LAUSR

INTRODUCTION Diaphyseal fractures with proximal humeral extension can be treated using a helical model, so it is lateral on the proximal aspect and on the diaphyseal segment in the anterior surface. OBJECTIVE Our objective was to evaluate possible rotational deviations using minimally invasive plate osteosynthesis (MIPO) and to determine how it affects upper limb function. METHODS We followed 11 patients for a period of two years. The proximal approach was anterior-lateral, and the distal approach was anterior, dividing the brachial muscle. For rotational evaluation, we used the semi-axial incidence described by Oztuna et al., assessing the degree of retroversion of the humeral head in relation to the elbow. During follow-up, we measured bilateral range of motion, shoulder function (UCLA), and upper limb function (DASH). RESULTS For patients whose final result was an increase in retroversion, there was an average difference of 9°, with an increase in the final difference of external rotation of 3° compared with the other shoulder, and no difference between the final levels of internal rotation. In the patients whose final result was a decrease in retroversion, where the distal fragment was fixed in internal rotation, the difference observed was an average of 6°. These patients had an average decrease of the external rotation of 5° with an increase of the internal rotation by two levels. The final functional scores were "good" and "excellent" in all patients, with a mean UCLA of 31.8 points (28-34) and a mean DASH of 9.11 points (0.83-22.2). CONCLUSION In all patients, there was a difference in the humeral head retroversion compared to the contralateral limb, but with little clinical repercussion and good or excellent functional scores.