Integration of polyurethane meniscus scaffold during ACL revision is not reliable at 5 years despite favourable clinical outcome

Abstract

Purpose The aim of this study was to evaluate the clinical outcome at 5-year follow-up of a one-step procedure combining anterior cruciate ligament (ACL) reconstruction and partial meniscus replacement using a polyurethane scafold for the treatment of symptomatic patients with previously failed ACL reconstruction and partial medial meniscectomy. Moreover, the implanted scafolds have been evaluated by MRI protocol in terms of morphology, volume, and signal intensity. Methods Twenty patients with symptomatic knee laxity after failed ACL reconstruction and partial medial meniscectomy underwent ACL revision combined with polyurethane-based meniscal scafold implant. Clinical assessment at 2-and 5-year follow-ups included VAS, Tegner Activity Score, International Knee Documentation Committee (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Lysholm Score. MRI evaluation of the scafold was performed according to the Genovese scale with quantiication of the scafold's volume at 1-and 5-year follow-ups. Results All scores revealed clinical improvement as compared with the preoperative values at the 2-and 5-year follow-ups. However, a slight, but signiicant reduction of scores was observed between 2 and 5 years. Concerning the MRI assessment, a signiicant reduction of the scafold's volume was observed between 1 and 5 years. Genovese Morphology classiication at 5 years included two complete resorptions (Type 3) and all the remaining patients had irregular morphology (Type 2). With regard to the Genovese Signal at the 5-year follow-up, three were classiied as markedly hyperintense (Type 1), 15 as slightly hyperintense (Type 2), and two as isointense (Type 1). Conclusion Simultaneous ACL reconstruction and partial meniscus replacement using a polyurethane scafold provides favourable clinical outcomes in the treatment of symptomatic patients with previously failed ACL reconstruction and partial medial meniscectomy at 5 years. However, MRI evaluation suggests that integration of the scafold is not consistent. Level of evidence Level IV.

Current advances in engineering meniscal tissues: insights into 3D printing, injectable hydrogels and physical stimulation based strategies

“…Microextrusion printing necessitates selection of a shear thinning polymer that can maintain its stability post extrusion to enable layer-by-layer fabrication of the implants, while low viscosity materials can be used for inkjet and nozzle-free 3D printing modalities [189,190]. Conventionally, synthetic materials such as poly (l-lactic acid) PLLA [191][192][193][194][195], polyglutamic acid (PGA) and PGA/PLA composites [196][197][198][199][200], PU and its composites [47,[201][202][203][204][205], polycarbonate based composites [206,207] and PCL and its composites [17,118,119,122,[208][209][210][211][212] have been used for the micro-extrusion-based fabrication of meniscus scaffolds. Additionally, synthetic photocrosslinking polymers [213][214][215] undergo facile crosslinking and high-resolution printing using nozzle-free photocuring printers.…”

“…Moreover, Actifit and NUsurface do not replicate the microarchitecture of native menisci including the special orientation of the circumferential and radial collagen fibres. Despite the high failure rates due to shrinkage of implants and insufficient degradation along with uncertain longterm effects, current meniscal scaffolds endow chondroprotection and prevent secondary OA as compared to non-surgical treatment strategies [28,40,[46][47][48].…”