Reconstruction of posterior trunk defects

Abstract

The posterior trunk roughly encompasses the upper back from the shoulders to the lumbar area above the iliac crests. Long-term outcomes in the treatment of defects of the spine and bony thorax have been proved superior if flaps were used. Many local muscle and fasciocutaneous flaps are available alternatives. A guideline, patterned according to arbitrary anatomic territories of the back, is suggested as a starting point for the selection of appropriate primary and secondary flap options. Depending on flap availability, the latissimus dorsi and trapezius muscles are the workhorse flaps for the upper back, whereas perforator flaps have become a useful alternative for the lumbar region in lieu of free flaps.

Keywords: Posterior trunk; back; latissimus dorsi; perforator flaps; trapezius muscles.

Figure 1

The posterior trunk can be divided into four arbitrary anatomic territories, basically according to available flap options, (A) with the primary selection being the workhorse alternative or (B) the secondary choice a reasonable backup option.

Figure 2

(A) Exposed vertebrae after cervical fusion. (B) Proposed lower trapezius musculocutaneous flap, with skin island extending slightly beyond palpable distal margin of muscle in this asthenic individual (circles denote protruding thoracic spinous processes). (C) Elevated flap rotated onto defect, prior to tunneling under intervening skin bridge. (D) Successful coverage 6 months later without further sequelae.

Figure 3

(A) Dehisced thoracic wound after spinal fusion. (B) Exposed orthopedic hardware after the requisite debridement. (C) Orthograde latissimus dorsi muscle flap covering hardware. (D) Direct skin approximation then could suffice to achieve wound healing.

Figure 4

(A) Exposed midthoracic vertebrae after resolution of infected cyst of uncertain cause. (B) Lateral back skin paddle on “reverse” pattern latissimus dorsi musculocutaneous flap. (C) Skin transferred into defect. (D) The healed back later that month.

Figure 5

(A) Lumbar pressure sore. (B) Transverse oriented propeller flap eccentrically designed about lumbar artery perforators, “x,” as identified with audible Doppler. Distance from right side of debrided pressure sore to perforator location or “hub” of flap equals distance from hub to left tip of flap. (C) Elevated flap with identified perforator (on microgrid) prior to rotation. (D) Flap rotated into defect about perforator “hub,” with right side of flap positioned to allow tension-free closure of part of donor site. (E) Coverage was achieved, with rest of donor site closed primarily.

Figure 6

(A) Extensive lumbosacral radiation ulcer, with skin paddle designed over left latissimus dorsi muscle. (B) Latissimus dorsi musculocutaneous free flap, with pedicle extended by long vein grafts (above) connected to the thoracodorsal vessels serving as the recipient site. (C) Successful wound coverage, but donor site of left upper back required extensive skin grafting.