Chapter 156 To Not Operate
For any new device to become a valuable, viable addition to the surgeon’s armamentarium, it must be either significantly “better” than what it is replacing in some way (e.g., safer, better outcomes, lower failure rate) or equivalent but less expensive.1 Most of the studies published on disc arthroplasty to date have demonstrated equivalence to fusion. However, long-term results and cost analysis are still lacking.
Interestingly, few studies have been published comparing motion preservation surgery with nonoperative therapy. 2 As nonoperative management of spinal pathology maintains the spine’s natural motion and has none of the operative risks of either fusion or disc arthroplasty, it may be the ultimate “motion-sparing” therapy for select spinal pathology.
Lumbar Spine
The major indication for lumbar disc arthroplasty is chronic back pain associated with degenerative disc disease. A number of studies have demonstrated that lumbar disc arthroplasty provides results equivalent to those of lumbar fusion. Three randomized controlled trials of fusion for chronic back pain, with mixed results, have been published in the last decade.3–5 Fritzell et al. concluded that fusion was more effective than conservative therapy for chronic low back pain, when compared with the “usual therapy” directed by the patient’s primary care physician.5 Brox et al. observed no difference between fusion and a program of cognitive therapy and exercise.4 Fairbank et al. found that fusion was only slightly more effective than a multidisciplinary rehabilitation program.4 However, in both the Fritzell and Fairbank studies, the mean improvement in the Oswestry Disability Index (ODI) score, their primary outcome measure—11.6 and 12.5, respectively—failed to reach the threshold of 15 that the FDA considers the minimally clinically important change for the ODI.1,6,7 Based on these trials, a number of authors have concluded that for nonradicular back pain, fusion is no more effective than an intensive rehabilitation program and is associated with only small to moderate benefit when compared with standard nonsurgical therapy.6–9
Only one study to date has compared lumbar disc arthroplasty directly with nonoperative management. Hellum et al.2
