After the induction of general anesthesia, the patient is moved to a prone position. The operative arm is placed in 90° of abduction and external rotation, with 30° of horizontal adduction. The upper arm, neck, and back all the way down to the posterior superior iliac spine should be prepped into the surgical field. Some surgeons may choose to prep the arm as a free extremity, but we have not found this to be necessary. We routinely use neuromonitoring in these cases, specifically for somatosensory evoked potential (SSEP), as patients can develop a brachial plexus palsy when reducing the scapula to the rib cage. If SSEP changes are noted intraoperatively, the scapular position can be altered to prevent this potential complication. Surgical landmarks should then be marked before the procedure, including the spinous processes of C7 to T4, the associated thoracic ribs, and the superior, medial, and lateral borders of the scapula (Figure 9-1). With the arm positioned as described previously, the spine of the scapula typically overlies the fourth rib and the scapula is rotated approximately 30° in relation to the spinous processes.

After surgical timeout, local anesthetic with epinephrine is utilized for both the scapular incision and the bone graft harvest site at the posterior iliac crest. An incision is performed over the posterior iliac crest, and dissection is carried down to the bone using electrocautery. A bone window is opened in the posterior iliac crest, and a large curette is used to harvest the autograft. It is necessary to obtain
both cancellous and cortical autograft from the bone graft harvest site. The authors cut the cortical bone into matchstick pieces for placement. Allograft bone chips and demineralized bone matrix may be mixed with the autograft to maximize the overall bone graft volume. An incision is then made along the medial border of the scapula, and subcutaneous flaps are raised to expose the trapezius over the entire dimension of the scapula. The lateral skin flap should be larger than the medial flap, which should not extend medial to the erector spinae. A split is then made in the trapezius to identify the medial border of the scapula (Figure 9-2). Detaching the trapezius will expose the rhomboid major and minor that lie deep to this plane. The supraspinatus and infraspinatus are then subperiosteally elevated with the use of a Cobb to expose the medial scapula. A towel clip is used to pull up on the scapula, essentially using this as a retractor, which puts tension on the rhomboids and levator scapulae muscles (Figure 9-3). These muscles are raised from the medial border of the scapula and tagged (Figure 9-4). It is critical to enter the scapulothoracic space between the serratus and the ribcage, instead of the interval between the serratus and the subscapularis. Visualization and palpation of the rib can be helpful to ensure that the correct space has been entered. Periosteal elevators and electrocautery may be used in tandem to elevate the subscapularis and serratus off the undersurface of the scapula.

Attention is then turned to the C7 spinous process, which then allows identification of the third through sixth ribs. Once these ribs are identified, a horizontal incision is made at the superior margin of each rib and the muscle is elevated off each rib subperiosteally in a circumferential fashion (Figure 9-5). Please recall the location of the intercostal neurovascular bundle at the inferior aspect of each rib and minimize injury to these structures. The parietal pleura must also be separated from the rib surface, in preparation for passage of FiberTape (Arthrex, Naples, FL). All soft tissue must be removed from the dorsal surface of the ribs and the ventral surface of the scapula to maximize the available surface area for fusion. The subscapularis and serratus muscles are excised using electrocautery to prevent interposition between the scapula and ribcage. In patients with FSHD these muscles tend to be atrophic without much bleeding. However, patients without FSHD may have a higher degree of vascularity in this area, requiring meticulous cauterization of these vessels. The dorsal surface of each rib is then lightly decorticated with a high-speed burr (Figure 9-6). A malleable retractor can be placed under each rib to protect the underlying lung tissue from the burr. The scapula is also decorticated on the ventral surface to promote an adequate bleeding bone surface for fusion.