Adjustable, Skin-Stretching External Fixation Device and Negative Pressure Wound Therapy Application for Infected Full-Thickness Skin Defects

A Case Series Study

Ye Peng, MD; Wei Zhang, MD; Faran Bokhari, MD; Zuo Cao, MD; Gongzi Zhang, MD; Shuwei Zhang, MD; Lihai Zhang, MD


Wounds. 2021;33(7):178-184. 

In This Article


Giant, infected full-thickness skin defects are a difficult problem, especially in conjunction with pelvic fractures and Morel-Lavallée injuries. Extensive fascial and muscle debridement complicates fracture management and eventual soft tissue coverage. Open reduction and internal fixation is the optimal treatment for most pelvic fractures; however, in cases involving large open wounds and soft tissue defects, these methods are not appropriate owing to the risk of infection.[10–11] Additionally, for giant wounds, full-thickness skin grafts and muscle flaps can be problematic, because they are technically demanding, require a large donor site, and are prone to morbidity as well as complications around the graft area.[10,11]

The indications for use of an adjustable, skin-stretching external fixation device and NPWT are as follows: (1) an infected skin defect; (2) large size of full-thickness skin defect (> 5 cm2) and no desire by the patient for skin flap or muscle flap; (3) lack of a good blood supply to the wound area or a donor site defect not fit for using a skin or muscle flap; or (4) a surgeon who is incapable of performing skin or muscle flap techniques. The skin-stretching technique is safe, effective, and simple to apply and previously has been described in a variety of clinical situations.[12–19] However, few studies have reported its use in the management of giant, infected defects in the lower back and hips. The present authors' experience demonstrates that the adjustable external fixation device can be used safely and effectively in these cases. The device can be assembled using 2 K-wires and 2 pressure bars, and the force and speed of the skin stretching is easily adjusted. This method has several advantages over traditional flap coverage, especially in the management of massive defects. First, the procedure can be performed under local anesthesia. Second, it avoids secondary injuries related to distant donor sites. Third, it can be combined with NPWT to control superficial infection and promote granulation tissue formation and wound healing. Also, there is no size limitation, but larger defects require more time to achieve coverage. Finally, functional outcomes may be better than those achieved with grafts or flaps due to to less scar tissue formation.

The standard of care is quite important for this skin-stretching technique. Before the wound is sutured, it must be checked frequently for complications. The NPWT dressing should be changed every 3 to 5 days. In the present cases, the negative pressure drainage was usually blocked by infected secretions in general and the dressing change was needed. After the wound is sutured, standard care for dressing the wound can be used.

In the present series, the average time to healing was 3.29 months (range, 1–6 months). This finding was similar to that of split-thickness skin grafts (1–2 months) and local flaps (3 months) The traction time mostly depended on the size of the defect.[20,21] Complications associated with the skin-stretching technique include necrosis of the skin edge, pin site infection, wound dehiscence, wound infection, and pain.[11] This process is also time-consuming, because the skin must be stretched gradually over a period of weeks. With appropriate medical care and monitoring, however, in certain cases stretching can be done at home (ie, on an outpatient basis).

Although scarring sometimes looks quite significant, the reasons for it are usually owing to a predisposition to scarring and a form of ulceration. The ulceration relates to the speed of traction and the thickness of the skin. The patient shown in Figure 5 has very few scars compared with the patients discussed in cases 1, 2, and 3. A lower speed of traction (0.7 mm/day) could be used in thin skin, and silicone gel with vitamin C (Dermatix Ultra) and laser treatment could be used for such patients to decrease the scar burden.