Table 5 Other Methods for Assessing Glenoid Bone Loss

De Filippo et al. [66]: Cadaveric study

10 cadavers

De Filipo Method: Fig. 6

Curved MPR CT:

Assessment:

Note: Curved MPR assessed curved structures very accurate

PE 1.03 %; inter-observer reliability (Cronbach alpha) 0.995

2 had anteroinferior defects created; 1 re-measured at 3 months; measured glenoid bone area on flat MPR & curved MPR of all 10 cadavers; laser scanner used directly on cadavers as gold standard; 3 radiologists measure once

Intra-observer reliability (ICC) 0.998

Outcome:

Flat MPR CT:

PE, reliability

PE 16.99 %

Inter-observer reliability (Cronbach alpha) 0.995

Note: Authors conclude curved gives more accurate glenoid contour

Diederichs et al. [59]: Cadaveric study

5 cadavers; 30 patients with no glenoid injury

Manually traced out border of glenoid; volume and surface area calculated with measurements made manually (to calculate volume, depth was assumed to be 10 mm)

Coefficient of variation:

Assessment:

Width 1.7 %

Glenoid width, height, surface area, & volume; osteotomy created on one cadaveric glenoid; compared to contralateral for calculation; 1 investigator measured study group; another measured the controls

Volume 1.3 %

Outcome:

Coefficient of varaition

Dumont et al. [49]: Technique description

Authors describe a new method to calculate surface area loss

Best-fit circle to inferior glenoid; measured angle (alpha) from center of circle between superior and inferior edges of lesion; converted measured angle to percentage area loss = [(alpha-sinalpha)/2π] x 100

No assessment of reliability or comparison to other methods

Note: This method avoids issues with defect orientation and is simple to apply without complicated software

Tauber et al. [56]; Retrospective case series

10 patients with associated glenoid fracture (>21 % glenoid length)

Fit circle to outer glenoid, measured glenoid length at 45° angle (A), measured length to defect (B); calculated bone loss as: (A x 0.965 – B)/A x 100

Inter-observer reliability:

Assessment:

ICC = 0.81

2 examiners measured once

Average width loss 26.2 %

Outcome:

Reliability

Van Den Bogaert et al. [69]: Cadaveric study

20 cadavers

Glenohumeral index:

Glenohumeral Index Compared to Gold Standard:

Assessment:

Maximal AP diameter of humeral head / maximal AP diameter of glenoid (axial images)

Non-significant difference

Diameter measured with a digital caliper in vitro (gold standard) followed by CT quantification; 3 observers measured once

Outcome:

Direct comparison