[Surgery treatment of neurofibromatosis associated severe cervical kyphotic deformity: mid- and long-term follow-up and efficacy analysis].

Objective: To investigate the surgical strategy and mid-and long-term outcomes of neurofibromatosis associated cervical kyphotic deformity. Methods: Thirteen patients with neurofibromatosis associated cervical kyphotic deformity operated in Shanghai Changzheng Hospital from January 1998 to December 2015 were analyzed retrospectively. There were 7 males and 6 females in this group, aged from 12 to 61 years, with an average age of (28±15) years. Eight patients were treated with anterior surgery (Group A) and 5 patients were treated with combined anterior and posterior surgery (Group A+P). Cobb angle correction of cervical kyphosis and improvement of clinical symptoms were followed up. Clinical efficacy between the two groups was compared and analyzed. Chi-square test, Fisher exact test and independent sample t test were used for comparative analysis between the two groups. Results: All patients were operated successfully and finished follow up. The follow-up period was from 42 to 128 months ((80±22) months). After the surgery, neurological symptoms and pain were significantly improved in all patients. Compared with preoperative values, Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) score for pain at the last follow-up were significantly improved (t=7.63, -5.19, 8.63, -4.75, all P<0.01). Cervical kyphosis was significantly improved in all patients after surgery. In group A, the Cobb angle was improved from 64°±24° preoperatively to 12°±11° at the last follow-up, and the average correction rate of Cobb angle was 82.6%. In group A+P, the Cobb angle was improved from 55°±10° preoperatively to 7°±9° at the last follow-up, and the average correction rate of Cobb angle was 88.3%. The operation time, intraoperative blood loss and length of stay in group A were all significantly lower than those in group A+P (t=-6.32, -11.92, -6.52, all P<0.01). At the last follow-up, there was no significant difference in Cobb angle, JOA score and VAS score between the two groups (t=0.89, 0.94, 1.02, all P>0.05). Conclusions: Mid-and long-term results of anterior and combined anterior and posterior surgery for neurofibromatosis associated severe cervical kyphosis are satisfactory. Moderate correction strategy for cervical kyphosis is safe and effective. The incidence of complications of nerve injury can be reduced.