Fundamentals of Spine Surgery

The Decision-Making Process

Clinical decision making is one of the most challenging tasks for any physician, particularly for spine surgeons. Often times, the decision to not offer surgery to a patient is as important as the decision to offer surgical intervention. Multiple factors influence the surgical and medical decision-making process, including comorbidities, family and social support network, and even availability to take time off of work, just to name a few. Although the patient is the surgeon’s first priority, other factors such as financial and social pressures must also be taken into consideration. This chapter addresses some of the fundamentals of this process, including patient selection, informed consent, surgical planning, biomechanics, technology, and medical economics.

Patient Selection

Patient selection is the most important and difficult task in the surgical treatment of spinal disorders. A technically perfect operation in the wrong patient might fulfill the surgical goals of the procedure but is unlikely to resolve the patient’s initial complaints and may also lead to clinical worsening in the future. Unfortunately, a proper study investigating the indications for spine surgery is not only difficult to design but also equally difficult to execute. Thus, the body of quality scientific literature to help guide the spine surgeon in making good clinical and operative decisions is scarce. The Spine Patient Outcome Research Trial (SPORT) highlights some of the difficulties in executing a randomized, multicenter trial. SPORT was the first comprehensive study to look at different ways of treating low back and leg pain and the effectiveness of those treatments. Even though this was a prospective, randomized trial, the amount of crossover between the surgical and nonsurgical arms ultimately rendered the analyses nonrandomized. Additionally, blinding was not possible in a surgical trial, which may have also introduced several confounders into the analyses.

Consequently, there is little prospective, randomized, controlled clinical trial evidence to guide the spine surgeon concerning indications, techniques, and timing of surgery. Without such data to guide clinical decision making, the problems of patient selection and designing a management strategy remain difficult. Previous attempts at analyzing the natural history and postsurgical outcome of spine disorders have yielded equivocal results, primarily because most studies were done retrospectively, and the data generated were, at best, level 2 or 3 evidence. Currently, there is a drive in the spine community to provide more prospective analyses, comparing treatment strategies along with outcome analyses using recognized scales, such as the Oswestry Disability Index (ODI) and the Short Form-36 Health Survey (SF-36). These analyses report patient satisfaction and quality of life after procedures, rather than fusion rate and neurological recovery. One notable study exemplifying this push was published in the New England Journal of Medicine : “Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis.” This randomized controlled trial compared the effectiveness of performing instrumented fusion versus decompressive laminectomy alone for patients with grade 1 degenerative spondylolisthesis. The primary outcome measure in this study was SF-36, with a secondary outcome measuring ODI. The results demonstrated that these patients had greater clinically meaningful improvement in quality of life when they underwent a fusion procedure as compared with just laminectomy alone. Certainly, although the results of this trial are important in guiding surgical decision-making, the analysis of quality of life outcomes from randomized clinical trials should continue to be emphasized to improve spine surgery as a whole.

In addition to increasing patient satisfaction and quality of life, other factors such as personal and financial considerations, defensive practice strategies, and third-party payers have motivated surgeons to address the challenges and difficulties of patient selection. In particular, third-party payers are reluctant to reimburse physicians, hospitals, and patients for procedures that lack clear indications or documented evidence of efficacy. In the current environment of cost containment, surgeons are increasingly pressured by outside influences to demonstrate that they practice safe and appropriate medicine by documenting their surgical outcomes. Although the motivations that underlie these powerful forces often are not completely altruistic, it should be evident that the results of outcomes research will benefit both the patient and the surgeon.

The excellent design and timely execution of carotid endarterectomy studies such as the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study provide a paradigm for the potential benefits of outcomes research. ^, These studies have clearly defined objective criteria for surgical treatment, based on risk and benefit ratios. Although outcome assessment is obviously more straightforward for carotid endarterectomy than for spine surgery, the carotid endarterectomy trials, nevertheless, serve as a reminder of the powerful influence such trials can exert on surgical practice. These trials not only have established the safety and efficacy of the procedure itself, but also have provided unambiguous guidelines for patient selection.