Abstract

Objective: The use of bioresorbable implants in the spine is at its relative infancy. Numerous modalities are in development throughout the spine. In March of 2004 we presented our experience in stabilization of the anterior cervical spine with a bioresorbable containment device in 26 patients. Now we set out to reevaluate those patients in terms of long-term outcome having implanted a bioresorbable anterior cervical containment device. Methods: An IRB-approved retrospective review of patients' charts and imaging was performed to determine the outcomes after the implantation of a bioresorbable anterior cervical containment device originally performed between March 2000 and November 2001. The levels included were C3-4, C4-5, C5-6, or C6-7. An attempt was made to contact all 26 of the original patients by phone or in person for a follow-up evaluation and examination. Results: In the time interval between the original surgery (March 2000 – November 2001) and now (September 2005), 14 patients have been lost to long-term follow-up. Data was available for 12 of the original 26 patients. Follow-up ranged from 1 year to 4.5 years for an average of 2.54 years (30.5 months). Nine patients resolved their radiculopathy and did well. One patient resolved her radiculopathy, but developed a Horner's syndrome which eventually resolved. One patient clinically resolved her radiculopathy, yet radiographically demonstrated a slight anterior displacement of a fragment of her interbody graft. Lastly, one patient initially did very well yet developed significant neck pain as well as adjacent level disease and underwent additional surgery and the placement of a titanium plate. No patients had any significant swallowing difficulties, developed fluid collections, wound healing problems, or infections. Eleven of the 12 patients demonstrated radiographical signs of fusion at the intended level, whereas the one patient with significant neck pain demonstrated significant adjacent level disease as well as a pseudoarthrosis at the original operated level. Conclusion: This study demonstrates signs of equivalence between standard titanium anterior cervical plates and bioresorbable anterior cervical containment devices with the distinct advantage of bioresorption and elimination of scatter artifact in possible subsequent MRI. Furthermore there is a presumed advantage in the allowance of subsidence in the bioresorbable device as well as a theoretical decreased risk of adjacent level disease. The number of patients in this study does not allow for sufficient power analysis of these points; however it does suggest that using a bioresorbable containment device in the anterior cervical spine is at least safe and equivalent to standard titanium plating. A large, randomized, controlled study is needed to adequately compare these devices.