Figure 2.

46-year old male patient with increasing bilateral sensomotor deficit at L5 one year postoperatively after implantation of a metal-on-metal stainless steel artificial disc (Maverick, Medtronic) at L4–L5 (a, b) presented major artifacts on MR imaging in T1 (c, d) and T2 (e, f). Neurophysiological investigations revealed acute bilateral L5-compression. Leading diagnostic procedure that could visualise a bilateral compression of L5 was plain myelography, which revealed an anterior compression of the thecal sac (g, h) and compression of the right (i) and left (j) L5-root. Therefore a posterior decompression and instrumented posterolateral fusion was performed while keeping the implant in situ (k, l). Intraoperatively facet hypertrophy and posterior bulging of remaining annulus was seen. The sensomotor deficit resolved completely. The patient regained function and returned to work.