Cervical fixation in the pediatric patient: our experience.

The surgical management of cervical instability in children is a challenging issue. Although the indications for internal fixation are similar to those for adults, accurate pre-surgery study and sharp surgical techniques are necessary because of the size of such patients' anatomy, their peculiar tissue biology and the wide spectrum of diseases requiring cervical fusion. Our case study is made up of 31 patients, 15 male and 16 female, with an average age of 7 years and 6 months (2 years and 6 months to 18 years) who underwent cervical fusion for instability. Their physical condition presented various different pathologies ranging from congenital deformity, systemic skeletal disease, tumors, trauma, post-surgery instability. We performed occipito-cervical fusion in 11 cases, 5 of which involved stabilization at the cranium-vertebral junction. We used instrumentation in 13 cases (3 sublaminar wiring, 10 rigid adult instrumentation). We used rigid adult instrumentation in three patients under 10 years of age, treated by rod, occipital screws and sublaminar hook instrumentation in steel C0-C2 (9-year-old male, affected by os odontoideum in Down's syndrome; male of 7 years and 10 months, affected by os odontoideum in Down's syndrome; female of 4 years and 6 months with occipito-cervical stenosis and C0-C2 instability in Hurler's syndrome). We operated on two patients under 3 years of age, using sublaminar wiring with bone precursors and allograft at level C0-C2 (one of these was a 30-month-old male with post-traumatic instability C0-C2, while the other was a 17-month-old male with C0-C2 instability in Larsen's syndrome). The average follow-up age was 7 years and 1 month (between 1 and 18 years). Cervical fusion was assessed by X-ray examinations at 4th and 12th weeks and at 6th and 12th months after surgery. Where implants could allow, RMN examination was performed at 1st month after surgery. In the other cases, in which implants do not allow RMN to be performed, CT scan and standard X-rays were carried out, and new X-rays were performed every other year. We experienced two cases of sublaminar wiring rupture without impairment of bone fusion. No patient suffered major complications (infection and osteomyelitis, rigid instrumentation mobilization, incomplete fusion with instability, neurologic impairment, insufficient cervical spine range of movement to cope with everyday life activities, cervical pain). Even though most authors still indicate that rigid instrumentation should be performed in cases over 10 years of age and sublaminar wiring in cases over 3 years of age, our findings demonstrate that this age limit can be lowered. We have treated children under 10 years of age by rigid adult instrumentation and under 36 months of age by wiring. The anatomic size of the patient is the most important factor in determining the use of instrument arthrodesis to treat pediatric cervical spine instability. Although not easy, it is possible and preferable in many cases to adapt fixation to child cervical spine even in very young patients.