Nonsteroidal anti-inflammatory drugs and bone metabolism in spinal fusion surgery: a pharmacological quandary.

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is ubiquitous in contemporary medical practice and these agents are efficacious in a number of clinical contexts. In particular, NSAIDs have proven to be highly effective adjuncts in the amelioration of postoperative pain in the subset of patients undergoing spinal surgery requiring fusion. NSAIDs act through inhibition of cyclooxygenase enzymes and therefore diminish prostaglandin production. However, prostaglandins are intimately involved in the modulation of bone metabolism and the balance of data, from both clinical and laboratory contexts, indicate that prostaglandins preferentially favor bone anabolism. Most recently, limited emerging evidence suggests that NSAID administration in patients undergoing spinal fusion surgery may increase nonunion rates, which in turn, has important ramifications to the patient, their family and the entire medical system. Hence, disparate views have evolved regarding the use of NSAIDs in postoperative pain control in patients undergoing spinal surgery requiring fusion. NSAIDs have proven efficacy in the management of postoperative pain in these patients, however, this must be weighed against the risk of nonunion and its associated consequences. In this review, the role of prostaglandins in bone metabolism, the pharmacology of NSAIDs and the modulation of bone metabolism by NSAIDs are discussed. Additionally, the current evidence examining the use of NSAIDs in spinal surgery is presented. As rates of spinal surgery continue to rise, it is imperative that the apparent pharmacological quandary surrounding the administration of NSAIDs in patients undergoing spinal surgery requiring fusion be addressed, both to guide present clinical practice and to outline further directions for investigation.