Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

Abstract

Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to 'conventional' methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions.

Keywords: ankle; biomaterials; osteochondral lesions; regenerative medicine; scaffold; tissue engineering.

Figure 1.

TERM applications on the ankle joint.

Figure 2.

(a) Grade 3 ulcer, (b) PRP application in wound and (c) chronic infected wound protected by collagen membrane with gentamicin sulfate.

Figure 3.

(a) Achilles tendon defect partial rupture identified in T2 MRI (arrow) and (b) endoscopic view of the defect.

Figure 4.

Photograph of the gellan gum microparticles obtained by precipitation in a phosphate buffered saline (pH 7.4) solution and possessing a size between 500 and 2000 µm.

Figure 5.

(a) Scanning electron microscopy image of MSCs seeded onto SPCL scaffolds and maintained in a standard osteogenic culture medium, after 14 days of culturing. Microscopy images of histological sections (haematoxylin and eosin staining) of (b) SPCL scaffold controls and (c) MSCs/SPCL construct explants after four weeks of implantation (Fischer rats subcutaneous model). Newly bone formed (NB), SPCL fibres (F) and fibrous tissue (FT).

Figure 6.

Photographs of gellan gum hydrogels: (a) single and (b) bilayered.

Figure 7.

(a) Photograph of TruFit PLGA-based scaffold delivery device, (b) defect zone prepared to receive the plug and (c) arthroscopically implanted device to resurface the defect preserving joint congruency.

Figure 8.

(a) Per-operative photograph of Hemicap ankle implant after tibial osteotomy and control X-ray in (b) frontal and (c) lateral views at 1 year follow-up.