11.5.11  Postoperative Synovial Cyst

11.5.11.1\ Discussion

Synovial (juxtafacet) cysts are responsible for about 1% of cases of failed back surgery syndrome. These can form as a consequence of altered biomechanics on the facet joints and may also be predisposed by disruption of the facet capsule. Patients tend to present with ipsilateral

a

leg pain that may or may not be accompanied by back pain. MRI can readily demonstrate synovial cysts and the associated mass effect (Fig. 11.110). These lesions are contiguous with the facet joint, and their contents generally follow fluid signal, although these may contain hemorrhage and solid components. Peripheral enhancement can also be observed. Cyst puncture and aspiration can provide symptomatic relief.

b

Fig. 11.110  Postoperative de novo synovial cyst. The patient underwent L3 and L4 laminectomy for decompression 6 months prior. There was no synovial cyst prior to surgery, and the patient initially did well after surgery, but a few months after, the patient began to develop back

and right leg pain. Axial (a) and sagittal (b) T2-weighted MR images show a juxtafacet cyst (arrows) arising from the right L4–L5 facet joint, where there is an effusion and compression of the adjacent nerve roots