1 Department of Anatomy, Faculty of Health Sciences, Aarhus University, Aarhus University2 Department of Forensic Medicine, Faculty of Health Sciences, Aarhus University, Aarhus University3 Department of Forensic Medicine - Retspatologisk, Department of Forensic Medicine, Health, Aarhus University4 Patologisk Institut, Århus Universitetshospital, Århus Amtssygehus5 Department of Forensic Medicine - Retspatologisk, Department of Forensic Medicine, Health, Aarhus University
Introduction:The lower cervical spine facet joints are important structures in cases of chronic pain syndromes following road traffic crashes. Pathophysiological segmental kinematics may occur, particularly during rear-impact collisions, which may cause injury to these joints. Detailed anatomical description of the facet joints is necessary for the optimal management of clinical conditions following road traffic crashes. Only few studies have dealt the preparation of large un-frozen specimen, in contrast to the many studies utilising cryomicrotomy of frozen tissues. We present a practicable method that prepares large un-frozen un-decalcified cervical spine specimens for analysis. Materials and Methods:The cervical spine segments from C4 to C7 are removed en bloc during autopsy. The specimen is fixed throughout in 70% increasing to 99% ethanol and embedded un-decalcified in hardening methyl methacrylate, producing a plastic bloc. This bloc is subdivided into 3-mm thick parasaggital slices using a bandsaw, from where slices containing facet joint structures are re-embedded in methyl methacrylate. From each re-embedded bloc several 5-10 µm thick histological sections can be produced using a heavy-duty microtome followed by relevant staining.Results:The described method produces fine detail histological sections that may visualise normal anatomical structures as well as discrete pathoanatomical lesions in the lower cervical spine facet joints.Discussion:The cervical spine facet joints can be analysed histologically following preparation according to the method proposed. It is vital that proper fixation is attained prior to embedding in methyl methacrylate. Furthermore, with large specimens containing three or more facet joints the thickness at microscopy is suggested to be 10 µm to reduces artificial damage of the porous structure. In our experience staining with Masson Goldner-Trichrome allows particularly detailed visualization of the articular structures during microscopy. Conclusion:We present a method, which produces fine histological sections allowing good detailed visualisation of cervical spine facet joint structures with the advantage of good preservation of anatomical relations and possibility of staining prior to microscopy.