Background
Methods
Three dimensional (3D) morphological analysis
Parameters | Our Study (Malay) | Mahaisavariya et al. (Thai)[19] | Rawal et al. (Indian)[16] | Bo et al. (Japan)[20] | Noble et al. (Caucasian)[3] | Massin et al. (France)[21] | Rubin et al. (Swiss)[22] |
---|---|---|---|---|---|---|---|
(n = 60) | (n = 108) | (n = 98) | (n = 100) | (n = 80) | (n = 200) | (n = 32) | |
Collo diaphyseal angle (o) | 130.46 ± 4.02 | 128.04 ± 6.14 | 124.42 ± 5.49 | 137.40 ± 4.80 | 125.40 | 123.10 ± 8.2 | 122.90 ± 5.76 |
Femoral head offset (mm) | 30.35 ± 4.26 | - | 40.23 ± 4.85 | 31.50 ± 5.00 | - | 41.00 ± 6.20 | 47.00 ± 7.20 |
Femoral neck length (mm) | 45.30 ± 4.74 | 46.22 ± 5.14 | 48.40 ± 5.66 | - | - | 49.40 ± 6.80 | - |
Femoral head diameter (mm) | 40.81 ± 3.43 | 43.98 ± 3.47 | 45.41 ± 3.66 | - | 45.90 | 45.60 ± 4.20 | 43.40 ± 2.26 |
Femoral neck diameter (mm) | 28.95 ± 3.37 | - | - | - | - | - | - |
Femoral head position (mm) | 53.14 ± 4.87 | 48.94 ± 4.95 | 52.33 ± 3.19 | - | - | 58.70 ± 7.20 | 56.10 ± 8.20 |
Anteversion (º) | 19.10 ± 8.67 | 11.37 ± 7.65 | 10.90 ± 4.22 | 27.00 ± 14.10 | 10.00 | - | - |
Medial cortex radius (mm) | 71.77 ± 30.59 | - | 100.00 | 96.70 ± 26.80 | - | - | - |
Lateral cortex radius (mm) | 82.90 ± 40.81 | - | 80.00 | 96.10 ± 23.50 | - | - | - |
Medial tapered angle (º) | 3.18 ± 2.53 | - | 4.00 | 3.80 ± 1.70 | - | - | - |
Lateral tapered angle (º) | 16.45 ± 3.52 | - | 4.00 | 3.70 ± 1.60 | - | - | - |
AP T + 20 width (mm) | 31.12 ± 3.70 | - | 26.26 ± 3.70 | - | - | - | - |
ML T + 20 width (mm) | 44.05 ± 4.59 | - | 36.78 ± 5.32 | - | 51.50 | 44.10 ± 6.00 | 43.10 ± 5.20 |
AP T-20 width (mm) | 17.54 ± 2.93 | - | 15.36 ± 2.37 | 15.00 ± 2.30 | - | - | - |
ML T-20 width (mm) | 18.45 ± 2.93 | - | 16.20 ± 2.71 | 18.00 ± 3.00 | - | 19.60 ± 2.90 | 21.00 ± 2.70 |
Isthmus position (mm) | 112.83 ± 11.80 | 112.93 ± 17.96 | 107.80 ± 9.73 | 73.00 ± 18.90 | 116.40 | - | 105.70 ± 17.90 |
AP Isthmus width (mm) | 13.12 ± 2.46 | - | 11.47 ± 2.11 | 10.40 ± 2.60 | - | - | - |
ML Isthmus width (mm) | 9.73 ± 1.80 | 10.50 ± 1.81 | 9.02 ± 1.92 | 11.90 ± 2.60 | 12.00 | 12.40 ± 2.30 | 13.10 ± 2.10 |
Canal flare index | 4.65 ± 0.83 | - | 4.23 ± 2.97 | - | - | 3.60 ± 0.80 | 3.36 ± 0.75 |
Philosophy behind stem design
Parameters | Lower Quartile | Upper Quartile | IQR | Mean | Minimum | Maximum | Range |
---|---|---|---|---|---|---|---|
Collo diaphyseal angle (o) | 126.67 | 132.78 | 6.11 | 130.68 ± 1.68 | 126.68 | 132.78 | 6.10 |
Femoral head offset (mm) | 27.29 | 33.09 | 5.80 | 30.55 ± 1.53 | 27.30 | 33.06 | 5.76 |
Femoral head position (mm) | 48.56 | 57.15 | 8.59 | 52.72 ± 2.45 | 48.76 | 57.12 | 8.36 |
Medial cortex radius (mm) | 50.19 | 95.35 | 45.16 | 65.84 ± 13.61 | 50.50 | 95.20 | 44.70 |
Lateral cortex radius (mm) | 52.56 | 95.95 | 43.39 | 74.07 ± 10.17 | 52.95 | 95.47 | 42.52 |
Medial tapered angle (º) | 1.14 | 4.36 | 3.22 | 3.74 ± 3.40 | 0.47 | 12.80 | 12.33 |
Lateral tapered angle (º) | 14.70 | 19.00 | 4.30 | 16.78 ± 1.24 | 14.76 | 18.84 | 4.08 |
AP T + 20 width (mm) | 28.66 | 32.95 | 4.29 | 31.12 ± 3.70 | 26.05 | 43.90 | 17.85 |
ML T + 20 width (mm) | 40.92 | 47.41 | 6.49 | 44.05 ± 4.59 | 33.83 | 53.47 | 19.64 |
AP T-10 width (mm) | 18.44 | 22.33 | 3.89 | 19.99 ± 0.98 | 18.53 | 22.20 | 3.67 |
ML T-10 width (mm) | 20.13 | 24.67 | 4.54 | 22.35 ± 2.97 | 15.77 | 29.43 | 13.66 |
AP T-40 width (mm) | 11.71 | 15.55 | 3.84 | 13.41 ± 1.02 | 11.80 | 15.54 | 3.74 |
ML T-40 width (mm) | 12.13 | 14.84 | 2.71 | 13.73 ± 3.11 | 9.19 | 19.29 | 10.10 |
Isthmus position (mm) | 100.00 | 120.00 | 20.00 | 112.86 ± 8.42 | 100.00 | 120.00 | 20.00 |
AP Isthmus width (mm) | 10.95 | 14.51 | 3.56 | 13.23 ± 3.36 | 9.01 | 21.10 | 12.10 |
ML Isthmus width (mm) | 8.29 | 10.89 | 2.60 | 9.58 ± 0.82 | 8.32 | 10.87 | 2.55 |
Fit and fill analysis through virtual hip arthroplasty surgery
Nonlinear 3D finite element analysis
Normal Walking | ||||
---|---|---|---|---|
Muscles point load (N) | x | y | z | Point load |
Hip contact | -378 | -229.6 | -1604.4 | P0 |
Abductor | 406 | 30.1 | 605.5 | P1 |
Tensor fascia lata, proximal part | 50.4 | 81.2 | 92.4 | P1 |
Tensor fascia lata, distal part | -3.5 | -4.9 | -133 | P1 |
Vastus lateralis | -6.3 | 129.5 | -650.3 | P2 |
Stairs Climbing
| ||||
Muscles point load (N)
|
x
|
y
|
z
|
Point load
|
Hip contact | -415.1 | -424.2 | -1654.1 | P0 |
Abductor | 490.7 | 201.6 | 594.3 | P1 |
Ilio-tibial tract, proximal part | 73.5 | -21 | 89.6 | P1 |
Ilio-tibial tract, distal part | -3.5 | -5.6 | -117.6 | P1 |
Tensor fascia lata, proximal part | 21.7 | 34.3 | 20.3 | P1 |
Tensor fascia lata, distal part | -1.4 | -2.1 | -45.5 | P1 |
Vastus lateralis | -15.4 | 156.8 | -945.7 | P2 |
Vastus medialis | -61.6 | 277.2 | -1869.7 | P3 |
Results
Three dimensional (3D) morphological analysis
Novel cementless femoral stem design
Three dimensional (3D) fit and fill analysis
Level | Fit (%) | Anteroposterior view | Mediolateral view | ||||
---|---|---|---|---|---|---|---|
Femur (mm2) | Implant (mm2) | Fill (%) | Femur (mm2) | Implant (mm2) | Fill (%) | ||
Proximal | 42.89 | 873.42 | 843.29 | 96.55 | 1108.56 | 600.00 | 54.12 |
Middle | 58.18 | 586.19 | 505.35 | 86.21 | 604.49 | 470.10 | 77.77 |
Distal | 62.65 | 934.52 | 621.90 | 62.19 | 747.46 | 621.90 | 83.20 |
Total | 53.68 | - | - | 83.10 | - | - | 71.70 |