Add paragraph text her5 degrees of loss of the radial bow equals 15 degrees loss of supination/pronation. Loss of the radial bow will also decrease grip strength. Restoration of the radial bow is critical for good functional outcome of the patient. Malreductions of the radius shaft fractures in adults can cause restriction of forearm rotation. 10 degrees of malrotation limits rotation by about 10 degrees. 10 degrees of angulation limits rotation by about 20 degrees. It produces widening and narrowing of the interosseous membrane during rotatory movement. In general, you are going to have loss of rotation motion with more than 10 degrees of angulation (try to avoid narrowing of the interosseous space). The deformity may indicate rotation, so if you have extensor bow or dorsal deformity, it indicates pronational deformity. To correct the deformity, you hide the deformity by supinating the forearm. If you see the apex of the deformity dorsally in the x-ray (AP view or clinically), then you hide the deformity by supinating the forearm so that you see the volar aspect and this means that you should correct it (supinate the distal fragment). To correct this rotational malalignment, the distal fragment needs to be remalipulated into supination so that it correctly aligns with the rotated/supinated proximal radius (usually happens more with proximal radius fractures). If you have a flexion bow or volar deformity, (supinational deformity), which means that the apex is volar, then hide the deformity by pronating the forearm. Hide the deformity, do the maneuvers so that you don’t see the apex anymore. Another trick in knowing if the fracture is not aligned or rotated is a sudden change in the width or the cortex or a break in the smooth curve of the radius will indicate malrotation, as shown in this diagram. Another clue is the position of the bicipital tuberosity. The theory is, that when the forearm is supinated, then the tuberosity lies medially and it is 180 degrees from the radial styloid process, so the styloid process is laterally and the tuberosity will be medially. This will help us in checking the rotation of the fractured radius on the x-ray to see if it is aligned or not. When it is aligned well, the tuberosity lies posteriorly in the mid position and lies laterally in pronation. In supination, the radial styloid process is lateral, so the tuberosity will be medial. In pronation, the thumb will be in, so the tuberosity will be out (lateral). When in mid position, the thumb is up, so the tuberosity will be posteriorly. That will help you identify rotation of the proximal fragment and line up the distal fragment in the same degree of rotation as the proximal fragment. So if you find that the bicipital tuberosity is rotated 90 degrees to the styloid process, then this is bad. Normally it should be directly opposite (should be 180 degrees to the styloid process). You need to remanipulate the fracture and may need to plate the fracture in the proper position.e.
