This cohort study was designed according to the guidance of the Helsinki declaration and approved by Jilin University, China (license number: SCXK (Ji) 20140084).This cohort study wasconducted on patients with soft-tissue defects on the volar surface of the finger because of trauma from March 2014 to March 2017,all patients signed the informed consent. For all the patients, full history was recorded and detailed clinical examination and radiography were performed to assess the skeletal effects and arterial duplex scanning to assess the vascular pattern of the hand.
Those who had systematic diseases, including diabetes mellitus, vascular sclerosis, and peripheral vascular disease, those who could not withstand long-time operation, and those who had a positive smoking history were excluded from this study, along with those with bad local conditions. Patients were notified about the merits and demerits of each method and themselves made the choice. Simultaneously, written informed consent was obtained from all the participants.
Total 24 patients were enrolled in the study with an average age of 38.9 years (20–65 years); 18 subjects were men (75%), and 6 were women (25%). All skin and soft-tissue defects were caused by trauma. The defects were localized at the volar surface of the finger with exposed flexor tendons. The patients were divided into the following 2 groups: the MPAF group and the DDMF group; all procedures were performed by a single surgeon. The locations were as follows: thumb, 7; index finger, 4; middle finger, 4; and ring finger, 9. Among of them, 13 had only skin and soft-tissue defects, and the other 11 fingers (MPAF: 6 cases/DDMF: 5 cases) had nerve defects/injury. The nerve was repaired applying different methods (MPAF: nerve bridging, DDMF: flap with neurovascular bundle or proper digital dorsal nerve was anastomosed with the digital nerve). Demographic patient data is presented in Table 1.
A survey was conducted at least 12 months after the surgery to investigate the operative time and complications, including flap necrosis, graft loss, infection, paresthesia, and donor-site morbidity that were carefully recorded. The Michigan Hand Outcomes Questionnaire (MHQ)[7] was applied to assess patient satisfaction with the result for all patients. The questionnaire consists of five domains, including hand function, activities of daily living, work performance, aesthetics, and satisfaction with hand function. It was scored on a scale from 0–100 (0 = worst result, 100 = best result). In particular, the aesthetic appearance (full appearance, soft texture, color consistent with the finger volar skin, and pigmentation) of the injured hand was measured with a cosmetics score (0 = worst cosmetic result, 10 = best cosmetic result). Differences between independent parametric variables were assessed with t-test for independent samples. Probabilities of < 0.05 were considered to indicate significance.
Surgical method/technology:
The wound was subjected to radical debridement before reconstruction because most cases were those of trauma. Necrotic tissue was removed, and antibiotic therapy was administered on the basis of microbiology results until the local wound bacterial culture confirmed the absence of infection. Thereafter, flap and nerve bridging were performed to repair the soft tissue and nerve defects in the second stage.
The operation was performed under general anesthesia or nerve block. The pneumatic tourniquet was applied to provide a bloodless field. Surface marker measurement and pre-operative photography was completed; antibiotics were injected intravenously before tourniquet application.
The MPAF is located in the non-weight-bearing area of the plantar on both sides of the axis and behind the head of the metatarsal bone. The size and shape of the flap can be designed and dissected as per the wound size, but generally cannot be > 4 × 8 cm[8,9]. The medial plantar artery and the medial plantar nerve can be identified between the abductor hallucis and flexor digitorum brevis. The flap was then elevated at the superficial muscle membrane of the abductor halluces and isolated from the distal to the proximal direction. The medial plantar artery was anastomosed with the digital proper arteries or the common palmar digital arteries; the dorsal veins of the finger or palm were anastomosed with the accompanying vein of the plantar metatarsal artery. In order to ensure that the flap was sensate, the branches supplying the flap were isolated and teased out from the main trunk of the medial plantar nerve. The proximal and distal ends of the flap nerve should be sutured with the proper digital nerve. The donor site of the flaps was primarily grafted with a split-thickness skin graft. Fig 1.
The DDMF was located between the metacarpals and with rotation point located at the proximal phalanx level. It was designed on the intermetacarpal spaces as an ellipse centered over the dorsal metacarpal arteries (DMA) that were ligated at the proximal margin of the flap. The flap was elevated in the interosseous fascial plane. The pivot point of the flap was located at the mid-point of the proximal phalanx where the proximal dorsal branch of the digital artery anastomoses with the dorsal digital artery. It can be transferred to the defect through an open tunnel, and the secondary defect was closed primarily or with skin graft. Fig 2.
Statistical Analyses:
The data are presented as the mean ± standard error of the mean values. The incidence of complications, functional outcomes, and other qualitative parameters were compared using the Fisher’s exact test. The mean operative time between the two groups and other quantitative were analyzed using the t-test. The level of significance was set at p < 0.05.