Abstract
The purpose of this study was to assess screw penetration of the humeral head after locking plate fixation of proximal humeral fractures.
The 14 patients, with an average age of 61.8 years, underwent locking plate fixation for proximal humeral fractures, and were followed up for an average one year. The types of proximal humeral fractures by Neer's classification were 2-part fractures in 2 cases, 3-part fractures in 8 cases, and 4-part fractures in 4 cases. Screw penetration of the humeral head was observed in four cases. The fracture type in all 4 cases was the 4-part fracture. A bony defect of the glenoid was suspected in two of these four cases on radiography. Removal of the implants was performed in 3 cases. In one case, screw penetration on the articular surface of the humeral head and damage of the articular cartilage on the inferior glenoid were observed during arthroscopic capsular release. Bone damage to the glenoid was not suspected in this case before arthroscopy. The average range of motion of the shoulder joint was 93 degrees in flexion and 19 degrees in external rotation in the cases of screw penetration, compared with 103 degrees in flexion and 54 degrees in external rotation in the cases without screw penetration.
The results of this study indicate that careful observation of the screw penetration and glenoid damage is required after locking plate fixation for 4-part fractures.
