[Modified semitubular blade plate for fixation of proximal humerus fractures part I: surgical technique.]

Based on our experience with proximal humerus fractures or non-unions in a group of 35 patients we describe the technique using a modified semitubular blade plate. This implant provides sufficient stability while preserving blood supply. Originally a semitubular blade plate modified after Weber was used which at present we have replaced with a similar plate with the blade shape of our own design. This plate is indicated in two- and some three-part fractures of proximal humerus and in non-unions occurring in this area. The approach is through a deltopectoral incision without the osteotomy of the coracoid process. It is advantageous to open the articular capsule along the long head of the biceps muscle in the length of approx. 1,5 cm which allows precise orientation as concerns the position of the head and also helps to avoid perforation of the plate or screws through the articular surface. The hole for the blade are made by a special chisel. The plate is inserted from the lateral aspect of greater tuberosity. In this respect it is important not to insert the plate too proximally as it may result in the impingement. One of the errors is also the insertion of a plate into the head in a varus position. It is helpful to improve fixation with a cancellous lag screw inserted proximomedially into the head. In case of the incidence of comminution firm impaction of both main fragments is desirable. In three-part fractures the fixation may be accomplished with a figure-eight wire passing through the rotator cuff. This may significantly contribute to the improvement of the stability of the fixation. In cases involving comminution in the area of the surgical neck primary cancellous bone grafting should be considered. The most common technical error is the insertion of the plate too proximally (impingement syndrome), stabilization of the head in a varus position, perforation of the articular surface by plate or tip of the screw. Our experience as well as clinical results relating to this implant are very good and they will be described in a separate article. Key words: proximal humerus fractures, fixation, modified semitubular blade plate.