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Aesthetic Comparison of Two Different Types of Web-Space Reconstruction for Finger Syndactyly

Yuan, Frank, M.D.; Zhong, Lin, M.D., M.P.H.; Chung, Kevin C., M.D., M.S.

Plastic and Reconstructive Surgery: October 2018 - Volume 142 - Issue 4 - p 963–971
doi: 10.1097/PRS.0000000000004798
Hand/Peripheral Nerve: Original Articles
Editor's Pick
Coding Perspective

Background: Syndactyly reconstruction incorporates techniques of applying skin grafts or dorsal advancement flaps without the use of skin grafts. Comparative outcome studies of these two approaches are lacking. The authors’ study compares the long-term aesthetic outcomes of these two flap techniques.

Methods: Forty-five patients were included in the authors’ study. The methods of reconstruction used were a dorsally based rectangular flap with skin graft from the groin and a dorsal pentagonal advancement flap without skin grafting. Eighteen independent raters completed a visual analogue scale and a unique classification scale to subjectively assess aesthetic outcomes. The authors used univariate analyses to determine which variables significantly influenced the outcome score. The authors then used multivariable regression models to compare the two flap types.

Results: Dorsally based rectangular flaps with skin graft had statistically significantly better visual analogue scale scores and greater odds of receiving an “excellent” rating compared with dorsal pentagonal advancement flaps.

Conclusions: Despite the use of skin grafting, with its associated donor-site morbidity, dorsal rectangular flaps may offer better overall aesthetic outcomes for patients. Future comparative studies should incorporate functional and patient-reported outcomes to better assess the optimal reconstruction type.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Coding Perspective for this Article is on Page 971.

Ann Arbor, Mich.

From the Department of Surgery, Section of Plastic Surgery, University of Michigan Medical School; and the Department of Surgery, Section of Plastic Surgery, University of Michigan Health System.

Received for publication October 25, 2017; accepted February 2, 2018.

Disclosure: The authors have no financial interest to declare in relation to the content of this article.

Kevin C. Chung, M.D., M.S., Section of Plastic Surgery, University of Michigan Health System, 2130 Taubman Center, SPC 5340, 1500 East Medical Center Drive, Ann Arbor, Mich. 48109-5340, kecchung@med.umich.edu

Syndactyly is the most common congenital hand malformation, affecting approximately one in 2000 live births, with up to 50 percent of cases occurring bilaterally.1 Because of failure of interdigit tissue to undergo apoptosis during early gestation, digits become joined by skin and soft tissue with or without underlying bony fusion.2 , 3 Syndactyly is classified as either simple, involving digits fused by skin and soft tissue only; or complex, involving bony fusion or anomalies of form, size, number, or position of the digits. Depending on the extent of the affected web space, syndactyly is also classified as partial, if the web terminates proximal to the fingertips, or complete, if the web extends to the fingertips.4

Correction of syndactyly is achieved by surgical separation, resulting in functionally independent and aesthetically satisfactory digits.4 Several variations of local skin flaps have been described for syndactyly web-space reconstruction, including the dorsal rectangular flap, dorsal triangular flap, interdigitating V-flap, and others.3 , 5–10 However, these procedures require skin grafting to the resultant defect and donor scars. Modifications of flap design, such as with the dorsal pentagonal advancement flap, incorporate more dorsal skin and thus do not require a skin graft and, ultimately, decrease surgical time. The pentagonal flap is an attractive alternative to traditional methods of web-space reconstruction using skin grafts and is an increasingly popular alternative procedure.2 , 11

It is unclear whether skin graft–sparing web-space reconstruction with dorsal pentagonal advancement flaps offers better aesthetic outcomes than dorsal rectangular flaps with skin grafting. Comparative studies of aesthetic outcomes between these two techniques are lacking.12 The aim of this study was to compare the aesthetic outcomes of skin graft–sparing dorsal pentagonal flaps with those of the traditional method of dorsal rectangular flaps with skin grafting. Understanding these outcomes will facilitate improvements in surgical planning and patient satisfaction.

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PATIENTS AND METHODS

In this retrospective study, we used the University of Michigan electronic database (CareWeb) and CPT codes 26560, 26561, and 26562 to identify all patients treated by the senior author (K.C.C.) who underwent syndactyly repair from 1998 to 2013. Patients were included if they had a primary elective repair of simple or complex syndactyly (complete and incomplete) using either a proximally based dorsal rectangular flap (Fig. 1, above) with a full-thickness skin graft or a dorsal pentagonal flap without skin grafting (Fig. 1, below). Patients were excluded if (1) they were treated with other methods of flap reconstructions, (2) their postoperative follow-up was less than 1 year, or (3) they had complicated syndactyly (e.g., congenital hand malformations associated with Apert syndrome, amniotic constriction bands, cleft hand). This study was approved by the Institutional Review Boards of the University of Michigan Medical School.

Fig. 1

Fig. 1

All patients treated at our center had preoperative, intraoperative, and postoperative photographs as standard procedures for documentation and educational purposes. A still postoperative photographic image of each patient’s hand was taken using a Canon PowerShot SX500 IS 16.0 (Canon, Inc., Tokyo, Japan) megapixel point-and-shoot digital camera under standard lighting conditions, camera settings, and a green background. To maintain standardization, we included those patients with photographs with a minimum of 2-year follow-up. The images were subsequently transferred to a computer for independent evaluation by members of an assessment panel, which consisted of 18 individuals (six men and 12 women): one hand fellowship–trained plastic surgeon, two current hand surgery fellows, one plastic surgery resident (chief year), four international hand surgery fellows, five occupational therapists who work exclusively with these patients postoperatively, and five lay persons, all of whom were women with children of their own, which we felt would provide a maternal perspective when evaluating outcomes. Panel members were instructed to score each image using two grading systems on paper. The first method was a visual analogue scale with a 10-cm line, with 0 being the best and 10 being the worst. The second method was a grading system that incorporated color, surface shine (or matte), and skin distortion to classify outcomes into the following categories: “excellent,” “very good,” “good,” or “poor” (Figs. 2 and 3). Examples of each grade were given to the evaluators for reference (Fig. 3). This grading system was based on the Manchester Scar Scale, which has shown good construct validity, interrater reliability, and feasibility when used to assess surgical scars.13–15 We chose not to use patient-reported outcome instruments or questionnaires because not only are our patients too young to adequately answer questionnaires, there are generally no validated questionnaires available for these outcomes.

Fig. 2

Fig. 2

Fig. 3

Fig. 3

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Statistical Analysis

The two study outcomes are (1) a numeric visual analogue scale score and (2) a categorical grading scale rating. To examine the interrater reliability among the 18 raters, we used kappa statistics for categorical grading. We divided the 18 raters into four groups—laypersons, international hand surgery fellows, occupational therapists, and surgeons—and calculated interrater reliability within each group and all 18 raters using Fleiss’ kappa. We then examined interrater reliability between two raters among the 18 raters using the Cohen kappa. We calculated the intraclass correlation coefficient for visual analogue scale among each group for the interrater reliability. For the intrarater reliability, we calculated kappa statistics for grading and the intraclass correlation coefficient for visual analogue scale for each of the 18 raters.

The primary predictor of the study cohort was the type of flap reconstruction (i.e., dorsal rectangular or dorsal pentagonal flap). We performed descriptive analyses on our study cohort for the distribution of each patient characteristic by type of flap received. We performed Fisher’s exact test for the association between flap type and categorical patient variables (i.e., type of syndactyly, patient age, patient sex, right versus left hand, type of rater, web space, and revision) and Wilcoxon rank sum test for continuous patient variables (i.e., patient age and number of years of follow-up).

To examine the correlation between visual analogue scale and each patient characteristic, we performed simple linear regression models for each patient characteristic as the predictor. Given that we had grading by 18 raters, we added a random intercept for each type of flap in each model to control for the intercorrelation of repeated measures. We had a total of 810 data points because each of our 18 raters reviewed 45 patients total (n = 18 × 45 = 810).

To control for patient characteristics that significantly influenced the visual analogue scale score, we then performed a multivariable linear regression model with a random intercept for each surgical reconstruction using the type of flap as the primary predictor. We used all characteristics with significant associations with the visual analogue scale score selected from our simple linear regression models as the covariates into the multivariable linear regression model; the final multivariable models were established by maximum likelihood. We reported adjusted mean visual analogue scale scores and 95 percent confidence intervals for each patient group. Using the same strategy, we performed univariate analysis on patient characteristics and the binary outcome excellent versus not excellent (which includes very good, good, or poor) using a simple logistic regression model with random effect on each type of flap reconstruction. We used binary outcomes to ensure less stratification of our results and more power. We then performed multivariable logistic regression with random effect using type of flap as the primary predictor while controlling for those patient characteristics that had significant associations with each grade. We reported odds ratios of being excellent for each patient characteristic (compared to the reference group) and 95 percent confidence intervals.

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RESULTS

A total of 45 patients were reviewed: 13 female and 32 male patients (Table 1). Patients who had dorsal pentagonal flap reconstruction were evaluated at a longer duration of follow-up compared to those patients who had dorsal rectangular flaps (1.6 years versus 2.3 years; p = 0.03). There was no significant difference in the distribution of other patient characteristics between the two different types of flap reconstruction. Sixteen patients underwent dorsal pentagonal flap reconstruction and 29 patients underwent dorsal rectangular flap reconstruction with full-thickness skin grafting. The majority of patients across both flap types had simple complete syndactyly. The third web space was the most commonly affected web space between both surgical groups. Twenty-five percent of patients required revision surgery after pentagonal flap surgery, whereas only 10 percent required revision surgery after rectangular flap reconstruction.

Table 1

Table 1

For grading between excellent and not excellent, the Fleiss kappa value among the four groups of raters ranged from 0.40 to 0.42; the Fleiss kappa value for all 18 raters was 0.38 (p < 0.001). The Cohen kappa value when comparing two raters’ grades ranged from 0.07 to 0.69, with significance ranging from p < 0.001 to p = 0.433. The intraclass correlation coefficient among our four groups of raters ranged from 0.52 to 0.65; the intraclass correlation coefficient for all 18 raters was 0.56 (p < 0.001). For grading between excellent and not excellent, kappa values among all of raters ranged from 0.16 to 0.76. The intraclass correlation coefficient among all of our raters ranged from 0.40 to 0.91. These values indicate that the raters generally agreed across all ratings.

Overall, the affected web space, patient age at follow-up, and length of follow-up were significantly associated with mean visual analogue scale values (Table 2). The mean visual analogue scale score among patients who underwent reconstruction of the fourth web space was 1.64 compared with 3.36 among those who underwent reconstruction of the second web space (p = 0.012), regardless of flap type. With 1 more year of follow-up, the average visual analogue scale score decreased by 0.36 (p = 0.003) across both flap types. Four patients with pentagonal flaps required revision surgery; three patients had web creep and one patient had a scar contracture. Three patients with rectangular flaps required revision surgery; two patients had scar contractures and one patient had web creep.

Table 2

Table 2

After controlling for the significant variables found in our univariate analysis (i.e., affected web space, patient age, and length of follow-up) (Table 2), multivariable analysis revealed that patients who underwent dorsal rectangular flap reconstruction had significantly lower visual analogue scale values, indicating better results, than patients who underwent dorsal pentagonal flap reconstruction (3.12 versus 4.24; p = 0.025) (Table 3).

Table 3

Table 3

Table 4 shows that, overall, the odds of getting an excellent rating were significantly associated with web space and number of years of follow-up. For example, the odds ratio of getting an excellent rating among patients who had second-web-space reconstruction compared to patients who had fourth-web-space reconstruction was 0.06 (95 percent CI, 0.01 to 0.59). With 1 more year of follow-up, the odds of getting an excellent rating increased 1.85 times (95 percent CI, 1.21 to 2.84 times).

Table 4

Table 4

Again, after controlling for significant variables (i.e., affected web space and length of follow-up) (Table 4), patients who underwent dorsal pentagonal flap reconstruction had significantly lower odds of getting an excellent rating compared with patients who underwent dorsal rectangular flap surgery (OR, 0.20; 95 percent CI, 0.05 to 0.83; p = 0.032) (Table 5).

Table 5

Table 5

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DISCUSSION

To date, no studies have compared long-term outcomes between skin graft and non–skin graft techniques in syndactyly reconstruction.6 , 12 Both proximally based dorsal rectangular flaps and dorsal pentagonal advancement flaps have been successfully used at our institution. In our study, we compared the long-term aesthetic outcomes between these two forms of web-space reconstruction. Our study shows that rectangular flaps with groin skin grafting result in better long-term aesthetic outcomes compared with pentagonal flaps.

Numerous methods of syndactyly reconstruction have been proposed. All methods use a common set of techniques that any surgeon must be comfortable with before attempting a repair: use of full-thickness flaps to resurface the web space, preservation of vascular supply to the digit, and a meticulous approach to reconstruction with attention to preserving anatomical proportions and details.2 , 3 Achieving aesthetically pleasing fingers is likely just as important to a child as achieving fully functional digits. Traditional methods of syndactyly reconstruction use full-thickness skin grafts, often from the groin region, to facilitate a tension-free closure between separated digits.2 , 3 , 5 However, these techniques require postoperative immobilization and bandaging, which can be cumbersome in a young active child, and can lead to scar contracture or graft failure.2 , 3 , 5 , 16 Moreover, case series have reported high incidences of hair growth in the grafted areas, resulting in revision of the grafted area, epilation, and trimming of the excessive skin. Recently, there has been a trend toward reconstruction without the use of skin grafts. However, extensive defatting of the interdigital space is often required, which can lead to nerve injury, venous congestion, and a withered finger appearance.2 , 3 , 5 , 16 , 17

From our review of the patients, the main reason patients underwent revision surgery after pentagonal flap reconstruction was web creep, although scar contracture was the impetus for revision surgery after rectangular flap reconstruction. A recent systematic review by Sullivan and Adkinson revealed that techniques using skin grafts resulted in higher rates of web creep and revision surgery compared with those using only dorsal advancement flaps. In their review, they mention that revision rates may not be a valid comparative measure, however, for several reasons, such as surgeon threshold, patient preference, or even change of surgeon.12 Thus, our revision results may be underestimated if patients were not willing to undergo reoperation (e.g., they were satisfied with their results even with a certain level of web creep or scar contracture).

This investigation has several limitations. First, the use of photographs as the only means of evaluating aesthetic outcomes is limited by the quality of the photographs. The distinction between different grades was made primarily based on color mismatch and skin distortion; matte was found to be difficult to assess in photographs. However, we did maintain consistency across all photographs used, as they were all taken with standardized views, backgrounds, camera settings, and lighting. In addition, even though our classification systems were based on distinct criteria, the evaluation of these criteria (e.g., skin distortion and matte) is completely subjective. Second, although our total sample size was sufficiently powered, we were not able to stratify our patients into syndactyly type because of small respective sample sizes. Third, our study focused only on aesthetic outcomes, as we felt that the majority of our patients would be too young to fully participate in functional testing (e.g., strength tests). In addition, future studies should incorporate patient-reported outcomes if possible, which would provide further insight into patient satisfaction and effects on daily life activities. Lastly, we did not use a standardized follow-up period at the time of photographic assessment. Patients with longer follow-up periods at the time of their photograph may have better aesthetic outcomes solely because their scars have had a longer time to heal and remodel.

Our study is unique in that it offers long-term comparative outcomes between syndactyly reconstruction with skin grafts and dorsal advancement flaps without skin grafts. The majority of previous studies are case series that only report outcomes of particular flap techniques, with the majority among patients with simple syndactyly.6 , 12 We found that our classification system was easy to use even by nonsurgeon observers, who are usually unaware of the details of different syndactyly release procedures. Interestingly, our results also showed that fourth-web-space reconstructions fared better in both classification systems, particularly when compared against second-web-space reconstructions, regardless of flap technique. These findings may be attributable to the smaller surface area of the fourth web space, thus requiring less graft for coverage, less manipulation of the graft (e.g., defatting), and a more tension-free closure. Moreover, our classification system properly captures the principle that as scars continue to heal, their appearance becomes more normalized compared with surrounding tissue.

The results from our study can serve as important discussion points when counseling patients on the types of syndactyly reconstruction available and adequately managing their postoperative expectations. Specifically, despite the fact that rectangular flaps use skin grafting with some donor site morbidity, overall outcomes may still be better than with advancement flaps. In addition, further attention should be made toward the technical aspects of these operations, particularly the liberal use of skin grafts to accomplish tension-free closure and minimize the risk of web creep. Future prospective comparative studies are needed that incorporate both functional and subjective criteria, with collection of both preoperative and postoperative data.

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ACKNOWLEDGMENTS

This publication was supported in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (2 K24-AR053120-06). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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REFERENCES

1. Tonkin MA. Failure of differentiation part I: Syndactyly. Hand Clin. 2009;25:171–193.
2. Oda T, Pushman AG, Chung KC. Treatment of common congenital hand conditions. Plast Reconstr Surg. 2010;126:121e–133e.
3. Goldfarb CA, Steffen JA, Stutz CM. Complex syndactyly: Aesthetic and objective outcomes. J Hand Surg Am. 2012;37:2068–2073.
4. Malik S. Syndactyly: Phenotypes, genetics and current classification. Eur J Hum Genet. 2012;20:817–824.
5. Lumenta DB, Kitzinger HB, Beck H, Frey M. Long-term outcomes of web creep, scar quality, and function after simple syndactyly surgical treatment. J Hand Surg Am. 2010;35:1323–1329.
6. Goldfarb CA. Congenital hand anomalies: A review of the literature, 2009-2012. J Hand Surg Am. 2013;38:1854–1859.
7. Tuma P Jr, Arrunategui G, Wada A, Friedhofer H, Ferreira MC. Rectangular flaps technique for treatment of congenital hand syndactyly. Rev Hosp Clin Fac Med Sao Paulo 1999;54:107–110.
8. Yildirim C, Sentürk S, Keklikçi K, Akmaz I. Correction of syndactyly using a dorsal separated V-Y advancement flap and a volar triangular flap in adults. Ann Plast Surg. 2011;67:357–363.
9. Jose RM, Timoney N, Vidyadharan R, Lester R. Syndactyly correction: An aesthetic reconstruction. J Hand Surg Eur Vol. 2010;35:446–450.
10. Wafa AM. Hourglass dorsal metacarpal island flap: A new design for syndactylized web reconstruction. J Hand Surg Am. 2008;33:905–908.
11. Gao W, Yan H, Zhang F, et al. Dorsal pentagonal local flap: A new technique of web reconstruction for syndactyly without skin graft. Aesthetic Plast Surg. 2011;35:530–537.
12. Sullivan MA, Adkinson JM. A systematic review and comparison of outcomes following simple syndactyly reconstruction with skin grafts or a dorsal metacarpal advancement flap. J Hand Surg Am. 2017;42:34–40.e6.
13. Beausang E, Floyd H, Dunn KW, Orton CI, Ferguson MW. A new quantitative scale for clinical scar assessment. Plast Reconstr Surg. 1998;102:1954–1961.
14. Durani P, McGrouther DA, Ferguson MW. Current scales for assessing human scarring: A review. J Plast Reconstr Aesthet Surg. 2009;62:713–720.
15. Vercelli S, Ferriero G, Sartorio F, Stissi V, Franchignoni F. How to assess postsurgical scars: A review of outcome measures. Disabil Rehabil. 2009;31:2055–2063.
16. Dao KD, Shin AY, Billings A, Oberg KC, Wood VE. Surgical treatment of congenital syndactyly of the hand. J Am Acad Orthop Surg. 2004;12:39–48.
17. Bates SJ, Hansen SL, Jones NF. Reconstruction of congenital differences of the hand. Plast Reconstr Surg. 2009;124(Suppl):128e–143e.
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CODING PERSPECTIVE

Coding perspective provided by Dr. Raymond Janevicius is intended to provide coding guidance.

  • 26560 Repair of syndactyly (web finger) each web space; with skin flaps
  • 26561 Repair of syndactyly (web finger) each web space; with skin flaps and grafts
  • 26562 Repair of syndactyly (web finger) each web space; complex (e.g., involving bone, nails)
  • Repair of a finger syndactyly using skin flaps only is reported with code 26560. This includes elevation and transposition of the flaps, as well as dressings, initial splints, and 90 days of uncomplicated postoperative care.
  • If skin flaps and skin grafts are used for syndactyly repair, code 26561 is reported. This code includes elevation and transposition of the flaps, harvest and placement of skin grafts, as well as dressings, initial splints, and 90 days of uncomplicated postoperative care.
  • Each web space reconstructed is separately reported. Thus, the release and reconstruction of syndactyly of the index-middle web space and syndactyly of the ring-small web space, each with skin flaps and skin grafts, is reported with two codes:
  • 26561 Index-middle web syndactyly reconstruction
  • 26561-59 Ring-small web syndactyly reconstruction
  • Complex syndactyly involves bone and/or nails. The reconstruction of complex syndactyly is reported with code 26562.

CODING PRINCIPLE: The syndactyly reconstruction codes are global and include elevation and transposition of skin flaps as well as skin grafts, including closure of donor sites. It is not appropriate to report codes 14040 (adjacent tissue transfer) or 15240 (full thickness skin graft) in addition to codes 26560, 26561, and 26562.

Disclosure: Dr. Janevicius (janeviciusray@comcast.net) is the president of JCC, a firm specializing in coding consulting services for surgeons, government agencies, attorneys, and other entities.

©2018American Society of Plastic Surgeons