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Page 6 of 12 Mitchell et al. Plast Aesthet Res 2023;10:35 https://dx.doi.org/10.20517/2347-9264.2023.14

Elbow flexion
The main function of the first FFMT is to maximize elbow flexion. The most common free muscle transfers
involve the gracilis. This superficial muscle lies in the medial aspect of the thigh and is supplied by a branch
from the profunda femoris, the medial femoral circumflex, and innervated by the obturator nerve. To
harvest, the muscle must be released from its origin on the pubic symphysis and its insertion at the pes
anserine. The medial femoral circumflex vessels and the obturator nerve can both be harvested at a length of
up to 10 cm, which will facilitate easy anastomosis and coaptation at the transfer site. A skin paddle is often
taken with the FFMT for postoperative monitoring [Figure 3]. Following the harvest of the gracilis muscle
from the medial thigh, the proximal attachment to the clavicle is secured with suture anchors. This first
FFMT is routed beneath the mobile wad proximal to the elbow joint and sutured to the extensor digitorum
communis (EDC) tendon, allowing for elbow flexion and digit extension. The innervation of the gracilis
muscle is accomplished by direct coaptation of the gracilis obturator nerve to the SAN. In addition, vascular
microsurgical anastomoses complete a reliable artery and vein. These can include the thoracodorsal,
transverse cervical, or thoracoacromial pedicles based on ease of reach and surgeon preference [Figure 4].

In the context of double FFMT, Doi showed good to excellent restoration of elbow flexion in 96% of
patients . Furthermore, the work by Maldonado et al. further demonstrated FFMT was able to restore M3/
[35]
[37]
M4 elbow function in a greater percentage of patients than ICN to MCN transfers (68% vs. 42%) . It is
important to inform patients that similar to extra-plexal nerve transfers, reinnervation and initial functional
[39]
return can be expected within six to nine months postoperatively .

Shoulder stabilization/abduction
Restoration of shoulder stability is once again prioritized in this reconstructive method. In the context of
double FFMTs, traditional extra-plexal donors to the SSN and axillary nerve (i.e., the SAN and ICN) are
being utilized for innervation of the free muscle flaps. With no other good donors for the SSN and axillary,
tendon transfers have been historically performed. However, poorly reported outcomes have led to shoulder
arthrodesis becoming a more universally accepted and implemented procedure [7,40] . When prepared with a
subacromial corticocancellous graft, one study reported successful glenohumeral fusion rates as high as
[41]
94%. Following fusion, scapulothoracic abduction and arc of rotation averaged 57 and 50 degrees .

Elbow extension
To restore elbow extension, the ICN 3-4 to triceps motor transfer is again selected as in the previously
described purely extra-plexal nerve transfer reconstructive method. While recent results for this transfer are
promising, it is also important to note that results for these transfers are highly contingent on patient BMI.
Several analyses have demonstrated that elevated BMI is inversely related to obtaining functional results [42,43] .

Hand function
In the second stage of the technique, an additional FFMT from the contralateral gracilis is attached to the
second and third ribs through a series of drill holes. This tendon is tunneled along the medial arm, beneath
the lacertus fibrosus, and deep to the pronator teres creating a pulley during muscle contraction. A second
forearm incision is made, and the terminal tendon is woven into the flexor digitorum profundus and flexor
pollicis longus muscle belly, providing rudimentary grasp capabilities. Options for vascular anastomosis
similarly include the regional vessels listed for the first FFMT, while innervation may be provided by ICN
5-6. Utilizing this approach, Doi published results where 65% of his patients achieved > 30 degrees of active
finger arc of motion through this second FFMT technique .
[44]