Implant Preservation versus Implant Replacement in Revision Surgery for Adjacent Segment Disease After Thoracolumbar Instrumentation: A Retrospective Study of 43 Patients.

Abstract Background Adjacent segment disease (ASD) is a problematic complication of instrumented spinal fusion. The purposes of this study were to evaluate the mechanical properties of a new connector rod aiming to preserve implants in revision surgery (RS) for ASD and to assess its clinical applicability. Methods The mechanical properties of the connector-rod construct (implant preservation) and traditional rod construct (implant replacement) were evaluated and compared. Forty-three patients underwent RS for ASD in the thoracolumbar spine with implant preservation or replacement, and their radiological and clinical outcomes were assessed. Results The mechanical properties in Group A were comparable to those in Group B. The total mean time from the prior surgery to RS was 6.86 ± 1.08 years. The surgical time and blood loss values of Group A were 40.14% and 29.29% statistically significantly smaller than those of Group B. In Group B, 12% (3/25) of patients developed surgical site infections. In both groups, the VAS-leg score decreased significantly after RS. The early postoperative (at the Post-1m and Post-3m follow-ups) ODI and VAS-back scores of Group A were significantly lower than those of Group B, and the difference in the VAS-back score between groups was significant until the six-month follow-up. No implant failures occurred, and spinal fusion was achieved in all cases. Conclusions The connector rod is considered safe and can reduce the surgical time, blood loss, risk of complications and medical costs. In addition, better early postoperative clinical outcomes can be achieved with the rod due to less surgical trauma.