Rhombic Flaps

Rhombic flaps are versatile geometric local transposition flaps commonly utilized for reconstructing small to medium-sized skin defects, particularly after skin cancer resection in the head and neck area. However, their utility extends beyond this, proving effective in various anatomical regions and pathologies, including spina bifida, burn contractures, chronic pilonidal sinuses, and hand and breast reconstruction. Like other local flaps, rhombic flaps take advantage of skin laxity adjacent to a defect to permit reconstruction with skin with characteristics similar to those of the excised tissue. This approach enhances cosmetic outcomes compared to alternative reconstructive methods such as skin grafting and regional or free tissue transfer. The term "rhombus" originates from Euclidean geometry, denoting a quadrilateral with 4 equal-length sides and opposing equal acute and obtuse angles. Conversely, "rhomboid" refers to any parallelogram with 2 acute and 2 obtuse angles. "Rhombic" accurately describes flaps resembling a rhombus, while "rhomboid" pertains to those resembling a parallelogram. Russian surgeon Alexander Limberg first described the rhombic flap in 1945 and published his findings in English in 1966. Limberg's design features a characteristic quadrilateral rhombus shape, facilitating transposition through a 60° arc into corresponding skin defects (see  Classic Limberg Rhombic Flap Design). In 1962, Claude Dufourmental refined Limberg's rhombic flap design, proposing a modification involving a narrower flap with a more acute rotation angle. This adjustment aims to facilitate closure and minimize the standing cutaneous deformity at the pivot point of transposition (see . Dufourmental Rhombic Flap Modification). When designing the defect, the acute angle (α) must fall between 60° and 75°. The flap itself is created by aligning the first incision (CE) to bisect the angle between the line of the short diagonal axis of the rhombus defect and its adjacent side, with the incision's length equaling 1 side of the defect. The flap angle (β) may equal the defect angle (α) or be slightly smaller if needed, providing flexibility in design and placement. Unlike the Limberg rhombic flap, the shape of the Dufourmental flap doesn't precisely match the defect; however, complete closure occurs through secondary movement of surrounding skin, similar to the Limberg flap. Advocates of the Dufourmental modification argue its superiority over the Limberg flap due to improved blood supply and easier donor site closure facilitated by a wider pedicle and a more adaptable design. Sebastian et al reported the Dufourmental flap's superior versatility in surgical reconstruction compared to the Limberg flap, particularly in chronic pilonidal disease (see . Limberg Rhombic Flap for Pilonidal Sinus). In 1978, Webster modified Limberg's rhombic flap design, incorporating a more acute 30° flap angle and an M-plasty to close the defect base (see  Webster Rhombic Flap Modification). The narrower 30° flap angle aims to decrease tension during donor site closure. At the same time, the M-plasty divides the rotation arc between two 30° angles, enhancing tension distribution and reducing tissue distortion at the flap's pivot point. In Webster's original case series, favorable outcomes were reported, including reduced scar widening and areas of skin excess, attributed to a more balanced tension distribution. Like the Dufourmental modification, the Webster rhombic flap design necessitates significant secondary tissue movement for closure, as the flap's shape does not precisely match the defect. In 1987, Quaba and Sommerlad introduced a rhombic flap modification for reconstructing circular defects. This technique involves utilizing a rhomboid flap to reconstruct a round defect, with each side of the flap measuring two-thirds the diameter of the defect and a flap angle of 60° similar to Limberg's original description (see  Comparison of Quaba-Sommerlad Modification and Classic Limberg Rhombic Flap Design.). The authors documented a series of 175 patients with head and neck skin defects reconstructed using Quaba-Sommerlad flaps. Advantages cited over the classic design included enhanced flexibility in flap transposition and donor site orientation, along with the absence of a need to sacrifice healthy tissue to create a rhombus-shaped defect. The Quaba-Sommerlad flap shares similarities with another rhomboid transposition flap known as the "note flap," first described by Walike and Larrabee in 1985 (see  Note Flap). Named for resembling a musical eighth note in certain orientations, the note flap employs a quadrilateral flap to close circular defects. However, unlike the Quaba-Sommerlad rhomboid flap, the note flap's first limb is incised tangentially to the circular defect, making it distinct among rhombic flap variants. Additionally, the side of the note flap measures 1.5 times the diameter of the defect, rather than only two-thirds. Both the note flap and the Quaba-Sommerlad flap utilize 60° flap angles in their designs. Numerous authors have described multiflap variants involving 2, 3, and even 4 rhombic flaps. These variants have been applied to reconstruct larger defects and in areas with reduced pliability of adjacent skin. El-Tawil et al published a series of 8 patients with pilonidal sinus disease reconstructed with double rhombic flaps, resulting in low recurrence and complication rates and obviating the need for complex reconstruction. Additionally, successful reconstruction of meningomyelocele defects with triple and quadruple rhombic flaps has been reported, yielding positive patient outcomes. While numerous designs of rhombic flaps exist for various anatomical sites, this article primarily focuses on the widely reported Limberg flap method employed in reconstructing head and neck skin defects.