Key points
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The rhomboid flap is a workhorse flap for reconstruction of facial and head and neck defects based on the transposition flap design.
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The rhomboid excision (60° and 120° angles) should parallel the skin tension line in the longitudinal axis.
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Disadvantages of this transposition flap are tension, incision in healthy native tissue leading to secondary scar, and the potential for excess “dog-ear” tissue.
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Multiple modifications have been described to reduce the side effects as mentioned above, to decrease pivotal restraint and minimize tension to the tip of the flap.
Introduction
Facial cutaneous defects of noncritical sizes are reconstructed with local flaps, which are advanced, rotated, or transposed into the area. Among these local flaps, the rhomboid flap is a geometrically random pattern–designed simple transposition flap. It follows the principles of flap design, retaining its vascularity from the connected limb of adequate width, with its tissue composition similar to the excised region.
Historical perspective
Alexander A. Limberg, a maxillofacial surgeon from Russia, introduced this original concept of transposing a rhomboid-shaped flap 120° for closure of a similarly shaped defect in 1946. As a result, this rhomboid flap is also described as the Limberg flap. The original Russian monograph, Mathematical principles of local plastic procedures on the surface of the human body , was subsequently published in 1966 in English as a “Design of local flaps” chapter for a plastic surgery textbook. Since that time, multiple modifications to his flap design have been proposed. In 1966, a modified technique was described by Claude Dufourmentel, whereby angles between 60 and 90° were designed for the local tissue transfer. Therefore, less healthy tissue was disturbed for the transposition with a wider pedicle width of the local flap. About a decade later, in 1978, Richard Webster described the 30° flap, whereby the distal flap is angulated only 30°, which helped with tip ischemia. However, closure of the defect base required an M-plasty, which helped minimize tension to the flap. In 1987, another modification surfaced known as the Quaba/Sommerlad flap, which was designed to close circular defects. The design of the transposed flap was smaller than that of the defect, and the defect was not converted to a geometric rhomboid-shaped defect.
It is interesting to note the origin and evolution of the Greek word rhombos (Latin rhombus ) and the derivative words rhomboid and rhombic. The original term rhombos predates the Euclidian era and was the name used in ancient Greece for the spinning top toy. The familiar shape of a spinning toy is a symmetric quadrilateral (usually not a parallelogram) with equal adjacent sides and having at least 2 of its 4 angles being equal. Later on, this definition was slightly changed by Euclidian geometry to denote the well-known shape of a parallelogram with 4 equal sides, opposite equal acute angles, and opposite equal obtuse angles (excluding the square). It therefore becomes obvious that the use of the term rhomboid (or rhombic) to describe the flap of Limberg is based on the Euclidian definition of the rhombus shape and not the one corresponding to the shape of the spinning top toy. It is also significant to clarify that the terms rhomboid (having shape/characteristics like that of a rhombus) and rhombic (having the shape/characteristics of a rhombus) are closely related, with the term rhombic being a slightly more precise descriptor of the Limberg flap ( Fig. 1 ).
Indications and contraindications
Small to medium defects that are too large for primary closure are very amenable to reconstruction with transposition flaps. For instance, anatomic subunits, including the forehead, malar, temple, and the inferior part of the chin and lip, are ideal locations for vector transposition using the rhomboid flap in the resting skin tension lines. Inadequate margin resection is an absolute contraindication to any reconstructive option until margins are negative from the oncologic standpoint. Relative contraindications include patient factors, such as anticoagulation, radiation history, impaired vascularity, previous local tissue rearrangement, and immunosuppressive pharmacologic considerations.
Surgical considerations
Rhomboid flaps are used in various anatomic regions of the entire body, making it an extremely versatile flap given its ability to reconstruct defects with similar tissue of texture and color. It has been demonstrated to be very useful in pilonidal cyst defects. However, it is still most commonly used in the face, head, and neck regions. For the maxillofacial surgeon, the rhomboid flap has great use in the temporal, periocular regions, nasal bridge, cheek/malar areas, chin, and neck regions. Pathologic condition, adequate margin resection, diameter of the lesion, scar orientation, area of maximal tension upon closure, skin laxity, and future reconstructive options (if necessary) are important considerations in any local flap reconstruction. The reconstructive ladder begins from secondary intention to free tissue transfer with the role of local or pedicled flaps chosen as an option for small to medium defects, which are aesthetically amenable to closure. Fillers, chemotherapeutic medications, lasers, scar modifiers like dermabrasion, and microneedling are additional adjunctive reconstructive aids to correct pin-cushioning or dog-ear deformities.
Anesthetic considerations
Vital considerations for an anesthetic evaluation include the patient’s medical history, medication allergies, family history, and compliance during the procedure. Most transposition flaps are amenable to local and regional anesthesia with or without sedation. General anesthesia is certainly a consideration for surgical execution in an anatomically complex defect, poor pain tolerance, and so forth.
Flap design
The essence of the donor site closure and reconstruction should minimize distortion of adjacent structures. Previous scars, muscle, and ligament attachments, like the lateral canthus, for instance, must be accounted for. The relaxed skin tension lines and vectors are identified before flap design ( Fig. 2 ). The line of the incision in adjacent normal donor skin is parallel to the relaxed skin tension lines, and the short-axis incision extension is placed within the lines of maximal extensibility ( Fig. 3 ). In the absence of obvious skin folds or creases, a pinch test of the skin would guide orientation. The base of the flap is the most important part of the flap design because it will maintain flap viability. The base of the pedicle should not be narrowed or undercut, and the flap design should account for anatomic subunits and tension lines to prevent stretching or tethering of the vasculature of flap.
