Complications of fixation to the occiput-anatomical and design implications.

Internal fixation provides an increased immediate stability for the craniovertebral junction; however, there is no current consensus on the optimal method of occipitocervical (OC) fusion. In this report, we present 25 cases of craniovertebral instability treated with OC fusion by plates and screws instrumentation. The 25 cases comprised 12 men and 13 women, whose ages ranged 20 to 78 years. The principal aetiologies that lead to the OC instability of the patients in this series included trauma, rheumatoid arthritis, neoplasm and congenital abnormality. The fusion levels ranged from occiput-C3 to occiput-C6. Two mortalities occurred. The other patients showed satisfactory union after a follow-up of eight to 24 months. OC fusion using a plates and screws system is a safe and highly effective method for providing immediate internal stability to the OC junction. The internal occipital anatomy, which cannot be seen at surgery, is important when dealing with this taxing and potentially dangerous aspect of surgery.