THE EARLY CLINICAL OUTCOME OF A CONSECUTIVE SERIES OF INTERSPINOUS DISTRACTION DEVICES

Purpose: To determine the clinical effectiveness of a stand alone interspinous distraction device Method: Prospective consecutive longitudinal study in five hospital sites. Outcome measures Oswestry Disability Index (ODI), Visual Analogue score for leg and back (VAS Leg, VAS Back). Implant failure determined by removal and revision. A cohort of 69 patients having clinical and radiological evidence of spinal stenosis. Selected according to recommendations of clinical trials groups for the x-stop, i.e. sitting tolerance of greater than 30 minutes. Clinical outcome data at average of 10 month (6–24) available for 66 patients (95% FU). Average age 67 years ( Range 49–84). The average outcomes were Pre op ODI 42, Post op ODI 27. A change from baseline of 15 points. Pre op VAS leg 7.2 post op 4.4, and VAS Back Pre 4.8, post op 3.6 Taking a 16 point change in ODI as representing a clinically significant improvement half the study group failed to achieve this. A small number (17 patients 25%) had a dramatic improvement of greater than 24 points, which significantly skews the average change from baseline. 17 Revisions have occurred so far (24% failure rate) Conclusion: A small proportion of successful results occur, however implant failure and revision rate is high. Ethics approval: NPIAG registered audit Interest Statement: No commercial or grant support