the authors have classified the configuration of laminas in the lower lumbar spine into three different types , ( wi , w2 , and n ) , based on the two characteristic features of the lamina : 1 ) whether or not the inferior articular processes are wider than the waist part of the lamina , and 2 ) whether or not the facet joint spaces can be recognized on plain anteroposterior ( ap ) radiographs .
C0022417
articular
C0222679
facet