A system for monitoring strain on a musculoskeletal element of a patient having an injury at an injury location, arranged to perform monitoring at least once a week, over a period of at least 12 weeks, or at least 12 times, the system comparing: an implantable load-bearing fixation and sensing device comprising: an implantable reinforcement structure; a deformation sensing arrangement physically coupled to the reinforcement structure to be at least partially implanted in the patient, the deformation sensing arrangement for sensing deformation of the implantable reinforcement structure; a power supply arrangement arranged to provide power to the deformation sensing arrangement; a short-range wireless transceiver arranged to communicate digital data using a first protocol; and a processor arranged to control the power supply arrangement to power the deformation sensing arrangement selectively, to obtain a measure indicative of deformation associated with stress or movement in the vicinity of the injury location, to communicate via the short range wireless transceiver to an external user device, to receive a first signal to trigger powering the deformation sensing arrangement and to transmit a second signal based on said measure to the external user device; a user device comprising: a first communication interface configured when positioned externally of the patient to send the first signal to trigger the processor to power the distributed strain sensing arrangement and obtain the measure indicative of deformation in the vicinity of the injury location, and to receive the second signal using the first protocol; a second communication interface configured to communicate measurement data based on the second signal to a remote server; and an arrangement for triggering a measurement correlated with the patient adopting a predetermined or known pose with respect to the injury location.