To Not Operate

Chapter 156 To Not Operate



The last 2 decades have seen the development of a number of “motion-sparing” implants to be used as an adjunct in spinal surgery. These implants are designed to obviate the need for fusion when one is indicated, thereby maintaining or restoring the normal multisegmental motion of the spine. In theory, maintenance of motion could lead to a smaller amount of adjacent-segment degeneration and, potentially, better outcomes.


A variety of motion-sparing implants have been developed. These include cervical and lumbar disc arthroplasties, nuclear replacements, facet replacements, and a variety of flexible rods and bands to be used with pedicle screws. Of these implants, only cervical and lumbar total disc arthroplasties (TDAs) have been approved by the U.S. Food and Drug Administration (FDA) for use as motion-sparing implants.


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.35 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.69


Only one study to date has compared lumbar disc arthroplasty directly with nonoperative management. Hellum et al.2 conducted a multicenter prospective randomized trial comparing disc arthroplasty at L4-5 or L5-S1 with a 12- to 15-day outpatient multidisciplinary rehabilitation program. The study was powered to detect a 10-point difference on the ODI at 2 years, which was their primary outcome measure. Secondary outcome measures included low back pain, quality of life (36-Item Short Form Health Survey [SF-36], EuroQuol [EQ-5D]), Hopkins symptom check list (HSCL-25), fear avoidance beliefs (FABQ), work status, patients’ satisfaction, and drug use. A total of 173 patients were enrolled, 86 with surgery and 87 with rehabilitation. Although the study did show a significant difference in ODI scores between the two groups, it was less than the 10 points the study was powered to detect. Moreover, there was no significant difference in any of the other outcome measures between the two groups.2

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Aug 31, 2016 | Posted by in NEUROLOGY | Comments Off on To Not Operate

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