Faculty Collaboration Database

Bioresorbable polylactide interbody implants in an ovine anterior cervical discectomy and fusion model: three-year results. Spine (Phila Pa 1976) 2008 Apr 01;33(7):734-42

Date

04/02/2008

Pubmed ID

18379399

DOI

10.1097/BRS.0b013e3181695716

Scopus ID

2-s2.0-41749097454 (requires institutional sign-in at Scopus site)   30 Citations

Abstract

STUDY DESIGN: In vivo study of anterior discectomy and fusion using a bioresorbable 70:30 poly(l-lactide-co-d,l-lactide) interbody implant in an ovine model.

OBJECTIVE: To evaluate the efficacy of the polylactide implant to function as an interbody fusion device, and to assess the tissue reaction to the material during the resorption process.

SUMMARY OF BACKGROUND DATA: The use of polylactide as a cervical interbody implant has several potential advantages when compared with traditional materials. Having an elastic modulus very similar to bone minimizes the potential for stress shielding, and as the material resorbs additional loading is transferred to the developing fusion mass. Although preclinical and clinical studies have demonstrated the suitability of polylactide implants for lumbar interbody fusion, detailed information on cervical anterior cervical discectomy and fusion (ACDF) with polylactide devices is desirable.

METHODS: Single level ACDF was performed in 8 skeletally mature ewes. Bioresorbable 70:30 poly (l-lactide-co-d,l-lactide) interbody implants packed with autograft were used with single-level metallic plates. Radiographs were made every 3 months up to 1 year, and yearly thereafter. The animals were killed at 6 months (3 animals), 12 months (3 animals), and 36 months (2 animals). In addition to the serial plain radiographs, the specimens were evaluated by nondestructive biomechanical testing and undecalcified histologic analysis.

RESULTS: The bioresorbable polylactide implants were effective in achieving interbody fusion. The 6-month animals appeared fused radiographically and biomechanically, whereas histologic sections demonstrated partial fusion (in 3 of 3 animals). Radiographic fusion was confirmed histologically and biomechanically at 12 months (3 of 3 animals) and 36 months (2 of 2 animals). A mild chronic inflammatory response to the resorbing polylactide implant was observed at both 6 months and 12 months. At 36 months, the operative levels were solidly fused and the implants were completely resorbed. No adverse tissue response was observed in any animal at any time period.

CONCLUSION: Interbody fusion was achieved using bioresorbable polylactide implants, with no evidence of implant collapse, extrusion, or adverse tissue response to the material. The use of polylactide as a cervical interbody device appears both safe and effective based on these ACDF animal model results.

Author List

Thomas KA, Toth JM, Crawford NR, Seim HB 3rd, Shi LL, Harris MB, Turner AS

Author

Jeffrey M. Toth PhD Associate Dean for Research in the School of Dentistry department at Marquette University

MESH terms used to index this publication - Major topics in bold

Absorbable Implants
Animals
Biomechanical Phenomena
Cervical Vertebrae
Diskectomy
Female
Polyesters
Range of Motion, Articular
Sheep, Domestic
Spinal Fusion