Exercise Enhances Angiogenesis During Bone Defect Healing in Mice

Holstein JH, Becker SC, Fiedler M, Scheuer C, Garcia P, Histing T, Klein M, Pohlemann T, Menger MD. J Orthop Res. 2011 Jan 21. doi: 10.1002/jor.21352. [Epub ahead of print]

Many clinicians have adopted the concept that while a patient has a musculoskeletal injury it is important to exercise the rest of the body to avoid detraining. We’ve also seen research suggesting that strengthening a limb can prevent muscle atrophy on the other limb. The authors in this animal study provide further support to the notion that patients should exercise the rest of their body when they experience a fracture. They evaluated adult mice to determine whether physical exercise affects the formation of new blood vessels during bone repair. The researchers divided the mice into two groups: a group with a running wheel and one without (they also recorded how much the animals ran). A circular bone defect was made in a cranial bone (so it is not the same mechanism as a typical fracture and it is a flat bone rather than a long bone like the radius). The group that exercised had faster bone healing and larger blood vessel diameters than the control animals. The authors suggest that this supports the idea that physical activity, in the absence of mechanical loading, promotes bone healing and new blood vessel formation in the injured bone.

There are some obvious limitations to applying this study to humans that suffer long bone fractures: 1) mice were studied for only a few days, 2) the bone trauma is not like traditional fractures, and 3) flat bones were injured rather than long bones. The authors suggest, however, that this data may be applicable to long bone healing. More research is needed to verify these claims but this is further evidence that we should encourage our patients to participate in safe physical activity while injured; just because one limb or joint is injured doesn’t mean the rest of the body has to sit idle. Properly supervised exercises may help minimize detraining, promote positive psychosocial benefits, and promote fracture healing.

Written by: Jeffrey Driban
Reviewed by: Stephen Thomas