|Home | About | Journals | Submit | Contact Us | Français|
Background: The management of contractures and soft tissue defects in the proximal interphalangeal (PIP) finger joint remains a challenge. We report a transposition flap from the lateral skin of the proximal phalanx that is based on perforating branches of the digital arteries and can be used safely for both palmar and dorsal cover defects. Methods: We first completed an anatomic study, dissecting 20 fingers in fresh cadavers with arterial injections and made the new flap in patients with dorsal or palmar defects in PIP joints. Results: In cadavers, we can reveal 4 constant branches from each digital artery in the proximal phalanx, with the more distal just in the PIP joint constituting the flap pedicle. Between February 2010 and February 2015, we designed 33 flaps in 29 patients, 7 for dorsal and 26 for palmar defects, with no instances of flap necrosis and 4 distal epidermolysis. The patients were between 4 and 69 years with no major complications, and all of the skin defects in the PIP joint were resolved satisfactorily without any relevant sequelae at the donor site. Conclusions: This flap procedure is an easy, reliable, versatile, and safe technique, and could be an important tool for the management of difficult skin defects and contractures at the PIP joint level.
Skin contractures in fingers can cause significant skin shortening, leading to major defects at contracture release. This problem often affects the proximal interphalangeal (PIP) joints in both the dorsal and palmar skin, and at present, there is no ideal method to replace the lost skin. The same principle applies to traumatic skin loses in this area. Total skin grafts can tend to contract, and thus could not be the best choice for tendon or neurovascular bundle exposition.1,5 For Dupuytren disease, some surgeons use the McCash technique waiting for secondary intention closures; however, this approach requires a long splinting time in extension. We have found descriptions of rotation flaps, homodigital and heterodigital flaps, and combinations of lateral transposition flaps taken from the proximal and middle phalanxes that have been used to achieve the complete closure of defects in the PIP joint.1,7 Such approaches, although successful, are usually complex, require multiple surgeries, and demand large incisions in the injured finger and/or healthy areas in other fingers, increasing regional morbidity. The lateral regions of fingers are very rich in arterial anastomosis6; they are usually protected from burns and able to retain healthy skin and subcutaneous tissues. Furthermore, the relative skin excess in this area allows for primary closure if used as a donor site.1,5,7 With this in mind, we have designed a new surgical technique calling for a flap to be taken from the lateral side of the proximal phalanx with a distal pivot point in the PIP joint. This approach can be easily modified for either the dorsum or the palm to cover any defects in this location within a single surgery without harming the adjacent fingers while still achieving a reliable vascular pedicle and minimal sequelae in the donor area.
After consulting many excellent studies detailing the vascular anatomy of the fingers, such as those published by Strauch and Moura,6 Voche and Merle,8 Braga Silva,4 and Bertelli,3 we decided to practice our vascular injection studies on fresh cadavers (see Figure 1). We dissected 20 fingers in 8 hands previously injected with a mixed fast setting acrylic and Chinese ink in the radial artery at the distal third of the forearm. At loupes magnification ×4.0 and ×6.0, we searched for branches of digital artery in the proximal phalanx and found that all of the fingers had 4 branches of digital artery in proximal phalanx; these we numbered 1 to 4, from proximal to distal. These branches create a rich anastomotic network that perfuses the lateral skin of the proximal phalanx. After beginning the flap dissection, we located branch numbers 1 and 2, which were sacrificed to continue the distal dissection. Branch number 3, also known as the “dorsal branch” for dorsal island flap described for Bertelli,3 arises from the digital artery, 6 or 7 mm proximal to the PIP joint palmar skin crease. Branch number 4 is our main flap pedicle and arises just at the level of the PIP joint. Next, we created a flap using the entire length of the proximal phalanx lateral skin (almost 4 cm in length and up to 6 mm in width), until we reached the subcutaneous tissue at the PIP joint palmar skin crease. Our study demonstrated an axial vessel piercing the fascia that entered at the base of the flap and remained in the proximal two-thirds.
We begin by noting the dimensions of the defect and drawing the flap at the donor site. We chose the most hidden side, which was the ulnar side in the second finger and the radial side in the fifth finger, unless there were any previous scars or an exposure incision was necessary on the preferred side (see Figures 2 and and3).3). The more proximal point of the flap can include some web skin to extend its length up to 4 cm, depending on each patient proximal phalanx length and ensuring no future scar retractions. This procedure was performed under regional or general anesthesia and using an arm tourniquet without compressive exsanguination for the easy visualization of the digital artery and its branches. All flaps were dissected by the senior author (Aldo Beltrán) using loupes ×6.0 magnification. We begin by raising the flap at the more proximal point of finger, using the midline of the lateral side of the finger as an axis. We calculate the flap width pinching lateral skin until we were able to close the primary donor defect, allowing an average of 6 mm of flap width. In some cases, requiring a greater flap width, we made a partial closure and left heal donor site for secondary intention. We used as much of the subcutaneous tissue as possible, cutting in this process branch numbers 1 and 2 and taking care not to harm the collateral artery or nerve. We preserved all of the fat tissue under the flap and over the collateral neurovascular bundle and stopped dissection 7 mm proximal to the interphalangeal joint to ensure that the two more distal branches of the digital artery were included. If the flap needed to be pivoted more distally, we cut branch number 3 and accordingly dissect the flap more distally, reaching the PIP joint. At this juncture, the more distal branch, our branch number 4, is able to perfuse the flap alone. We were able to see the arterial branches at the undersurface of the flap in only some of the clinical cases and anatomic specimens. When incision was close to the palmar skin crease of PIP joint, we stopped dissection to attempt to bring the flap to the defect. Next, we closed the donor area using continuous sutures, leaving the flap in its original position and releasing tourniquet. We waited 3 to 5 minutes for flap reperfusion and fixed the flap in the receptor area using very few stitches. In the process of transposition, we can observe a transitory slow arterial perfusion in the flaps, many of which improved spontaneously in 4 to 5 minutes. We left the subcutaneous tissue exposed because the flaps are normally thicker than the skin in the receptor area. Although initially we believed that this partial closure can cause an irregular contour, the healing and reepithelialization process moved quickly to repair all significant defects in the contouring. All of our patients were previously informed about the surgical technique, risks and benefits, and we obtained informed consent from each. Our institutions do not require board approval for use of different or new surgical techniques with reasonable risks; it is requested for pure experimental purposes only.
Between February 2010 and February 2015, we performed 33 flaps in 29 patients, 7 for dorsal and 26 for palmar defects. The patient’s ages ranged between 4 and 69 years (average 34.3). All patients with a contracture or skin defect at the PIP joint were included. A previous suspected collateral pedicle injury was considered a relative contraindication that could be solved by approaching the flap from the contralateral side. We did not exclude patients for other pathologies, such as diabetes, atherosclerosis, or smoking, and there were no age limits. Only one patient was excluded for no possibility of clinical follow-up; a big number of our patients come from very far towns, circumstance that made difficult the postoperative appointments.
We encountered no cases of total flap necrosis. Distal epidermolysis that resolved spontaneously developed in 3 flaps: 1 in a patient with several fibroses secondary to an old tenosynovitis, 1 in a young patient with severe Dupuytren disease, and 1 in the only finger that was subjected to 2 simultaneous flaps. In another case, we had to delay the flap for 3 weeks due to a large scar on the finger from a previous flexor tendon injury. Clinical follow-up was completed for an average of 121.6 days, although we considered patients ranging between 14 and 476 days after the procedure. However, complete healing and full movement took close to 3 weeks in all patients (see Table 1).
Lateral proximal phalanx flaps with proximal bases have been described by Green5 as a good alternative for contractures or defects on the palmar side of the metacarpophalangeal joints. The authors mention the previously described advantages of the lateral phalanx as a donor site, such as the skin redundancy that allows for primary donor site closure; however, their description resembled that of a random flap, designed on a base : length ratio between 1:1.5 and 1:2. Indeed, a high risk of tip necrosis may emerge if the flap exceeds these dimensions.5 However, analyzing the vascular anatomy of the fingers,3,4,6,8 we can suppose that branches 1 and 2 are the real vascular pedicles of this flap, which makes it possible for Green’s limits to be exceeded.
The currently described flap approach is very safe. Acikel1 published a cases series with 11 patients (37 fingers) undergoing PIP joint contractures managed with 2 lateral flaps of the proximal base, one from the proximal phalanx and another from the contralateral side of the middle phalanx. Ülkür7 described 8 cases of combined usage of the lateral proximal phalanx flap with a proximal base and cross-finger flap for severe contractures of the PIP joint. Bertelli2 designed an island dorsal flap in severe flexion contractures, preserving a 5-mm pedicle proximal to the PIP joint. We believe that this pedicle was included in our study as the number 3 branch, which allowed for an island design. The donor defect was closed primarily because the flexion contracture caused a dorsal skin expansion. However, all these previous techniques have significant limitations as only availability for palmar defects (Bertelli’s flap), middle phalanx is smaller and gives us small flaps (Acikel) harming both sides of the injured finger, or using an adjacent healthy finger (Ülkür).
Using our technique, we were able to take advantage of all properties of the lateral skin of the proximal phalanx as donor site, including that is the longest phalanx, skin redundancy, protection of lateral side of the finger in burns, and the constant presence of arterial branches that allow the flap to be pivoted at a distal base, easily reaching either dorsal or palmar defects at the PIP joint. Our flaps were not random; based on our anatomic study, we were able to demonstrate the branching of an arterial perforator at the level of the PIP joint, which is constant and allows large flaps to be created, exceeding the ratio base-length of 1:2. Such dissections are not complex and, using loupes magnification and the appropriate instruments, the surgical time is quite short (5 minutes or less). Morbidity at the donor site is minimal, and the clinical results are very satisfying.
We consider the proximal phalanx flap with distal base to be a versatile (can reach dorsal and palmar defects), safe (constant vascular pedicle), easy, and reliable alternative technique for the management of challenging soft tissue defects in the PIP joint.
The authors thank Instituto Nacional de Medicina Legal de Colombia for providing us fresh cadavers for anatomical study.
Institutions: We made this flap in multiple centers in Bogotá, Colombia, where we develop our institutional and private practice, but our principal center is Hospital Central Policía Nacional de Colombia (Bogotá, Colombia).
Meeting Presentations and Awards:
Ethical Approval: This study was approved by our institutional review board.
Statement of Human and Animal Rights: This study takes care of respect all humans rights in clinical research; our institutions do not require approval from a review board if the study does not involve any experimental technique or unusual surgical or medical risks; all patients know the nature of procedure, other treatment choices, and sign an informed consent. The clinical study do not require any funding, and anatomical study was all covered for authors’ own funding resources; any institution or company gives us money for financing this project.
Statement of Informed Consent: Informed consent was obtained when necessary.
Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: We are our own funding source in the anatomical stage of this study.