Parathyroid hormone administered to tendons promotes meniscal regeneration in rat models

Parathyroid hormone administered to tendons promotes meniscal regeneration in rat models

The knee meniscus is an important tissue that protects the joint; When the meniscus is damaged - from sports injuries or aging - it often does not heal on its own. There are two surgical methods to treat a torn meniscus: repair with suture and graft or removal.

Because removing the meniscus results in further damage, graft surgery is preferred for meniscus reconstruction. In countries where donated meniscus allograft is not available, the patient's own tendon can be transplanted into the knee to strengthen the damaged meniscus. However, differences between tendon and meniscus tissue mean that the results of meniscus transplants are not consistent.

A group led by researchers from Osaka Metropolitan University, Professor Hiroaki Nakamura, Dr. Yusuke Hashimoto and graduate student Kazuya Nishino, MD, at the Department of Orthopedic Surgery, Graduate School of Medicine, thought they might be able to treat the transplanted tendon, creating a tissue similar to that of the original meniscus; This would improve treatment outcomes and protect the knee cartilage from further damage. They turned to parathyroid hormone, which is used to treat osteoporosis.

The research group administered parathyroid hormone to cells from the rat Achilles tendon and cultured them. They observed increased production of cartilage matrix and expression of genes involved in chondrogenic differentiation. The same was found when parathyroid hormone was injected into the Achilles tendon of rats, creating a cartilaginous matrix within the tendon tissue.

The researchers transplanted the parathyroid hormone-injected Achilles tendons into the meniscal defect area of ​​rats with meniscectomy to evaluate chondrogenesis. They found increased expression of genes involved in chondrogenesis after 4 weeks, suggesting that parathyroid hormone may act on tendon cells or undifferentiated mesenchymal stem cells within the tendon to maintain chondrogenic differentiation, creating a more meniscus-like tissue.

We have made a highly novel discovery that parathyroid hormone administered to tendons induces tendon cartilage chondrocyte differentiation without ossification. We hope to improve the outcome of meniscus reconstruction surgery and protect knee cartilage in patients who have had their meniscus removed at a young age.”

Kazuya Nishino, MD, first author

Source:

Osaka Metropolitan University

References:

Nishino, K., et al. (2022) Transplantation of parathyroid hormone-treated Achilles tendon promotes meniscus regeneration in a rat meniscus defect model. The American Journal of Sports Medicine. doi.org/10.1177/03635465221112954.

.