Stiffness of cervical spine after hybrid fusion

Cervical spondylosis also known as arthritis of the neck, is the degeneration of the joints in the neck. This degenerative disorder is becoming increasingly more common as people age. For patients suffering from such disorders, there are a few options of treatment available such as drug and therapeutic treatment. Surgical treatments are most likely to be considered for patients whose quality of life is significantly affected. A new spinal fusion technique, known as hybrid fusion, is a combination of spinal fusion and total disc replacement (TDR). Unlike the simple spinal fusion technique, the risk of adjacent level degeneration and instability, movement restriction and pain in the post-operative period is minimised. However, there are different combinations for hybrid fusion and their behaviour have not been studied. The aim of this project to improve the three dimensional (3D) finite element (FE) model of the C3-T1 cervical spine generated by the previous final year project student. The model is then used for investigating of the behaviour of a fusion model with a fused C5-C6 level, and three different combinations of hybrid fusion (HFBotTDR, HFTopTDR, and HFBiTDR). A concept study to compare between the models found that the HFTopTDR model is the best option for hybrid fusion as it minimises hypermobility from occurring in the non-operated segments of the spine. The option is also cost effective as it uses only one artificial disc when compared to the HFBiTDR model, which produces almost similar results in C3-T1 range of motion with two artificial discs. The HFBotTDR model displays similar motion effects to the fusion model at C4-C5 level which could lead to long term adjacent segment disorders. Due to the deformities found in the intact spine model which could be traced back to the CT datasets used, the future work of the study may require the acquisition of a new set of CT data to generate the spine model.Bachelor of Engineering (Mechanical Engineering