A Crucial But Neglected Anatomical Factor Underneath Psoas Muscle and Its Clinical Value in Lateral Lumbar Interbody Fusion-The Cleft of Psoas Major (CPM).

and below. Although the occurrence and distribution of neurovascular structures within the CPM is complex and varies greatly, it can provide a potential cavity for visualization during lateral lumbar interbody fusion. Using psoas major as a reference, this novel grid system can be used to identify the risk factors in CPM and thus identify a safe entry point for surgery.