PEEK versus Silicon Interspinous Spacer for Reduction of Supradjacent Segment Degeneration following Decompression and Short-Segment Instrumentation for Degenerative Lumbar Spinal Stenosis

Table 8

Demographic characteristics at baseline of 55 patients.

Characteristics	Group R	Group S	Group C	P-Value
Number	17	18	20
Female/male ratio	(10:7)	(12:6)	(13:7)	0.72
Age	64±17	59±13	61±12	0.49