Total disc arthroplasty periprosthetic fracture: report of two cases of coronal plane fractures.

Total disc arthroplasty (TDA) has emerged as a viable surgical option for intractable/disabling lumbar discogenic pain in suitable patients. The surgical aims of TDA are to maintain the natural biomechanics of the intervertebral segment, decrease symptoms, preserve motion and reduce further degeneration at adjacent segments. Approach-related complications associated with anterior retroperitoneal surgical access include sexual dysfunction (retrograde ejaculation), vascular injury (arterial and venous injuries, thrombosis), abdominal wall hematoma, and infections. Besides approach related complications, there may also be implant related complications such as implant mal-positioning, incomplete locking of polyethylene spacer, implant migration, subsidence, loosening, and device failure. However, unique fractures resulting in implant failure have been rarely reported. In this case report, we present two cases with an unusual complication of a coronal plane fracture at L5 vertebral body following ProDisc-L implantation at L5/S1 requiring revision surgery.