Transposition Flaps

Anatomy and Physiology

Two major layers form the skin—the epidermis on the surface and the dermis underneath. The epidermis contains 4 to 5 distinct strata, depending on location. These layers are the stratum corneum, stratum lucidum (present only on the palms and soles), stratum granulosum, stratum spinosum, and stratum basale. The dermis comprises a superficial papillary layer and a deeper reticular layer, both essential for maintaining mechanical integrity and cutaneous perfusion.

Vertically oriented perforating vessels from the subdermal plexus, located at the dermal–subcutaneous junction or within the deep reticular dermis, supply cutaneous perfusion. These vessels branch into a dense capillary network within the papillary dermis, delivering nutrients crucial for flap viability and removing metabolic waste. A clear understanding of the skin’s vascular hierarchy and anatomical pathways supports the design of flaps with dependable perfusion and enhances wound healing outcomes.[11][12]

Understanding relaxed skin tension lines (RSTLs) and lines of maximum extensibility (LMEs) is essential to effective flap design. First described by Karl Langer and later expanded by Guillaume Dupuytren, RSTLs follow the predominant orientation of dermal collagen fibers and align with natural skin folds and wrinkle patterns. On the face, these lines generally lie perpendicular to the contraction direction of the underlying mimetic muscles. LMEs, in contrast, run perpendicular to RSTLs and define the axis along which skin stretches most readily to accommodate tissue transfer.

Familiarity with the viscoelastic behavior of skin further enhances flap mobility while reducing closing tension. "Skin creep" refers to gradual elongation under sustained tension, while "stress relaxation" describes the skin's ability to maintain an extended length with progressively less force. These properties may be exploited intraoperatively to mobilize adjacent tissue for flap advancement or rotation. Planning flaps with both mechanical and aesthetic factors in mind, such as placing incisions along RSTLs and concealing scars within aesthetic subunit boundaries (eg, nasal sidewalls, perioral area, periorbital region), helps minimize postoperative distortion and optimize cosmetic results.[13][14]

Indications

Transposition flaps are indicated when primary closure, secondary intention healing, skin grafting, or sliding flaps would result in functional impairment or unsatisfactory cosmetic outcomes. These flaps are especially valuable in regions with limited tissue laxity or where redirecting wound tension is necessary to preserve the appearance and function of adjacent structures, such as the lip, nasal ala, or eyelid. Compared to large sliding flaps, transposition flaps typically require less undermining and more effectively shift tension vectors away from free margins and critical aesthetic or functional units. These flaps are most often used for reconstruction following oncologic resection, such as Mohs micrographic surgery on the face, but also serve in correcting congenital anomalies, revising scars, and reconstructing traumatic soft tissue loss, including dog bite injuries (see Image. Rhombic Flap for Mohs Defect of the Right Cheek).[15][16][17]

Rhombic flaps work particularly well for defects near the medial and lateral canthi, cheeks, and upper lateral 2/3 of the nose, while also offering effective closure for wounds on the lateral forehead, temple, perioral area, inferior chin, and dorsum of the hand.[18] Bilobed flaps serve best for small to medium defects of the lower 1/3 of the nose and are also used in repairs involving the helical rim and posterior auricle, where adjacent tissue mobility is often limited.[19]

Nasolabial (melolabial) flaps provide reliable coverage for medium-sized defects of the nasal ala due to the favorable skin match in color and texture, robust vascular supply, and the ability to conceal donor site scars within the nasolabial fold.[20] Z-plasties are primarily reserved for lengthening contracted scars, particularly those that cross RSTLs, and for reorienting scars to reduce visibility or relieve contractures by redistributing tension.[21]

Contraindications

Contraindications must be thoroughly evaluated before proceeding with transposition flap reconstruction. Careful patient selection requires assessment of medical comorbidities, functional status, and the patient’s ability to comply with postoperative care. These procedures should be avoided in patients who are noncompliant, cognitively impaired, or unable to care for the surgical site due to physical limitations or lack of caregiver support.

Absolute contraindications include incomplete tumor clearance and active infection at the operative site. Residual tumor, particularly at deep margins, can proliferate within undermined planes and evade early detection, leading to more extensive disease. This risk is minimized by confirming tumor-free margins or performing Mohs micrographic surgery prior to flap reconstruction. Incorporating infected or inflamed tissue into a flap markedly increases the likelihood of wound dehiscence, flap failure, and postoperative morbidity.

Relative contraindications include tobacco use, coagulopathies, and impaired vascular supply. Smoking disrupts wound healing and elevates the risk of flap necrosis, dehiscence, infection, and delayed reepithelialization. Smoking cessation for at least 2 weeks before and a week after surgery is strongly advised. Patients with inherited bleeding disorders or those receiving anticoagulant or antiplatelet therapy face heightened risks of hematoma and perioperative bleeding. Preoperative consultation with hematology or internal medicine specialists is advisable in these cases. Most antithrombotic medications can be safely continued with meticulous intraoperative hemostasis to prevent thrombotic complications.[22][23]

Tissue with poor perfusion, including irradiated skin, heavily scarred regions, or previously manipulated flaps, carries an increased risk of vascular compromise. In such scenarios, alternative reconstructive strategies may yield more favorable outcomes.[24][25]

Equipment

The equipment required for performing a transposition flap procedure aligns with standard cutaneous surgery tools, with additional focus on tissue handling and hemostasis. Alcohol swabs or solutions containing chlorhexidine and alcohol cleanse and degrease the skin prior to flap marking, helping to reduce skin flora. A surgical marker ensures precise flap design and alignment, particularly for complex transposition patterns. Local anesthetic, typically 1% lidocaine with epinephrine (1:100,000), is used to numb the area. This agent may be optionally buffered with sodium bicarbonate (1:10 ratio) to alleviate injection discomfort and improve the onset of anesthesia. Sterile surgical drapes maintain an aseptic field throughout the procedure.

Intraoperative equipment includes a #15 scalpel blade for precise skin and subcutaneous tissue incision, Adson or Adson-Brown forceps for atraumatic tissue manipulation, and dissecting scissors (Shea or Metzenbaum) for undermining and flap elevation. Serrated scissors (Kaye blepharoplasty or Gorney-Freeman) are used for trimming adipose tissue on the underside of the flap to improve apposition. A bipolar electrosurgical unit ensures effective hemostasis while minimizing thermal injury. Skin hooks or double-prong retractors are used for gentle tissue traction during undermining and suturing. A needle driver is employed for precise suture placement, while sterile saline is utilized for irrigation to maintain tissue viability.

Suture materials include absorbable options (eg, polyglactin or poliglecaprone) for dermal closure and nonabsorbable materials (eg, nylon or polypropylene) for epidermal closure. Selection depends on flap location, tension, and surgeon preference.

Postoperatively, petrolatum ointment helps maintain a moist healing environment and prevents crust formation. Nonadherent dressings protect the incision without adhering to the wound bed, while sterile gauze provides mild compression and absorbency as a secondary dressing. Hypoallergenic surgical tape or adhesive bandages secure the dressing while minimizing skin irritation.

Personnel

Most facial transposition flaps may be performed in the office with a surgeon and a nurse, sometimes involving an additional assistant for more complex cases. Larger flaps, especially those on the trunk and limbs, necessitate an operating room with general anesthesia, requiring a circulating nurse, surgical technician, anesthesia provider, and an assistant.

Preparation

Preoperative counseling should clearly explain the anticipated defect size following tumor clearance and the rationale for using a transposition flap, including the expected orientation and length of the final scar. Managing patient expectations plays a critical role in optimizing both postoperative compliance and satisfaction with cosmetic outcomes. Additionally, educating patients about the importance of perioperative smoking cessation is vital.[26]

Many patients underestimate tumor extent. Visualizing the defect after excision, either through direct observation or preoperative discussion, can help contextualize the resulting scar. Photographic documentation should be obtained, capturing the lesion before excision, the postclearance defect, and the completed repair.

Patients should be informed about typical postoperative changes, such as edema, bruising, and contour irregularities, as well as the potential need for revision procedures (eg, laser resurfacing or dermabrasion) to optimize cosmesis.[27][28]

Technique or Treatment

Transposition flaps demand meticulous preoperative planning and execution, as even minor errors can result in significant functional or aesthetic complications. For oncologic reconstruction, complete tumor clearance must precede flap transfer. Key anatomical features, such as prior surgical scars, facial subunits, and RSTLs, should be assessed both at rest and during expression to guide incision placement and flap design.

Rhombic Flap

The rhombic flap, first described by Limberg in 1946, remains a cornerstone technique in cutaneous reconstruction. The procedure is particularly effective in repairing defects near the medial and lateral canthi, cheeks, and the lateral upper 2/3 of the nose, with additional applications in the lateral forehead, temple, perioral region, inferior chin, and dorsal hand.

In the classic Limberg design, the surgical defect is shaped into a rhombus with 2 opposing 60° angles and 2 opposing 120° angles. The flap is drawn off the short axis of the rhombus, and the incision extends from this axis at a 120° angle, with a length equal to the sides of the rhombus. A 2nd incision, of equal length, is made at a 60° angle from the endpoint of the 1st incision (see Image. Classic Limberg Rhombic Flap Design). Wide subdermal undermining facilitates the transposition of the flap into the defect. If needed, the primary defect should be deepened to the same level as the flap base to prevent pincushioning. After achieving hemostasis, both the primary and secondary defects are closed in layers, first with deep dermal sutures, followed by superficial interrupted or vertical mattress sutures. Once complete, the flap configuration resembles a question mark.[29]

Variations of the rhombic flap enhance its versatility. The Dufourmentel modification involves making the initial incision at an angle that bisects the short axis of the rhombus and a line extending from one of its sides. This technique shortens the arc of rotation, reducing the risk of tip necrosis or dog-ear formation. The 2nd limb is still drawn at a 60° angle to the 1st (see Image. Dufourmentel Rhombic Flap Modification). The Webster modification builds on the Dufourmentel flap, using a 30° angle for the 2nd incision and incorporating an M-plasty into the inferior corner. This adaptation allows for more controlled closure and improved tension distribution between the primary and secondary defects (see Image. Webster Rhombic Flap Modification).

The Quaba-Sommerlad modification leaves the defect circular rather than converting it into a rhombus, placing the donor site closure along RSTLs. This technique is particularly useful in areas like the cheek and temple, where minimizing tension is crucial. The Quaba-Sommerlad modification is especially advantageous when the primary defect’s geometry makes traditional rhombic angles less suitable (see Image. Comparison of Quaba-Sommerlad Modification and Classic Limberg Rhombic Flap Design).[30][31] These adaptations maintain the principles of tension redistribution while improving geometric flexibility and alignment with RSTLs, LMEs, and surrounding anatomy.[32]

Bilobed Flap

Esser described the bilobed flap in 1918, with Zitelli modifying it in 1989 to the version most commonly used today. This flap proves especially useful for defects of the lower 1/3 of the nose, although it can also be applied to areas like the face, neck, helix, and posterior ear, eyelids, feet, hands, and trunk. The bilobed flap consists of 2 lobes based on a single pedicle, offering the advantage of using more mobile tissue with favorable tension vectors. Zitelli's modification, which employs a 90º arc of rotation instead of the 180º used in Esser's design, reduces the risk of standing cutaneous cone deformities and minimizes tension during flap rotation.

The flap is designed for a circular or oval defect. The pivot point is chosen at least 1 radius from the defect's edge, and lines are drawn tangential to the defect’s perimeter to create a Burow triangle that will be excised to avoid dog-ear formation at the flap's base.

The first or primary lobe is positioned at a 45º angle from the pivot point and is designed with a similar length and diameter as the defect. If the skin lacks elasticity, as on the tip of the nose, the lobe should match the defect's size. When skin is more elastic, the lobe can be around 80% of the defect's area. The secondary lobe is placed at a 90º angle from the pivot point, or 45º from the center of the primary lobe, and should be slightly longer but narrower towards the base. A 30º triangular tip is excised to form a linear scar at the tertiary defect. The width of the secondary lobe balances closure ease for the tertiary defect with the need to displace surrounding structures and typically is around 80% of the diameter of the 1st lobe (see Video. Marking the Bilobed Flap).

Wide undermining of the flap and the peripheries of the donor and defect sites follows the flap incision. Hemostasis is achieved, and the flap is then lifted and rotated approximately 45º. The primary lobe fills the original defect, while the secondary lobe covers the primary lobe donor site. The tertiary defect is closed first using deep dermal sutures, followed by deep dermal suturing of the primary lobe into the defect. The secondary flap tip is trimmed to fit the remaining defect, the primary lobe donor site, and sutured in a similar manner. The Burow triangle is excised last. Superficial sutures, such as simple interrupted, vertical mattress, or occasionally running or single interrupted sutures, are placed to reapproximate the superficial epidermal edges. The final closure of the bilobed flap resembles the top of a heart (see Image. Bilobed Flap, Zitelli Modification).

An important variation of the Zitelli bilobed flap is the trilobed transposition flap. This modification is especially useful for larger alar defects and rigid sebaceous nasal skin, preventing the ipsilateral alar depression and contralateral alar elevation often seen after reconstruction. Designed similarly to the bilobed flap with approximately 45º angles between lobes, this technique uses 3 lobes instead of 2, allowing the tension vector to remain perpendicular to the nasal ala and preserve alar symmetry.[33][34]

Nasolabial Transposition Flap

Dieffenbach originally described the nasolabial (melolabial) flap in 1830 when he used superiorly-based nasolabial flaps to reconstruct the nasal ala. This technique should not be confused with the 2-stage interpolated nasolabial flap. In 1920, Esser modified the technique by employing an inferiorly-based flap to close a palatal fistula. This modification laid the foundation for the method commonly used today. The nasolabial flap is particularly useful for defects of the lateral and central ala but may also be applied to nasal sidewall defects and others. The flap uses the sebaceous skin from the medial cheek, adjacent to the nasolabial fold, and transposes it into a nasal defect, allowing the scar to blend well within the nasolabial fold at the boundary of the medial cheek and the cutaneous upper lip.

The flap is typically planned around a circular defect. The medial margin is drawn within the nasolabial fold, and the lateral margin extends onto the medial cheek, either superiorly or inferiorly, depending on the location where the flap will be transposed. Planning the flap to be longer than the primary defect (after excising the Burow triangle) compensates for the contraction that occurs when the flap is lifted onto the nose. The base of the flap should match the width of the defect. After incision, wide undermining at the donor site is needed to advance the cheek medially. Most surgeons place a tacking or anchoring suture from the dermal undersurface of the flap to the periosteum of the maxilla, in the concavity of the nasofacial sulcus. This technique minimizes flap tension on the alar defect when sutured into place and prevents blunting of the nasofacial sulcus.

The secondary defect is closed using deep dermal absorbable 4-0 or 5-0 sutures. The flap is then transposed into the defect and carefully trimmed to ensure a precise fit. Miscalculations during this step can lead to functional or aesthetic complications, such as alar retraction and pincushioning. The epidermal edges are approximated using simple, interrupted, or running or simple continuous nonabsorbable 5-0 or 6-0 sutures (see Image. Melolabial Note Flap for Nasal Sidewall Reconstruction).[35][36]

Z-Plasty

The first example of contemporary Z-plasty was described by Berger in 1904, with subsequent improvements made by Morestin in 1914. Limberg further expanded the understanding of the flap's dynamics shortly after. This transposition flap is primarily used for scar revision following cutaneous surgery. Indications for Z-plasty include enhancing scar cosmesis by reorienting scars, particularly those crossing RSTLs, and releasing scar contractures or webs by redistributing tension over the wound. Tension redistribution is particularly important for scars that distort free margins or other cosmetically sensitive features.

The Z-plasty technique generally involves creating 2 flaps from 3 equal-length incision limbs and 2 identical angles, ultimately lengthening and rotating the scar. Several Z-plasties may be performed in series to address longer scars. Typically, the Z-plasty is oriented so that the central limb of the Z either widens into an ellipse to resect a scar or is incised along the ridge of a scar web. Though counterintuitive, incising down the middle of a scar web is necessary, as the geometry of the Z-plasty dictates that the scar be incised longitudinally rather than transversely.

The 1st limb of the Z-plasty is drawn along the long axis of the scar from one end to the other. Two equal-sized limbs are then drawn at equal angles at either end of the 1st limb, although the length and angles of the limbs do not necessarily have to be identical. The angles formed by the junction of the limbs should range between 30º and 75º. An angle less than 30º may cause tip necrosis, while an angle greater than 75º creates flaps that are difficult to rotate, leading to increased tension and larger standing cutaneous deformities. The angles also determine the expected lengthening of the scar. A 30º angle results in ~25% lengthening with 30º rotation, 45º leads to ~50% lengthening with 60º rotation, and 60º yields ~75% lengthening with 90º rotation.

After making the incisions, wide undermining should be performed around both triangular flaps and the edges of the central wound, followed by meticulous hemostasis. The tips of the flaps are then transposed. Deep dermal absorbable sutures are placed starting with the lateral limbs, and the epidermal edges are approximated using simple, interrupted, or vertical mattress nonabsorbable sutures (see Image. Running Z-Plasty Technique for Burn Scar Contracture Release). Notably, the rhombic flap is essentially a Z-plasty with the defect located in one of the limbs, rather than in the center.

Complications

Transposition flap procedures carry several potential complications, many of which are common to cutaneous surgery. These complications include postoperative edema, pain, infection, bleeding or hematoma formation, scarring, flap necrosis, and the development of hypertrophic scars or keloids. Flap necrosis usually results from inadequate vascular supply or excessive tension and is more likely in patients with vascular compromise, a smoking history, or significant comorbidities.[37] When necrosis occurs, minimal debridement should be performed, and a local wound care regimen should be prescribed.

Prior to necrosis, arterial ischemia of the flap, indicated by pallor, can be treated with topical nitroglycerin paste and oral pentoxifylline. Venous congestion, which is more common than arterial insufficiency, causes the flap to become dusky and distended, with dark blood oozing from the incision lines. This condition may be managed with leech therapy, accompanied by fluoroquinolone antibiotics as prophylaxis against Aeromonas hydrophila infection, a bacterium that may be carried by medical leeches.[38]

Two complications more specific to transposition flaps are the "trapdoor" and "pincushion" deformities, where the flap elevates above the surrounding skin. The trapdoor deformity occurs when the periphery of the flap is raised above the surrounding skin, typically when the flap is superiorly based and the lymphovenous outflow is partially compromised by gravity, resulting in long-term dependent edema. This condition may also contribute to the pincushion deformity, where the entire flap develops a mounded appearance, particularly at its center.

Factors that may cause pincushioning include insufficient tissue undermining, use of an oversized flap, excess subcutaneous fat beneath the flap, and inadequate apposition of the flap to the wound base.[39] When these deformities occur, they may be managed conservatively with massage or corticosteroid injection. However, surgical revision or resurfacing may be necessary if the deformities persist or become cosmetically bothersome.[40][41]

Clinical Significance

Transposition flaps are a cornerstone of cutaneous reconstruction, providing a reliable method for closing surgical defects that would be functionally or cosmetically suboptimal with simpler techniques such as primary closure, secondary intention healing, or grafting. The ability of these flaps to redirect tension vectors, recruit nonadjacent but lax skin, and avoid distortion of nearby anatomical landmarks makes them particularly valuable in high-risk or cosmetically sensitive areas, such as the face, hands, and lower extremities.

By preserving adjacent tissue and minimizing donor site morbidity, transposition flaps not only optimize aesthetic outcomes but also support faster recovery and improved patient satisfaction. When planned and executed with careful attention to anatomy, tension lines, and defect geometry, these flaps can significantly reduce postoperative complications, improve scar camouflage, and maintain the functional integrity of nearby structures.

Enhancing Healthcare Team Outcomes

An interprofessional team, including a surgeon and a nurse assistant, should perform the procedure in most cases. A wound care nurse and a clinician experienced in the follow-up of transposition flaps should monitor the patient for potential complications, such as infections, necrosis, and poor perfusion. Effective coordination of care, open communication, and meticulous record-keeping are essential to the successful implementation of the interprofessional healthcare team model.

Nursing, Allied Health, and Interprofessional Team Interventions

Nurses and allied health professionals play a crucial role in both preoperative preparation and postoperative recovery following flap-based reconstructive procedures. Nursing interventions include preoperative patient education, assisting with surgical site marking, verifying consent, and ensuring appropriate skin preparation. Postoperatively, nurses implement wound care protocols, manage dressings, administer prescribed medications, and reinforce activity modifications to protect the flap. Allied health professionals, such as physical and occupational therapists, help maintain mobility, especially when reconstruction involves functionally significant areas like the face or extremities. Coordinated planning with pharmacists and case managers further enhances pain control, antimicrobial stewardship, and discharge readiness.

Nursing, Allied Health, and Interprofessional Team Monitoring

Monitoring responsibilities center on the early identification of complications and ensuring adherence to postoperative protocols. Nurses regularly assess flap viability using clinical parameters such as color, temperature, capillary refill, and turgor. Signs of hematoma, infection, or ischemia, such as pallor or duskiness, must be promptly reported to the surgical team. In the immediate postoperative period, vital signs, pain levels, and drainage output (if applicable) are monitored closely. Allied health professionals track functional recovery milestones, while patient navigators or care coordinators ensure that follow-up appointments, wound checks, and suture removals occur as scheduled. This ongoing surveillance enables early intervention and supports optimal long-term outcomes.