Percutaneous pinning of three- or four-part fractures of the proximal humerus in elderly patients in poor general condition: MIROS® versus traditional pinning

Abstract

Purpose: Elderly subjects often have fractures of the proximal humerus, which may be difficult to manage in patients in poor general condition. The MIROS is a new percutaneous pinning device allowing correction of angular displacement and stable fixation of fracture fragments. We evaluated the results of percutaneous fixation of three- or four-part fractures of the proximal humerus of patients in the American Society of Anesthesiologists physical status three or four treated either with MIROS or traditional percutaneous pinning (TPP).

Methods: A total of 31 patients treated with MIROS and 27 undergoing TPP were enrolled in the study. Pre-operatively anteroposterior and transthoracic or axillary radiographs were obtained in all cases and computed tomography scans in patients with the most complex fractures. Follow-up evaluations were carried out at three, six, 12 and 16 weeks, and six months, one year and two years postoperatively, using the Constant Score (CS) and subjective shoulder value (SSV) methods.

Results: Of the 58 patients, 52 could be evaluated at all follow-ups. In both three- or four-part fractures there were significantly higher CS and SSV scores in the MIROS compared to the TPP group at all the late follow-ups. Lower rates of deep infection, pin tract infection and pin mobilisation were found in the MIROS group (p < 0.001). In both groups there was a significant association between the final result (CS) and either the type of fracture or complications (p < 0.001).

Conclusions: The MIROS resulted in better clinical results and less complications than TPP in elderly patients. This method, however, may not be indicated for younger patients in good general condition.

Fig. 1

Fluoroscopic view after insertion of the four K-wires of MIROS. The numbers indicate the sequence with which the wires are inserted. The arrow points to the externally placed metallic clip

Fig. 2

Photograph taken after implantation of the MIROS, showing the external part of the system

Fig. 3

A 74-year-old woman with a four-part fracture of the upper humerus and ASA PS four treated with MIROS. a, b Preoperative 3-D CT scans. c Post-operative anteroposterior radiograph. d Anteroposterior radiograph obtained at the six-month follow-up