Application of a 3D custom printed patient specific spinal implant for C1/2 arthrodesis.

The study aims to describe a three-dimensional printed (3DP) posterior fixation implant used for C1/C2 fusion in a 65-year-old female. Spinal fusion remains a common intervention for a range of spinal pathologies including degenerative disc and facet disease when conservative methods are unsuccessful. However, fusion devices are not always entirely efficacious in providing the desired fixation, and surgeons rely on 'off the shelf' implants which may not provide an anatomical fit to address the particular pathology. 3DP refers to a process where three-dimensional objects are created through successive layering of material, so called 'additive manufacturing'. Although this technology enables accurate fabrication of patient-specific orthopaedic and spinal implants, literature on its utilization in this regard is rare. A 65-year-old female, with severe facet arthropathy at the C1/C2 level, osteophyte formation and impingement of the exiting C2 nerve root underwent a C1/C2 posterior fusion and rhizolysis of the C2 nerve roots. A custom posterior fixation implant was designed and on-laid over the C2 spinous process and lamina, with screw holes made to a depth and angulation that was pre-calculated based on the preoperative CT based 3D modelling. The patient had an uneventful recovery and reported a significant reduction in occipital neuralgia and sub-occipital pain and 2-month follow-up. We report the first case of a customized 3DP spinal prosthesis for posterior C1/C2 fusion. The implant added significant value reducing the overall time of the procedure, and safety with a reduced risk of neurovascular compromise.