An implantable sensing device includes a sensing element and a mounting element. The mounting element has a first end and a second end with a longitudinal axis therethrough. The sensing element is positioned at the first end of the mounting element with the mounting element having a length that is adjustable along the longitudinal axis. The mounting element includes a sleeve having a first open end and a second open end with the longitudinal axis therethrough. The sensing element is positioned in the second open end and includes a lead body connected thereto extending through the second open end. The sleeve includes an outer sleeve member coupled for adjustment along the longitudinal axis with respect to an inner sleeve member. Further, the mounting element may include a flexible element about the first open end extending outwardly relative to the longitudinal axis and a flange element extending outwardly relative to the longitudinal axis from at least a portion of the second end. The device can be implanted in a bone with the flange element and the flexible element for direct or indirect contact with the anterior and posterior surface of the bone.