Pre-operative Halo-Pelvic Traction for Neurofibromatosis Patients with Severe Proximal Thoracic Spinal Deformity: Indications and Early Treatment Outcome

Myelopathy Associated with Rapid Progression of a Dystrophic Neurofibromatosis-1 Curve - A Case Report and Review of Literature

Introduction

Thoracic myelopathy in neuro fibromatosis-1 (NF-1) is most commonly due to intra-spinal neurofibromas/dumb-bell tumors/intra-canal rib head penetration (RHP) causing cord compression. However, acute thoracic myelopathy due to rapid progression of the kyphoscoliotic curve alone in NF-1 without a significant spinal cord compression occurs very rarely. This case report discusses our experience with one such patient and we also discuss intraoperative and post-operative challenges encountered with this patient and a rare complication of hemothorax postoperatively.

Case Report

A 15-year-old male presented to the clinic after being lost to follow-up for 4 years with a rapid acute deterioration of dystrophic curve and no myelopathic symptoms (Scoliosis - 65°, Kyphosis - 77°). His subsequent examination in 6 weeks showed acute development of myelopathic gait with right ankle and extensor hallucis longus weakness. He was admitted for halo gravity traction for 6 weeks and a single-stage posterior instrumentation with excision of rib heads at the apex was planned. Postoperatively, the patient developed massive left hemothorax and loss of power in both lower limbs at day 2. He subsequently regained full power and complete resolution of myelopathic symptoms at the end of 9- month follow-up with a satisfactory alignment of spine in the follow-up X-rays.

Conclusion

Acute onset of myelopathy is a rare and uncommon finding with a rapid deterioration of dystrophic curve alone without any major spinal cord compromise. Early detection of dysplastic changes with early aggressive surgical management and deformity correction is necessary with dystrophic NF-1 curves to prevent pre-operative and post-operative morbidities.

Evaluation of Pulmonary Function After Halo-Pelvic Traction for Severe and Rigid Kyphoscoliosis Utilizing CT with 3D Reconstruction

BACKGROUND

The purpose of the present study was to evaluate changes in pulmonary function, caused by preoperative halo-pelvic traction (HPT) for the treatment of extremely severe and rigid kyphoscoliosis, with use of 3-dimensional computed tomography (3D-CT) reconstruction and pulmonary function tests (PFTs).

METHODS

Twenty-eight patients with severe and rigid scoliosis (Cobb angle, >100°) underwent preoperative HPT and staged posterior spinal fusion. CT, radiographic assessment, and PFT were performed during pre-traction and post-traction visits. The changes in total lung volume were evaluated with use of 3D-CT reconstruction, and the changes in pulmonary function were evaluated with PFTs at each time point. Differences were analyzed with use of 2-tailed paired Student t tests, and correlations were analyzed with use of Spearman rank tests.

RESULTS

None of the patients had pulmonary complications during traction, and all radiographic spinal measurements improved significantly after HPT. The main Cobb angle was corrected from 143.30° ± 20.85° to 62.97° ± 10.83° between the pre-traction and post-traction evaluations. Additionally, the C7-S1 distance was lengthened from 280.48 ± 39.99 to 421.26 ± 32.08 mm between the pre-traction and post-traction evaluations. Furthermore, 3D lung reconstruction demonstrated a notable increase in total lung volume (TLV) (from 1.30 ± 0.25 to 1.83 ± 0.37 L) and maximum lung height (from 176.96 ± 27.44 to 202.31 ± 32.45 mm) between the pre-traction and post-traction evaluations. Moreover, PFTs showed that total lung capacity (TLC) improved between the pre-traction and post-traction evaluations (from 2.06 ± 0.32 to 2.98 ± 0.82 L) and that the changes in T1-T12 distance and maximum lung height were correlated with changes in TLV (p = 0.0288 and p = 0.0007, respectively).

CONCLUSIONS

The application of HPT is a safe and effective method for improving pulmonary function in patients with extremely severe and rigid scoliosis before fusion surgery. The TLV as measured with CT-based reconstruction was greatly increased after HPT, mainly because of the changes in thoracic height.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

A Novel Hybrid Technique in the Treatment of Dystrophic Scoliosis Secondary to Neurofibromatosis Type 1 Lacking Pedicles in the Apical Area

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

To introduce a novel hybrid technique using segmentation correction (SC) and to compare it with traditional correction (TC) in treating dystrophic scoliosis secondary to neurofibromatosis type 1 (NF1-S) lacking pedicles in the apical area.

METHODS

We reviewed the NF1-S cases lacking pedicles diagnosed in our hospital between January 2015 and December 2019. Patients were divided into the SC and TC groups and were followed up for at least 2 years. The degree of deformities, correction rate, and vertebral rotatory subluxation (RS) were assessed before the operation, post-traction, post operation, and during follow-up visits.

RESULTS

A total of 27 patients were included in the SC group and 21 in the TC group. There was no significant difference in the 2 groups before the surgery regarding age, height, weight, degree of deformities, and spinal flexibility. The correction rate of patients in the SC group was higher (57.7% ± 17.3% vs. 40.9% ± 19.0%, P = 0.002) than in the TC group. During the 2-year follow-up, the loss of Cobb angles of the SC group in both coronal and sagittal planes were lower than those of the TC group (coronal plane, 1.2° ± 1.1° vs. 2.0° ± 1.4°, P = 0.039; sagittal plane, 0.9° ± 0.5° vs. 1.7° ± 1.0°, P = 0.002).

CONCLUSIONS

The SC technique showed better deformity correction than TC, suggesting that SC may be an alternative method for treating NF1-S patients lacking pedicles in the apical area.

Effects of combined adjustable Halo-pelvic fixation brace on cervical spine alignment in patients with severe rigid spinal deformity

Objective

To evaluate the effect of continuous traction with a combined adjustable Halo-pelvic fixation brace on the cervical spine alignment in patients with severe rigid spinal deformity and analyze its related factors.

Methods

We conducted a retrospective cohort study of 21 patients with severe rigid spinal deformity treated in our department between 2015 and 2019. All subjects received combined adjustable Halo-pelvic fixation brace traction before secondary orthopedic surgery. The influence of the Halo-pelvic fixation brace on the cervical spine alignment was evaluated by measuring the parameters of lateral cervical X-ray at three time points: before traction, at the end of traction, and 6 months after orthopedic surgery. The correlation between parameter changes and total traction duration was analyzed to explore factors influencing cervical alignment.

Results

The C2L-C7L angle was 22.40 ± 15.91° before traction, which decreased to 5.91 ± 6.78° at the end of traction but increased to 14.51 ± 10.07° after orthopedic surgery (BT vs ET p < 0.005, ET vs AOS p < 0.005, BT vs AOS p < 0.005). Accordingly, C2L-C7U angle, C2L-C6L angle, C2L-C6U angle, C2L-C5L angle, C7 or T1 slope, C2-C7 SVA, SCA, C2-T1 Ha, C0 slope, and C0-C2 angle also changed similarly to C2L-C7L angle. Furthermore, moderate correlation was observed between C2L-C7L angle and total traction volume (r = 0.563, p = 0.008) and SCA and traction duration (r = 0.525, p = 0.015). However, no significant correlation was found between other cervical alignment parameters and total traction volume and traction duration.

Conclusions

The continuous traction of a combined adjustable Halo-pelvic fixation brace can affect the cervical spine alignment of patients with severe rigid spinal deformity and straighten the physiological curvature of the cervical spine. However, the sagittal alignment gradually recovers after the traction, without any adverse effects on the orthopedic surgery and global balance after the operation; therefore, this apparatus is worthy of wide application.