Pain assessment.

Pain usually is the major complaint of patients with problems of the back, thus making pain evaluation a fundamental requisite in the outcome assessment in spinal surgery. Pain intensity, pain-related disability, pain duration and pain affect are the aspects that define pain and its effects. For each of these aspects, different assessment instruments exist and are discussed in terms of advantages and disadvantages. Risk factors for the development of chronic pain have been a major topic in pain research in the past two decades. Now, it has been realised that psychological and psychosocial factors may substantially influence pain perception in patients with chronic pain and thus may influence the surgical outcome. With this background, pain acceptance, pain tolerance and pain-related anxiety as factors influencing coping strategies are discussed. Finally, a recommendation for a minimum as well as for a more comprehensive pain assessment is given.