In an embodiment, the loop structure includes an openable closed loop structure comprising a section that is configured to penetrate through the body part at least at one point of the body part. As described earlier, the closed loop structure may be defined by the closed curve. In an embodiment, the openable closed loop structure includes a closed loop structure comprising an openable section that includes a primary end and a secondary end. The openable section is attached to rest section of the loop structure at the primary end and adapted to open the section at the secondary end (i.e. defining an open mode when the section is opened) to allow access to the hollow section and positioning of the part of the body part within the hollow section. The closed mode is defined when the openable section is engaged with rest of the section at the secondary end to form the closed curve. The openable section is adapted (typically through use of the fixation unit) to penetrate through the body part at least at one point of the body part. In particular, the secondary end of the openable section is adapted to penetrate through the body part at least at one point of the body part. Alternatively, the openable closed loop structure may include multi-parts loop structure wherein the multi-parts includes a plurality of detachable parts that are configured to attach with one another to form a closed loop structure. The closed mode is defined when the plurality of detachable parts is attached to one another. Accordingly, an open mode may be defined when the plurality of detachable parts is not attached to one another and in the open mode, the loop structure is adapted to allow positioning of a part of the body part within the hollow section of the loop structure. The plurality of detachable parts individually includes at least a first end and a second end. The first ends of the plurality of detachable parts and the second ends of the plurality of detachable parts are adapted to connected to each other respectively to form a closed loop structure. At least one of the first ends or the second ends of at least one of the plurality of detachable parts is adapted to penetrate through the body part at least at one point of the body part.