Thomas G. Lowe

Goals of Treatment

1. To balance and provide correction and stabilization of kyphosis of the spine, and maintain maximum flexibility.

2. Final correction of thoracic kyphosis should be between 40 and 60 degrees.

3. Lumbar lordosis should be 20 to 30 degrees greater than thoracic kyphosis.

4. The sagittal plumb line should include the bodies of T1, T12, and the sacral promontory.

Diagnosis

The diagnosis is based on clinical examination and radiographic criteria. Clinical examination is based on the presence of a sharp, structural kyphosis of the thoracic or thoracolumbar spine, which is most visible in the forward-bending position (Adam’s test). It is frequently associated with a flexible kyphosis of the cervicothoracic junction and a hyperlordosis of the lumbar spine. Tight hamstrings are also commonly found.

Radiographic criteria of Scheuermann’s disease are based on the criteria of Sorenson, which include wedging of greater than 5 degrees of three contiguous vertebrae. Commonly associated findings include disc narrowing, end-plate irregularity, and Schmorl’s nodes. Radiographs should include standing 36-inch posteroanterior (PA) and lateral as well as a hyperextension lateral utilizing a bolster over the apex of the kyphotic deformity.

Indications for Surgery

1. Skeletally mature patients with recalcitrant thoracic or thoracolumbar back pain, severe cosmetic deformity, and occasionally pulmonary compromise.

2. The above indications would generally include patients with thoracic kyphosis (T1-T12) greater than 80 degrees or patients with thoracolumbar kyphosis (T10-L2) greater than 50 degrees.

Contraindications

1. Patients with severe osteopenia where adequate fixation may not be achievable

2. Patients with abnormal PFTs who may not tolerate a thoracotomy

Advantages

1. It allows for preservation of segmental vessels, which contribute to the blood supply of the spinal cord.

2. Includes the use of anterior structural support (structural graft or cages) at the thoracolumbar junction, which helps to preserve normal sagittal profile and to prevent pseudarthrosis and rod breakage postoperatively.

3. Provides for rigid internal fixation, which under normal circumstances eliminates the need for bracing.

Disadvantages

1. The need for a combined anterior-posterior approach as opposed to a posterior alone approach, which has a higher failure rate. The use of a thoracoscopic anterior release and fusion may offer some advantages in the future, but at the present time this requires a longer operative time and does not shorten the hospital stay.

2. Increased risk of complications associated with need for a thoracotomy (incisional pain, atelectasis, pneumothorax, or pneumonitis).

Procedure

Anterior Release and Fusion

The thoracotomy is usually performed on the right side (to avoid the vena cava) at the uppermost level of the release and fusion. This part of the procedure may be eliminated in skeletally immature individuals where remaining anterior growth will often fill in anterior column deficiencies according to Wolf’s law, similarly to what is seen with brace treatment.

Selection of anterior fusion levels: Anterior fusion levels should include all “fixed” levels on the hyperextension lateral radiograph along with all thoracolumbar levels extending to the distal end of the anticipated posterior instrumentation and fusion levels.

Use of structural grafts or cages: Structural support should be used at all levels below T10 to preserve the sagittal profile of the spine and help prevent rod breakage and pseudarthrosis. All other levels should be packed with morselized rib graft.