Is Degenerative Spondylolisthesis a Contraindication for Total Disc Replacement? Kineflex Lumbar Disc Replacement in 7 Patients With 24-Month Follow-up

Insertion Technique

Position A: Spondylolisthetic disc space before operation. Position B: Initial engagement of the prosthesis into the disc space after full nucleotomy, disc space mobilization, and cutting of the insertion grooves. The further insertion is performed with a fully freed prosthetic mechanism. Position C: Advancement of the prosthesis into the disc space, until almost flush with the posterior wall of the cephalad vertebral body. The prosthetic endplates are individually advanced, alternating between top and bottom prosthetic endplate. Position D: Further advancement of the bottom prosthetic endplate, until almost flush with the posterior wall of the caudad; full reduction of the spondylolisthesis. During this advancement the inferior endplate pivots around the articulating mechanism of the prosthesis, reducing the pressure between the leading edge of the inferior prosthetic endplate and the bony endplate. Position E: Securing of the final reduced position by placement of a screw into the into the insertion groove of the inferior vertebra. This counteracts the displacing forces (For more information on insertion technique, see Hähnle et al.¹³)