Table 1.

The strategies to repair AF and their feasibility.

Repair Strategies
Strategy	Current Status	Feasibility
Early AF closure device (Xclose®, Inclose®)	Not available anymore	Not effective to stop re-herniation and improve the rate or strength of the AF healing.
Suturing techniques	Rarely used	Are not reliable to sustain complex cyclic loading and not efficient yet.
Thermal therapies (pulse radiofrequency and intra-discal electro-thermal therapies)	In use	Are likely to be effective to seal the structural defects in the mildly ruptured AF. Sever AF defects are unlikely to be treated and their contribution to IVD degeneration in the long term is not known.
Advanced AF closure devices (Barricaid®)	Clinical trial	Being effective to reduce the rate of re-herniation and alleviate pain. The key limitation is being different from the native tissue in terms of structure and property, hence it may accelerate the degeneration process.
Injectable bio-adhesives	Laboratory trial	The appropriate properties (i.e., adhesion, mechanical strength) and long-term capacity to resist high stresses during daily activities have remained a major concern.
Polymeric implants	Laboratory trial	Not sufficient data available to evaluate their feasibility and no further clinical practice was reported.