THE LATISSIMUS DORSI MUSCULOCUTANEOUS FLAP USED TO

RESURFACE A DEFECT ON THE UPPER ARM

EXTENSION TO THE ELBOW

By A. I?. LANDRA, MS., F.R.C.S. P.O. Box 56854, Nairobi, Kenya

AND RESTORE

THE latissimus dorsi musculocutaneous flap (LDMF) is now recognised as one of the safe musculocutaneous flaps. The following example of its use may be of interest.

CASE REPORT

A 33-year-old man sustained multiple injuries when his car was blown up by a land mine in Southern Ethiopia. The particular injury with which this account is concerned was a com- pound cornminuted fracture of the left elbow (Fig. I) with loss of skin and muscle on the posterior aspect of the joint and the lower third of the upper arm. He was referred to Nairobi but his general condition was such that over 2 weeks elapsed before the elbow region could be debrided and the fractures stabilised (Fig. 2). The area of skin loss over the lower third of the upper arm and the elbow joint was about IO x 8 cm. The elbow joint was exposed posteriorly and the distal third of the triceps muscle and its tendon were missing (Fig. 3). Fortunately the radial nerve was intact.

A further episode of infection and some further necrosis of skin and muscle occurred but I month after his injury, the LDMF was designed (Fig. 4) and partly delayed by dividing the interdigitations of the muscle with the external oblique muscle and also the arterial supply to the latissimus dorsi from the intercostal arteries (Fig. 5).

FIG. I. The fracture.

FIG. 2. The fracture reduced.

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276 BRITISH JOURNAL OF PLASTIC SURGERY

FIG. 3. The soft tissue loss.

FIG. 4. The outline of the flap at the time of the delay.

FIG. 5. The delay.

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FIG. 6. The skin island transposed with the muscle.

FIG. 7. The transposed musculocutaneous flap.

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THE LATISSIMUS DORSI MUSCULOCUTANEOUS FLAP 277

FIG. 8. Sixteen days after the transfer.

The flap was completely elevated and transposed on its neurovascular pedicle IO days later (Fig. 6). The lower origin of the muscle which is wide and fan-shaped but thin was rolled upon itself so that it fitted the defect and then sutured firmly to the olecranon with 3/0

Nylon with the elbow partially flexed (Fig. 7). The defect on the back was spht skin grafted. The flap survived completely. A small sinus developed below the medial condyle related

to the internal fixation ironmongery. This will be explored when bony union is complete. Eighteen days after the transfer, although unable to walk because of a concomitant fractured pelvis, he discharged himself from hospital because he had urgent business to attend to in the area where he had been blown up! At this time the flap was well healed in position (Fig. 8). He could already bend his arm and keep it partially extended against gravity.

Discussion

In this case the length of the flap from the axis of rotation in the axilla was 42 cm. It extended distally 2 cm below the iliac crest. The skin overlying the muscle extended 4 cm beyond the most distal iliac muscle fibres.

If the muscle is to be used as a motor extensor to the upper arm the root origin of its nerve, the thoraco-dorsal, is the same as the radial nerve’s, namely C7 and C8. It is interesting to note that embryologically the latissimus dorsi is developed in the extensor compartment of the upper limb and migrates to its wide attachment on the trunk taking its nerve with it. In this case the radial nerve and the proximal two-thirds of the triceps were intact and the latissimus dorsi was only bridging the gap and providing the insertion on the olecranon.

If the patient has a pelvic or hip injury on the same side of the contemplated LDMF, it is worth remembering that by transposing the muscle one will impair the pelvis’ stability on that side.

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