Difficulty in surgical procedure selection for myelopathy with atlantoaxial instability in a highly aged patient: A case report of an 85-year-old female who required additional occipitocervical fusion after C1 laminectomy

Myelopathy with atlantoaxial instability is a relatively rare condition. It is treated with various surgical methods to treat upper cervical problems, including atlantoaxial fusion, occipitocervical fusion, and C1 laminectomy. However, the choice of surgical method, especially in highly aged （≥80 years） patients, is controversial. This case report describes the difficulty of selecting the appropriate surgical procedure for upper cervical and occipitocervical diseases in highly aged patients. An 85-year-old woman complained of neck pain and bilateral hand numbness. The Japanese Orthopedic Association score for cervical myelopathy （C-JOA） of the patient was 9 out of a possible score of 17. Plain radiographs showed atlantoaxial subluxation （AAS） and vertical subluxation （VS）, whereas magnetic resonance imaging showed spinal cord compression and myelomalacia at C1-2. The patient underwent a C1 laminectomy to minimize invasive procedures. After surgery, her symptoms improved, and her C-JOA score increased to 12. Fifteen months after surgery, her neurological conditions gradually deteriorated again. Her VS progressed postoperatively, with spinal canal restenosis at the craniovertebral junction. After an additional occipitocervical fusion, her symptoms improved, and she had no evidence of recurrence at her final follow-up. Although surgeons tend to choose less-invasive procedures when treating highly aged patients, appropriate surgical procedures may be required （even if invasive for the patient） when less-invasive treatments failed. Hence, it is important to avoid over-selecting less-invasive surgical procedures for highly aged patients.