Table 2.

Comparative 36 Month Success Rates between Superion^® and X-STOP^® for Primary and Secondary Clinical Outcomes

36-month clinical outcomes	Superion® ISS	X-STOP®	P-value*
Pain
VAS back: ≥20 mm decrease	76.8% (63/82)	69.7% (53/76)	0.37
VAS leg (worse): ≥20 mm decrease	84.1% (69/82)	69.7% (53/76)	0.037
Back and stenosis-related outcomes
ZCQ physical function: ≥0.5 point decrease	80.5% (66/82)	77.9% (60/77)	0.70
ZCQ symptom severity: ≥0.5 point decrease	82.9% (68/82)	75.3% (58/77)	0.25
ZCQ patient satisfaction: ≤2.5 points	91.5% (75/82)	88.3% (68/77)	0.60
ODI: ≥15 point decrease	69.5% (57/82)	71.4% (55/77)	0.86

Note:

^*Fisher’s exact test, two-tailed.

Abbreviations: ISS, InterSpinous Spacer; ODI, Oswestry Disability Index; VAS, visual analog scale; ZCQ, Zurich Claudication Questionnaire.