Aim: The treatment of the fractures to three and four fragments of the humerus still represents a challenge. The authors describe the surgical technique and results with a modular prosthesis that permits an anatomical reconstruction of the proximal humerus from the calcarside, that becomes the point reference of reconstruction with the “Puzzle-Pieces” technique.

Methods: From February 2000 to February 2007 41 patients were treated with modular prosthesis. They were 8 males and 33 females aged between 56 and 79 years. In 23 cases the interested shoulder has been the right, in 18 the left. All fractures were diagnosed with X-ray and CT-scan. The type of fracture includes: 20 fractures of four fragments, 15 pluri-fragmentary fractures, and 6 fracture\dislocations. At the follow-up we evaluated 26 patients.

Results: The functional results were evaluated in 26 patients by Constant score with a mean follow-up of 4 years. All the patients reviewed have executed a X-Ray, while in 18 cases we also have evaluated the reconstruction of the tuberosities with CT-scan. In one case there has been had a complete resorption of the tuberosities with insufficiency of rotator cuff. The mean of forward elevation was 132° Conclusion: The plant of a humeral pros-thesis for fractures is a very complex intervention. The technique, for modular prostheses it’s not very codified. Moreover the results from the Literature are inconstant in particular as to function of the shoulder, not predictable and often were it accompanied by complications.

The technique we described consists in the identification and reconstruction of the medial part of calcar that becomes “the thread conductor” for restoration of the height and the retrotorsion of the humeral head.