The Keystone Flap: Our prospective clinical experience with a hundred consecutive cases

Background The keystone island flap can be utilized in various sizes and locations to reconstruct different skin defects in any location of the body. It can provide an excellent reconstruction alternative for skin deficiencies, in which microsurgical reconstruction is not possible. We aimed to determine the feasibility and safety of immediate keystone island flaps in managing various soft tissue defects in a variety of anatomical locations and to assess the influence of comorbidities on flap survival and surgical complications. Methods A hundred prospective immediate consecutive keystone flaps employed to cover skin defects in various sizes and anatomical locations, following wide local excision of malignant tumors and benign skin lesions, trauma, chronic ulcer and soft tissue infection were executed. Results Eighty eight (88%) of the keystone flap were of type IIA (direct closure with division of the deep fascia). Five flaps (5%) were considered as major complications, i.e. complete flap necrosis (one flap) and four partial flap necrosis over bony prominence as tibia and scalp. Soft tissue defect size, BMI over 30 kg/m 2 , active smoking, diabetes and hypertension had no correlation with complications. The employment of keystone flaps over joints at their flexion aspects (elbow, popliteal fossa), nape and Achilles have proved to maintain functionality. Conclusions It is recommend to use with caution keystone flaps to cover soft tissue defects over bony prominences (tibia and scalp) due to limited skin laxity and unique vascular anatomy in these areas. The keystone flap can be employed in the presence of comorbidities such BMI over 30 kg/m 2 , active smoking, diabetes and hypertension without the increased risk of complications. The keystone flap island flap is feasible and safe in managing various soft tissue defects, it maintains functionality over joints, is reproducible and obtains local tissue aesthetic similarities i.e. color and contour match, and might be included as a fundamental first-line immediate soft tissue reconstructive tool. Level of Evidence: Level IV, risk / prognostic study