Table 3.
Results of meta-analyses calculating the difference in range of motion of intact spinal segments and after ball-and-socket total disc replacement of each spinal segment, motion direction and device using finite element models (FEMs). CAD Charité artificial disc, bsTDR ball-and-socket total disc replacement, AbsTDR all bsTDR (activL, CAD, InOrbit, Maverick, NewPro, Prodisc-L, prototype of an artificial disc in development, Slide-Disc, Triumph), CROM change in range of motion in degree, CI confidence interval (l lower and u upper limit), n number of studies, reference no. reference number.
| FEMs | L3/4 |
L4/5 |
L5/S1 |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| overall sagittal motion | extension | flexion | lateral bending | axial rotation | overall sagittal motion | extension | flexion | lateral bending | axial rotation | overall sagittal motion | extension | flexion | lateral bending | axial rotation | ||
| CAD | CROM | 2.27 | 3.32 | −1.03 | 2.85 | 1.16 | ||||||||||
| CI 95% l | 0.16 | −0.33 | −3.1 | 1.73 | −1.03 | |||||||||||
| CI 95% u | 4.38 | 6.96 | 1.05 | 3.97 | 3.34 | |||||||||||
| p-value | 0.035 | 0.074 | 0.33 | <0.00001 | 0.3 | |||||||||||
| Chi2 | 1.95 | 6.22 | 2.17 | 3.95 | 1.87 | |||||||||||
| I2 | 0% | 51.8% | 0% | 49.4% | 0% | |||||||||||
| n | 4 | 4 | 4 | 3 | 3 | |||||||||||
| reference no. | [5], [38], [41], [42] | [5], [38], [41], [42] | [5], [38], [41], [42] | [5], [41], [42] | [5], [41], [42] | |||||||||||
| Maverick | CROM | 1.32 | 1.32 | 0 | 0.29 | −0.05 | ||||||||||
| CI 95% l | −1.41 | −0.9 | −1.58 | −1.08 | −0.36 | |||||||||||
| CI 95% u | 4.05 | 3.54 | 1.58 | 1.66 | 0.25 | |||||||||||
| p-value | 0.34 | 0.24 | >0.99999 | 0.68 | 0.72 | |||||||||||
| Chi2 | 0.61 | 0.83 | 0.3 | 0.21 | 0.05 | |||||||||||
| I2 | 0% | 0% | 0% | 0% | 0% | |||||||||||
| n | 3 | 3 | 3 | 2 | 2 | |||||||||||
| reference no. | [10], [35], [38] | [10], [35], [38] | [10], [35], [38] | [10], [35] | [10], [35] | |||||||||||
| Prodisc | CROM | 3.84 | 2.96 | 0.88 | 1.45 | 1.59 | 2.38 | 3.32 | −0.97 | 2.8 | 1.79 | |||||
| CI 95% l | −4.34 | −0.2 | −4.17 | 0.29 | −0.11 | 1.3 | −0.11 | −3.33 | −0.51 | −0.66 | ||||||
| CI 95% u | 12.01 | 6.12 | 5.92 | 2.61 | 3.28 | 3.46 | 6.76 | 1.39 | 6.11 | 4.24 | ||||||
| p-value | 0.36 | 0.067 | 0.73 | 0.014 | 0.067 | 0.000016 | 0.058 | 0.42 | 0.098 | 0.15 | ||||||
| Chi2 | 10.6 | 8.08 | 5.3 | 2.46 | 3.79 | 1.37 | 4.64 | 1.95 | 2.61 | 1.78 | ||||||
| I2 | 62.3% | 50.5% | 24.5% | 0% | 0% | 0% | 56.9% | 0% | 61.7% | 43.8% | ||||||
| n | 5 | 5 | 5 | 5 | 5 | 3 | 3 | 3 | 2 | 2 | ||||||
| reference no. | [4], [32], [33], [40], [43] | [4], [32], [33], [40], [43] | [4], [32], [33], [40], [43] | [4], [32], [33], [40], [43] | [4], [32], [33], [40], [43] | [5], [38], [42] | [5], [38], [42] | [5], [38], [42] | [5], [42] | [5], [42] | ||||||
| AbsTDR | CROM | 2.88 | 2.42 | 0.46 | 1.09 | 1.1 | 1.31 | 1.84 | −0.53 | 1.36 | 0.67 | 2.55 | ||||
| CI 95% l | −4.79 | −0.74 | −4.19 | −0.79 | −1.52 | −1.35 | −1.74 | −2.74 | −1.74 | −1.29 | 2.45 | |||||
| CI 95% u | 10.55 | 5.58 | 5.1 | 2.97 | 3.72 | 3.97 | 5.42 | 1.68 | 4.45 | 2.64 | 2.65 | |||||
| p-value | 0.46 | 0.13 | 0.85 | 0.25 | 0.41 | 0.34 | 0.31 | 0.64 | 0.39 | 0.5 | <0.00001 | |||||
| Chi2 | 11.08 | 8.66 | 6.63 | 2.62 | 4.8 | 1.96 | 5.26 | 2.47 | 3.39 | 1.96 | 1.45 | |||||
| I2 | 45.8% | 30.7% | 9.5% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 30.9% | |||||
| n | 7 | 7 | 7 | 6 | 6 | 7 | 7 | 7 | 6 | 6 | 2 | |||||
| reference no. | [4], [32], [33], [34], [36], [40], [43] | [4], [32], [33], [34], [36], [40], [43] | [4], [32], [33], [34], [36], [40], [43] | [4], [32], [33], [34], [40], [43] | [4], [32], [33], [34], [40], [43] | [5], [6], [10], [35], [38], [41], [42] | [5], [6], [10], [35], [38], [41], [42] | [5], [6], [10], [35], [38], [41], [42] | [5], [6], [10], [35], [41], [42] | [5], [6], [10], [35], [41], [42] | [37], [39] | |||||