Sat., 10/20/07 Upper Extremity, Paper #54, 10:36 am OTA-2007
Glenoid Fractures Do Not Medialize
William T. Obremskey, MD, MPH1 (a-Synthes); Bryan Armitage, BA2 (n); Bradley Corr, BA1 (n);
1Vanderbilt University, Nashville, Tennessee, USA;
2University of Minnesota, Minneapolis, Minnesota, USA
Purpose: Our objective is to show that glenoid fractures that are associated with scapula fractures do not displace medially, using 3-dimensional (3D) reconstruction measurements.
Methods: A retrospective review of displaced scapular fractures that underwent internal fixation from 1998 to 2004 were reviewed by radiographs and CT scans. 14 patients with adequate films were identified who had preoperative and postoperative radiographic and CT measurements from the most lateral aspect of the glenoid to the midline of the spine on both the injured and noninjured sides. To confirm our results, we used Mimetics software to create 3D renderings of the images to measure displacements of the glenoid purely in the coronal plane. The software allows creation of a 3D image that can account for angulation and rotation as well as medial/lateral displacement. This transformation allowed us to adjust our final measurements to account for patient positioning or fracture rotation and angulation.
Results: Using the OTA classification for scapula fractures, there were three type 9-A2.2, five type 9-A2.3, one type 9-A3.1, one type 9-A3.2, one type 9-B2.3, and three type 9-B3.2 fractures. The CT measurements indicated no patient had significant medialization of the injured glenoid to midline measurement. Two-tailed paired Student t tests of measurements of the CT and CT reconstructions indicate that no difference is present in measurements from the lateral border of the scapula of the injured compared to the noninjured side using either measurement technique (P <0.039 and P <0.027). No correlation was found comparing fracture type and displacement.
Conclusion and Significance: CT and radiographic statistical analysis demonstrates that in this patient population, the glenoid does not medialize with fractures of the scapula. The commonly held belief that the glenoid medializes in scapula fractures may not be accurate.
If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing.