Escalas de Avaliação para Flacidez da Pele

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<p>Validated Assessment Scales for Skin Laxity on the</p><p>Posterior Thighs, Buttocks, Anterior Thighs, and Knees in</p><p>Female Patients</p><p>Michael S. Kaminer, MD* Gabriela Casabona, MD,† Wouter Peeters, MD,‡</p><p>Rolf Bartsch, MD,x Kimberly Butterwick, MD,║ Yates Yen-Yu Chao, MD,¶</p><p>Joana Costa, MD,** Joseph Eviatar, MD,†† Sabrina Guillen Fabi, MD,║</p><p>Thorin L. Geister, PhD,‡‡ Kate Goldie, MD,xx Jenny Grice, BSc,║║ Doris Hexsel, MD,¶¶</p><p>Paul Lorenc,MD,***Mary Lupo,MD,†††Rainer Pooth,MD, PhD,‡‡‡Gerhard Sattler,MD,xxx</p><p>Heidi A. Waldorf, MD,║║║ Yana Yutskovskaya, MD,¶¶¶ and Martina Kerscher, MD****</p><p>BACKGROUND The demand for noninvasive skin-tightening body procedures is increasing.</p><p>OBJECTIVE To develop a set of grading scales for the objective assessment of skin laxity and assess their</p><p>reliability and validity.</p><p>MATERIALS AND METHODS Two photonumeric grading scales were created and validated for skin laxity in</p><p>female patients: Skin Laxity—Posterior Thighs/Buttocks, and Anterior Thighs/Knees. Fifteen aesthetic experts</p><p>rated photographs of 50 women in 2 validation sessions. Responses were analyzed to assess inter-rater and</p><p>intra-rater reliability.</p><p>RESULTS Overall inter-rater reliability according to intraclass correlation efficient (ICC) 2.1 and weighted</p><p>kappa was at least “substantial” for both scales in both sessions, and “almost perfect” ($0.81) for the Anterior</p><p>Thighs and Knees scale in session 2. Intra-rater reliability was “almost perfect” for both scales (ICC 2.1) and</p><p>“substantial” to “almost perfect” by weighted kappa. A correlation between the skin laxity scales and body</p><p>mass index, age, weight, sun exposure, and cellulite severity was observed.</p><p>CONCLUSION The skin laxity photonumeric grading scales are valid and reliable instruments for assessing</p><p>laxity on the posterior thighs and buttocks, and anterior thighs and knees. The scales will be of value for</p><p>standardizing clinical evaluations and quantifying outcome measurements in research and clinical practice.</p><p>Supported by Merz Pharmaceuticals GmbH, Frankfurt, Germany. The authors received an honorarium for partici-</p><p>pating in the consensus meeting. The authors have indicated no significant interest with commercial supporters.</p><p>The appearance of lax skin on the body, whether it</p><p>is a result of aging or mechanical stretching of the</p><p>skin after excessweight gain, can be distressing and is a</p><p>major cosmetic concern for many people. Treatments</p><p>to tighten the skin were once restricted to surgical</p><p>procedures, but individuals with mild-to-moderate</p><p>skin laxity are increasingly seeking noninvasive</p><p>options that have minimal downtime and no scarring.</p><p>*SkinCare Physicians, Chestnut Hill, Massachusetts; †Clı́nica Vida, São Paulo, Brazil; ‡AZ KLINA, Brasschaat,</p><p>Belgium; xThe Aesthetics, Vienna, Austria; ║Cosmetic Laser Dermatology, San Diego, California; ¶CHAO Institute</p><p>of Aesthetic Medicine, Taipei, Taiwan; **Clı́nica Dermatológica Joana Costa, Brası́lia, Brazil; ††Omni Aesthetic,</p><p>New York, New York; ‡‡Merz Pharmaceuticals GmbH, Frankfurt, Germany; xxEuropean Medical Aesthetics Ltd.,</p><p>London, United Kingdom; ║║Le Prioldy, Bieuzy les Eaux, France; ¶¶Brazilian Center for Studies in Dermatology,</p><p>Porto Alegre, Brazil; ***Z. Paul Lorenc Aesthetic Plastic Surgery, New York, New York; †††Lupo Center for</p><p>Aesthetic & General Dermatology, New Orleans, Louisiana; ‡‡‡Merz Pharmaceuticals GmbH Consultant,</p><p>Frankfurt, Germany; xxxRosenparkklinik, Darmstadt, Germany; ║║║Waldorf Dermatology Aesthetics, Nanuet,</p><p>New York; ¶¶¶Department of Cosmetology, Pacific State Medical University of Health Ministry of Russia, Moscow,</p><p>Russia; ****Division of Cosmetic Sciences, University of Hamburg, Hamburg, Germany</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.</p><p>ISSN: 1076-0512 · Dermatol Surg 2019;45:S12–S21 · DOI: 10.1097/DSS.0000000000001994</p><p>S12</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>The aim of noninvasive skin-tightening procedures is</p><p>to improve dermal strength and elasticity by remod-</p><p>eling of the dermis with neocollagenesis and elasto-</p><p>genesis. This is achieved by using targeted energy to</p><p>penetrate varying depths of the dermis, while leaving</p><p>the outer epidermal layer undamaged.1 A range of</p><p>noninvasive skin-tightening devices are available and</p><p>cleared by the US FDA and in Europe. These use</p><p>energy from a variety of sources including monopolar</p><p>andbipolar radiofrequency, broadband and laser light</p><p>sources, ultrasound, and most recently microfocused</p><p>ultrasound with visualization (MFU-V).2–5</p><p>Skin laxity frequently occurs in areas where a large</p><p>amount of adipose tissue is covered by a relatively thin</p><p>layer of skin such as the buttocks, thighs, the region</p><p>above the knee, and the upper arms. In these areas, the</p><p>skin is subject to the mechanical action of weight</p><p>exerted by adipose tissue and other subcutaneous</p><p>structures as well as the effects of gravity. Treatments</p><p>such as MFU-V have proven effective at improving</p><p>skin laxity as well as the appearance of cellulite in the</p><p>buttocks and upper thighs,6,7 but there is currently no</p><p>validated skin laxity scale for these areas to allow for</p><p>objective and consistent assessment of treatment out-</p><p>comes. In this article, the authors present the skin</p><p>laxity grading scales for the objective quantification of</p><p>skin laxity severity in the posterior thigh and buttocks,</p><p>and anterior thigh and knee areas.</p><p>Methods</p><p>Creation of the Skin Laxity Scales</p><p>The methods for the development of the skin laxity</p><p>scales followed the methodology for the creation and</p><p>validation of other Merz Aesthetic Scales8–11 and are</p><p>outlined in detail in a related publication in this issue.12</p><p>In brief, a photographic database of 120 female sub-</p><p>jects representing a range of skin laxity severities in the</p><p>posterior thighs, buttocks, anterior thighs, and knees</p><p>was established, and from these images, one was</p><p>selected to serve as the base image for each treatment</p><p>area. Additional images were then selected from the</p><p>database to superimpose varying degrees of skin laxity</p><p>severity onto the base image for the creation of two 5-</p><p>point photonumeric scales: Skin Laxity—At Rest for</p><p>Posterior Thighs and Buttocks, and Skin Laxity—At</p><p>Rest for Anterior Thighs and Knees (Figure 1). For</p><p>both scales, all images were obtained in the resting</p><p>state (a dynamic scale was not produced).</p><p>All subjects were photographed by a professional</p><p>photographer using a Nikon D800 camera/70 to</p><p>200mm lens (NikonCorporation, Tokyo, Japan). The</p><p>angle of the lights and distances between the platform,</p><p>lights, and camera were all standardized and con-</p><p>firmed for each photography session (Figure 2). The</p><p>areas to be captured covered posterior thighs and</p><p>buttocks, and the anterior thighs and knees. Images</p><p>included both posterior and oblique (45� angle) views</p><p>of both sides and were taken at rest only. Microrelief</p><p>images were also obtained.</p><p>The skin laxity scales differ slightly from other Merz</p><p>Aesthetic Scales, in that 2 additional reference images</p><p>were included for each severity grade. These were</p><p>designed to act as a photo guide to be used alongside</p><p>the photonumeric scale to aid physicians with the</p><p>grading process. The reference images covered all</p><p>Fitzpatrick skin types.</p><p>Demographic data were collected for all subjects</p><p>including age, ethnicity, bodymass index (BMI) class,</p><p>smoking status, Fitzpatrick skin phototypes, and self-</p><p>reported exposure to sunlight (based on a 5-point</p><p>rating scale where 0 = never and 4 = very often). All</p><p>subjects were informed of the objectives and targets</p><p>of the study and gave consent to their photographs</p><p>being rated, analyzed, and used in publications for</p><p>scientific</p><p>purposes.</p><p>Validation of the Skin Laxity Scales</p><p>After the creation of the scales, 16 international</p><p>experts in the field of aesthetics conducted a psycho-</p><p>metric validation to assess their validity and reliability.</p><p>As described for the Cellulite Dimple scales also pub-</p><p>lished in this issue,12 a validation booklet was pro-</p><p>duced which contained images of 50 subjects</p><p>displaying all levels of skin laxity in the buttock, pos-</p><p>terior and anterior thigh, and knee area, presented</p><p>alongside the 2 skin laxity grading scales: Skin</p><p>Laxity—At Rest for Posterior Thighs and Buttocks,</p><p>and Skin Laxity—At Rest for Anterior Thighs and</p><p>KAMINER ET AL</p><p>45 : 8 S : AUGUST S PEC IAL I S SUE 2 0 1 9 S13</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>Knees. As described above, the booklets also con-</p><p>tained images of 2 reference subjects alongside each</p><p>severity grade image to assistwith grading. Two sets of</p><p>validation booklets were produced for each expert, so</p><p>that ratings could be performed in 2 validation cycles</p><p>at least 2 weeks apart to reduce any memory effects</p><p>between sessions.</p><p>Subjects’ imageswere presented in a randomized sequence</p><p>in the booklets for each of the 2 sessions by assigning a</p><p>pagenumber to the respective subject’s image.Raterswere</p><p>blinded with respect to the chosen subjects, subject iden-</p><p>tifiers, subject characteristics, and subject randomization</p><p>sequences in the booklets. The ratings of each aesthetic</p><p>expertwere entereddirectly into thebooklet for each scale.</p><p>Figure 1. (A) Final set of Skin Laxity At Rest—Posterior Thighs and Buttocks and (B) Skin Laxity At Rest—Anterior Thighs</p><p>and Knees Scales.</p><p>AS SE S SMENT SCALES FOR SK IN LAX ITY</p><p>DERMATOLOG IC SURGERYS14</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>Statistical Analyses</p><p>During the validation of the skin laxity scales, one</p><p>expert inadvertently used an earlier version of the</p><p>scales for rating the subjects, and the respective ratings</p><p>were therefore invalid. As a result, rating data for the</p><p>statistical analysis were only available for 15 aesthetic</p><p>experts. All rating data from the validation booklets</p><p>were entered into a database using the double-entry</p><p>method and subjected to quality control. Rating</p><p>results from the first and second validation sessions</p><p>were summarized by descriptive statistics including</p><p>number of ratings (n), arithmetic mean, SD, median,</p><p>range, and number of missing values.</p><p>Inter-rater and Intra-rater Reliability</p><p>The reliability between pairs of aesthetic experts and</p><p>experts overall (inter-rater reliability) and the reli-</p><p>ability between the first and second validation sessions</p><p>for each aesthetic expert and aesthetic experts overall</p><p>(intra-rater reliability) were assessed by the intraclass</p><p>correlation coefficient (ICC) 2.1 of Shrout and Fleiss.13</p><p>To account for the fact that the validated scales are</p><p>ordinal scales and the ICC derivation assumes a</p><p>quantitative scale, weighted kappa values (Fleiss–</p><p>Cohen weights) were also derived.14,15 The quality of</p><p>reliability was defined by the following ICC ranges for</p><p>interpretation of both inter-rater and intra-rater</p><p>results16,17: ICC values of 0.00 to 0.20 denote slight</p><p>reliability, 0.21 to 0.40 fair, 0.41 to 0.60 moderate,</p><p>0.61 to 0.80 substantial, and $0.81 almost perfect</p><p>reliability. Lower ICC values indicate variability in the</p><p>assessment of subjects (e.g., different ratings for the</p><p>same subject by the raters). Based on the above clas-</p><p>sifications, ICC values of >0.60 were considered to</p><p>demonstrate a high consistency of scale ratings.</p><p>Bivariate scatter plots (bubble plots) for validation</p><p>session 1 versus validation session 2 were also gener-</p><p>ated for representation of intra-rater reliability for all</p><p>aesthetic experts combined.</p><p>Correlation</p><p>Validity of the scales was explored by means of Spear-</p><p>man correlation coefficients with bias adjustment for</p><p>subject demographic variables including age, height,</p><p>weight, BMI, smoking status, Fitzpatrick skin classifi-</p><p>cation, and self-rated level of sun exposure. The corre-</p><p>lation coefficients were calculated by validation session</p><p>for each aesthetic expert and over all aesthetic experts.</p><p>All analyses were written, validated, and performed</p><p>using SAS version 9.3.</p><p>Results</p><p>For each validation session and each skin laxity scale,</p><p>there were 750 planned ratings for the 15 aesthetic</p><p>experts (15 aesthetic experts · 50 subjects rated). A</p><p>few aesthetic experts did not provide a rating for each</p><p>subject, but missing data were few (<1%) in both</p><p>validation sessions. For most experts, the mean dura-</p><p>tion between the 2 validation sessions was 3 weeks.</p><p>Subject Characteristics</p><p>All the subjectswerewomenwith amean ageof 35.86</p><p>13.8 years in the Skin Laxity—Posterior Thighs and</p><p>Buttocks population and 33.86 13.1 years in the Skin</p><p>Laxity—Anterior Thighs and Knees population.</p><p>Mean BMI values were 23.5 6 4.6 and 23.3 6</p><p>4.3 kg/m2, respectively, and current smokers accoun-</p><p>ted for 22.0%and28.0%of participants, respectively.</p><p>All Fitzpatrick skin Types I to VI were represented</p><p>across both scales, but the most common was type III</p><p>(38.0% and 40.0%, respectively). For both skin laxity</p><p>scale populations, 76% reported exposure to sunlight</p><p>“seldom,” “seldom to sometimes,” or ”sometimes.”</p><p>Figure 2. Photo setup for posterior thigh, buttocks, ante-</p><p>rior thigh, and knee photography (top view).</p><p>KAMINER ET AL</p><p>45 : 8 S : AUGUST S PEC IAL I S SUE 2 0 1 9 S15</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>Expert Characteristics</p><p>Of the 16 aesthetic experts (9 women and 7 men), 12</p><p>were dermatologists, 3 were plastic surgeons, and 1</p><p>was an ophthalmologist.</p><p>Descriptive Statistics</p><p>For the“SkinLaxity—PosteriorThighs andButtocks”</p><p>scale, the grading of aesthetic experts at validation</p><p>session 1 covered all severity scores from grade 4“very</p><p>severe” (12.7%ofwomen) toGrade 0 “none” (11.7%</p><p>of women). For validation session 2, grading ranged</p><p>betweenGrade 4 (12.4%) andGrade 0 (9.7%) (Figure</p><p>3). In both validations sessions, most women were</p><p>graded as having mild or moderate skin laxity. Mean</p><p>ratings were comparable between validation sessions</p><p>1 and 2 at 1.9 (SD: 1.18) and 1.9 (SD: 1.25), respec-</p><p>tively, indicating mild-to-moderate skin laxity on the</p><p>posterior thighs and buttocks.</p><p>For the “Skin Laxity—Anterior Thighs and Knees”</p><p>scale, the grading of experts at validation session 1</p><p>ranged fromGrade 4“very severe” (15.5%ofwomen)</p><p>to Grade 0 “none” (13.3% of women) (Figure 3). For</p><p>validation session 2, grading ranged between Grade 4</p><p>(16.0%) to Grade 0 (11.1%). Most women in both</p><p>validation sessions were graded as having mild or</p><p>moderate skin laxity. Mean ratings were again com-</p><p>parable for validation sessions 1 and 2 at 1.9 (SD:</p><p>1.25) for both sessions, indicating mild-to-moderate</p><p>skin laxity on the anterior thighs and knees.</p><p>Inter-rater Reliability</p><p>The ICC and weighted kappa values for overall inter-</p><p>rater reliability of the 2 skin laxity scales are presented</p><p>by validation</p><p>session in Table 1. Weighted kappa and</p><p>ICC values for inter-rater reliability in validation ses-</p><p>sions 1 and 2 were very similar for Skin Laxity—Pos-</p><p>terior Thighs and Buttocks and identical for Skin</p><p>Laxity—AnteriorThighs andKnees.Overall inter-rater</p><p>reliabilitywas determined to be substantial (0.61–0.80)</p><p>at both validation sessions for the Skin Laxity—Poste-</p><p>rior Thighs and Buttocks scale. For Skin Laxity—</p><p>Anterior Thighs and Knees, inter-rater reliability was</p><p>substantial at validation session 1 and almost perfect</p><p>($0.81) at validation session 2. For both scales, inter-</p><p>rater reliability was$0.7 in both validation sessions.</p><p>Intra-rater Reliability</p><p>The ICC and weighted kappa values for intra-rater</p><p>reliability of the 2 skin laxity scales are presented in</p><p>Table 2. For the Skin Laxity—Posterior Thighs and</p><p>Buttocks scale, overall intra-rater reliability was</p><p>determined to be almost perfect ($0.81) based on ICC</p><p>2.1 and substantial (0.61–0.80) based on the weighted</p><p>kappa. For the Skin Laxity—Anterior Thighs and</p><p>Knees scale, intra-rater reliability was almost perfect</p><p>based on both ICC 2.1 and weighted kappa values.</p><p>Intra-rater reliability of individual aesthetic experts for</p><p>the Posterior Thighs and Buttocks and Anterior</p><p>Thighs and Knees scales ranged from 0.67 to 0.95 and</p><p>0.60 to 0.94, respectively.</p><p>Bubble plots for all experts pooled, illustrating the</p><p>frequency of rating combinations between the first</p><p>and second validation session for the “Skin Laxity—</p><p>Posterior Thighs and Buttocks” scale, are shown in</p><p>Figure 4. There were 430 of 742 ratings with perfect</p><p>agreement and 30 of 742 ratings with a difference of</p><p>more than 1 grade. The location of the high-</p><p>frequency ratings on the diagonal line of the bubble</p><p>plot demonstrates the high intra-rater reliability. The</p><p>bubble plot for ratings of “Skin Laxity—Anterior</p><p>Thighs and Knees” shows 436 of 742 ratings with</p><p>perfect agreement and 25 of 742 ratings with a dif-</p><p>ference of more than 1 grade (Figure 5). For both</p><p>scales, the results for the 2 validation sessions were</p><p>similar.</p><p>Validity of the Scales</p><p>The Spearman correlations between the skin laxity</p><p>scale ratings and subject demographic characteristics</p><p>are shown in Table 3. For the Skin Laxity—Posterior</p><p>Thighs and Buttocks scale, several positive Spearman</p><p>correlation coefficients were observed, the strongest</p><p>was for BMI, followed in descending order by age,</p><p>weight, and sun exposure. A negative correlation was</p><p>observed for height. There were no relevant associa-</p><p>tions for Fitzpatrick skin type or smoking status.</p><p>For the Skin Laxity—Anterior Thighs andKnees scale,</p><p>positive Spearman correlation coefficients were</p><p>observed for age, BMI, weight, and sun exposure. A</p><p>negative correlation was again observed for height as</p><p>A S SE S SMENT SCALES FOR SK IN LAX ITY</p><p>DERMATOLOG IC SURGERYS16</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>well as for Fitzpatrick skin type. Therewas no relevant</p><p>association for smoking status.</p><p>A high correlation was observed between the 2 Skin</p><p>Laxity scales and the Cellulite Dimple at Rest and</p><p>Dynamic scales, which are also published in a related</p><p>article in this journal issue.12</p><p>Discussion</p><p>Women of all ages are increasingly seeking non-</p><p>surgical aesthetic treatments to tighten skin in the</p><p>thighs, knees, and buttocks to achieve a toned body</p><p>appearance and/or because skin laxity in these areas</p><p>may stand out in contrast to a smooth appearance in</p><p>other exposed areas of the body such as the face,</p><p>hands, neck, and décolletage. This has led to a number</p><p>of innovations in energy-based devices such as ultra-</p><p>sound, radiofrequency, and infrared laser devices,</p><p>which can deliver controlled heat to the dermis to</p><p>stimulate neocollagenesis and improve skin laxity.</p><p>Microfocused ultrasound with visualization is one</p><p>modality developed to meet the growing public</p><p>demand for noninvasive skin-lifting and skin-</p><p>tightening procedures. To standardize clinical evalu-</p><p>ations, quantify results, guide best techniques, and</p><p>measure the longevity of the treatment effects, assess-</p><p>ment tools are required to grade skin laxity both before</p><p>Figure 3. Range of skin laxity severity for the 50 women graded for the (A) Skin Laxity—Posterior Thighs and Buttocks scale,</p><p>and (B) Skin Laxity—Anterior Thighs and Knees scale.</p><p>KAMINER ET AL</p><p>45 : 8 S : AUGUST S PEC IAL I S SUE 2 0 1 9 S17</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>and after treatments. However, until now, no specifi-</p><p>cally designed grading scales were available. To</p><p>address this need, Merz Aesthetics has developed and</p><p>validated 2 skin laxity grading scales for the posterior</p><p>thighs and buttocks, and the anterior thighs and knees</p><p>using accepted criteria for the reporting of reliability</p><p>studies.18 The scales are intended to be intuitive, easy</p><p>to use, and reliable outcome evaluation tools for use by</p><p>aesthetic experts.</p><p>Validation of these scales was performed by 15 aes-</p><p>thetic experts who graded real-life photographs</p><p>against images in a 5-point photonumeric scale over 2</p><p>validation sessions. The results showed substantial</p><p>inter-rater reliability (degree of rating agreement</p><p>between aesthetic experts) for the Posterior Thighs</p><p>and Buttocks scale, and substantial to almost perfect</p><p>inter-rater reliability for the Anterior Thighs and</p><p>Knees scale, with consistent results between validation</p><p>sessions. Intra-rater reliability (degree of rating</p><p>agreement for a single aesthetic expert at different</p><p>rating sessions) was almost perfect for both scales.</p><p>Reliability is a useful measure of how consistently</p><p>values are rated and is amajor determinant of a scale’s</p><p>utility and application.18 It is affected by the degree of</p><p>discrimination between the different scale grades that</p><p>users are required to make. The skin laxity scales and</p><p>other Merz Aesthetic scales use a 5-point photo-</p><p>numeric grading system because this has been deter-</p><p>mined to provide the optimal degree of discrimination</p><p>between the different severity levels of the aesthetic</p><p>trait of interest with the highest degree of reliability.</p><p>This assumption was confirmed in the current study</p><p>where there was high agreement between aesthetic</p><p>experts for patients presenting with a range of skin</p><p>laxity severities.</p><p>For evaluation scales to be accurate, they must reflect</p><p>the target population assessed. Reliability of the scales</p><p>was demonstrated across a heterogeneous population</p><p>covering the whole spectrum of age, BMI, Fitzpatrick</p><p>skin phototypes (I–IV), and skin laxity severities that a</p><p>physician is likely to encounter in clinical practice.</p><p>Regardless of differences in skin color, texture, and</p><p>TABLE 2. Intra-rater Reliability Estimates for the Skin Laxity Grading Scales</p><p>Scale ICC 2.1 [Asymptotic 95% CI]</p><p>Mean Weighted Kappa*</p><p>(Fleiss–Cohen) [SD]</p><p>Skin Laxity—Posterior Thighs and Buttocks 0.81 (almost perfect†) [0.78–0.83] 0.80 (substantial†) [0.085]</p><p>Skin Laxity—Anterior Thighs and Knees 0.83 (almost perfect†) [0.81–0.85] 0.83 (almost perfect†) [0.081]</p><p>*Mean of all aesthetic experts.</p><p>†Substantial: 0.61 to 0.80, almost perfect: $0.81.</p><p>TABLE 1. Inter-rater Reliability Estimates by Validation Session for Skin Laxity Posterior Thighs and</p><p>Buttocks and Skin Laxity Anterior Thighs and Knees at Rest Rating Scales</p><p>Scale ICC 2.1 (Asymptotic 95% CI)</p><p>Mean Weighted Kappa*</p><p>(Fleiss–Cohen) [SD]</p><p>Skin</p><p>Laxity—Posterior Thighs and Buttocks</p><p>Validation session 1 0.76 (substantial†) [0.67–0.84] 0.77 (substantial†) [0.087]</p><p>Validation session 2 0.74 (substantial†) [0.65–0.82] 0.73 (substantial†) [0.093]</p><p>Skin Laxity—Anterior Thighs and Knees</p><p>Validation session 1 0.78 (substantial†) [0.71–0.85] 0.78 (substantial†) [0.106]</p><p>Validation session 2 0.81 (almost perfect†) [0.75–0.87] 0.81 (almost perfect†) [0.051]</p><p>*Mean of all rater combinations.</p><p>†Substantial: 0.61 to 0.80, almost perfect: $0.81.</p><p>AS SE S SMENT SCALES FOR SK IN LAX ITY</p><p>DERMATOLOG IC SURGERYS18</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>degree of laxity, the scales have proven to be highly</p><p>reliable and reproducible.</p><p>The robustness of the scales was further demonstrated</p><p>by the consistency of the ratings among a large group</p><p>of 15 experts who had received no specific training on</p><p>their use. The statistical model used in the analysis</p><p>(ICC 2.1) assumes a random subset of raters from a</p><p>population of experts in aesthetic medicine. The</p><p>results can therefore be assumed to be a conservative</p><p>estimate of inter-rater reliability, and real inter-rater</p><p>reliability may be even higher.</p><p>Skin laxity is an inevitable consequence of aging. His-</p><p>tologic studies of lax skin show dermal atrophy, pri-</p><p>marily due to loss of collagen, degradation of elastin</p><p>fibers, and loss of hydration.19–21 The breakdown is</p><p>exacerbated by extrinsic factors, such as ultraviolet</p><p>radiation and excess weight gain. In the current study,</p><p>the validity of the scales was also explored bymeans of</p><p>correlations of the scale grades with subject demo-</p><p>graphic variables that might influence skin laxity. For</p><p>both scales, a high correlation was observed between</p><p>worsening skin laxity and increasing age and BMI.</p><p>Positive correlations were also observed for weight and</p><p>level of sun exposure, and for the Anterior Thighs and</p><p>Knees scale only, there was a negative correlation for</p><p>Fitzpatrick skin type. Similar to the cellulite dimple</p><p>severity scales,12 a small negative correlationwas found</p><p>between severity of skin laxity and subject’s height, for</p><p>example, smaller women had less severe skin laxity—</p><p>probably because the available area is more limited.</p><p>There was no correlation between the skin laxity scales</p><p>and smoking status. A high correlation was observed</p><p>between the 2 skin laxity scales and the recently devel-</p><p>oped cellulite dimple scales (the development and vali-</p><p>dation of these scales is published in an accompanying</p><p>article in this issue).12 Previous studies have shown that</p><p>cellulite severity is influencedby skin laxity, particularly</p><p>inolder individuals.22,23 Improvingdermal strengthand</p><p>elasticity are therefore also important goals for treat-</p><p>ments targeting cellulite dimples.12</p><p>To the authors’ knowledge, there are currently no</p><p>other aesthetic scales that have been specifically</p><p>designed to evaluate skin laxity in the knee, upper</p><p>thigh, and buttock areas. The cellulite severity scale</p><p>developed by Hexsel and colleagues24 included a</p><p>skin laxity component, but only as part of the overall</p><p>cellulite scale. When used in combination with</p><p>standardized photographic equipment and param-</p><p>eters, the current skin laxity scales will prove of</p><p>value in clinical practice as well as for ongoing</p><p>research. The photographic documentation,</p><p>Figure 4. Intra-rater reliability: Bubble plot for “Skin Lax-</p><p>ity—Posterior Thighs and Buttocks.”</p><p>Figure 5. Intra-rater reliability: Bubble plot for “Skin Lax-</p><p>ity—Anterior Thighs and Knees.”</p><p>KAMINER ET AL</p><p>45 : 8 S : AUGUST S PEC IAL I S SUE 2 0 1 9 S19</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>without the need for any measurements, is easy to</p><p>use in clinical practice and allows for rapid and</p><p>consistent subject assessment. Further studies are</p><p>now warranted to evaluate the use of the scales for</p><p>live assessment of subjects rather than from 2-</p><p>dimensional photographic images. Their use for</p><p>communicating the success of skin laxity treatments,</p><p>as well as for establishing a common benchmark for</p><p>research into treatment, results with energy-based</p><p>devices and other procedures targeting skin laxity</p><p>should also be investigated.</p><p>Conclusion</p><p>The results of this validation study confirm that the</p><p>newly developed Merz Aesthetics skin laxity grading</p><p>scales are a reliable and reproducible scoring system</p><p>for aesthetic evaluation of clinical photographs of skin</p><p>laxity on the posterior thighs and buttocks, and ante-</p><p>rior thighs and knees in conjunctionwith standardized</p><p>photographicmethods. The scales have been validated</p><p>using photographs and should be of practical value for</p><p>assessing live patients; this will be confirmed in clinical</p><p>trials. Further evaluation in live patients will confirm</p><p>the ability of the scales to assess clinical outcomes after</p><p>skin laxity treatment.</p><p>References</p><p>1. Zelickson B, Ross EV, Strasswimmer J. Definition and proposed</p><p>mechanisms of non-invasive skin tightening. In: Alam M, Dover JS, editors.</p><p>Non-surgical Skin Tightening and Lifting. Philadelphia: Saunders, Elsevier;</p><p>2009.</p><p>2. Carruthers J, Fabi S, Weiss R. Monopolar radiofrequency for skin</p><p>tightening: our experience and a review of the literature. Dermatol Surg</p><p>2014;40(Suppl 12):S168–73.</p><p>3. Loesch MM, Somani AK, Kingsley MM, Travers JB, et al. Skin</p><p>resurfacing procedures: new and emerging options. Clin Cosmet</p><p>Investig Dermatol 2014;7:231–41.</p><p>4. Alam M, White LE, Martin N, Witherspoon J, et al. Ultrasound</p><p>tightening of facial and neck skin: a rater-blinded prospective cohort</p><p>study. J Am Acad Dermatol 2010;62:262–9.</p><p>5. Fabi SG, Burgess C, Carruthers A, Carruthers J, et al. Consensus</p><p>recommendations for combined aesthetic interventions using botulinum</p><p>toxin, fillers, and microfocused ultrasound in the neck, décolletage,</p><p>hands, and other areas of the body. Dermatol Surg 2016;42:1199–208.</p><p>6. Goldberg DJ, Hornfeldt CS. Safety and efficacy of microfocused</p><p>ultrasound to lift, tighten, and smooth the buttocks. Dermatol Surg</p><p>2014;40:1113–7.</p><p>7. Casabona G, Pereira G. Microfocused ultrasound with visualization</p><p>and calcium hydroxylapatite for improving skin laxity and cellulite</p><p>appearance. Plast Reconstr Surg Glob Open 2017;5:e1388.</p><p>8. Flynn TC, Carruthers A, Carruthers J, Geister TL, et al. Validated</p><p>assessment scales for the upper face. Dermatol Surg 2012;38:309–19.</p><p>9. Geister TL, Bleßmann-Gurk B, Rzany B, Harrington L, et al. Validated</p><p>assessment scale for platysmal bands. Dermatol Surg 2013;39:1217–25.</p><p>10. Landau M, Geister TL, Leibou L, Blessmann-Gurk B, et al. Validated</p><p>assessment scales for décolleté wrinkling and pigmentation. Dermatol</p><p>Surg 2016;42:842–52.</p><p>TABLE 3. Correlation of Skin Laxity Scale Ratings With Subject Demographic Data by Validation Session</p><p>(Spearman Correlation Coefficient With Bias Adjustment and 95% Confidence Interval)</p><p>Validation Session 1 Validation Session 2</p><p>Skin Laxity—At Rest/Posterior Thighs and Buttocks</p><p>Age (yr) 0.51 (0.45 to 0.56) 0.51 (0.46 to 0.56)</p><p>Height (cm) 20.27 (20.33 to 20.20) 20.24 (20.31 to 20.17)</p><p>Weight (kg) 0.41 (0.34 to 0.47) 0.41 (0.35 to 0.47)</p><p>BMI (kg/m2) 0.56 (0.51 to 0.61) 0.56 (0.51 to 0.61)</p><p>Smoker status (yes/no) 0.04 (20.03 to 0.11) 0.05 (20.03 to 0.12)</p><p>Fitzpatrick skin type (I–VI) 20.09 (20.16 to 20.02) 20.09 (20.16 to 20.02)</p><p>Sun exposure (0 = never to 4 = very frequent) 0.17 (0.10 to 0.24)</p><p>0.15 (0.07 to 0.21)</p><p>Skin Laxity—At Rest/Anterior Thighs and Knees</p><p>Age (yr) 0.67 (0.63 to 0.71) 0.70 (0.66 to 0.73)</p><p>Height (cm) 20.23 (20.30 to 20.16) 20.22 (20.29 to 20.15)</p><p>Weight (kg) 0.28 (0.21 to 0.35) 0.30 (0.23 to 0.36)</p><p>BMI (kg/m2) 0.40 (0.34 to 0.46) 0.41 (0.35 to 0.47)</p><p>Smoker status (yes/no) 0.02 (20.05 to 0.09) 0.01 (20.06 to 0.08)</p><p>Fitzpatrick skin type (I–VI) 20.25 (20.32 to 20.18) 20.24 (20.31 to 20.17)</p><p>Sun exposure (0 = never to 4 = very frequent) 0.18 (0.11 to 0.24) 0.18 (0.11 to 0.25)</p><p>BMI, body mass index.</p><p>AS SE S SMENT SCALES FOR SK IN LAX ITY</p><p>DERMATOLOG IC SURGERYS20</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p><p>11. Rzany B, Carruthers A, Carruthers J, Flynn TC, et al. Validated</p><p>composite assessment scales for the global face. Dermatol Surg 2012;</p><p>38:294–308.</p><p>12. Hexsel D, Fabi SG, Sattler G, Bartsch R, et al. Validated assessment</p><p>scales for cellulite dimples on the buttocks and thighs in female patients.</p><p>Dermatol Surg 2019;45:S2–11.</p><p>13. Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater</p><p>reliability. Psychol Bull 1979;86:420–8.</p><p>14. Fleiss JL, Cohen J, Everitt B. Large sample standard errors of kappa and</p><p>weighted kappa. Psychol Bull 1969;72:323.</p><p>15. Fleiss JL, Cohen L. The equivalence of weighted kappa and the</p><p>intraclass correlation coefficient as measures of reliablilty. Educ Psychol</p><p>Meas 1973;33:613–9.</p><p>16. Landis JR, Koch GG. The measurement of observer agreement for</p><p>categorical data. Biometrics 1977;33:159–74.</p><p>17. Shrout PE. Measurement reliability and agreement in psychiatry. Stat</p><p>Methods Med Res 1998;7:301–17.</p><p>18. Kottner J, Audigé L, Brorson S, Donner A, et al. Guidelines for</p><p>reporting reliability and agreement studies (GRRAS) were proposed. J</p><p>Clin Epidemiol 2011;64:96–106.</p><p>19. Uitto J. The role of elastin and collagen in cutaneous aging: intrinsic</p><p>aging versus photoexposure. J Drugs Dermatol 2008;7:s12–6.</p><p>20. Nürnberger F, Müller G. So-called cellulite: an invented disease. J</p><p>Dermatol Surg Oncol 1978;4:221–9.</p><p>21. Piérard GE, Nizet JL, Piérard-Franchimont C. Cellulite: from standing</p><p>fat herniation to hypodermal stretch marks. Am J Dermatopathol 2000;</p><p>22:34–7.</p><p>22. Rosenbaum M, Prieto V, Hellmer J, Boschmann M, et al. An</p><p>exploratory investigation of the morphology and biochemistry of</p><p>cellulite. Plast Reconstr Surg 1998;101:1934–9.</p><p>23. Stavroulaki A, Pramantiotis G. Cellulite, smoking and angiotensin-</p><p>converting enzyme (ACE) gene insertion/deletion polymorphism. J Eur</p><p>Acad Dermatol Venereol 2011;25:1116‒7.</p><p>24. Hexsel DM, Dal’forno T, Hexsel CL. A validated photonumeric</p><p>cellulite severity scale. J Eur Acad Dermatol Venereol 2009;23:523–8.</p><p>Address correspondence and reprint requests to: Michael S.</p><p>Kaminer, MD, Skincare Physicians, 1244 Boylston Street,</p><p>Chestnut Hill, MA 02467, or e-mail:</p><p>mkaminer@skincarephysicians.net</p><p>KAMINER ET AL</p><p>45 : 8 S : AUGUST S PEC IAL I S SUE 2 0 1 9 S21</p><p>© 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.</p><p>D</p><p>ow</p><p>nloaded from</p><p>http://journals.lw</p><p>w</p><p>.com</p><p>/derm</p><p>atologicsurgery by B</p><p>hD</p><p>M</p><p>f5eP</p><p>H</p><p>K</p><p>av1zE</p><p>oum</p><p>1tQ</p><p>fN</p><p>4a+</p><p>kJLhE</p><p>Z</p><p>gbsIH</p><p>o4X</p><p>M</p><p>i0hC</p><p>yw</p><p>C</p><p>X</p><p>1A</p><p>W</p><p>nY</p><p>Q</p><p>p/IlQ</p><p>rH</p><p>D</p><p>3i3D</p><p>0O</p><p>dR</p><p>yi7T</p><p>vS</p><p>F</p><p>l4C</p><p>f3V</p><p>C</p><p>1y0abggQ</p><p>Z</p><p>X</p><p>dtw</p><p>nfK</p><p>Z</p><p>B</p><p>Y</p><p>tw</p><p>s=</p><p>on 04/26/2024</p>