Identification of Cutaneous Functional Units Related to Burn Scar Contracture Development

Abstract

The development of burn scar contractures is due in part to the replacement of naturally pliable skin with an inadequate quantity and quality of extensible scar tissue. Predilected skin surface areas associated with limb range of motion (ROM) have a tendency to develop burn scar contractures that prevent full joint ROM leading to deformity, impairment, and disability. Previous study has documented forearm skin movement associated with wrist extension. The purpose of this study was to expand the identification of skin movement associated with ROM to all joint surface areas that have a tendency to develop burn scar contractures. Twenty male subjects without burns had anthropometric measurements recorded and skin marks placed on their torsos and dominant extremities. Each subject performed ranges of motion of nine common burn scar contracture sites with the markers photographed at the beginning and end of motion. The area of skin movement associated with joint ROM was recorded, normalized, and quantified as a percentage of total area. On average, subjects recruited 83% of available skin from a prescribed area to complete movement across all joints of interest (range, 18-100%). Recruitment of skin during wrist flexion demonstrated the greatest amount of variability between subjects, whereas recruitment of skin during knee extension demonstrated the most consistency. No association of skin movement was found related to percent body fat or body mass index. Skin recruitment was positively correlated with joint ROM. Fields of skin associated with normal ROM were identified and subsequently labeled as cutaneous functional units. The amount of skin involved in joint movement extended far beyond the immediate proximity of the joint skin creases themselves. This information may impact the design of rehabilitation programs for patients with severe burns.

Treatment and Rehabilitation of Knee Joints Straight Stiffness After Burns

“…Skin scar contracture tension and joint stiffness are important factors in a patient's recovery from burns [16][17][18]. Skin grafting is commonly used to handle skin tightening in knee straight stiff release surgery to treat burns.…”

The Utilization of Nintendo® Wii™ During Burn Rehabilitation

“…Participants were alternated into the Wii or control treatment groups and stratified based on joint region of burn. Joints of interest based on cutaneous functional units 27 were those with the greatest limitations in AROM, relative to the contralateral side if bilateral burn injuries were sustained. Richard et al 27 describe cutaneous functional units as fields of skin involved in a joint's ROM, which include the location of the burn injury relative to joint skin creases.…”

Methods and Tools Used for the Measurement of Burn Scar Contracture

“…In a recent study, Richard et al 89 found that during neck extension, shoulder abduction, and shoulder flexion, subjects recruited skin on the trunk to complete the motion and often the skin was some distance from the joint tested. Palmieri et al 22 found that after axillary contracture formation, trunk movement unexpectedly became "stiff," appearing to be linked to shoulder movement, which resulted in decreased trunk extension during high reach.…”

“…A review of the literature indicates that apart from using calipers, which is not recommended around the eye, a tape measure/ruler and photography are the best clinical techniques for documenting the effect of scar contracture in this region. 108 Because of influence of the cutaneous functional unit on scar tissue, 89 it is important to measure eyelid closure in a variety of end-range positions (ie, with neck neutral, extension or rotation, with mouth opened, and during sleep). Also important to note are the intrinsic effects of scar tissue in the region of the eyes (eyelid closure, epicanthal hooding, etc).…”