Achilles tendon healing: Long‐term biomechanical effects of postoperative mobilization and immobilization in a new mouse model

Abstract

The aim of the study was to investigate the long-term effects of postoperative immobilization as opposed to mobilization on the biomechanical attributes of healing Achilles tendons in a new experimental mouse model. Postoperative mobilization resulted in a continuous and significantly more rapid restoration of load to failure in comparison to the immobilization group. Tendon deflection was decreased by postoperative mobilization, whereas under immobilization it paradoxically increased still further in the later course. After 112 days the tendons of the mobilization group had regained their original tendon stiffness, whereas the tendons after immobilization reached only about half the values seen in the control tendons. Histologically, postoperative mobilization led to increased immigration of inflammatory cells in the early phase. In the late phase, as compared to immobilization, tendon structure was more mature, with fibre bundles arranged in parallel and interposed tendocytes.Tensile loading of the healing tendon by postoperative mobilization leads to fundamental changes in the biological process of tendon healing resulting in accelerated restoration of load to failure and reduced tendon deflection.

How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks?: Interplay between early regeneration and mechanical stimulation

“…As long as the muscle is relaxed and pliable, traction forces in the tendon callus should be low. Earlier models have used immobilization (Murrell et al 1994, Ishida et al 1996, Iwuagwu and McGrouther 1998, Yamamoto et al 1999, Palmes et al 2002, Matsumoto et al 2003. In animals, it is unclear to what extent immobilization really leads to unloading.…”

Physical activity modulates nerve plasticity and stimulates repair after achilles tendon rupture

“…The experiments clearly showed that increased physical activity accelerated the healing process in agreement with earlier published studies. [35][36][37] Maximum activity level represented by the wheel-running group was found to result in the greatest diameter of organized collagen. The diameter at 4 weeks corresponded to that reached at 14 weeks in the control group, that is, in the freely moving rats of the longitudinal study.…”

The Role of Mechanical Loading in Tendon Development, Maintenance, Injury, and Repair

“…This approach is supported by several animal models, in which early motion accelerates the repair process and results in superior tissue quality 128 . Twaddle and Poon found comparable functional results and no significant difference in rerupture rate when controlled early motion was instituted following immobilization for ten days in patients treated with or without surgery 129 .…”