The amount of impaction and loss of reduction in osteoporotic proximal humeral fractures after surgical fixation.

Abstract

After surgical fixation, osteoporotic proximal humeral fractures often show high impaction and loss of reduction. This study aims at assessing the amount of impaction and loss of reduction at a short and medium follow-up. We found an alarming percentage of cases showing these complications in the first postoperative months. This study seeks to quantify the amount of humeral head impaction and loss of reduction in a consecutive series of osteoporotic proximal humerus fractures treated with a locking plate. A series of displaced proximal humerus fractures were prospectively treated with minimally invasive reduction and ostheosynthesis using a locking plate. Diagnosis and classification of fractures were based on X-ray examination and CT scan. Proximal humerus cortical bone thickness (CBTAVG) was studied to assess osteoporosis. Amount of loss of reduction and head fragment impaction were noted at 3 and 18 months of follow-up. Constant score was calculated at 6 and 18 months of follow-up. Thirty-one osteoporotic fractures were studied. Most of the fractures (21, 67.7 %) had a CBTAVG of less than 4 mm. At 3 months of follow-up, 7 cases (22.5 %) had significant loss of reduction and the mean amount of impaction was 2.8 mm. At 18 months of follow-up, only 1 additional fracture showed loss of reduction and mean impaction was 3 mm (p < 0.05). At 6 months follow-up, the mean Constant score was 58 %; while at 18 months, it was 70 % (p = 0.02). Amount of impaction was significantly correlated to age of patients (p = 0.031), female sex (p = 0.011), CBTAVG (p = 0.019), and metaphyseal comminution (p = 0.013). Osteoporotic proximal humerus fractures may present an important impaction and loss of reduction in the first 3 months after surgery even if treated with a rigid device and multiple head screws. Surgeons treating these osteoporotic fractures should be aware of these complications even when using a rigid device.