Adolescent/adult scoliosis: Rib prominence is associated with rigid, rotated, decompensated thoracic and double major curves. In these patients, a convex thoracoplasty may be necessary if it is not possible to fully derotate the curves during posterior instrumented spinal fusion. An example would be a rib hump greater than 4 cm, rib angle greater than 15 degrees, and curve flexibility less than 50%.

Rib hump deformity is a common finding in the three-dimensional evolution of adolescent idiopathic scoliosis. Albeit a cosmetic concern, rib hump deformity is a major source of patients’ postoperative dissatisfaction if not corrected to their expectations. The effect of thoracoplasty on pulmonary function has been a topic of interest, with varying reports of clinical significance.

Rib prominence associated with a compensated curve, where posterior spinal fusion is not necessary or a previously fused curve is present: the indication may be poor appearance or discomfort when sitting in a chair or leaning against a wall.

To increase flexibility of the curve: concave rib osteotomies and elevation of the concavity dorsally out of the chest may be present.

To procure autologous bone graft for fusion

Measurement of angle of thoracic rotation (ATR) by inclinometer

Pulmonary function testing

Radiographs: full-length posteroanterior, lateral, bending, and Stagnara views

Clinical photos of the patient

Ribs/transverse process: parts of the ribs corresponding to vertebrae in the structural curve are resected.

Thoracolumbar fascia

Serratus posterior

Latissimus dorsi

Intercostal neurovascular bundle

Pleura

The patient is positioned prone on a Jackson table in the standard manner for a posterior spinal fusion. Preparation and draping with wide lateral margins is advised to better assess and visualize the rib prominence.

Single incision technique

For concave rib osteotomies to increase scoliotic curve flexibility, the steps are similar.

A small protective shell is applied over the rib resection area if desired. This shell helps avoid a postoperative flail chest and minimizes the motion of the cut ribs over the pleura, and it may decrease the accumulation of a pleural effusion. (This is optional.)

Thoracoplasty may increase pain or mildly prolong the postoperative course following spinal fusion with instrumentation.

To allow mobilization, aggressive pulmonary toileting and chest physiotherapy is necessary, with adequate pain control.

Patients with moderate or severe pulmonary symptoms are monitored with semierect radiographs for 2 to 3 days. If a significant amount of pleural fluid accumulates and the patient is symptomatic, a thoracocentesis is performed; if fluid accumulation occurs a second time, a chest tube is considered.

For small pleural effusions, oral or intravenous furosemide may be used to diurese the patient.

A consistent decrease in pulmonary function is observed in the early postoperative period, which mandates proper patient selection. A decline of forced vital capacity (FVC) of 22%, forced expiratory volume in 1 second (FEV-1) of 24%, and total lung capacity of 25% were found in the first 6 months. Gradual improvement occurs over the next 3 years. Patients with less than 60% of predicted values should be cautiously approached as candidates for thoracoplasty.

In 2007, Newton and colleagues set out to determine what factors could predict 2-year postoperative pulmonary function tests (PFTs) in patients with adolescent idiopathic scoliosis. In their prospective study, they found thoracoplasty to result in a significant PFT reduction. Their cohort included 107 patients who underwent thoracoplasty, out of 254 total patients. Of these 107, 51 were posterior spinal fusion (PSF) with thoracoplasty, and 56 were anterior approach with thoracoplasty. Fifty-four percent of thoracoplasty patients saw a 15% or greater decrease in their predicted PFTs. The decrease in PFTs was greater in the group who underwent anterior surgery.

In 2008, Suk and associates retrospectively reviewed outcomes of thoracoplasty in the setting of thoracic adolescent idiopathic scoliosis corrected with pedicle screw instrumentation. Three surgical groups were compared, looking specifically at deformity correction, the effects on pulmonary function tests, and complications. The groups were representative of no thoracoplasty, thoracoplasty without direct vertebral rotation, and thoracoplasty with direct vertebral rotation.

Suk demonstrated a statistically significant difference in the correction of rib hump deformities across the three surgical groups. Thoracoplasty with direct vertebral correction offered the greatest amount of correction. Additionally, there were no statistically significant decreases, nor differences between surgical groups regarding pulmonary function testing at the time of most recent follow-up (specifically measuring FVC and FEV-1). Suk recognized the failure to include a group with direct vertebral rotation alone and states this was because the population numbers were too small to include in statistical analyses.

Greggi and colleagues retrospectively reviewed outcomes of patients treated by posterior spinal fusion compared with those who underwent posterior spinal fusion with thoracoplasty. Their cohorts consisted of 40 patients each, with the majority of curves classified as Lenke 1 in both groups.

They found that PSF with thoracoplasty resulted in a significantly better main thoracic curve reduction, in addition to the absolute rib hump correction and the percent reduction of rib hump. Scoliosis Research Society scores were used to assess patient satisfaction, and no statistically significant differences were found between the groups, indicating thoracoplasty did not necessarily result in a more satisfactory cosmetic improvement than PSF alone. Regarding PFTs, there were no significant differences between the groups preoperatively and postoperatively. However, within each group, FVC and FEV-1 showed a statistically significant improvement postoperatively at the latest follow-up.

Newton demonstrated that curves greater than 50 degrees in magnitude had a high risk of restrictive lung disease. None of the patients in the Suk or Greggi study suffered restrictive lung disease preoperatively. Thus the data they have presented demonstrating improvements in pulmonary function postoperatively, although statistically significant, may not be clinically significant.

In summary, thoracoplasty does improve appearance and patient satisfaction in those patients undergoing surgery for scoliosis but increases operative time, blood loss, and may have a cost to pulmonary function and patient comfort.