Table 2.

Characteristics of the Patients with Reoperation.

A. Number and average age of patients at surgery
Gender	Number of patients	Average age at primary laminoplasty (years)
Male	31	56 (range: 34-71)
Female	9	64 (range: 43-76)
Total	40	58 (range: 34-76)
B. Number of revision surgeries by durations after primary surgery
Duration between primary and revision surgery		Number of surgeries
≤1 year		10
1-3 years		11
3-5 years		6
5-10 years		8
10-15 years		2
15-20 years		2
≥20 years		1
Average 4.6 years (range: 22 days-23.3 years)