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Mitchell et al. Plast Aesthet Res 2023;10:35 https://dx.doi.org/10.20517/2347-9264.2023.14 Page 5 of 12

carpometacarpal joint should be fused in approximately 35 of palmar abduction, 30 of radial abduction and
15 of pronation. The bone graft can be utilized to aid in fusion which can be achieved by a variety of
methods including plates, compression screws, staples or wires [24-26] . Similarly, the thumb interphalangeal
joint can be fused with several techniques, including tension bands, staples or compression screws across
the decorticated articular surfaces. To optimize function, the thumb should be flexed between 15 and 35.

Several studies have shown exceptional fusion rates at each joint. Furthermore, following a patient self-
assessment, 97% of polled PBPI patients were satisfied with wrist stability following fusion and 89% stated
[27]
the fusion enhanced upper extremity function . A similar study demonstrated subjective patient
assessments of disability of the arm, shoulder, and hand (DASH) scores improved from 51 to 23, which was
a statistically significant improvement. Additionally, following fusions, patients reported improved
[26]
appearance, function, hygiene, and satisfaction .
Hand sensation
The intercostobrachial nerve (ICBN) is a stout sensory nerve providing cutaneous innervation to the axilla
and proximal medial arm. This nerve can be utilized as a nerve transfer to the lateral cord contribution to
median nerve (LCMN) to restore hand sensation. To accomplish this, the same submammary incision used
to harvest ICN nerves is extended posteriorly along the lateral border of the pectoralis major. In this region
within the second intercostal space, piercing superficially through the serratus anterior, the ICBN can be
found traveling within subcutaneous fat into the axillary region. The dissection is carried through its
terminal axillary branches, where the ICBN is released. The axillary incision is extended until it is in
continuity with upper medial arm dissection. The pectoralis major is retracted superiorly, and the pectoralis
minor is released off the coracoid as necessary to expose the infraclavicular plexus. The LCMN is identified
at its origin and transected. The ICBN is then mobilized with as much length as possible and redirected into
the infraclavicular space for direct coaptation .
[28]
Initial data for this technique has demonstrated impressive results, as 91% of patients registered the return
of hand sensation . This is a notable improvement to sensory rami of ICN or supraclavicular nerve
[28]
reconstruction techniques that afford limited sensation recovery [29-33] . Anatomic data shows that at only
1,000 nerve fibers, and a diameter of 2.7 mm, the ICBN is much smaller than the average 5,300 nerve fibers
and 3.7 mm diameter of its target LCMN. However, with more than double the average axon count of the
sensory rami of ICN, the ICBN is considered by many to be a superior choice to ICN, even when
incorporating two donor ICN .
[29]

Graftable C5
With an available C5 nerve root, sural nerve grafting to the anterior division of the brachial plexus upper
trunk is recommended. This will provide innervation to the MCN and median nerve, aiming to restore
elbow flexion, rudimentary grasp, and hand sensation. As above, restoration of shoulder stability will
[7]
require a SAN to SSN transfer and elbow extension will require ICN 3-4 to triceps transfer .
Method 2: double free functional muscle transfer
Initially described by Doi out of Yamaguchi, Japan in the late 1990s, the use of the gracilis FFMT has slowly
gained popularity [34,35] . Some authors have demonstrated greater improvements in elbow function over
extra-plexal nerve transfers and this reconstructive technique has the benefit of providing secondary
improvements to hand function [36-38] .