Degeneration in the Zygapophysial Joint of the Fifth Lumbar Vertebra: The V-Shaped Sign Revealed by Bone Scintigraphy

OBJECTIVE: The aim of the study was to explore the nature of a V-shaped sign in the backbone of the fifth lumbar vertebra revealed by whole-body bone scintigraphy (WBBS). METHODS: A local single-photon emission computed tomography (SPECT) scan plus a computed tomography (CT) scan were performed on 41 patients in our department who had a V-shaped sign in the backbone of the fifth lumbar vertebra detected by WBBS. Image fusion was conducted to understand the manifestations of the changes in the V-shaped sign in the CT images in WBBS and to determine the nature of the lesion. RESULTS: All 41 patients presented with degenerative changes observed in the bilateral posterior zygapophysial joint of the fifth lumbar vertebra in the CT imaging bone window, bone hyperplasia of the articular process, joint surface hardening, and a joint gap. The vacuum sign could also be seen in some of these patients. CONCLUSION: The typical V-shaped sign in the posterior zygapophysial joint of the fifth lumbar vertebra revealed by WBBS suggests degenerative changes in the zygapophysial joint of the fifth lumbar vertebra.