In horses, proximal suspensory desmitis (injury) may involve just the ligament itself and/or the bone that it originates. This also applies to suspensory branch injuries since the suspensory ligament branches insert on sesamoid bones as they support the fetlock. In some cases, there is bony remodeling at the attachment sites of the suspensory ligament which can be treated with shockwave in addition to other adjunct therapies.
Can shockwave be used for other soft tissue injuries?
We are going to explain the mechanisms of healing that shockwave can produce for bone healing as well as soft tissue injuries regarding suspensory ligament injuries. Although suspensory desmitis is one of the most common soft tissue injuries that can be treated with shockwave, these mechanisms apply to other soft tissue and bony injuries as well.
How does shockwave heal bony injuries?
Bone healing: Shockwave therapy is known to stimulate multiple growth factors which stimulate new bone growth. Shockwave promotes stromal cell growth and differentiation into osteogenic cells, fibroblast formation, stem cell migration, and tenocyte proliferation.
Shockwave is also chondroprotective by increasing cell surface mediators (beta-1 integrin) and decreasing harmful cytokines and interleukin cells (TNF alpha and IL-10). In other words, shockwave promotes protective barriers to the bone while inhibiting harmful inflammatory mediators that break bone down.
Once the shockwave contacts the bone, a majority of the energy is transmitted about 1-2cm into the bone. This energy stimulates new bone formation by increasing regional blood flow, activating osteogenic (bone) factors, and recruits cells that stimulate stromal cell growth as mentioned previously.
In studies, it is found that bone treated with shockwave therapy had a 56% increase in activated osteons compared to non-treated bones. The osteon is the portion of bone that supplies protection and strength to compact bone. Both new bone formation and new cartilage formation occurs with shockwave therapy.
How does shockwave heal soft tissue injuries?
Soft Tissue: In studies comparing ligament injuries, those treated with shockwave had a faster defect filling and improved fiber alignment on ultrasound compared to non-treated limbs. A second study looking at proximal suspensory desmitis found increases in anti-inflammatory cell signaling cytokines (TGF-beta1) in addition to faster filling defects of the lesion. Shockwave has been shown to increase capillary formation in soft tissue, decrease pain, decrease inflammation, and lead to more rapid development of longitudinal tissue fibers.