• L5/S1 PLIF noted with bilateral pedicle screws which are satisfactorily sited. There is a large posterior epidural haematoma extending from L4-S1 with a rough craniocaudal dimension of 40mm with small gas locules. This is compressing and effacing the cauda equina nerve roots with just minimal sparing of the anterior thecal sac. Certainly at the L4/L5 level the thecal sac is almost completely compressed and displaced anteriorly. In addition there is an elongated elliptical shaped hyperintense T1 and T2 signal intra dural haematoma component extending from the level of L1/L2 disc to the L3/L4 disc with direct communication to the aforementioned extradural component. The cauda equina nerve roots at the cranial aspect of the intradural haematoma are clumped together posteriorly with loss of intervening CSF signal. The cord proximally otherwise appears of normal calibre with the conus sited at T12/L1. Normal marrow appearances throughout. The bladder is grossly distended.
• Large post operative L4-cranial aspect of S1 extra dural haematoma with direct extension and communication with an elliptical shaped L1/L2 to L3/L4 intradural haematoma. The latter is rather unusual, but could be explained by a dural tear at the time of initial surgery. The caudal extradural haematoma is compressing and almost completely effacing the entire thecal sac with frank cauda equina nerve root compression in keeping with severe central canal stenosis. The bladder is grossly distended and requires urgent decompression with catheterisation