Hyaluronan-based polymers in the treatment of osteochondral defects

Citation
La. Solchaga et al., Hyaluronan-based polymers in the treatment of osteochondral defects, J ORTHOP R, 18(5), 2000, pp. 773-780
Citations number
56
Categorie Soggetti
da verificare
Journal title
JOURNAL OF ORTHOPAEDIC RESEARCH
ISSN journal
07360266 → ACNP
Volume
18
Issue
5
Year of publication
2000
Pages
773 - 780
Database
ISI
SICI code
0736-0266(200009)18:5<773:HPITTO>2.0.ZU;2-U
Abstract
Articular cartilage in adults has limited ability for self-repair. Some met hods devised to augment the natural healing response stimulate some regener ation, but the repair is often incomplete and lacks durability. Hyaluronan- based polymers were tested for their ability to enhance the natural healing response. It is hypothesized that hyaluronan-based polymers recreate an em bryonic-like milieu where host progenitor cells can regenerate the damaged articular surface and underlying bone. Osteochondral defects were made on t he femoral condyles of 4-month-old rabbits and were left empty or filled wi th hyaluronan-based polymers. The polymers tested were ACP sponge, made of crosslinked hyaluronan, and HYAFF-11 sponge, made of benzylated hyaluronan. The rabbits were killed 4 and 12 weeks after surgery, and the condyles wer e processed for histology. All 12-week defects were scored with a 29-point scale, and the scores were compared with a Kruskall-Wallis analysis of vari ance on ranks. Untreated defects filled with bone tissue up to or beyond th e tidemark, and the noncalcified surface layer varied from fibrous to hyali ne-like tissue. Four weeks after surgery, defects treated with ACP exhibite d bone filling to the level of the tidemark and the surface layer was compo sed of hyaline-like cartilage well integrated with the adjacent cartilage. At 12 weeks, the specimens had bone beyond the tidemark that was covered wi th a thin layer of hyaline cartilage. Four weeks after surgery, defects tre ated with HYAFF-11 contained a rim of chondrogenic cells at the interface o f the implant and the host tissue. In general, the: 12-week defects exhibit ed good bone fill and the surface was mainly hy aline cartilage. Treated de fects received significantly higher scores than untreated defects (p < 0.05 ), and ACP-treated defects scored significantly higher than HYAFF-11-treate d defects (p < 0.05). The introduction of these hyaluronan-based polymers i nto defects provides an appropriate scaffolding and favorable microenvironm ent for the reparative process. Further work is required to fully assess th e long-term outcome of defects treated with these polymers.