Unilateral Heat Accelerates Bone Elongation and Lengthens Extremities of Growing Mice

作者：Serrat Maria A^*; Schlierf Thomas J; Efaw Morgan L; Shuler Franklin D; Godby Justin; Stanko Laura M; Tamski Holly L

来源：Journal of Orthopaedic Research, 2015, 33(5): 692-698.

DOI：10.1002/jor.22812

• growth plate
• endochondral ossification
• temperature
• phenotypic plasticity
• noninvasive therapeutic bone lengthening

Linear growth failure results from a broad spectrum of systemic and local disorders that can generate chronic musculoskeletal disability. Current bone lengthening protocols involve invasive surgeries or drug regimens, which are only partially effective. Exposure to warm ambient temperature during growth increases limb length, suggesting that targeted heat could noninvasively enhance bone elongation. We tested the hypothesis that daily heat exposure on one side of the body unilaterally increases femoral and tibial lengths. Mice (N=20) were treated with 40 degrees C unilateral heat for 40min/day for 14 days post-weaning. Non-treated mice (N=6) served as controls. Unilateral increases in ear (8.8%), hindfoot (3.5%), femoral (1.3%), and tibial (1.5%) lengths were obtained. Tibial elongation rate was >12% greater (15m/day) on the heat-treated side. Extremity lengthening correlated with temperature during treatment. Body mass and humeral length were unaffected. To test whether differences persisted in adults, mice were examined 7-weeks post-treatment. Ear area, hindfoot, femoral, and tibial lengths were still significantly increased approximate to 6%, 3.5%, 1%, and 1%, respectively, on the heat-treated side. Left-right differences were absent in non-treated controls, ruling out inherent side asymmetry. This model is important for designing noninvasive heat-based therapies to potentially combat a range of debilitating growth impediments in children.

• 出版日期2015-5