Superior Facet Joint Violations during Single Level Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Preliminary Retrospective Clinical Study

Figure 2

Radiographic method. (a) Average intervertebral disc height (AIDH): (1) anterior of intervertebral disc height, (2) middle of intervertebral disc height, (3) the posterior of intervertebral disc height, AIDH: ((1) + (2) + (3))/3; (b) adjacent superior average intervertebral disc height (ASAIDH) and adjacent superior intervertebral disc Cobb angle (ASIDCA): (4) anterior of adjacent superior intervertebral disc height, (5) middle of adjacent superior intervertebral disc height, (6) posterior of adjacent superior intervertebral disc height, ASAIDH: ((4) + (5) +(6))/3, ∠D for ASIDCA: angle of upper and low endplate; (c) lumbar sagittal curvature: ∠A represents lumbar Cobb: angle of L1 upper endplate and S1 upper endplate, ∠B for the L4/5 Cobb: angle of L4 upper endplate and L5 low endplate, ∠C for L5/S1 Cobb: angle of L5 upper endplate and S1 upper endplate.

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