Cervical Spine Deformity

Indications, Considerations, and Surgical Outcomes

Samuel K. Cho, MD; Scott Safir, MD; Joseph M. Lombardi, MD; Jun S. Kim, MD

Disclosures

J Am Acad Orthop Surg. 2019;27(12):e555-e567. 

In This Article

Posterior

For posterior osteotomies, the patient is placed prone in a Jackson frame with maximum reverse Trendelenburg. The foot of the Jackson frame is placed in the lowest rung of bottom bracket, and the top of the frame is placed in the lowest rung of the top bracket. We recommend that the head is placed in Gardner-Wells tongs with bivector traction. Typically, 15 pounds of weight is applied on the inline traction at the beginning of the procedure. This weight is then placed on the extension rope at the conclusion of the osteotomy to aid in correction.

Blood pressure should be closely monitored by an arterial line or a well-placed blood pressure cuff. We prefer to keep the blood pressure relatively high (around 85 mm Hg) in the setting of myelopathy to ensure adequate spinal cord perfusion. Foley catheter placement is inserted to assess fluid balance. A warming blanket can prevent hypothermia and thereby coagulopathy. Hemostatic techniques (eg, hemostatic agents, intraoperative blood salvage) can be used to minimize blood loss.

A posterior midline incision is made. The raphe of the paraspinal muscles is identified and dissected to minimize blood loss during exposure. Previous posterior fusions with a mobile anterior column are amenable to correction with multiple Smith-Petersen osteotomies. We advise prophylactic foraminotomies to prevent nerve root entrapment with correction of the deformity. A tension band construct can be used by connecting available spinous processes with a cable. This is done to help maintain the extension of the spine and hold correction until rods can be placed and tightened into position.

The Simmons osteotomy was classically described as an opening wedge osteotomy of the lower CS that compromises the anterior column opening by hinging on the posterior column. This was inherently unstable, and subsequently, pedicle subtraction osteotomy (PSO) at C7 was developed as a means of shortening the posterior column while leaving the anterior column intact (Figure 3). We recommend that all available points of fixation be used. In cases where the occipital-cervical junction is mobile, we leave this joint alone. In cases where the occipital-cervical junction is autofused, good boney purchase can be made in the occipital protuberance. It is the author's preference to use C2 pedicle screws over laminar screws because they allow for collinear rod attachment. Pedicle or pars screws and laminar screws can be used together, that is, three or four points of fixation at C2, in case of poor bone quality resulting in poor fixation (Figure 8). The fusion should be extended down into the thoracic spine inferior to the level of the osteotomy. We recommend that if any question of bony purchase comes up, then the surgeon supplements the posterior fixation with anterior plate fixation at the level of the osteotomy. The technical details of a cervical PSO have been described in the literature.[33] Recently, some surgeons have found C8 or T1 nerve root palsy with profound intrinsic hand weakness after C7 or T1 PSO and recommend that the three-column osteotomy be performed at T2 or below (Figure 9).

Figure 9.

Rigid cervical kyphosis after laminectomy and fusion (A). The patient underwent C2-T4 revision fusion with T2 pedicle subtraction osteotomy to correct the deformity while avoiding C8 or T1 radiculopathy (B).

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....