Total Lumbar Disc Replacement Using the SB III Charite Prosthesis

53 Total Lumbar Disc Replacement Using the SB Charité Prosthesis

Fabien D. Bitan, Michael G. Neuwirth, and Norman Bloom

Goals of Surgical Treatment

The goal is to treat degenerative disc disease of the last two lumbar segments by insertion of a prosthetic device. This device has been designed to avoid intervertebral fusion and to restore a physiologic range of motion and an appropriate intervertebral height. The restoration of motion is expected to prevent gradual degeneration of the adjacent levels, and in the meantime to provide an eradication of the source of pain associated with foraminal stenosis.

Indications for Surgery

The main indication is a degenerative disc disease of one of the last two lumbar segments documented by discogram, magnetic resonance imaging (MRI), and/or computed axial tomography (CAT) scan. The discogram should unequivocally reproduce the patient’s pain. Studies should demonstrate the absence of significant nerve root or dural sac compression by either an extruded disc fragment of a degenerative stenosis. Also the posterior facets‘ arthritis should be minimal or absent. Symptoms associated with foraminal stenosis do not constitute contraindications, provided the compression is not due to a foraminal disc. The patient must document at least 6 months of serious conservative treatment.

Contraindications

1. Degenerative spinal stenosis

2. Extruded disc fragment responsible for nerve root compression

3. Severe posterior facet arthritis

4. Spondylolisthesis and scoliosis

5. Bone pathology (osteoporosis, osteomalacia, tumor, infection)

6. Previous spinal fusion in the lumbar spine

Advantages

1. Addresses the problem of disc disease by eradicating the source of pain

2. Avoids spinal fusion in selected cases

3. Protects the integrity of the adjacent levels

4. Restores normal alignment (lordosis) and disc height

Disadvantages

1. Requires a anterior abdominal approach.

2. Indications are limited to selected patients.

3. Experience is still limited, and 10-year follow-up studies include only a small number of patients.

Procedure

Positioning

The table used must be radiolucent because intraoperative fluoroscopy is required. The patient is positioned supine, the pelvis located at the break of the table. Anteroposterior and lateral views should be easily obtained intraoperatively.

Approach

The approach is anterior retroperitoneal. A transperitoneal approach may be acceptable if necessary. The incision can be:

1. Horizontal (the Pfannenstiel type).

2. Vertical medial opening the linea alba.

3. Pararectal, approaching the retroperitoneal space lateral to the left rectus muscle (Fig. 53–1).

4. The retroperitoneal space is gradually developed and the vessels are exposed (Fig. 53–2).

5. For an L5-S1 level, the disc is exposed in the bifurcation of the vessels. Great care is taken, especially in men to avoid any electrical cautery of the anterior aspect of the disc that could lead to postoperative retrograde ejaculation. The dissection is carried on using sponge sticks, and the presacral vessels are ligated and cut. The two iliac veins are the main dangers. They are gradually separated from the disc and retracted laterally. Some adherences sometimes make this dissection difficult. The adjacent portion of the vertebral bodies is also exposed.

6. For the L4-L5 level the dissection is carried on from the left side of the vessels, which are gradually retracted to the right side. Some collateral vessels might be ligated and cut, such as the lumbar ascending vein and the left L4 segmental. The dissection to adequately expose the disc is a little more difficult than at the L5-S1 level.

7. When the disc is sufficiently exposed, retractors are used to keep the vessels away from the instruments. Specific Homans retractors have been designed, but any other mean is acceptable, such as Steinmann pins or hand-held retractors (Wiley) (Fig. 53–3).

Exposure Secrets

1. The exposure should be wide enough to provide a clear field to safely insert the prosthesis. With experience the incision becomes smaller and smaller.

2. One should not hesitate using a vertical incision if necessary.

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