A review of the literature showed a discrepancy between biomechanical and clinical studies on fracture fixation failure in patients with poor bone quality. The objective of the present study is to assess the influence of local bone status on complications after surgical treatment of proximal humerus fractures. A prospective cohort study was initiated in 2007. The inclusion criteria were closed displaced fractures of the proximal humerus, primary fracture treatment with a Philos plate, patients aged 50 to 90, normal pre-trauma function of both shoulders in accordance to age, and monotrauma. There was active follow-up for one year with radiological assessment at clinical centers from four countries. Bone quality at the proximal humerus was determined preoperatively for the contralateral side of the fracture by CT scan, and at the contralateral radius within six weeks post-surgery by DXA. The occurrence of complications was monitored up to one year post-surgery. Independent x-ray evaluation and final classification of all complications will be performed at the end by a study review board using anonymous data and x-rays.Introduction
Methods
We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus.
