 In this investigation, it will be investigated whether the effectiveness of surgical intervention with Coflex is equivalent to surgical decompression after 12 months in people with intermittent claudication. The main advantage of coflex might be a faster recovery after surgery, but after long term follow-up it is unknown if this treatment effect remains. Therefore in addition, it will be investigated whether surgical intervention with coflex is more effective than surgical decompression on short-term follow-up 8 weeks to 6 months and whether surgical intervention with coflex is more cost-effective after 12 months than surgical decompression. 