Subsidence after anterior cervical inter-body fusion. A randomized prospective clinical trial

In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group1: Solis™ cage, Stryker Company and group2: Shell™ cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom’s criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group1 than in group2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven patients of group1 and two patients of group2. A significant correlation is found between Odom’s criteria and subsidence. Although there was no significant difference in a short-term clinical result between the two treatment groups, we recommend the use of cages which preserve the determined segmental height and lordosis. Disclaimer  None of the authors has received any financial support from any company cited in this study, and none of the authors has any financial or other interest in a company involved in this study.