Trauma-series x-rays of a 75-year-old woman at the follow-up of three months after surgery, the black arrow pointed at the screw penetrating the joint while it was missed on the true glenoid anteroposterior and transscapular lateral radiographs.

<p>Trauma-series x-rays of a 75-year-old woman at the follow-up of three months after surgery, the black arrow pointed at the screw penetrating the joint while it was missed on the true glenoid anteroposterior and transscapular lateral radiographs.</p

Correlation between classification and secondary screw penetration in proximal humeral fractures

<div><p>Objectives</p><p>In this study, we investigated the correlation between fracture classification and secondary screw penetration.</p><p>Methods</p><p>We retrospectively identified 189 patients with displaced proximal humeral fractures treated by ORIF at our hospital between June 2006 and June 2013. All fractures were classified radiographically before surgery and follow-up for least 2 years after surgery was recommended. At each follow-up, radiographs were taken in three orthogonal views to evaluate secondary screw penetration.</p><p>Results</p><p>The study population consisted of 189 patients. Of these, 70 were male and 119 female, with a mean age of 59.1 years; the mean follow-up time was 28.5 months. Secondary screw penetration occurred in 26 patients. The risk of developing secondary screw penetration was 11.3-fold higher in four-part fractures than two-part fractures (<i>P</i> < 0.05), 8.6-fold higher for type C fractures than type A fractures (<i>P</i> < 0.05) and 11.0-fold higher for medial hinge disruption group than intact medial hinge group fractures (<i>P</i> < 0.05). However there was no difference between three-part fractures and two-part fractures (<i>P</i> = 0.374), and between type B and type A fractures (<i>P</i> = 0.195). Age, gender, time to surgery and the number of screw in humeral head had no influence on the secondary screw penetration rate (<i>P</i> > 0.05).</p><p>Conclusions</p><p>Patients with four-part fractures, type C fractures and medial hinges disruption are vulnerable to secondary screw penetration. This allows additional precautions to be instituted and measures to be taken as needed.</p></div

Screw penetration rate in the three fracture classification systems.

<p>Screw penetration rate in the three fracture classification systems.</p