The present study evaluates a new method for determining the glenoid track using CT-scan with multiplanar reconstruction and compare it with the already published method using 3D reconstructed images
The glenoid track is a useful tool to predict engagement and therefore the risk of recurrence of dislocation, in the presence of Hill-Sachs and/or Bony Bankart lesions. To assess the glenoid track preoperatively, only methods using 3D reconstructed images have been described, but these lack a standardised, reliable and easy description.
The present study evaluates a new method for determining the glenoid track using CT-scan with multiplanar reconstruction (MPR) in comparison with using 3D reconstructed images (3DR). Our hypothesis is that the MPR-method is easier to standardize and more reproducible.
Materials And Methods
52 patients whose (arthro-) CT-scan revealed a Hill-Sachs lesion whether or not in combination with a Bony Bankart lesion were included. DICOM data from the 52 CT-scans were all analysed in Horos. Glenoid width with or without associated bony defect, as well as the Hill Sachs interval (HSI) were measured on MPR as well as on 3DR images. all measurements obtained with both methods were directly compared and evaluated for intra- and interobserver reliability.
In absolute values, only small differences were seen between the MPR and the 3D, amounting to a maximal difference of 0,7 mm for the HSI and 0,4 mm for the glenoid width. For glenoidal measurements, both methods were similar. For humeral measurements, the MPR-method demonstrated a higher inter- and intraobserver reliability than the 3DR-method.
The newly described MPR-method for the assessment of the glenoid track and HSI is at least as accurate as the published 3DR-method, with a better intra- and interobserver reliability. Since MPR are also easier to obtain, this method could be recommended for on/off track evaluation in daily practice.