Table 4.
Comparison of agreement between four residents and four attending surgeons using 3D printed models
| Parameter | Residents (conventional + 3D) | Attending surgeons (conventional + 3D) | |||||||
| Kappa | Agreement | Kappa | Agreement | ∆ kappa | p value | ||||
| Characteristic | |||||||||
| Humeral head split | 0.66 | (0.37-0.95) | Substantial | 0.75 | (0.48-1.00) | Substantial | 0.09 | (-0.31 to 0.49) | 0.65 |
| Medial hinge displacement > 2 mm | 0.07 | (-0.18 to 0.33) | Slight | 0.62 | (0.24-1.00) | Substantial | 0.54 | (0.09-0.99) | 0.02 |
| Metaphyseal extension > 8 mm | 0.28 | (0.08-0.48) | Fair | 0.16 | (-0.02 to 0.33) | Slight | 0.12 | (-0.39 to 0.14) | 0.36 |
| Surgical neck fracture | 0.13 | (-0.15 to 0.40) | Slight | 0.54 | (0.10-0.98) | Moderate | 0.42 | (-0.10 to 0.94) | 0.11 |
| Anatomic neck fracture | 0.28 | (0.00-0.55) | Fair | 0.42 | (0.17-0.66) | Moderate | 0.14 | (-0.23 to 0.51) | 0.45 |
| Displacement of the humeral head | 0.10 | (-0.07 to 0.26) | Slight | 0.69 | (0.41-0.97) | Substantial | 0.60 | (0.27-0.92) | < 0.001 |
| LT displacement > 10 mm | 0.17 | (-0.06 to 0.40) | Slight | 0.11 | (-0.05 to 0.28) | Slight | 0.06 | (-0.34 to 0.22) | 0.68 |
| GT displacement > 10 mm | 0.13 | (-0.13 to 0.39) | Slight | 0.13 | (-0.14 to 0.40) | Slight | 0.00 | (-0.38 to 0.38) | > 0.99 |
| Fracture pattern | |||||||||
| Neer classification | 0.04 | (-0.05 to 0.13) | Slight | 0.05 | (-0.04 to 0.13) | Slight | 0.01 | (-0.12 to 0.13) | 0.90 |
| Hertel classification | 0.13 | (0.03-0.23) | Slight | 0.06 | (-0.01 to 0.19) | Slight | 0.07 | (-0.22 to 0.07) | 0.30 |
A kappa value less than 0 indicates poor agreement; A ∆ kappa value less than 0 indicates that agreement for residents is lower than for attending surgeons; LT = lesser tuberosity; GT = greater tuberosity.