Elbow joint function after shortening fixation of the comminuted olecranon fractures / 中华骨科杂志

ABSTRACT

Objective The olecranon is likely to become shorter following the treatment of its comminuted fractures, which will lead to the compromise of the function of elbow joint. So through the cadaver experiment, introduce the method of making different thickness and direction in osteotomy so as to intimate the shape change of the olecranon after the comminuted fractures, and explore its effect on the flexion-extension function of the elbow joint. Methods Through three cadaver(six arms), osteotomy at 25 mm below the olecranon process was made horizontally and fixed with two screws temporarily, furthermore, the bone fragment of 1 mm, 3 mm and 5 mm in length was resected in order, then specimens were divided into two groups: In the first group, osteotomy was made up to 7 mm and 8 mm continually, and the changes of the range of the elbow joint movement were measured; in the second group, the additional wedge osteotomy of 5 mm and 7 mm was performed respectively, then the outcomes between the two groups were compared. Results If the osteotomized bone was within 3 mm, shortening internal fixation was satisfactory for the reconstruction of the elbow joint function. However, in cases of osteotomized bone of 5 mm, the extension function would be limited as the loss of the trochlear notch is too much. In order to keep the normal range motion of the elbow, the dorsal cortex distal to osteotomy should be scarified about 3 mm for the wedge osteotomy. When the shortage attained to 7 mm, the elbow instability would occur, even if advanced wedge osteotomy was accomplished. Conclusion In cases of the comminuted olecranon fractures, if the osteotomy is made within 3 mm, the shortening fixation is appropriate; if it has not exceeded 5 mm, the fracture should be treated with advanced wedge osteotomy tilting back to keep the radian of the trochlea; and if it has reached 7 mm, bone grafting is necessary for recovering of the flexion-extension of the elbow joint.