What do we know about shockwave therapy for orthopedic management?

Content sponsored by Zomedica

At the Fetch DVM360® Conference in San Diego, held December 2-4, 2022, David Dycus, DVM, MS, CCRP, DACVS-SA, Nexus Veterinary Bone & Joint Center at Nexus Veterinary Specialists, spoke about extracorporeal shockwave therapy (ESWT) as a part of a multimodal plan—including a comprehensive rehabilitation program, post-surgery, and more—to manage musculoskeletal conditions such as osteoarthritis (OA), tendinopathies, and pain management.¹

Shockwave therapy has been used since the 1970s as a way of fragmenting uroliths so they could pass through the urinary system. Now it is used in other areas of the body for fragmentation.

Shockwave therapy

The term shockwave is often misinterpreted, Dycus said, but it is simply a high-energy acoustic wave or impulse created by changes in pressure. The medical reasoning behind using shockwaves is to direct the sound energy into the tissue for a healing response. More specifically, ESWT is acoustic nonlinear waves of high pressure and velocity generated from outside the body. Cavitation that is produced in the tissues increases cellular permeability, produces free radicals, and generates anti-inflammatory cytokines and growth factors.

To produce shockwaves, 3 types of focused shockwave generators are used with varying focal volumes and energy levels:

• Electrohydraulic
• Electromagnetic
• Piezoelectric

Focusing energy allows for greater tissue penetration depth with a rapid decline of energy at the periphery, delivering an intense amount of energy to a small area. Radial pressure is an alternative to focused ESWT, as it creates pressure waves, rather than shockwaves, that are longer, slower, less intense, and shallower in penetration. Knowing the differences among shockwaves is important because their energy settings are not comparable.

The literature

Some of the well-demonstrated benefits of ESWT are faster healing and an increase in the quality of healing in the soft tissue and bone, chondrocytes protection, dissolved fibrous/calcification, and attracting bone marrow stem cells to the treatment site, and pain reduction.

“The literature [shows] evidence for bone healing and tendinopathies,” Dycus said. During his presentation, he reviewed studies on bone healing, tendinopathy, desmopathy, and OA.

“The production and release of various growth factors that are associated with bone healing, in particular, upregulating the family of bone morphogenic proteins (BMPs), is what really helps stimulate bone healing,” Dycus pointed out. Increases in BMPs that stimulate bone healing have been seen as early as four weeks after treatments. Further, shockwave therapy not only improves the biological side of healing but also increases bone mineral density—the quality and strength of the bone—citing an early 1994 study.²

In the world of sports medicine, research shows that “shockwave therapy helps improve tendon and ligament healing through various biologic [responses],” Dycus said. “A rat model showed improved release of various growth factors for Achilles’ tendinopathy,³ and a rabbit model for patellar tendinopathy found it improved strength as well.⁴”

Further, in a study with client-owned dogs, post-tibial plateau leveling osteotomy (TPLO), the mean patellar ligament thickness was lower in the ESWT group compared to the control group.⁵

ESWT has ample support for its use in animals as a means to manage, in conjunction with other therapies, tendinopathies, OA, and other conditions by targeting tissue to decrease inflammatory mediators and increase the release of growth factors to stimulate healing.

References:

1. Dycus D. Shockwave Therapy for Orthopedic Management: What Do We Know? Presented at: Fetch dvm360® Conference; San Diego, California. December 2-4, 2022.
2. Johannes EJ, Kaulesar Sukul DM, Matura E. High-energy shock waves for the treatment of nonunions: an experiment on dogs. J Surg Res. 1994;57(2):246-252. doi:10.1006/jsre.1994.1139
3. Chen YJ, Wang CJ, Yang KD, et al. Extracorporeal shock waves promote healing of collagenase-induced Achilles tendinitis and increase TGF-beta1 and IGF-I expression. J Orthop Res. 2004;22(4):854-861. doi:10.1016/j.orthres.2003.10.013
4. Hsu RW, Hsu WH, Tai CL, Lee KF. Effect of shock-wave therapy on patellar tendinopathy in a rabbit model. J Orthop Res. 2004;22(1):221-227. doi:10.1016/S0736-0266(03)00138-
5. Gallagher A, Cross AR, Sepulveda G. The effect of shock wave therapy on patellar ligament desmitis after tibial plateau leveling osteotomy. Vet Surg. 2012;41(4):482-485. doi:10.1111/j.1532-950X.2012.00958.x