timing and techniques as well as long-term outcomes. MATERIALS AND METHODS We conducted a retrospective study of burn patients admitted to the Firefighters’ Burn Treatment Unit at the University of Alberta Hospital during a 30-year period, using the burn registry to identify patients. Approval to perform this study was obtained from the Health Research Ethics Board of the University of Alberta. We collected demographic data such as age, sex, date of injury, TBSA, total full-thickness burns, and length of stay. In addition, comorbidities, postadmission complications, HO location and their radiographic imaging studies, total number of related burn surgeries, and HO treatment modalities were also reviewed. The ROM of joints undergoing surgery were evaluated before and 3 months after surgery. To process data, Microsoft Excel ® 2008 (Redmond, WA) and GraphPad InStat 3 (GraphPad Software Inc, La Jolla, CA) for windows were used. Data are presented as mean ± SEM. Statistical analysis was performed by two-tailed paired t-test. A P value ≤.05 was considered statistically significant. Copyright © 2013 by the American Burn Association 1559-047X/2014 DOI: 10.1097/BCR.0b013e3182957768 Heterotopic ossification (HO) is a clinical condition of ectopic bone formation in soft tissue. This clinical entity has been associated with genetic disorders, traumatic injuries, and musculoskeletal surgeries. In this regard, functional impairments secondary to scar contractures seen in burn injuries may be exacerbated with underlying HO. The appropriate prevention or management of this complication is crucial to optimize outcome in burn patients. This clinical study reviews the incidence of HO in our burned patients, diagnostic methods, therapeutic approaches including surgical timing and techniques.(J Burn Care Res 2014;35:251–256) From the *Wound Healing Research Group, Division of Plastic and Reconstructive Surgery, †Division of Critical Care Medi- cine, and ‡Firefighters’ Burn Treatment Unit, Department of Surgery, University of Alberta, Edmonton, Canada. Address correspondence to Edward E. Tredget, MD, MSc, FRCSC, University of Alberta, 2D2.28 WMC, 8440-112 Street, Edmonton, Alberta, Canada, T6G 2B7. Characterization of Heterotopic Ossification in Burn Patients Abelardo Medina, MD, PhD,*‡ Heather Shankowsky, RN,* Bohdan Savaryn, BSc,* Barb Shukalak, BSc,‡ Edward E. Tredget, MD, MSc, FRCSC*†‡