Of the 59 patients, 13 were men and 46 were women. Thirty-five patients were diagnosed with adolescent idiopathic scoliosis (AIS), six with neuromuscular scoliosis (including three with cerebral palsy, two with syringomyelia, one with Arnold–Chiari malformation, and one with spinal muscular atrophy), 15 with syndromic scoliosis (including seven with Marfan syndrome, four with neurofibromatosis, two with Turner syndrome, one with Hunter syndrome, and one with Rett syndrome), and two with congenital scoliosis (including one with hemivertebra and one with unsegmented bar). The mean age of the patients was 15.2 (range, 5–36) years, mean height, 149.7 (range, 99.3–183.8) cm, mean weight, 44.3 (range, 13.5–99.8) kg, and mean BMI, 19.1 (range, 12.5–36.9). The curve apex was thoracic in 48 cases, thoracolumbar in four, and lumbar in six. The mean TBWR was 0.44 (range, 0.23–0.78), mean Cobb angle was 96.9° (range, 62.0°–138.0°), and mean sagittal angle was 26.5° (range, −34.0°–93.0°). The intraobserver measuring error of the Cobb angle was 0.896, and the interobserver error was 0.813. Furthermore, 10 patients underwent halo-gravity traction, 43 underwent halo-pelvic traction, and six underwent halo-femoral traction. The mean traction duration was 3.1 (range, 1–7) weeks.
The mean Cobb angle on the bending radiographs was 72.9° (range, 40°–108°) (24.8% correction rate, range, 0%–52.4%), and the mean Cobb angle after applying traction was 63.3° (range, 42°–102°) (34.4% correction rate, range, 8.1%–63.3%). In total, 54 patients underwent posterior fusion after HT; however, in two patients, HT was reapplied because it was ineffective. One of these patients underwent posterior column osteotomy, and the other underwent anterior column release and then had HT reapplied before the final operation. Five patients underwent growing rod insertion. In 52 patients (except the two patients who underwent reapplied HT) who underwent posterior fusion surgery, the mean postoperative Cobb angle was 32.5° (range, 13.0°–66.0°), and the correction rate was 65.9% (range, 35.2%–87.7%). The mean postoperative sagittal angle was 22.2° (range, −29.0°–47.0°), and the correction rate was 16.29% (range, −30.2%–45.4%) (Figure 2A–D). The mean postoperative Cobb angle at 2 years' follow-up was 39.4° (range 21.3°–73.5°), and the correction rate was 59.3% (range, 30.5%–79.8%). The mean postoperative sagittal angle at 2 years' follow-up was 23.5° (range −30.5° to 49°), and the correction rate was 11.3% (range, −28.6% to 42.8%) (Table 1).
Radiographic improvement in the coronal curve. (A) Pre-traction, (B) Post-bending, (C) Post-traction, and (D) Postoperative.
The mean correction rate after applying HT was 28.2% in the first week (mean Cobb angle: 71.9°, range, 35.1°–116.8°) in 59 patients and 34.0% in the second week of traction (mean Cobb angle: 66.1°, range, 32.5°–103.2°) in 58 patients. In the third week of traction, the mean correction rate was 33.8%, and the mean Cobb angle was 67.5° (range, 33.5°–101.7°) in 41 patients. The mean correction rate and Cobb angle were 32.2% and 69.9° (range, 40.3°–97.4°), respectively, in 13 patients in the fourth week of traction. A statistically significant difference was noted in the correction rate up to the first week and the second week (first week, P < 0.001; second weeks, P < 0.001; third weeks, P = 0.244; and fourth weeks, P = 0.082) (Table 2).
We divided the patients into two groups: group A (PTC ≒ PBC) and group B (PBC < PTC). There were 30 patients in group A and 29 patients in group B. The mean age of group A was 15.6 (range, 6–28) years, mean height 154.9 (range, 99.3–183.8) cm, mean weight 49.1 (range, 13.5–74.5) kg, and mean BMI 20.0 (range, 13.7–26.7) kg/m2. The types of diseases included AIS in 18 cases, NM scoliosis in four, congenital scoliosis in one, and syndrome-associated scoliosis in seven. The traction types encountered included gravity traction in seven cases and pelvic traction in 23; there were no cases of femoral traction. The mean traction period was 3.1 (range, 2–5) weeks. The mean age of group B was 14.8 (range, 9–36) years, mean height was 144.4 (range, 103.3–173.0) cm, mean body weight was 39.4 (range, 17.0–99.8) kg, and mean BMI was 18.2 (range, 12.5–36.9) kg/m2. The types of disease included AIS in 17 cases, NM scoliosis in three, congenital scoliosis in one, and syndrome-associated scoliosis in eight. The traction types encountered included gravity traction in three cases, pelvic traction in 20, and femoral traction in six. The mean traction period was 3.1 (range, 1–7) weeks. Compared with patients in group A, group B patients were significantly shorter (P = 0.029) and had a lower mean body weight (P = 0.017), higher mean TBWR (P = 0.025), and more cases of femoral traction (P = 0.018) (Table 3).
Initial coronal curve size was positively correlated with correction rate in total patients (halo-correction rate, P = 0.021, r = 0.31; postoperative correction rate, P = 0.038, r = 0.28). On the contrary, there was no significant correlation between initial coronal curve size and correction rate in each group (halo-correction rate of group A, P = 0.865, r = −0.03; halo-correction rate of group B, P = 0.846, r = −0.21; postoperative correction rate of group A, P = 0.547, r = −0.11; postoperative correction rate of group B, P = 0.840, r = 0.04). There was no significant correlation between initial sagittal curve size and correction rate in total and each group (halo-correction rate, P = 0.147, r = −0.202; postoperative correction rate, P = 0.749, r = 0.045; halo-correction rate of group A, P = 0.240, r = −0.230; halo-correction rate of group B, P = 0.290, r = 0.220; postoperative correction rate of group A, P = 0.776, r = −0.056; postoperative correction rate of group B, P = 0.270, r = −0.234) (Table 4).
In total, 10 patients developed complications during the traction period, of whom four experienced vomiting on the first and second day of HT but not on any other day. Two patients experienced intolerable pin site pain, of whom one developed pain on the first postoperative day and had recovered by the next day. The other patient developed pain around the head and shoulders on the fifth day of applying halo-pelvic traction. At that time, the weight was 4 kg at the head and 4 kg at the pelvis, and the weights were slowly increased within the patient's tolerance level. The pain alternately improved and deteriorated, and finally, on the 20th day, the final surgery was performed with 8 kg of head traction and 6 kg of pelvis traction. One wound problem was recorded: a pelvic abrasion was noted on the 17th day of pelvic traction. One pin site infection was found that occurred at the halo pin insertion site on the 19th day. There was one case of skull fracture; one day after insertion, a patient complained of pain and vomiting and was subjected to brain computed tomography examination. A fracture at the pin insertion site was then found. On the third day, the halo pin was reinserted. In one case, liver enzymes were elevated. On the 20th day after halo insertion, aspartate aminotransferase and alanine aminotransferase values increased to 79 IU/L, 145 IU/L in one patient. No abnormality was noted on additional examination, and a decline in the values was recorded after 4 days. Accordingly, the operation was postponed for approximately 5 days.
There were three cases of postoperative neurological complications. Two patients complained of postoperative tingling sensations in their arms (one case underwent T1-L4 fusion and the other case underwent C6-T11 fusion), which improved within a week. There was one case with a major neurological complication. A patient with Marfan syndrome underwent T2-L4 fusion with T8 vertebral wedge osteotomy. During rod assembly and derotation maneuvering, neuromonitoring readings changed to flat. Further surgery was abandoned and delayed second stage surgery was planned. The motor powers of both legs in this patient after index surgery were recorded as grade 0. The neurological deficit was gradually recovered after mega-dose steroid therapy and final surgery was completed after 2 weeks.
Spine. 2020;45(18):E1158-E1165. © 2020 Lippincott Williams & Wilkins