Total disc replacement arthroplasty using the AcroFlex lumbar disc: a non-human primate model

Cunningham, Bryan W.; Lowery, Gary L.; Serhan, Hassan; Dmitriev, Anton E.; Orbegoso, Carlos M.; McAfee, Paul C.; Fraser, Robert D.; Ross, Raymond; Kulkarni, Samir S.

doi:10.1007/s00586-002-0481-z

Cited by 42 publications

(12 citation statements)

References 31 publications

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“…The Flexibility test method has been described [13], and used in many studies of fusion devices [2,4,7,12], and non-fusion devices [5,10]. In the present study, the input was unconstrained pure moment applied in flexion/extension: maximum of 8 Nm in the presence of 400 N follower load [16].…”

Section: Flexibility Test Methodsmentioning

confidence: 99%

StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects

et al. 2007

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Rationale behind motion preservation devices is to eliminate the accelerated adjacent-level effects (ALE) associated with spinal fusion. We evaluated multidirectional flexibilities and ALEs of StabilimaxNZ and simulated fusion applied to a decompressed spine. StabilimaxNZ was applied at L4-L5 after creating a decompression (laminectomy of L4 plus bilateral medial facetectomy at L4-L5). Multidirectional Flexibility and Hybrid tests were performed on six fresh cadaveric human specimens (T12-S1). Decompression increased average flexion-extension rotation to 124.0% of the intact. StabilimaxNZ and simulated fusion decreased the motion to 62.4 and 23.8% of intact, respectively. In lateral bending, corresponding increase was 121.6% and decreases were 57.5 and 11.9%. In torsion, corresponding increase was 132.7%, and decreases were 36.3% for fusion, and none for StabilimaxNZ ALE was defined as percentage increase over the intact. The ALE at L3-4 was 15.3% for StabilimaxNZ versus 33.4% for fusion, while at L5-S1 the ALE were 5.0% vs. 11.3%, respectively. In lateral bending, the corresponding ALE values were 3.0% vs. 19.1%, and 11.3% vs. 35.8%, respectively. In torsion, the corresponding values were 3.7% vs. 20.6%, and 4.0% vs. 33.5%, respectively. In conclusion, this in vitro study using Flexibility and Hybrid test methods showed that StabilimaxNZ stabilized the decompressed spinal level effectively in sagittal and frontal planes, while allowing a good portion of the normal rotation, and concurrently it did not produce significant ALEs as compared to the fusion. However, it did not stabilize the decompressed specimen in torsion.

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Section: Flexibility Test Methodsmentioning

confidence: 99%

StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects

et al. 2007

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“…The regions of trabecular contact were subsequently traced, quantified in pixels, and expressed as a percentage of the total endplate area (% ingrowth = apparent bone contact area/gross total endplate area). The above quantitative evaluation method has been widely used in several previous studies [ 11 – 15 ].…”

Section: Methodsmentioning

confidence: 99%

In-vivo study of osseointegration in Prestige LP cervical disc prosthesis

Lou¹,

Wang²,

Wu³

et al. 2018

BMC Musculoskelet Disord

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BackgroundA study was designed to quantify the extent of porous osseointegration at the prosthesis-bone interface in the Prestige LP prosthesis containing a plasma-sprayed titanium coating.MethodsUsing an anterior surgical approach, cervical disc arthroplasty was performed in 8 mature male goats at the C3-C4 segment, followed by implantation of the Prestige LP prosthesis. The vertebral specimens were examined using microcomputed tomograph for histomorphometric quantification, and proceeded by routine paraffin processing for histological observation. Hence, the porous osseointegration at the prosthesis-bone interface was evaluated based on histologic and histomorphometric analyses.ResultsAt 6 months after surgery, there was no evidence of prosthesis migration, loosening, subsidence, or neurologic or vascular complications. Based on gross histologic analysis, there was excellent porous ingrowth at the prosthesis–bone interface, without significant histopathologic changes. Histomorphometric analysis at the prosthesis-bone interface indicated the mean porous ingrowth of 48.5% ± 10.4% and the total ingrowth range of 36.6 to 59.8%.ConclusionsAs the first comprehensive in vivo investigation into the Prestige LP prosthesis, this project established a successful animal model in the evaluation of cervical disc arthroplasty. Moreover, histomorphometric analysis of porous ingrowth at the prosthesis-bone interface was more favorable for cervical disc arthroplasty with the Prestige LP prosthesis compared to historical reports of appendicular total joint arthroplasty.Electronic supplementary materialThe online version of this article (10.1186/s12891-018-1957-2) contains supplementary material, which is available to authorized users.

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“…The first version, a precursor of the Freedom disc named Acroflex (Depuy, Acromed Inc. Raynham Mass. ), was an unconstrained lumbar design consisting of porous coated titanium endplates with a polyolefin rubber core [25]. Although the rubber was extensively tested for its fatigue life and wear properties [26], the results of this study demonstrated rubber tears in 36% of the patients [27].…”

Section: Endplate Sandwiched -Monoblockmentioning

confidence: 99%

Viscoelastic cervical total disc replacement devices: Design concepts

2020

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Cervical disc replacement (CDR) is a motion-preserving surgical procedure for treating patients with degenerative disorders. Numerous reports of first generation CDR "ball-and-socket" articulating devices have shown satisfactory clinical results. As a result, CDR devices have been safely implemented in the surgeon's armamentarium on a global scale. However, only minor design improvements have been made over the last few years, as first generation CDRs devices were based on traditional synovial joint arthroplasty designs. As a consequence, these articulating designs have limited resemblance to the complex kinematic behavior of a natural disc. This has driven the development of deformable viscoelastic CDR devices to better mimic the biomechanical behavior of a natural disc. As a result, several viscoelastic CDR devices have been developed in recent years that vary in terms of materials, design and clinical outcomes. Since these viscoelastic CDR devices are fairly new, their weaknesses and strengths, which are related to their design characteristics, have not been well described. Therefore, this literature review discusses design related advantages and disadvantages of deformable viscoelastic CDR devices. As such, this paper can provide insight for surgeons and engineers on specific design characteristics of several viscoelastic devices and could potentially help to develop and design future implants. Eleven viscoelastic CDR devices were identified. An extensive database search on the devices' tradenames in Medline and PubMed was performed next. The devices were categorized based on common design characteristics to give an overview of both category and device specific complications and advantages. Overall, literature shows that most of these viscoelastic CDR devices can provide motion in all six degrees-of-freedom and have a variable center of rotation. Nevertheless, the viscoelastic materials used do not have an extensive history in orthopedics, so the long-term material behavior in vivo is still unknown. Although the viscoelastic devices have common benefits and risks, each specific design and category also has its own design related advantages and drawbacks that are described in this review. Altogether, viscoelastic total disc replacements seem to be a promising option for the future of cervical arthroplasty, but long-term clinical outcome is needed to confirm the advantages of mimicking the viscoelasticity of a natural disc.

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Total disc replacement arthroplasty using the AcroFlex lumbar disc: a non-human primate model

Cited by 42 publications

References 31 publications

StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects

StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects

In-vivo study of osseointegration in Prestige LP cervical disc prosthesis

Viscoelastic cervical total disc replacement devices: Design concepts

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