Intentional Overscrewing of Humeral Head in Comminuted Fracture of Proximal Humerus and its Impact on Shoulder Function . A Case Study.

An 86-year-old female was operated on due to a comminuted fracture of the right proximal humerus whose configu-ration necessitated over-screwing of the humeral head to improve stability, with the screws directed divergently: anteriorly and poste-riorly, to minimize their conflict with the acetabulum. 3.5 years later she sustained a corresponding fracture of the left shoulder which was stabilized without over-screwing. On both occasions, the fractures were stabilized with titanium interlocking plates (ChM, Poland) and the limbs were immobilized in a shoulder brace for three weeks followed by in-tensive rehabilitation. The patient attended a follow-up visit at 12 months (i.e. 52 months post the right shoulder fracture) which included an assess-ment of radiographs, pain and limb function as well as tests of the range of movement of the shoulder and girdle. Assessments were repeated at 12 and 18 months afterwards. Patient denied limb pain and dysfunction. Abduction was reduced by 20°, which was compensated for by the scapulothoracic joint. Shoulder (girdle) abduction reached 50° (150°) for the right and 70° (170°) for the left extremity. Flexion was reduced by 20°, but extension and rotations were comparable. At 12 months post fracture, no improvement of limb mobility was noted despite continued intensive physiotherapy. X-rays showed satisfactory bone union. The patient scored 87 for the right and 89 for the left shoulder according to the Con-stant score and 6.8 points for each limb according to the QuickDash score. Overscrewing of the humeral head is not the most beneficial method for improving stability of comminuted proximal humeral fractures; however, it may be used when alternative and more suitable methods are unavailable. Moreover, directing screws divergently anteriorly and posteriorly to minimize their conflict with the scapular acetabulum does not interfere with joint function outcomes.