Abstract
Cervical disc arthroplasty (CDA) is an approved surgical treatment option in selected
patients with cervical spinal disc degeneration. Even though CDA is a standard procedure
since 20 years, there is a lack of information about long term performance. The published
reoperation rates after CDA are low and comparable to anterior cervical fusion. The
authors describe a severe failure and dysfunction with a partial core dislocation
of a cervical prosthesis into the spinal canal (M6-C, Spinal Kinetics, Sunnyvale,
CA, USA). Six years after implantation of a cTDR (cervical Total Disk Replacement)
of the M6 type at C4/5 level, a 52 year-old women presented herself with new clinical
signs of cervical myelopathy and radicular pain. Complete posterior dislocation of
the central core of the implant into the spinal canal was identified as a cause. The
failed device was removed completely and an ACCF (anterior cervical corpectomy and
fusion) was performed. Intraoperatively, rupture of
the posterior portion of the mesh tissue with posterior dislocation of the whole
prosthesis core was detected. This is the second described case of a severe implant
failure with core dislocation in this type of cTDR device. Even though there are thousands
of successful implantations and middle term outcomes, it seems to be necessary to
continue with long term radiological follow up to exclude similar failure in this
type of prosthesis.
Key words
cervical total disk replacement - implant failure - cervical arthroplasty
