Using Cutaneous Functional Units (CFUs) to understand burn characteristics associated with range of motion at hospital discharge in adult burn survivors.

Background: Burn injuries often lead to the development of burn scar contractures (BSC) and subsequent motion loss, which significantly impact function and quality of life for burn survivors. Understanding the relationship between burn characteristics and motion outcomes is critical to improving patient care and outcomes. We used a Cutaneous Functional Units (CFU) framework to investigate acute burn features at or near the time of injury associated with joint-level range of motion at hospital discharge.

Methods: This study is an exploratory analysis of data collected as part of a previous prospective multicenter cohort study (N= 307 patients, 7441 joint motions). CFU features, including burn extent, skin grafting, burn location (proximal/ distal to joint crease), and adjacent CFU involvement, were evaluated while controlling for demographic and clinical variables. Fractional regression models evaluated associations between CFU burn features and range of motion.

Results: A higher percentage of CFU burned and CFU grafted, as well as advanced age, were significantly associated with reduced range of motion (p<0.01). Burn extent in the proximal CFU areas also had a significant negative relationship with range of motion (p<0.01). Total body surface area (TBSA) burned and TBSA grafted were not associated with motion outcomes. Based on this exploratory analysis, a prediction model for BSC risk is proposed for further testing.

Conclusion: Our findings highlight the significance of burn characteristics within CFUs as key factors influencing motion outcomes. The CFU framework provides a standardized and functionally relevant approach to evaluating the localized impact of burn characteristics on joint motion, addressing a critical gap in the understanding of motion loss following burn injuries.