Double Thoracic Curve Research Articles

Analysis of the upper thoracic curve in surgically treated idiopathic scoliosis. A new concept of the double thoracic curve pattern.

The authors reviewed 246 idiopathic scoliosis patients with the upper thoracic curve of more than 20 degrees. Group I (138 patients) had positive T1 tilt and a spinal fusion which was extended over both the upper and lower thoracic curve with the diagnosis of double thoracic curve. Group II (43 patients) had positive T1 tilt, but the fusion was limited to the lower thoracic curve. Group III (65 patients) had negative or neutral T1 tilt and the fusion was limited to the lower thoracic curve. The average age at operation was 15.9 years (range, 11.2-35 years) and the average length of follow-up was 4.8 years (range, 2-29.5 years). Positive T1 tilt did not correlate well with left shoulder elevation contrary to previous reports. The upper thoracic curve was more rigid than the lower curve in all groups and the lumbar curve was significantly more flexible than the upper and lower thoracic curves in all groups (P < 0.05). No significant difference in the flexibility of the upper thoracic curve was found between the groups regardless of the direction of T1 tilt. When only the lower curve was fused (groups II and III), progression of the upper thoracic curve was less than 5 degrees, and spontaneous correction of the unfused upper curve occurred in the majority of the cases following the supine bending study. Correction and fusion on the lower curve (groups II and III) aggravated shoulder imbalance of all patients with left shoulder elevation. Based on the findings of this study, the authors proposed that the diagnosis of idiopathic double thoracic patterns should be limited to those patterns which require fusion of both the upper and lower curves. This pattern of idiopathic scoliosis includes double thoracic curves with left shoulder elevation and/or a rigid upper thoracic curve.

Outcome of Wisconsin instrumentation in idiopathic scoliosis. Minimum 5-year follow-up.

Wisconsin segmental spinal instrumentation was developed by Drummond et al to provide rigid fixation for correction of spinal deformities without the risk of neurologic injury associated with the passage of sublaminar wires. Up to this point, there have been no outcome studies with follow-up of longer than 2 years. Thirty-five patients with adolescent idiopathic scoliosis treated by the Wisconsin procedure between 1984 and 1987 were reviewed by radiographs, physical examination, and an outcome scale. Minimum length of follow-up was 5 years with an average of 6.3 years. Curves were corrected from a mean of 59 degrees preoperatively to 32 degrees postoperatively (46%), and 36 degrees at final follow-up (39%). Wisconsin segmental spinal instrumentation did not increase thoracic kyphosis. There was evidence of slight lumbar flattening in long fusions. According to the criteria described, 92% had a successful outcome. Complications of the procedure included two wound infections (one superficial, one deep), one rod displacement, and two wire breakages. No pseudarthroses or neurologic complications were identified in this series. Wisconsin segmental spinal instrumentation safely achieves the objectives of partial correction, arthrodesis, and early return to function. The technique may still have a role, particularly in the thoracic region, in selective thoracic fusion of King type II curves, rigid curves, and double thoracic curves.

Surgical treatment of adolescent idiopathic scoliosis. A comparative analysis.

Three hundred and fifty-two patients had a one-stage posterior spinal arthrodesis between 1960 and 1984 using one of four types of instrumentation: a Harrington distraction rod, Harrington distraction and compression rods, Harrington distraction and compression rods with a device for transverse traction, and a Harrington distraction rod with sublaminar wires. All of the patients were female (age-range, eleven to nineteen years), and all had idiopathic scoliosis with a single right or double thoracic curve. The minimum length of follow-up was two years. No significant difference was found among the four groups relative to the amount of correction that was obtained at operation or maintained two years after operation. An average of 13.5 per cent of correction was lost during follow-up in the patients who were treated with postoperative immobilization, and an average of 27 per cent was lost in the patients who were treated with sublaminar wires without immobilization. The use of a straight Harrington rod reduced normal thoracic kyphosis, the addition of a compression rod corrected hyperkyphosis, and the use of a rod with sublaminar wires corrected thoracic hypokyphosis or thoracic lordosis.

The Role of Harrington Instrumentation and Posterior Spine Fusion in the Management of Adolescent Idiopathic Scoliosis

The Harrington instrumentation system was the first widely used, internationally accepted internal fixation system for the correction of idiopathic scoliosis when combined with a spinal arthrodesis. It has been generally available to the orthopedic surgeon for more than 25 years, and therefore its capabilities and limitations have been identified through this long experience. Its implantation requires minimal invasion of the spinal canal and is associated with a low (less than 0.5 per cent) incidence of neurologic complications. It provides predictable correction of spinal deformity with little subsequent loss of correction. When compared with other newer, more complex internal fixation systems for spinal deformities, the Harrington system has a shorter, less difficult "learning curve"; requires less operating time and blood loss to insert; implants a smaller mass of metal; and in some cases costs substantially less for the implant system. The Harrington system has an extremely low incidence of hook dislodgment and pseudoarthrosis formation in single thoracic curves, being reported as near zero for these curves in two recently published series. Conversely, there are some disadvantages to the Harrington system when compared with other types of fixation. It has limited ability to provide sagittal plane control. It does not effectively and predictably derotate the spine. A recent study showed that at an average of 4 years postoperatively, nearly two thirds of the patients had an actual increase in their rib prominence. The pseudoarthrosis rate is high, up to 4 per cent, in the thoracolumbar and lumbar spine. Hook dislodgment approaches 3 per cent when used below the thoracic region. Another disadvantage is the necessity for postoperative external support. As a result, the Harrington system remains an excellent means of treating single and double thoracic idiopathic curves in a safe and predictable manner, while admittedly having limited derotation and sagittal plane control. Other systems that are more sophisticated at segmental fixation of the spine appear to be more appropriate for scoliotic deformities requiring fusion of the thoracolumbar or lumbar spine and those associated with significant sagittal plane deformities.

Spinal Deformities in Patients with Charcot-Marie-Tooth Disease

Twelve patients with Charcot-Marie-Tooth disease and scoliosis, seven girls and five boys (average age at presentation, ten years), were investigated for an average of 49 months. All but one of the patients were ambulatory. The curve patterns were thoracic in two, thoracolumbar in four, and double thoracic and lumbar curves in six. There was an associated kyphosis in six. Three patients had brace treatment with curve control in two. Four patients underwent posterior spinal fusion with Harrington instrumentation, one with segmental sublaminar wires. Post-operative management consisted of a cast for one patient and a brace for the remaining three. Follow-up period in the surgical patients ranged from 19 to 45 months (average, 32 months). One patient had a superior mesenteric artery syndrome and two had a pseudarthrosis.