Fig. 2. Case of revision surgery after cervical arthroplasty. (A) A 68-year-old male with cervical compressive myelopathy and bony spur had an initial Japanese Orthopaedic Association score of 12. He underwent cervical arthroplasty with a Mobi-C prosthesis. A postoperative T2-weighted image showed intramedullary high signal changes at the region of the compressed cord. (B) Cervical computed tomography showed an artificial disc, which was inappropriately small. (C) The patient underwent cervical laminectomy with fusion at C3–4–5. (D) Postoperative T2-weighted magnetic resonance imaging demonstrated successful decompression of the spinal cord at C3–4. The patient had a recovery ratio of 66.67%.