Visualisation of facet joint recesses of the cadaveric spine: a micro-CT and sheet plastination study

OBJECTIVES: The size and shape of a joint cavity are the key determinates for the mobility of the joint. The anatomy and configuration of the facet joint (FJ) recesses at different levels of the spine remain unclear and controversial. The aim of this study was to identify the configuration of the FJ recesses in the cervical, thoracic and lumbar spine using a combination of micro-CT and sheet plastination techniques. METHODS: Of 19 cadavers (9 males, 10 females, age range of 54–89 years), the FJ cavities of 3 spines were injected with contrast filling and scanned with micro-CT, and 16 plastinated spines were prepared as the series of sagittal (9 sets), transverse (5 sets) or coronal (2 sets) sections with a thickness of 2.5 mm and examined under a stereoscopic microscope. RESULTS: This study characterised the FJ spaces and recesses of the spine and found that (1) the configuration and extent of the FJ recesses varied along the spine. The optimal needle approach to the FJ cavity was via an anterolateral or posterolateral recess at the cervical level, along the tip of the inferior articular process at the thoracic level and via the posteromedial recess at the lumbar level. (2) The FJ cavity did not communicate with the retrodural space. CONCLUSION: The anatomical features of the FJ recesses at different levels of the spine confirm no direct communication between the FJ cavity and retrodural space.