21 - X-Stop versus Decompressive Surgery for Lumbar Neurogenic Claudication...

#21 X-Stop versus Decompressive Surgery for Lumbar Neurogenic Claudication - A Randomized Controlled Trial With Two-year Follow-up

General Session: Advocacy of MIS

Presented by: B. Strömqvist


B. Strömqvist (1)
S. Berg (2)
P. Gerdhem (3)
R. Johnsson (1)
A. Möller (4)
T. Sahlstrand (4)
A. Soliman (5)
T. Tullberg (2)

(1) Skåne University Hospital, Orthopedics, Lund, Sweden
(2) Stockholm Spine Center, Upplands Väsby, Sweden
(3) Karolinska Institute, Clinical Science, Stockholm, Sweden
(4) Skåne University Hospital, Orthopedics, Malmö, Sweden
(5) Tanta University, Neurosurgery, Tanta, Egypt


While decompression is the golden standard for lumbar spinal stenosis surgery, interspinous spacers have been developed for the same purpose but the two modalities have not been compared in a study.

Purpose: To compare the outcome of indirect decompression by means of the X-Stop implant to conventional decompression in patients with one to two level-symptomatic lumbar spinal stenosis.

Study Design/Setting: Prospective randomized controlled trial. Non-inferiority hypothesis.Two-year follow-up.Intention-to-treat as well as As-Treated analyses. Patient Sample: After power calculation 100 patients included, 50 in treatment in each group. Randomization performed by envelope. X-Stop operations performed under local anaesthesia. Primary outcome measurement: Zürich Claudication Questionnaire (patient satisfaction, symptom severity and physical function). Secondary outcome measurement: VAS pain leg, back, SF-36, complications and re-operations.

Results: Patients in both surgical groups improved significantly regarding both primary and secondary outcome measures. The results were similar at 6, 12 and 24 months and at no time point any statistical difference between the two types of surgery was seen. Three patients in the decompression group had further surgery, compared to 13 patients in the X-Stop group (7 of which operated on in one center). Results were identical in ITT and AT analysis.

Conclusion: For lumbar spinal stenosis with neurogenic claudication, decompressive surgery as well as X-Stop are rewarding procedures. Similar results were achieved in both groups, however, with a higher number of re-operations in the X-Stop group. Patients having X-Stop removal and decompression experienced results similar to those randomized to and treated with primary decompression.