Two-year results of X-stop interspinous implant for the treatment of lumbar spinal stenosis: a prospective study.
METHODS
Prospective Observational Study.


OBJECTIVE
To prospectively assess the clinical outcome of patients treated for symptomatic spinal stenosis with the X-stop device.


BACKGROUND
The X-stop device is used in the treatment of symptomatic lumbar spinal stenosis. The preliminary results of this study of 40 patients at 1 year were published in 2007. The 2-year results of 57 patients are reported in this paper. Zucherman et al report 60% significant improvement at 1 year and 48.4% at 2 years.


METHODS
Fifty-seven consecutive patients with radiologically confirmed lumbar spinal stenosis were enrolled and treated with the X-stop device. The device was implanted at a maximum of 2 affected levels. Clinical response was evaluated with the Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index, and Short Form-36 questionnaires preoperatively and 6, 12, and 24 months postoperatively.


RESULTS
Of the 57 patients enrolled, 54 completed the ZCQ questionnaire at 1 year and 46 patients at 2 years. Clinically significant improvement was attained by 65% at 1 year and 57% at 2 years and 70% were satisfied with the outcome of the surgery. Single level and double level insertions did not have significant difference in clinical outcome.


CONCLUSIONS
This study demonstrates with the use of ZCQ scores as primary outcome measures that improved clinical outcomes are maintained at 2 years after X-stop implantation.
NHS Grampian and University of Aberdeen, Department of Orthopaedics, Positional MRI Centre, Woodend Hospital, Aberdeen, Scotland, UK. anjalinandakumar@yahoo.co.uk
Anjali
A
Nandakumar
Natasha A
NA
Clark
Francis W
FW
Smith
Douglas
D
Wardlaw
D005260:Female; D006801:Humans; D016268:Internal Fixators; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D013130:Spinal Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome