Use of split‐thickness plantar skin grafts in the management of leg and foot skin defects

Abstract

The basic principle of donor site selection is to take skin from areas that will heal with minimal scarring while balancing the needs of the recipient site. For skin loss from the lower legs and feet, the most common harvest site for split‐thickness skin grafts is the anterior or posterior thigh; grafts from the plantar areas have been mostly used to cover the volar aspect of digits and palms. Between September 2015 and September 2017, 42 patients with areas of skin loss on the legs or feet were treated with plantar skin grafts because of their cosmetic benefits and the convenience of the surgical procedure and postoperative wound care. Our technique of harvesting a single layer of split‐thickness skin graft (0.014 in. thick) from a non‐weight‐bearing area of the foot of the injured leg is simple and provided good functional and cosmetic outcomes at both the donor and recipient sites. All patients were very satisfied with the recovery progress and final results. Therefore, in the management of skin defects in the lower legs or feet that comprise less than 1.5% of the total body surface area, our surgical method is a reliable alternative to anterior or posterior thigh skin grafting.

1. INTRODUCTION

The technique of skin grafting was first performed 2000 years ago in India and has evolved rapidly since the mid‐to‐late 19th century.1 Today, skin grafting remains one of the most effective ways to reconstruct skin defects; however, it is associated with great technical variation, including the selection of the donor site and the thickness of the skin graft.

Split‐thickness grafts (STSGs) are usually used as the first line of treatment for skin defect wounds of the lower leg that cannot be closed primarily or where undue tension is predicted. Although any surface of the body can be a harvest site for STSGs, for cosmetic reasons, the upper anterior and lateral thighs are the most commonly chosen donor sites. By comparison, the plantar is rarely chosen as a donor site, except for covering skin defects in the volar aspect of the digits and hands.2, 3, 4, 5, 6, 7

Skin on the plantar aspect of the feet differs from skin on other parts of the body because it is glabrous skin, which has special attributes, including a thicker epidermis with a well‐defined stratum lucidum and a more compact but less elastic dermis. In addition, it has abundant sweat glands and dermal papillae that allow rapid healing but fewer melanocytes and no sebaceous glands or hair follicles.8, 9, 10 These characteristics make plantar skin functionally and aesthetically different from the skin found on the rest of the body but also provide some advantages for its use as an STSG to cover lower‐leg wounds, especially considering that the location of plantar skin is convenient for surgical preparation and that scarring can be concealed more easily. Therefore, in 2015, we began harvesting plantar skin grafts to cover skin‐loss wounds on the lower legs. The purpose of this study was to analyse the success and complication rates of this surgical method.

2. MATERIALS AND METHODS

The study included 42 patients who sustained partial‐thickness skin defect wounds on their lower leg and underwent split‐thickness skin grafting from the plantar surface of the foot at the Plastic and Reconstructive Surgery Department of Tri‐Service General Hospital (Taipei, Taiwan) between 2015 and 2017. All patients had been followed up for at least 3 months postoperatively: once a week in the first month, every 2 weeks in the second month, and then once a month in the following few months.

The age and gender of each patient and their wound aetiology, area and size of skin defect, donor site, size of skin graft, and outcomes were recorded and are listed in Table 1. Outcomes were analysed to identify complications, the rate of skin graft engraftment to wound beds, the patient's satisfaction, and their Vancouver Scar Scale (VSS) scores. Complications were defined as adverse postoperative events occurring as a direct consequence of skin grafting that required additional treatment beyond that normally associated with skin grafting.

Table 1.

Summary of demographics of patients, the surgical method used, and the outcomes assessed by postoperative Vancouver Scar Scale score and patient satisfaction

Case	Age/gender	Cause of wound	Defect site/size (cm2)	Donor site	Graft size (cm2)	Take %	Cause of failed skin graft area	Overall satisfaction level1, 2, 3, 4, 5	Donor site satisfaction level1, 2, 3, 4, 5	Postop VSS score (recipient/donor)
1	25/F	Friction burn	Left ankle/14	Left plantar	15	100		3	5	3/1
2	24/M	Venous ulcer	Right ankle/16	Right plantar	18	100		5	5	4/2
3	45/M	Post‐surgical wound infection	Left ankle/6	Left plantar	7	100		5	5	3/1
4	57/M	Post‐surgical wound infection	Right heel/23	Right plantar	25	100		5	5	3/1
5	44/M	Diabetic ulcer	Right foot/60	Right plantar	65	90	Shear force	4	4	4/2
6	68/M	Infection	Left dorsal foot/6	Left plantar	6	100		4	5	3/1
7	54/M	Crush injury	Left dorsal foot/24	Left plantar	25	90	Haematoma	4	4	5/3
8	79/M	Scald burn	Left dorsal foot/28	Left plantar	30	90	Haematoma	4	4	6/3
9	85/F	Crush injury	Left medial leg/35	Left plantar	40	100		5	5	3/1
10	52/M	Contact burn	Right dorsal foot/26	Right plantar	30	100		5	5	5/2
11	60/M	Infection	Right foot/ 6	Right plantar	8	100		4	5	4/1
12	39/M	Venous ulcer	Right leg and foot/66	Right plantar	70	90	Seroma	4	5	4/2
13	90/F	Venous ulcer	Both legs/169	Bilateral plantar	180	90	Haematoma	4	5	5/2
14	51/F	Diabetic ulcer	Right first MTP joint/48	Right plantar	50	100		4	5	3/2
15	88/M	PAOD	Right lateral foot/20	Right plantar	20	90	Shear force	4	5	4/2
16	79/M	Infection after open fracture	Right pretibial region/9	Right plantar	10	100		5	5	4/2
17	78/M	Chemical burn	Left dorsal foot/15	Left plantar	16	100		5	5	4/1
18	46/M	Infection after open fracture	Right medial ankle/24	Right plantar	25	100		4	5	3/2
19	66/F	Corns	Medial plantar aspect of big toe, left/4	Right plantar	5	100		5	5	2/0
20	44/F	Corns	Lateral side of the base of left little finger/6	Left plantar	6	100		5	5	2/0
21	17/F	Friction burn	Right lateral ankle/18	Right plantar	20	100		3	5	2/1
22	68/M	Diabetic ulcer	Left lateral ankle/8	Left plantar	10	90	Shear force	5	5	4/1
23	62/F	Infection	Left plantar area/24	Left plantar	25	90	Haematoma	4	5	3/2
24	49/M	Friction burn	Right dorsal foot/14	Right plantar	16	100		4	5	2/1
25	93/M	Infection	Left lateral ankle/10	Left plantar	12	100		5	5	3/1
26	24/M	Friction burn	Left dorsal foot/48	Left plantar	50	100		4	5	2/1
27	55/M	Corn	Right sole/12	Right plantar	15	100		4	5	1/1
28	19/M	Corn	Right sole/2	Right plantar	2	100		5	5	1/0
29	48/F	Traumatic skin necrosis	Left dorsal foot/9	Left plantar	10	100		3	5	3/2
30	58/M	Traumatic skin necrosis	Right heel/6	Right plantar	8	100		5	5	2/2
31	22/M	Friction burn	Right lateral ankle/15	Right plantar	16	100		5	5	2/1
32	73/M	Traumatic skin necrosis	Right heel/48	Right plantar	50	100		4	5	3/2
33	21/M	Contact Burn	Left calf/115	Left plantar	120	100		4	5	3/2
34	66/F	Infection	Right leg/96	Right plantar	100	90	Haematoma	4	4	4/2
35	65/F	Corn	Right sole/5	Right plantar	6	100		5	5	1/0
36	22/M	Friction burn	Left dorsal foot/7	Left plantar	9	100		5		2/1
37	81/M	Traumatic skin necrosis	Right dorsal foot/5	Right plantar	6	100		5	5	3/1
38	42/M	Venous ulcer	Right calf/48	Right plantar	50	95	Seroma	4	5	4/2
39	25/M	Corn	Right sole/9	Right plantar	10	100		5	5	1/0
40	45/F	Contact burn	Right ankle/30	Right plantar	30	100		4	5	2/1
41	61/F	Friction burn	Left calf/12	Left plantar	15	100		5	5	3/1
42	19/M	Friction burn	Left dorsal foot/42	Left plantar	45	100		5	5	2/1

MTP, metatarsophalangeal; PAOD, peripheral arterial occlusive disease; VSS, Vancouver Scar Scale.

2.1. Surgical technique

A plantar area of the foot of the injured leg was chosen as the donor site and was washed thoroughly with antimicrobial skin cleanser on the day of surgery. The defect was measured, and the required graft size was marked on a non‐weight‐bearing area of the plantar surface of the foot. Chlorhexidine was used for preoperative skin preparation. Under tourniquet control, the skin defect wound was debrided until the recipient bed was well vascularised and free of bacterial contamination. A separate instrument setup was prepared for the donor site. To reduce bleeding during skin harvest, the plantar donor site was infiltrated with tumescent fluid comprising 0.05% lidocaine and 1:1 000 000 epinephrine in saline to induce swelling. The dermatome was generally set at 0.014 in. and was pressed onto the tissue at 45° to the skin surface and then moved across the surface at uniform pressure and speed. During the harvesting process, an assistant picked up the skin graft with 2 pairs of anatomical forceps to avoid damage to the graft. The graft was fixed edge to edge over the defect site edge with a bolster tie‐over dressing. The donor site was covered with a single layer of sterile dressing. Then, the whole lower leg, including the plantar side of the foot, was wrapped in an elastic bandage, and a lower‐leg splint was constructed. The initial bolster tie‐over dressing was removed 3 days postoperatively to ensure that that there was no haematoma or seroma beneath the graft. The skin graft was applied with a light layer of bacitracin and then covered with a light gauze. If the donor site was only on the sole of the foot, the patient was allowed to begin ambulation with the compressive dressing 1 week after surgery. If the glabrous dermal graft site was also on the foot, ambulation was not allowed until the second week after surgery to allow for complete epithelialisation of the graft.

3. RESULTS

Between September 2015 and September 2017, 42 patients were included for review. All of the patients were Asian and had wounds on their legs. The aetiology of the wounds were burns (13 patients), diabetic ulcer (3 patients), venous ulcer (4 patients), infection (9 patients), traumatic wound (6 patients), hyperkeratosis (6 patients), and peripheral arterial occlusive disease (1 patient). The average size of the area requiring skin grafting after debridement was 28.3 cm². The average follow up was 16.5 months (range, 3.0‐25 months). All patients were alive at follow up. No direct complications occurred in these 42 patients, and the engraftment area was 100% of the wound area in 32 cases, 95% in 1 case, and 90% in 9 cases (the reason of the failed skin graft area is given in the Table 1) In all patients, the donor site healed within 2 weeks with minimal scarring. Scars at both the donor and recipient sites were evaluated using VSS, and the results were excellent: the mean scores were 3.02 and 1.37 for recipient and donor sites, respectively.

All patients were pleased with their donor site scar (excellent: 38; good: 4) and had no complaints about the splinting: 92.9% (39/42; excellent: 20; good: 19) of the patients were satisfied with the final result. Three patients reported “fair” satisfaction because of hypopigmentation of the scar at the recipient site. A typical surgical course is presented in Figure 1. Figure 2 illustrates an example of a typical case with a 6‐month follow up. Images for a third patient are presented in Figure 3.

Figure 1.

An 85‐year‐old woman had a traumatic subcutaneous haematoma causing skin necrosis in her left leg. A, After 1 debridement. B, The defect was measured and marked on the non‐weight‐bearing plantar surface of the foot. C, A split‐thickness plantar skin graft (0.014 in. thick) was harvested with a dermatome. D, The graft was fixed edge to edge over the defect site. E, The corneum of the graft peeled away after 3 weeks and revealed a well‐engrafted pink graft. F, The condition of the donor site at 2‐month follow up

Figure 2.

A 90‐year‐old woman had multiple chronic venous ulcers over her right leg. A, After surgical debridement. B, A split‐thickness plantar skin graft (0.014 in. thick) was harvested. C, The graft was fixed edge to edge over the defect site. D, The corneum of the graft peeled away after 2 weeks. E, The condition of the donor site at 1‐month follow up

Figure 3.

A 21‐year‐old man had a third‐degree contact burn injury on his left calf, comprising about 1% of his total body surface area. A, After debridement. B, A split‐thickness plantar skin graft was harvested from the foot of the injured leg, which simplified the surgical preparation and the postoperative care. C, At 2‐month follow up. The donor site scarring can be concealed easily

4. DISCUSSION

The technique of split‐thickness plantar skin grafting was first described in 1963 by Le Worthy.3 Since then, many authors have praised the merits of this type of skin grafting, which is able to provide a good match for wounds of the digits and palm.2, 3, 4, 5, 6, 7, 9 However, review of the literature indicates that our study is the first retrospective study of the use of medium‐thickness plantar skin grafts to reconstruct lower‐leg and foot skin defects. We obtained excellent aesthetic, functional, and technical results.

In our study, patient‐reported cosmetic satisfaction was high, especially concerning the location of the donor site scar, which is concealed when the patient is standing. Although about 30% of the patients complained of donor site pain within the first 3 days postoperatively, this did not interfere with their postoperative activities because the graft was harvested from the sole of the foot ipsilateral to the recipient site on the injured leg, which in any case required splint immobilisation for at least 1 week. The patients also felt that it was much easier to take care of their donor site and grafted wounds. For the surgeons, graft harvesting from the plantar area of the foot of the injured leg makes it easier to position the patient and allows them to work in a single position.

Little graft contraction was observed in our patients, especially for the 13 patients with wounds in the joints (9 in the ankle, 3 in the heel, and 1 in the first metatarsophalangeal joint). Previous studies also reported little contraction when resurfacing palmar and digital wounds.2, 7, 9 This might be because the connective tissue of the dermis in plantar skin is less elastic and more compact than that in other types of skin. Therefore, plantar skin grafting might be a good choice for resurfacing wounds in joint areas.

In addition, we found that our grafts all engrafted well, even when quite large haematomas developed after surgery. The thick corneum of plantar skin might have played an important role in this process by acting as a biological dressing to shield the underlying dermis until engraftment occurred. As shown in Figures 1E and 2D, the corneum of the graft peeled away within 2 to 3 weeks, revealing pink grafted tissue, the colour of which subsequently became similar to that of the adjacent skin.

Plantar skin has abundant sweat glands that produce multi‐centric epithelial budding and contribute towards rapid and good‐quality healing of the plantar area. Thus, the average donor site healing time in our patients was 10 days, which is faster than that of other more traditional donor sites.

In previous studies that aimed to resurface digital and palmar wounds, full‐thickness skin grafts or thick split‐skin grafts were harvested, which led to significant donor site morbidity, including prolonged healing, hypertrophic scarring, hyperpigmentation, or a requirement for secondary skin grafting of the donor site.3, 5, 11, 12 A modified surgical method was reported recently, in which 2 layers of plantar skin grafts were harvested from the same site and the first‐harvested split‐thickness skin graft was returned to the original donor site.2, 7 In our study, we used only a medium‐thickness plantar skin graft (0.014 in. thick). We encountered no problems, and the functional and cosmetic results at both recipient and donor sites were excellent. These results indicate that, although plantar skin has a thicker epidermis, harvesting a medium‐thickness plantar skin graft (0.014 in. thick) was sufficient to transfer an adequate percentage of dermis to allow excellent engraftment at the recipient site. In addition, this graft thickness allowed rapid healing of the donor site without morbidities such as prolonged healing, hypertrophic scarring, hyperpigmentation, or the requirement for secondary skin grafting.

A limitation of our study is that the surgical method cannot be applied to large skin defects because we used only non‐weight‐bearing sections of the plantar area as donor sites. However, relatively large split‐thickness skin grafts of up to 120 cm² could be harvested, although with some difficulty.

Another limitation of this study was the relatively small number of patients. Nevertheless, the study still provided clinically positive feedback for the use of split‐thickness plantar skin grafts in the management of lower‐leg and foot skin defects.

In our study, there was no specific consideration for diabetic patients, and the surgical outcome showed no difference between patients with and without diabetes. In 10 patients who did not have 100% successful grafting, only 2 of 10 patients had diabetes. The reason for 10% failure taken graft in these diabetic patients is shear force, which might be related to Charcot foot, the foot deformity both patients both suffered from. The lesson we learned from these 2 cases is that we performed a much tighter bolster tie‐over dressing for fixing skin graft in the diabetic patients with Charcot foot deformity.

In conclusion, our surgical method of using a single‐layer medium‐thickness skin graft (0.014 in. thick) from non‐weight‐bearing plantar areas to cover a leg wound is safe and simple and provides good functional and cosmetic outcomes at both donor and recipient sites. In addition, all patients reported high levels of satisfaction with the whole recovery progress and the final results. Therefore, in the management of skin defects in the lower legs or feet that cover less than 1.5% of the total body surface area, plantar skin grafting is a reliable alternative to anterior or posterior thigh skin grafting.

Liu H‐H, Chang C‐K, Huang C‐H, et al. Use of split‐thickness plantar skin grafts in the management of leg and foot skin defects. Int Wound J. 2018;15:783–788. 10.1111/iwj.12927