As with the chest and shoulders, the arms are often relatively straightforward to close, as for all but the largest defects ample tissue is generally available for recruitment. When conceptualizing closure options on the arms, the anatomic location—the upper arm, inner arm, flexor versus extensor surface, and the degree of atrophy shoulder all be considered.
Classic approaches to closures on the extremities often advocate for attempting closure along the long axis of the extremity. While this approach may be reasonable for large defects, many smaller defects benefit from a closure either perpendicular to the long axis of the arm (ie, horizontally oriented) or on a diagonal. In either event, taking the time preoperatively to assess the degree of skin laxity and its direction is critical in designing the ideal closure. Sometimes, this orientation falls along the relaxed skin tension lines or Langer’s lines, but this is not always the case, as closures must consider not only minimizing the tension across the wound but also minimizing the appearance of standing cones or dog ears.
On convex surfaces, such as the outer arms (as well as others, such as the forehead), it may be difficult to ensure a completely flat contour in the immediate postoperative period, though a significant degree of standing cone blunting often occurs in the postoperative period.
Closures along the long axis of the upper arm and forearm similarly may result in a more profound dog-ear appearance, as the central portions of the closure are tightened relative to the surrounding skin leading to an exaggerated standing cone appearance at the apices. Therefore, when possible, horizontally oriented closures may be preferable in these anatomic locations.
A major challenge relating particularly to forearm closures is the profound atrophy present in this sun-exposed area. Even closures under minimal tension must contend with the challenges of suture placement in atrophic areas, as the tendency toward suture material tear through may be a problem even in the absence of marked tension. Percutaneous approaches, horizontally oriented techniques, and the use of tape bolsters may help in effectively closing such atrophic areas.
For modest-tension closures on the upper arms, 3-0 or 4-0 absorbable suture material is generally adequate, while most forearm closures may be accomplished with 4-0 absorbable suture. Rarely, high-tension closures, such as those effected after a large melanoma resection on the muscular upper arm of a young patient, may benefit from 2-0 absorbable suture.
Transepidermal sutures, if used, are usually 5-0 nonabsorbable suture, though 5-0 absorbable monofilament suture may also be used for a subcuticular closure on the upper arm. In atrophic skin, subcuticular approaches are best avoided, as there is little dermis available to grasp and the small volume of surrounding skin means that suture absorption may be delayed.