**THORACIC PEDICLE SCREW CORRECTION OF ADULT IDIOPATHIC SCOLIOSIS
Paul B. Suh MD,
Jody L. Jones Ph.D.,
Joel A. Berquam MA,
Stephen A. Grubb MD
North Carolina Spine Center, Chapel Hill, North Carolina, USA

Thoracic pedicle screw fixation, as reported by Suk, gives superior correction of adolescent idiopathic scoliosis. Given the rigid nature of adult curves, pedicle screws should also demonstrate improved correction. We are unaware of such a series that utilizes pedicle screws throughout the thoracic spine. The purpose of this study is to report on the safety and corrective ability of pedicle screw fixation treating idiopathic scoliosis in an exclusively adult population. Twenty–four consecutive patients fulfilled the following entry criteria: diagnosis of idiopathic scoliosis, age 18 or older at surgery, no prior attempted fusion, and surgical construct using pedicle screws throughout the curve. Twenty–two (92%) were located with a minimum 2–year follow up. Mean follow up was 55.6 months (24–109). Nineteen were female. Mean age at surgery was 48.9 years (33–68). A total of 121 screws were placed from T2 – T12. Charts were reviewed for smoking status, health risks, operative data, and complications. Standing AP and lateral radiographs were analyzed pre–op, immediately post–op, and at final follow up.

Results
Pre
Post
Final
1º coronal curve
67.7 (40–100)
30.9 (6–55)
32.1 (9–50)
Apical Vert. Rot (Nash)
3.0 (2–4)
1.2 (0–2)
1.3 (1–2)
Apical Vert. Trans. (cm)
6.0 (2.5–10.4)
3.3 (0.6–7.6)
3.2 (0–7)
Coronal Plumb (cm)
1.6 (0–5.7)
2.0 (0–4.3)
1.7 (0–7.0)
T5–T12 sagittal
31.7 (3–78)
27.3 (10–60)
30.2 (5–58)
T12–sacrum sagittal
44 (–24–77)
52.6 (8–79)
55 (23–87)
Sagittal plumb (cm)
1.7 Ant
(3P–13.3A)
0.8 Ant
(5.5P–7.6A)
0.3 Ant (7.5P–5.7A)

Complications related to surgery included the following: one patient underwent immediate hardware revision secondary to loss of sacral fixation and another for coronal decompensation; two patients had dural tears; one patient had a wound dehiscence and another with superficial infection; one patient had a unilateral lumbar plexus traction neuropraxia that resolved in six months; four patients complained of hardware prominence with two electing hardware removal; one patient developed a compression fracture above her fusion; and one patient developed a pseudoarthrosis that was repaired. Medical complications included three patients with UTI, one patient with ARDS, and one patient with phlebitis. In sum, pedicle screw correction is a safe and effective method of correcting adult idiopathic scoliosis. No neurologic complications occurred as a result of screw placement. Due to the impressive corrective ability of this system, traction neuropraxias are possible. Coronal plane correction of 54% (30–80) is quite favorable in comparison to 42% correction reported by Kostuik using hooks. Sagittal plane correction showed maintenance of normal thoracic kyphosis with an increase of lumbar lordosis. Maintenance of correction with this method is also excellent with a 1.2º (8 improvement–14) average loss of coronal correction or 78% maintaining within 5º, of initial correction. The fusion rate for this series was 95%.

** The FDA has not cleared a drug and/or medical device for the use described in this presentation. (i.e., the drug or medical device is being discussed in an “off–label: use).