Updated guidelines for fusion procedures in the lumbar spine


The July 2014 issue of Journal of Neurosurgery: Spine was dedicated to the American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) Joint Section on Disorders of the Spine and Peripheral Nerves guideline update for fusion procedures for degenerative disease of the lumbar spine. Michael G Kaiser, former chairman of the joint section guidelines committee, reviews the key differences between the update and the original guidelines.

As medical research continues to enhance our understanding of the application and efficacy of various treatment strategies for degenerative spine disease, an update of guidelines is periodically required to incorporate the new evidence and modify or strengthen previous recommendations.

Since the current work is intended as an update, the same topics from the 2005 guidelines were selected—including an assessment of functional and radiographic outcome measures, an analysis of surgical indications, and an evaluation of the operative techniques. The value of clinical guidelines are as follows: to categorise the strength of medical evidence and identify treatment alternatives that are supported by robust evidence compared to strategies that are supported by weak or no evidence; to provide practising clinicians with a practical and concise summary of vast amounts of available information; to identify gaps in our knowledge base and stimulate future research; and to provide persuasive arguments to third party payers and policymakers about the utility of various procedures that are beneficial to patients under specific circumstances. 

The methodology of this update was similar to that used during the original guidelines. A multidisciplinary panel of neurosurgical and orthopaedic spinal specialists was convened to assess the quality and strength of the current medical evidence and formulate recommendations. Previous recommendations were re-evaluated to ensure that the updated information did not conflict with the 2005 recommendations. In contrast to the original guidelines, the panel elected to use the North American Spine Society strategy for evidence assessment and recommendation grading in an effort to improve transparency and conform to guidelines published by other subspecialty organisations. The level of medical evidence was assessed using a five-tiered strategy as opposed to the three-tiered classification strategy used in the 2005 publication. Differentiating lower levels of evidence was the primary difference between strategies. Qualitative grading of the recommendations was abandoned for a more objective four-tiered grading scale.

When compared to the 2005 guidelines, the update provides more detailed and specific recommendations regarding assessment of functional outcome and economic benefit of various fusion procedures. However no significant differences were observed regarding recommendations pertaining to surgical indications or efficacy of various fusion techniques. The most dramatic difference was observed in the chapter addressing bone graft extenders and substitutes. Publications about the application of biological fusion enhancers, such as the bone morphogenetic proteins, have dramatically increased in number since the previous publication. A total of 27 articles are currently included in the evidentiary tables with 11 recommendations specifically related to bone morphogenetic proteins. In contrast, there were only three articles and two recommendations in the 2005 guidelines. 

Despite the new evidence reviewed for this update, it was encouraging to learn that most, if not all, of the 2005 recommendations were reinforced by the new evidence. Future efforts of the AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves guidelines committee include thoracolumbar trauma and spinal metastatic disease guidelines. Hopefully, these and future guidelines will serve as an effective summary and provide a foundation to guide practising clinicians in formulating an effective treatment plan, based not only on their experience and patient preferences, but also on the best available medical evidence.

Michael G Kaiser, associate professor of Clinical Neurological Surgery; associate director, Spine Center, Department of Neurological Surgery, Columbia University, New York, USA