Security analysis of the preservation of the intraspinal rib head when correcting the spinal deformity in neurologically intact patients with scoliosis secondary to Neurofibromatosis type 1 / 中华骨科杂志

ABSTRACT

Objective To observe the safety and efficacy of the posterior spinal instrumentation (PSI) with preserving of the intraspinal rib head in neurologically intact patients with scoliosis secondary to Neurofibromatosis type 1 (NF1).Methods The clinical and radiographic data of nine NF1 scoliosis patients with rib head protrusion into the spinal canal,who had undergone PSI from August 1998 to March 2012,were retrospectively investigated.The average age of these patients (4 males,5 females) was 15.4±7.6 years,and their neurological status all were Frankel grade E preoperatively.The intraspinal rib head was not resected in all patients intraoperatively.The following parameters,including the magnitude of rib head penetration into the spinal canal (MRPC),the angle between the bilateral rib (ABR),the angle between the dislocated rib and the posterior vertebral wall (ARV),the coronal Cobb angle and the sagittal Cobb angle,were measured before and after surgery.Results The follow-up period was 0.5 to 4.8 years.The average MRPC decreased from preoperative 32.8％±9.9％ to postoperative 16.8％±15.2％ (P=0.026); the average ARV increased from preoperative 34.7°±16.4° to postoperative 47.8°±17.5° (P=0.001); the average ABR decreased from preoperative 83.0°±19.5° to postoperative 67.9°±13.3° (P=0.009); the average coronal Cobb angle decreased from preoperative 70.7° ±17.7° to 35.4°±17.0° immediately after operation (P=0.000) and the sagittal Cobb angle decreased from preoperative 59.7°±17.6° to 24.7°±10.8° immediately after operation (P=0.001).The coronal Cobb angle and sagittal Cobb angle had no significant change during follow-up period.The neurological status was Frankel grade E in all patients immediately after operation and at final follow-up.Conclusion For NF1 scoliosis patients with rib head penetration into the spinal canal without impingement of the spinal cord and neurological deficits,the deformity can be corrected safely and effectively without resecting the intraspinal rib head.