Table 3. Hounsfield attenuation units (HU), stresses in the tarsometatarsus’s coordinate system (+x anterior, +y medial, +z proximal), and von Mises stresses σvm, at anatomical features and positions along the tarsometatarsus shaft.
Brick numbers are sampled tetrahedral elements at the specified locations (Fig 7). Abbreviations are as in Figs 1–4; CLP = collateral ligament pit, and ITM IV = the centerpoint of Trochlea metatarsi IV. Positive values indicate tension, and negative indicates compression. Except at constraints (LCML = ligamentum collaterale mediale longum, CL = Cotyla lateralis), the greatest compressive stresses occur along the bone’s long axis (σZZ) on the medial and anterior surfaces, and tensile stresses posteriorly and laterally at midshaft and just distal to this (“Mid-distal”). σvm are also highest at these positions. Note artificially high stresses where compact and cancellous elements meet in the collateral ligament pit of MT IV, low shear stresses (σXY, σYZ, σXZ) except at constraints, and low stresses at the trochlear applications of the ground reaction force (TM III lateral and medial; ITM IV).
| Stress (MPa) | |||||||||
| Feature: | Brick | HU | σXX | σYY | σZZ | σXY | σYZ | σXZ | σvm |
| CM | 132270 | 244 | -2.58 | 0.95 | -0.45 | 0.14 | 2.08 | 0.96 | 5.03 |
| CL | 9221 | 280 | -30.90 | -18.60 | -27.70 | -0.85 | 1.83 | -8.36 | 18.60 |
| FI | 480006 | 955 | 1.48 | -1.31 | -4.30 | -0.90 | -5.17 | 0.21 | 10.40 |
| H | 257214 | 238 | 0.26 | 0.83 | 9.69 | -0.15 | -1.02 | 2.32 | 10.20 |
| CLP III | 140472 | 1278 | -0.31 | -0.22 | -4.03 | -0.17 | 0.86 | 0.14 | 4.07 |
| CLP IV | 77995 | 672 | 1.75 | -0.84 | -12.40 | -0.90 | 2.54 | 3.72 | 15.30 |
| TM III lat | 70590 | 491 | 0.10 | 0.48 | 0.50 | 0.37 | -0.05 | -0.02 | 0.76 |
| TM III med | 70666 | 275 | 0.03 | -0.50 | -1.96 | -0.23 | -0.18 | 0.17 | 1.88 |
| ITM IV | 376 | 206 | -0.66 | 0.46 | -1.34 | 0.03 | 0.86 | 0.52 | 2.34 |
| LCL | 131524 | 600 | -1.29 | -0.59 | 0.05 | -0.59 | 0.80 | 0.46 | 2.23 |
| MFB | 8996 | 257 | 0.10 | 0.55 | 0.20 | 0.20 | 0.74 | -0.71 | 1.85 |
| LCML | 127255 | 417 | -1.44 | -2.56 | -18.00 | 1.62 | 5.89 | -4.29 | 20.60 |
| Shaft position: | Stress (MPa) | ||||||||
| Anterior | Brick | HU | σXX | σYY | σZZ | σXY | σYZ | σXZ | σvm |
| Proximal | 480229 | 1753 | -2.02 | -0.88 | 0.73 | 2.89 | -2.73 | -2.62 | 8.59 |
| Mid-proximal | 67642 | 1642 | -1.15 | -0.60 | -31.10 | -0.80 | 0.30 | -0.47 | 30.30 |
| Midshaft | 102208 | 1590 | 1.88 | -1.71 | -33.70 | 1.16 | -0.13 | -1.77 | 34.10 |
| Mid-distal | 93774 | 1767 | 0.64 | -0.53 | -31.90 | -0.77 | -1.47 | -3.45 | 32.60 |
| Distal | 2276 | 1741 | 0.74 | -0.81 | -12.60 | 0.60 | -0.02 | -0.04 | 12.70 |
| Posterior | |||||||||
| Proximal | 123907 | 1191 | -0.07 | -0.22 | 7.91 | 0.11 | 0.25 | 0.68 | 8.16 |
| Mid-proximal | 238875 | 1655 | 1.09 | 0.89 | 24.80 | -0.51 | -1.00 | 1.87 | 24.10 |
| Midshaft | 100989 | 1635 | -0.54 | -0.30 | 30.80 | -0.25 | -1.49 | 0.85 | 31.40 |
| Mid-distal | 94452 | 1623 | 0.67 | -0.08 | 25.20 | -0.80 | 1.82 | 3.48 | 25.80 |
| Distal | 86165 | 1725 | 0.53 | -1.05 | -0.42 | -0.02 | 1.78 | -0.36 | 3.43 |
| Medial | |||||||||
| Proximal | 66935 | 1448 | 0.19 | 0.60 | -17.30 | -0.39 | 6.82 | -1.66 | 21.40 |
| Mid-proximal | 112946 | 1830 | -0.54 | -0.70 | -25.70 | 0.29 | 2.95 | -0.05 | 25.60 |
| Midshaft | 22786 | 1892 | -0.32 | -0.11 | -22.60 | 0.06 | 1.62 | 0.75 | 22.60 |
| Mid-distal | 93732 | 1848 | 0.41 | 0.03 | -23.40 | 1.02 | 0.60 | 0.05 | 23.70 |
| Distal | 11522 | 1822 | -0.50 | -1.02 | -16.20 | 0.25 | -2.51 | 0.90 | 16.10 |
| Lateral | |||||||||
| Proximal | 123797 | 1256 | -0.41 | 0.29 | -5.78 | -0.19 | -0.36 | -1.91 | 6.67 |
| Mid-proximal | 6052 | 1721 | -0.24 | 0.63 | 6.24 | -0.19 | -0.87 | -1.13 | 6.58 |
| Midshaft | 101465 | 1792 | -1.13 | 0.56 | 15.40 | -0.64 | -0.25 | 1.12 | 15.90 |
| Mid-distal | 93738 | 1856 | 2.57 | 1.27 | 14.60 | 0.38 | 1.14 | 3.01 | 13.90 |
| Distal | 86766 | 1830 | 0.05 | 0.03 | 4.02 | -0.28 | -0.43 | 0.29 | 4.11 |