Implant related complications in patients operated on with expandable pedicle screws and technical solutions for revision surgery

Background It is reported that expandable pedicle screws are effective and a safer alternative to pedicle screws with cement augmentation application in patients with poor bone quality. Aims To study implant related complications associated with expandable pedicle screws application and to propose revision options in case of implant failure. Methods A retrospective analysis of a heterogeneous cohort of patients operated on because of traumatic injuries and degenerative diseases of the lumbar spine and thoracolumbar junction was performed. 42 patients with osteopeny or osteoporosis were enrolled, the duration of the follow-up accounted for 18 months. Cases with implant failure (loosening and screw breakage) were registered and revision pedicle screws fixation was performed. Results Out of 42 enrolled patients 3 were presented with implant failure (a screw loosening in one case and a screw rupture and loosening in 2 cases). The attempts to remove retained fractured fragments were unsuccessful, therefore, alternative bypass creation and a direct screw placement into a retained fractured fragment were carried out and suggested as an alternative strategy to osteotomy with a fractured screw fragment removal. Conclusion In case of rupture, expandable screws have a poor feasibility for a revision pedicle screw fixation because of fractured fragments strong anchorage in bone. The alternative bypass for a revision screw without fractured fragment removal or tapping and direct screw placement into retained expanded fragment of a screw are less invasive alternatives to osteotomy that can help overcome the discussed issue.