Could Bone Marrow Aspirate Help Heal Tendon Injuries?

Could Bone Marrow Aspirate Help Heal Tendon Injuries?

Superficial digital flexor tendon injury is common in athletic horses, and the road to recovery tends to be long and sometimes unsuccessful.

Photo: Anne M. Eberhardt/The Horse

Tendon injuries in horses are notoriously tricky to manage with conventional conservative treatment methods. The good news, however, is that research into regenerative therapies—which could potentially improve tendon healing—is ongoing.

“When tendons are injured, the body repairs them with scar tissue, which is not as strong or elastic as the original tendon tissue,” said Tom Russell, BVMS, Dipl. ECVS, from the Bendigo Equine Hospital, in Victoria, Australia. “As a result, horses are prone to (potentially) career-ending re-injury.”

Superficial digital flexor tendon (SDFT) injury is common in athletic horses, and the road to recovery tends to be long and sometimes unsuccessful. In one study, for example, researchers found that horses were laid up for an average of 13.5 months; only 46% of injured horses returned to work; and 35% of those that did return to function suffered re-injury. Other reports suggest that while almost all horses with an SDFT injury return to racing, 80% of them subsequently re-injure the tendon.

Conventional treatment approaches include rest, intralesional (in the lesion) injections, and surgery. More recently, veterinarians and researchers have also explored the impact of regenerative therapies, such as stem cells, on tendon healing.

Russell and colleagues tested the impact of another regenerative therapy—bone marrow aspirate (which contains stem cells and other materials necessary for optimal healing to occur) injections—on SDFT healing. The team recruited 105 racehorses diagnosed with acute, severe (Grade 3 or 4 on a scale of 0 to 4) SDFT lesions. The team anesthetized each horse and collected a sample of the animal’s bone marrow—a rich source of stem cells and inflammatory mediators. Then, the team injected the bone marrow directly into the core SDFT lesion. Some horses also underwent a superior check ligament desmotomy depending on surgeon preference and injury severity. That procedure that involves cutting the superior check ligament—the accessory ligament of the SDFT—based on the premise that the ligament, once healed, will be slightly longer than it was pre-cutting, resulting in less strain on the SDF.

Ultimately, the team determined that racehorses treated with bone marrow had a good chance of returning to racing and competing in at least five starts. Combining a superior check ligament desmotomy with the bone marrow aspirate, however, did not improve a horse’s chance of returning to racing.

“This technique is simple and inexpensive … and (performed in) a single procedure, which may be attractive to some clients,” Russell concluded.

The study, “Autologous bone marrow aspirate for treatment of superficial digital flexor tendonitis in 105 racehorses,” was published in the Veterinary Record

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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