Table 3.
Published studies concerning loads, stresses and sagittal balance after TDA
| References | Model | Study type | Mechanical variables | Prosthesis | Compared to | Results |
|---|---|---|---|---|---|---|
| Cakir et al. [6] | Human | Radiographic | Sagittal balance | ProDisc (semi-constrained) | – | Increased segmental lordosis, overall lordosis preserved |
| Chung et al. [9] | Human | Radiographic | Sagittal balance | ProDisc (semi-constrained) | – | Increased segmental and overall lordosis |
| Denozière and Ku [20] | Human | Computational | Motion,stability, ligament tensions, facet pressure | Ball and socket (semi-constrained) | Fusion | Greater risk of instability and further degeneration relative fusion |
| Dooris et al. [21] | Human | Computational | Motion, facet loads, intradiscal pressure, shear stresses | Ball and socket (semi-constrained) | – | Modification of the spinal bending stiffness in the sagittal plane |
| Goel et al. [28] | Human | Computational | Motion, facet loads, intradiscal pressure, shear stresses | Charité(unconstrained) | – | Increased motion at the L5-S1 level in flexion/extension; decreased facet loads; higher shear stresses at the TDA L5 endplate relative to those at S1 interface |
| Huang et al. [34] | – | – | Constraint | Semi-constrained, unconstrained | – | Unconstrained disc prostheses may have a kinematical advantage; semi-constrained disc prostheses may protect the posterior structure in shear |
| Kadoya et al. [37] | Ovine | Experimental | Static, viscoelastic and fatigue properties; histological analysis | 3D fabric disc (unconstrained) | – | Mechanical behavior similar to natural sheep disc; no debris detected |
| Ledet et al. [53] | Non-human primate | In vivo | In vivo interbody force | Instrumented interbody spacer | – | The baboon may be an appropriate animal model of the human lumbar spine |
| Le Huec et al. [52] | Human | Radiographic | Sagittal balance | Maverick (semi-constrained) | – | Preserved sagittal balance |
| Le Huec et al. [51] | Human | Radiographic | Sagittal balance, facet loads | Maverick (semi-constrained) | – | Facet loads may be not increased after implantation of a semi-constrained disc prosthesis |
| Lemaire et al. [56] | Human | Radiographic | Sagittal balance | Charité (unconstrained) | – | 87% patients had a restoration of lumbar sagittal balance |
| Mathew et al. [60] | Human | – | – | ProDisc (semi-constrained) | – | Complication: bilateral pedicle fracture, probably related to the lordosis angle distribution of the prosthesis design |
| McAfee et al. [62] | Human | Ex vivo | Motion | Charité (unconstrained) | – | TDA accentuates scoliotic tendencies in the lumbar spine |
| Moumene and Geisler [66] | Human | Computational | Loading on the facet joints, stress on the polyethylene core | Unconstrained, semi-constrained | – | Unconstrained TDA unloads facet joints and presents decreased core stress as compared to fixed-core (semi-constrained) TDA |
| Rohlmann et al. [77] | Human | Computational | Alignment in standing position and flexion | ProDisc (semi-constrained) | – | Implant position strongly influences intersegmental rotation in standing and flexion |
| Rousseau et al. [78] | Human | Experimental | Motion, facet forces | Charité (unconstrained) ProDisc (semi-constrained) | – | ProDisc: decreased facet forces, IAR variable; Charité: increased facet forces, IAR less variable |
| Shim et al. [84] | Human | – | – | ProDisc (semi-constrained) | – | Case report of two split fractures of the vertebral body due to the keel design |
| Tournier et al. [88] | Human | Radiographic | Motion, disc height, sagittal balance | Charité (unconstrained) Maverick, ProDisc (semi-constrained) | – | Preserved motion and disc height, preserved sagittal balance, modification of the lumbar curvature |
| Trouillier et al. [89] | Human | Radiographic | Facet joint integrity | Charité (unconstrained) | – | Implantation of the disc prosthesis was not associated to increased loading in the facet joints |
| Van Ooij et al. [91] | Human | Radiographic | Degeneration, stability | Charité (unconstrained) | – | Observed complications: degeneration of adjacent discs, facet joint arthrosis at the implanted and other levels, subsidence |
| Wenzel and Sheperd [94] | Human | Computational | Contact stresses on the articulating surfaces | Ball-and-socket | – | Stresses below the fatigue strength of the employed materials |
TDA total disc arthroplasty, IAR instantaneous axis of rotation