Biomechanical effect of different lumbar interspinous implants on flexibility and intradiscal pressure

Wilke, Hans–Joachim; Drumm, J.; Häussler, K.; Mack, C.; Steudel, Wolf-Ingo; Kettler, Annette

doi:10.1007/s00586-008-0657-2

Cited by 188 publications

(145 citation statements)

References 20 publications

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“…A recent finite-element analysis suggested that the Wallis lowers stress in the disc fibers and annulus matrix, which may contribute to its ability to relieve pain [24]. Recent studies showed that Wallis not only stabilized and reduced intradiscal pressure during extension, but also restricted flexion [7,25]. Results of the current study confirm its effect on motion, and extension was the most affected.…”

Section: Discussionsupporting

confidence: 75%

“…Since the 1980s, non-rigid, dynamic implants have been studied in an attempt to reduce ASD. The most commonly used dynamic stabilization systems are either fixed in the pedicles, or secured between the spinous processes [2][3][4][5][6][7]. The first pedicle screw-based system was likely the Graf ligamentoplasty, which used knitted Dacron bands (INVISTA, Wichita, KS, USA) to lock the facet joints in extension and thus limit flexion [18,19].…”

Section: Discussionmentioning

confidence: 99%

“…''Dynamic'' or ''semi-rigid'' stabilization are terms used to describe instrumentation systems designed to restore stiffness to lumbar motion segments with degenerative instability that are associated with chronic low back pain. A number of dynamic stabilization implants applied via a posterior approach have been developed since the 1980s [2][3][4][5][6][7]. The most common designs are pedicle screw systems and interspinous implants.…”

Section: Introductionmentioning

confidence: 99%

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Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

et al. 2010

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Treatment of chronic low back pain due to degenerative lumbar spine conditions often involves fusion of the symptomatic level. A known risk of this procedure is accelerated adjacent level degeneration. Motion preservation devices have been designed to provide stabilization to the symptomatic motion segment while preserving some physiologic motion. The aim of this study was to compare the changes in relative range of motion caused as a result of application of two non-fusion, dynamic stabilization devices: the Universal Clamp (UC) and the Wallis device. Nine fresh, frozen human lumbar spines (L1-Sacrum) were tested in flexion-extension, lateral bending, and axial rotation with a custom spine simulator. Specimens were tested in four conditions: (1) intact, (2) the Universal Clamp implanted at L3-4 (UC), (3) the UC with a transverse rod added (UCTR), and (4) the Wallis device implanted at L3-4. Total range of motion at 7.5 N-m was determined for each device and compared to intact condition. The UC device (with or without a transverse rod) restricted motion in all planes more than the Wallis. The greatest restriction was observed in flexion. The neutral position of the L3-4 motion segment shifted toward extension with the UC and UCTR. Motion at the adjacent levels remained similar to that observed in the intact spine for all three constructs. These results suggest that the UC device may be an appropriate dynamic stabilization device for degenerative lumbar disorders.

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Section: Discussionsupporting

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

et al. 2010

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“…These implants can be divided in interspinous devices and pedicle-based devices [14]. Biomechanical studies have shown, that interspinous devices have a stabilising effect on decompressed segments in extension, but are hardly capable of stabilising a decompressed segment in axial rotation [7,13,23,26,29]. Laboratory in vitro studies of various posterior devices also mainly show a stabilising effect in flexion/extension and lateral bending and only a limited stabilising effect in axial rotation [3,18,20,[24][25][26]32].…”

Section: Introductionmentioning

confidence: 99%

Non-fusion instrumentation of the lumbar spine with a hinged pedicle screw rod system: an in vitro experiment

et al. 2009

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In advanced stages of degenerative disease of the lumbar spine instrumented spondylodesis is still the golden standard treatment. However, in recent years dynamic stabilisation devices are being implanted to treat the segmental instability due to iatrogenic decompression or segmental degeneration. The purpose of the present study was to investigate the stabilising effect of a classical pedicle screw/rod combination, with a moveable hinge joint connection between the screw and rod allowing one degree of freedom (cosmicMIA). Six human lumbar spines (L2-5) were loaded in a spine tester with pure moments of ±7.5 Nm in lateral bending, flexion/extension and axial rotation. The range of motion (ROM) and the neutral zone were determined for the following states: (1) intact, (2) monosegmental dynamic instrumentation (L4-5), (3) bisegmental dynamic instrumentation (L3-5), (4) bisegmental decompression (L3-5), (5) bisegmental dynamic instrumentation (L3-5) and (6) bisegmental rigid instrumentation (L3-5). Compared to the intact, with monosegmental instrumentation (2) the ROM of the treated segment was reduced to 47, 40 and 77% in lateral bending, flexion/ extension and axial rotation, respectively. Bisegmental dynamic instrumentation (3) further reduced the ROM in L4-5 compared to monosegmental instrumentation to 25% (lateral bending), 28% (flexion/extension) and 57% (axial rotation). Bisegmental surgical decompression (4) caused an increase in ROM in both segments (L3-4 and L4-5) to approximately 125% and approximately 135% and 187-234% in lateral bending, flexion/extension and axial rotation, respectively. Compared to the intact state, bisegmental dynamic instrumentation after surgical decompression reduced the ROM of the two-bridged segments to 29-35% in lateral bending and 33-38% in flexion/extension. In axial rotation, the ROM was in the range of the intact specimen (87-117%). A rigid instrumentation (6) further reduced the ROM of the two-bridged segments to 20-30, 23-27 and 50-68% in lateral bending, flexion/ extension and axial rotation, respectively. The results of the present study showed that compared to the intact specimen the investigated hinged dynamic stabilisation device reduced the ROM after bisegmental decompression in lateral bending and flexion/extension. Following bisegmental decompression and the thereby caused large rotational instability the device is capable of restoring the motion in axial rotation back to values in the range of the intact motion segments.

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“…While the research group was planning to perform a randomized controlled trial (RCT), such a prospective comparative study of this implant is not available in Pubmed. After the introduction of this implant by Senegas, the development of other IPDs followed, such as Minns, X-stop and Coflex [13][14][15][16]. Cadaveric studies did not show any biomechanical difference between the various IPDs, and they were therefore considered as interchangeable, although differences in clinical effectiveness were not investigated [15].…”

Section: Interspinous Process Devices Versus Microdecompressionmentioning

confidence: 99%

Minimally invasive surgery for lumbar spinal stenosis

Moojen

Gaag

2016

Eur J Orthop Surg Traumatol

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Recent trends in spine surgery, such as endoscopic and other ''micro'' techniques, promise less invasive procedures with better outcomes compared to conventional open techniques for decompressing nerves. Minimally invasive surgery (MIS), highly promoted by commercial parties for instrumented cases in particular, is popular with patients and physicians [1]. Widespread adoption of these techniques should always be preceded by careful evaluation to ensure safety and determine added value of such so-called surgical innovation [2,3]. Actual and controversial topics concerning MIS for lumbar spinal stenosis (LSS) were recently addressed in high-quality studies: open laminectomy versus microdecompression by Nerland et al. and decompression versus interspinous process implant by our group [4,5]. In some way, the opposite of MIS was addressed in a recent landmark study by Försth et al.; does decompression versus decompression plus instrumented fusion for LSS yield better outcomes [6]? The three studies address very relevant issues of the neurosurgical daily practice and will be discussed hereafter. The authors analyze data from a large, well-maintained and comprehensive national registry in Norway (the Norwegian Registry for Spine Surgery, NORspine). Thirty six out of 40 centers performing lumbar spine surgery in Norway record data prospectively in NORspine, making it a one of the unique national resource for spine research. Nerland and colleagues identified 885 eligible patients (out of 2745 screened) of whom 81 % completed the 1-year follow-up. Open laminectomy versus microdecompressionOpen laminectomy and microdecompression were associated with similar and statistically equivalent improvements in Oswestry disability scores and quality of life (EuroQol EQ-5D) at 1-year follow-up. Furthermore, the techniques did not differ in older people and obese patients in predefined subgroup analyses. The number of patients with complications was higher in the open laminectomy group (15.0 vs. 9.8 %, P = 0.018), but this difference did not hold after propensity matching (P = 0.23). Patients in the microdecompression group had shorter hospital stays, both for single-level decompression (difference 1.5 days, 95 % confidence interval 1.7-2.6, P \ 0.001) and two-level decompression (0.8 days, 1.0-2.2, P = 0.003).The authors concluded that microdecompression is the treatment of choice for patients with stenosis of the lumbar spine for the technique shows good clinical results, equal to open laminectomy at 1-year follow-up. Theoretically,

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Biomechanical effect of different lumbar interspinous implants on flexibility and intradiscal pressure

Cited by 188 publications

References 20 publications

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

Non-fusion instrumentation of the lumbar spine with a hinged pedicle screw rod system: an in vitro experiment

Minimally invasive surgery for lumbar spinal stenosis

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