Symptomatic osteochondral defects in the knee can cause great functional impairment to a wide patient demographic. The osteochondral surfaces of the knee are vulnerable to damage due to the delicate nature of the tissue, avascular structure and poor ability to self-heal; and the treatment pathway remains challenging, could hydrogels be the answer?
The latest treatment option to be offered for osteochondral damage is the incorporation of a hydrogel scaffolding substance to the classic cartilage stimulation procedure, micro-fracturing. The hydrogel substance is made of acellular material and there are variety of different compositions and brands. The objective of the hydrogel is to enhance the cartilaginous surfaces of the knee by providing a scaffold in which osteocytes can bond and optimise the generation of new cartilage. This technique is aimed to slow down or prevent the evolution of osteoarthritis.
It’s too soon to say whether hydrogels should be considered as first line treatment for osteochondral knee defects. Recent trials have shown promising results of high patient satisfaction rates as well as histological evidence of an enhanced chondrogenic environment being created following the procedure. Importantly, the evidence suggests the decision for surgical intervention should be considered based on lesion size, location and the age of the patient. Most of the available evidence comes from animal and small-scale studies and long-term evaluation is yet to be completed.
The implications for physiotherapists involved in the care approach for these patients is to reinforce the information regarding weight bearing and rehabilitation steps to optimise the outcomes of the procedure. Weight bearing is largely dictated by the product used in the procedure with some hydrogels allowing for immediate postoperative weight bearing and others requiring a period of weeks of non-weight bearing.
References
Pipino, G., Risitano, S., Alviano, F., WU, E. J., Bonsi, L., Vaccarisi, D. C., & Indelli, P. F. (2019). Microfractures and hydrogel scaffolds in the treatment of osteochondral knee defects: A clinical and histological evaluation. Journal of Clinical Orthopaedics and Trauma, 10(1), 67.
Guo, X., Park, H., Young, S., Kretlow, J. D., Van den Beucken, J. J., Baggett, L. S., … & Jansen, J. A. (2010). Repair of osteochondral defects with biodegradable hydrogel composites encapsulating marrow mesenchymal stem cells in a rabbit model. Acta biomaterialia, 6(1), 39-47.
Camarero-Espinosa, S., & Cooper-White, J. (2017). Tailoring biomaterial scaffolds for osteochondral repair. International journal of pharmaceutics, 523(2), 476-489.