Results of Spine Surgeries in Nonagenarians Compared with Octogenarians: A Propensity-Matched Analysis.

Purpose: While spinal surgery is common in octogenarians, it is less frequent in nonagenarians. Most research highlights complications and mortality, but few studies compare actual recovery outcomes between these groups. This study examines how spinal surgery outcomes differ between nonagenarians (people in their 90s) and octogenarians (people in their 80s).

Methods: This study included patients aged 80-99 years who underwent spinal surgery between 2017 and 2022 at Kyoto University Hospital and affiliated institutions. Patients who underwent spinal surgery for degenerative disease or trauma and were followed up for more than one year were included. Exclusion criteria comprised surgeries limited to balloon kyphoplasty and procedures for tumors or infections. Patients were matched 1:1 based on sex, body mass index, modified Frailty Index-5 score, and American Society of Anesthesiologists Physical Status grade. Clinical outcomes, including preoperative and postoperative Japanese Orthopedic Association (JOA) scores and JOA recovery rates, and perioperative complications were analyzed.

Results: Each group consisted of 41 patients. Nonagenarians exhibited significantly lower preoperative JOA scores compared with octogenarians (8.9 vs. 12.2, p=0.02). However, there were no significant differences in postoperative JOA scores (15.4 vs. 17.6) or JOA recovery rates (33.6% vs. 38.1%) between the two groups. There were no significant differences in perioperative complications.

Conclusion: Despite lower preoperative JOA scores, nonagenarians achieved postoperative outcomes comparable to those of octogenarians, with similar recovery rates. These findings suggest that spinal surgery can yield satisfactory results in nonagenarians, highlighting the importance of careful patient selection and thorough risk assessment to optimize outcomes.