Considerations in Determining the Severity of Burn Scar Contractures With Focus on the Knee Joint.

Scar contractures are a common complication after burn injuries. These contractures are characterized by impairment of joint mobility, leading to a risk for limitations during daily activities, and restrictions in participation in society. Qualifying its severity is not well established in burn care. This study, therefore, examined different approaches to determine the severity of limited mobility in the knee joint due to scar contracture. To determine the severity of burn scar contractures development of the knee over time, the following approaches were analyzed: prevalence, the degree of limitation, the ability to perform basic daily activities, and the need for reconstructive surgery. Range of motion data of the knee joint was extracted from a 12-month prospective multicenter cohort study in the Netherlands. Based on prevalence, mean degree of limitation, and the classification based on mathematical division, limitations in knee flexion would be seen as giving the most problems. On the other hand, when classified in terms of impact on function, limitations in extension were found to be giving most problems, although flexion limitations interfered slightly longer with the basic activities of standing, walking, and climbing stairs. Depending on the chosen approach, the severity of burn scar contractures is projected differently. Interpreting the severity of a burn scar contracture of the knee, preferably should be based on a function-based classification system of the degree of range of motion impairment, activity limitations and participation restrictions in society. Because that does justice to the real impact of burn scar contracture on the individual burn survivor.

Rating scales for shoulder and elbow range of motion impairment: Call for a functional approach.

BACKGROUND: To evaluate the effect of (new) treatments or analyse prevalence and risk factors of contractures, rating scales are used based on joint range of motion. However, cut-off points for levels of severity vary between scales, and it seems unclear how cut-off points relate to function. The purpose of this study was to compare severity ratings of different rating scales for the shoulder and elbow and relate these with functional range of motion. METHODS: Often used contracture severity rating scales in orthopedics, physiotherapy, and burns were included. Functional range of motion angles for the shoulder and elbow were derived from a recent synthesis published by our group. Shoulder flexion and elbow flexion range of motion data of patients three months after a burn injury were rated with each of the scales to illustrate the effects of differences in classifications. Secondly, the shoulder and elbow flexion range of motion angles were related to the required angles to perform over 50 different activities of daily living tasks. RESULTS: Eighteen rating scales were included (shoulder: 6, elbow: 12). Large differences in the number of severity levels and the cut-off points between scales were determined. Rating the measured range of motions with the different scales showed substantial inconsistency in the number of joints without impairment (shoulder: 14-36%, elbow: 26-100%) or with severe impairment (shoulder: < 10%-29%, elbow 0%-17%). Cut-off points of most scales were not related to actual function in daily living. CONCLUSION: There is an urgent need for rating scales that express the severity of contractures in terms of loss of functionality. This study proposes a direction for a solution.

Prevalence of scar contractures after burn: A systematic review.

OBJECTIVE: Burn scar contractures are the pathological outcome of excessive scarring and ongoing scar contraction. Impairment of joint range of motion is a threat to performing activities in daily living. To direct treatment strategies to prevent and/or correct such contractures, insight into the prevalence, course, and determinants is essential. METHODS: A literature search was conducted including Pubmed, Cochrane library, CINAHL, and PEDro. Articles were included if they provided burn scar contracture data to calculate the point prevalence. The quality of the articles was scored. Data were extracted regarding study, subject and burn characteristics, method of scar contracture assessment, point prevalence, and possible determinants. RESULTS: Nine articles and one abstract could be included for data extraction. The prevalence at discharge was 38-54%, but with a longer time after burn, the prevalence was lower. Contractures were more likely to occur in more severe burns, flame burns, children, female, the cervical spine, and the upper extremity. CONCLUSIONS: The prevalence of burn scar contractures varies considerably between studies. When prevalence is unclear, it is also difficult to investigate potential determinants and evaluate changes in interventions. There is a need for extensive, well-designed longitudinal (inter)national studies that investigate prevalence of scar contractures, their evolvement over time, and risk factors.

Adaptation of the dermal collagen structure of human skin and scar tissue in response to stretch: an experimental study.

Surgeons are often faced with large defects that are difficult to close. Stretching adjacent skin can facilitate wound closure. In clinical practice, intraoperative stretching is performed in a cyclical or continuous fashion. However, exact mechanisms of tissue adaptation to stretch remain unclear. Therefore, we investigated collagen and elastin orientation and morphology of stretched and nonstretched healthy skin and scars. Tissue samples were stretched, fixed in stretched-out position, and processed for histology. Objective methods were used to quantify the collagen orientation index (COI), bundle thickness, and bundle spacing. Also sections were analyzed for elastin orientation and quantity. Significantly more parallel aligned collagen bundles were found after cyclical (COI = 0.57) and continuous stretch (COI = 0.57) compared with nonstretched skin (COI = 0.40). Similarly, more parallel aligned elastin was found after stretch. Also, significantly thicker collagen bundles and more bundle spacing were found after stretch. For stretched scars, significantly more parallel aligned collagen was found (COI = 0.61) compared with nonstretched scars (COI = 0.49). In conclusion, both elastin and collagen realign in a parallel fashion in response to stretch. For healthy skin, thicker bundles and more space between the bundles were found. Rapid changes in extension, alignment, and collagen morphology appear to be the underlying mechanisms of adaptation to stretching.

Collagen bundle morphometry in skin and scar tissue: a novel distance mapping method provides superior measurements compared to Fourier analysis.

Histopathological evaluations of fibrotic processes require the characterization of collagen morphology in terms of geometrical features such as bundle orientation thickness and spacing. However, there are currently no reliable and valid techniques of measuring bundle thickness and spacing. Hence, two objective methods quantifying the collagen bundle thickness and spacing were tested for their reliability and validity: Fourier first-order maximum analysis and Distance Mapping, with the latter constituting a newly developed morphometric technique. Histological slides were constructed and imaged from 50 scar and 50 healthy human skin biopsies and subsequently analyzed by two observers to determine the interobserver reliability via the intraclass correlation coefficient. An intraclass correlation coefficient larger than 0.7 is considered as representing good reliability. The interobserver reliability for the Fourier first-order maximum and for the Distance Mapping algorithms, respectively, showed an intraclass correlation coefficient above 0.72 and 0.89. Additionally, we performed an assessment of validity in the form of responsiveness, in particular, demonstrating medium to excellent results via a calculation of the effect size, highlighting that both methods are sensitive enough to measure a treatment effect in clinical practice. In summary, two reliable and valid measurement methods were demonstrated for collagen bundle morphometry for the first time. Due to its superior reliability and more useful measures (bundle thickness and bundle spacing), Distance Mapping emerges as the preferred and more practical method. Nevertheless, in the future, both methods can be used for reliable and valid collagen morphometry of skin and scars, whereas further applications evaluating the quantitative microscopy of other fibrotic processes are anticipated.