Implantation of a Polycaprolactone Scaffold with Subchondral Bone Anchoring Ameliorates Nodules Formation and Other Tissue Alterations

Abstract

press-fit technique in a cartilage defect after microfracture surgery in the femoral condyle of the knee joint of the sheep and histologic and mechanical evaluation was done 4.5 months later. The first group consists of a biodegradable Polycaprolactone, PCL, scaffold with double porosity. The second test group consists of a PCL scaffold attached to a Poly(L-lactic acid), PLLA, pin anchored to the subchondral bone. Results: For both groups most of the defects (75%) exhibited the articular surface completely or almost completely repaired with a neotissue. Nevertheless, the surface had a rougher appearance than controls and the repair tissue was immature. In the trials with solely scaffold implantation, severe subchondral bone alterations were seen with many large nodular formations. These alterations were ameliorated when implanting the scaffold with a subchondral bone anchoring pin. Discussion: The results show that tissue repair is improved by implanting a PCL scaffold compared to solely microfracture surgery, and most importantly, that subchondral bone alterations, normally seen after microfracture surgery, were partially prevented when implanting the PCL scaffold with a fixation system to the subchondral bone.

Comparison of Fixation Techniques of 3D-Woven Poly(ϵ-Caprolactone) Scaffolds for Cartilage Repair in a Weightbearing Porcine Large Animal Model

“…Histologically the PCL scaffold showed evidence of fibrous ingrowth, consistent with studies of PCL scaffolds. [11][12][13][14] The loss of trabecular architecture around the scaffold and anchor are also consistent with descriptions of histologic findings by Vikingsson et al 23 following PCL fixation with a pin.…”

Biostable Scaffolds of Polyacrylate Polymers Implanted in the Articular Cartilage Induce Hyaline-Like Cartilage Regeneration in Rabbits

“…Our aim was to compare in vivo cartilage regeneration by implanting scaffolds made of biostable materials of similar composition but with varying compliance, preseeded with chondrocytes or not, using a series of polyacrylate polymer and copolymer networks, previously used in in vitro studies on cell adhesion and viability (14–18). In contrast to other studies (11, 19, 20), the materials we used were biocompatible, biostable polymers; thus, our results are not affected by any effect attributable to material degradation products or to loss of mechanical properties over time due to scaffold degradation.…”

A cell‐free approach with a supporting biomaterial in the form of dispersed microspheres induces hyaline cartilage formation in a rabbit knee model

“…Cell density increases both in immature cartilage and in fibrocartilage, an increase observed in the M series with respect to the native cartilage was expected, but the increase observed in groups PLLA+CHT and M and the decrease observed in group PLLA have unclear meaning. Chondrocyte clustering was also described as a negative feature associated with degeneration in ostheoarthritic tissue (Vikingsson et al, ). Other studies interpret these clusters as a sign of immature cartilage during the healing process (Bell, Hurtig, Quenneville, Rivard, & Hoemann, ; Kumar et al, ; Kuo et al, ).…”

“…These scaffolds should be non‐immunogenic and biodegradable to avoid deposits, porous to allow migration and adhesion of cells from subchondral bone, and mechanically stable to sustain the regeneration process. Bioresorbable polyesters such as polylactide (PLA) (Chu et al, ; Conoscenti et al, ) or polycaprolactone (PCL) (Martinez‐Diaz et al, ; Vikingsson et al, ) have been used previously in cartilage engineering animal models. Cell‐free strategies using PCL (Martinez‐Diaz et al, ; Vikingsson et al, ) or biostable acrylic scaffolds of varying stiffness (Sancho‐Tello et al, ; Sancho‐Tello et al, ) probed in rabbit knee models their capacity to induce the formation of histologically high‐quality tissue with the characteristics of hyaline cartilage.…”