A PROSPECTIVE-STUDY OF CENTRALIZATION OF LUMBAR AND REFERRED PAIN - APREDICTOR OF SYMPTOMATIC DISCS AND ANULAR COMPETENCE

Study Design. The presence or absence of rapidly centralizing, periphe ralizing, or abolishing low back and radiating pain, as identified dur ing a McKenzie mechanical lumbar assessment of patients with chronic l umbar pain, was compared prospectively with discographic pain provocat ion and anular competency. Objectives. To evaluate any relation betwee n the responses of centralization and peripheralization with discograp hic findings. Summary of Background Data. Centralization of referred p ain has been reported as a very common occurrence during McKenzie asse ssment and treatment. Patients whose pain centralizes have been shown to achieve superior treatment outcomes. A dynamic internal disc model has been hypothesized as an underlying mechanism for centralization th at has not been studied previously. Methods. Patients with chronically disabling low back pain who were referred for discography underwent p reliminary blinded McKenzie clinical assessment and were categorized i nto three groups by their pain response. Patterns, or lack thereof, of pain response were then compared with blinded discographic pain provo cation and anular findings. Results. During the McKenzie assessment, t he referred pain of 50% centralized with 74% having positive discogram s, of which 91% had an intact anulus. The pain of 25% peripheralized o nly (would not centralize); 69% of these had positive discograms, but only 54% had an intact anulus. The distal pain of 25% did not respond at all, and only 12.5% of these had positive discograms. Conclusion. T he McKenzie assessment process reliably differentiated discogenic from nondiscogenic pain (P < 0.001) as well as competent from an incompete nt anulus (P < 0.042) in symptomatic discs and was superior to magneti c resonance imaging in distinguishing painful from nonpainful discs.