scholarly journals In cervical arthroplasty, only prosthesis with flexible biomechanical properties should be used for achieving a near-physiological motion pattern

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Manfred Muhlbauer ◽  
Ernst Tomasch ◽  
Wolfgang Sinz ◽  
Siegfried Trattnig ◽  
Hermann Steffan
Keyword(s):  
Healthy Volunteers ◽  
Biomechanical Properties ◽  
Prosthesis Design ◽  
X Rays ◽  
Disc Prosthesis ◽  
Motion Pattern ◽  
Healthy Individuals ◽  
Cervical Arthroplasty ◽  
Flexion Extension ◽  
Physiological Motion

Abstract Background In cervical arthroplasty, qualitative motion analysis generally investigates the position of the center of rotation (COR) before and after surgery. But is the pre-op COR suitable as reference? We believe that only a comparison against healthy individuals can answer whether a physiological motion pattern has been achieved. The aim of our study was to examine how the COR for flexion/extension after insertion of 3 biomechanically completely different types of disc prostheses compares to healthy volunteers, and whether and how prosthesis design contributes to a more natural or maybe even worse motion pattern. Methods In 15 healthy volunteers, MRI in flexion and in extension was taken, and the coordinates for the CORs (COR-HV) from C3 to C7 were determined. Then pre- and post-op flexion/extension x-rays from 30 patients with a one-level disc prosthesis underwent analysis for determination of COR from C3 to C7; 10 patients who received a Bryan, a Prestige STLP, or a Discover prosthesis were chosen, respectively. Change of post-op COR position was investigated in relation to the COR-HV. Results The pre-operative COR is not congruent with the COR found in healthy subjects and therefore cannot be used as reference for investigation whether a disc prosthesis resembles natural motion. However, the comparison with healthy individuals shows that prosthesis insertion can change the coordinates of the COR to any direction in all levels from C3/4 to C6/7 regardless of the operated segment. Prostheses with flexible biomechanical properties can contribute to shift the COR toward normal, but devices with unphysiological biomechanical design, like fixed ball socket designs, for instance, can make the motion pattern even worse. Conclusions Even if the small cohorts in our study do not allow strong conclusions, it seems that in cervical arthroplasty, the biomechanical concept of the prosthesis has a significant impact whether a near-physiological motion pattern can be achieved or not. As it is a rumor but not scientifically proven that prosthesis design has no influence on clinical outcome, surgeons should only choose devices with flexible biomechanical properties for disc replacement.

scholarly journals In Cervical Arthroplasty Only Prostheses with Flexible Biomechanical Properties Should be Used for Achieving a Near-Physiological Motion Pattern

2020 ◽  
Author(s):  
Manfred Muehlbauer ◽  
Ernst Tomasch ◽  
Wolfgang Sinz ◽  
Siegfried Trattnig ◽  
Hermann Steffan
Keyword(s):  
Healthy Volunteers ◽  
Biomechanical Properties ◽  
Prosthesis Design ◽  
X Rays ◽  
Disc Prosthesis ◽  
Motion Pattern ◽  
Healthy Individuals ◽  
Cervical Arthroplasty ◽  
Flexion Extension ◽  
Physiological Motion

Abstract Background: In cervical arthroplasty, qualitative motion analysis generally investigates the position of the Center of Rotation (COR) before and after surgery. But is the prae-op COR suitable as reference? We believe that only a comparison against healthy individuals can answer whether a physiological motion pattern has been achieved. The aim of our study was to examine how the COR for flexion / extension after insertion of 3 biomechanically completely different types of disc prostheses compares to healthy volunteers, and whether and how prosthesis design contributes to a more natural or maybe even worse motion pattern.Methods: In 15 healthy volunteers MRI in flexion and in extension was taken, and the coordinates for the CORs (COR-HV) from C3 to C7 were determined. Then prae- and post-op flexion-/extension x-rays from 30 patients with a one-level disc prosthesis underwent analysis for determination of COR from C3 to C7; 10 patients who received a Bryan-, a Prestige STLP- or a Discover prosthesis were chosen, respectively. Change of post-op COR position was investigated in relation to the COR-HV.Results: The pre-operative COR is not congruent with the COR found in healthy subjects and therefore cannot be used as reference for investigation whether a disc prosthesis resembles natural motion. However, the comparison with healthy individuals shows that Prosthesis-insertion can change the coordinates of the COR to any direction in all levels from C3/4 to C6/7 regardless of the operated segment. Prostheses with flexible biomechanical properties can contribute to shift the COR towards normal, but devices with unphysiological biomechanical design, like fixed ball-socket designs, for instance, can make the motion pattern even worse.Conclusions: Even if the small cohorts in our study do not allow strong conclusions, it seems that in cervical arthroplasty, the biomechanical concept of the prosthesis has a significant impact whether a near-physiological motion pattern can be achieved or not. As it is rumor but not scientifically proofed that prosthesis-design has no influence on clinical outcome, surgeons should only choose devices with flexible biomechanical properties for disc replacement.

scholarly journals In Cervical Arthroplasty Only Prostheses With Flexible Biomechanical Properties Should Be Used for Achieving a Near-physiological Motion Pattern

2020 ◽  
Author(s):  
Manfred Muehlbauer ◽  
Ernst Tomasch ◽  
Wolfgang Sinz ◽  
Siegfried Trattnig ◽  
Hermann Steffan
Keyword(s):  
Healthy Volunteers ◽  
Biomechanical Properties ◽  
Prosthesis Design ◽  
X Rays ◽  
Disc Prosthesis ◽  
Motion Pattern ◽  
Healthy Individuals ◽  
Cervical Arthroplasty ◽  
Flexion Extension ◽  
Physiological Motion

Abstract Background:In cervical arthroplasty, qualitative motion analysis generally investigates the position of the Center of Rotation (COR) before and after surgery.But is the prae-op COR suitable as reference? We believe that only a comparison against healthy individuals can answer whether a physiological motion pattern has been achieved. The aim of our study was to examine how the COR for flexion / extension after insertion of 3 biomechanically completely different types of disc prosthesescompares to healthy volunteers,and whether and how prosthesis design contributes to a more natural or maybe even worse motion pattern.Methods: In 15 healthy volunteers MRI in flexion and in extension was taken, and the coordinates for the CORs (COR-HV) from C3 to C7 were determined.Thenprae- and post-op flexion-/extension x-rays from 30 patients with a one-level disc prosthesis underwent analysis for determination of COR from C3 to C7; 10 patients who received a Bryan-, a Prestige STLP- or a Discover prosthesis were chosen, respectively. Change of post-op COR position wasinvestigated in relation to the COR-HV.Results:The pre-operative COR is not congruent with the COR found in healthy subjects and therefore cannot be used as reference for investigation whether a disc prosthesis resembles natural motion. However, the comparison with healthy individuals shows that Prosthesis-insertion can change the coordinates of the COR to any direction in all levels from C3/4 to C6/7 regardless of the operated segment. Prostheses with flexible biomechanical properties can contribute to shift the COR towards normal, but devices with unphysiological biomechanical design, like fixed ball-socket designs, for instance, can make the motion pattern even worse.Conclusions: In cervical arthroplasty, the biomechanical concept of the prosthesis has a significant impact whether a near-physiological motion pattern can be achieved or not.As it is rumor but not scientifically proofed that prosthesis-design has no influence on clinical outcome, surgeons should only choose devices with flexible biomechanical properties for disc replacement.

scholarly journals Correction to: In cervical arthroplasty, only prosthesis with flexible biomechanical properties should be used for achieving a near-physiological motion pattern

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Manfred Muhlbauer ◽  
Ernst Tomasch ◽  
Wolfgang Sinz ◽  
Siegfried Trattnig ◽  
Hermann Steffan
Keyword(s):  
Biomechanical Properties ◽  
Motion Pattern ◽  
Cervical Arthroplasty ◽  
Physiological Motion

An amendment to this paper has been published and can be accessed via the original article.

Fusion around Cervical Disc Prosthesis: Case Report

Neurosurgery ◽  
2005 ◽  
Vol 57 (1) ◽  
pp. E194-E194 ◽  
Author(s):  
Ronald H.M.A. Bartels ◽  
Roland Donk
Keyword(s):  
Signs And Symptoms ◽  
Herniated Disc ◽  
Cervical Disc ◽  
X Rays ◽  
Disc Prosthesis ◽  
Cervical Arthroplasty ◽  
Bony Fusion ◽  
Bryan Disc ◽  
Cervical Disc Prosthesis ◽  
The Right

Abstract OBJECTIVE AND IMPORTANCE: Cervical arthroplasty is a relatively new method to maintain motion after cervical anterior discectomy. Two cases are presented in which bony fusion occurred around a cervical disc prosthesis. CLINICAL PRESENTATION: A 30-year-old man and a 49-year-old woman underwent a right-sided anterior cervical discectomy because of pain in the right arm resulting from a herniated disc (C5–C6). INTERVENTION: A cervical disc prosthesis (Bryan disc prosthesis) was implanted. Postoperatively, the patients were completely free of pain. At the regular 1- and 2-year follow-up examinations, bony fusion was seen on plain x-rays of the cervical spine. The patients were still completely free of signs and symptoms. CONCLUSION: This is the first report in the literature of bony fusion after cervical arthroplasty with the Bryan disc prosthesis.

Toward a pragmatic migraine model for drug testing: 1. Cilostazol in healthy volunteers

Cephalalgia ◽  
2015 ◽  
Vol 36 (2) ◽  
pp. 172-178 ◽  
Author(s):  
Emma Katrine Hansen ◽  
Song Guo ◽  
Messoud Ashina ◽  
Jes Olesen
Keyword(s):  
Physical Activity ◽  
Healthy Volunteers ◽  
Migraine Headache ◽  
Drug Testing ◽  
Rescue Medication ◽  
No Reduction ◽  
Healthy Individuals ◽  
Double Blind ◽  
Headache Intensity ◽  
Accompanying Symptoms

Background A model for the testing of novel antimigraine drugs should ideally use healthy volunteers for ease of recruiting. Cilostazol provokes headache in healthy volunteers with some migraine features such as pulsating pain quality and aggravation by physical activity. Therefore, this headache might respond to sumatriptan, a requirement for validation. The hypothesis of the present study was that sumatriptan but not placebo is effective in cilostazol-induced headache in healthy individuals. Methods In a double-blind, randomized, cross-over design, 30 healthy volunteers of both sexes received cilostazol 200 mg on two separate days, each day followed by oral self-administered placebo or sumatriptan 50 mg. Headache response and accompanying symptoms were registered in a questionnaire by the participants themselves. Results Cilostazol induced a reproducible headache in 90% of the participants. The headache had several migraine-like features in most individuals. Median peak headache score was 2 on the sumatriptan day and 3 on the placebo day ( p = 0.17). There was no reduction in headache intensity two hours after sumatriptan ( p = 0.97) and difference in AUC 0 to four hours between two experimental days was not significant ( p = 0.18). On the placebo day eight participants took rescue medication compared to 3 on the sumatriptan day ( p = 0.13). Conclusion Despite similarities with migraine headache, cilostazol-induced headache in healthy volunteers does not respond to sumatriptan.

scholarly journals Biomechanical Evaluation of Unilateral Versus Bilateral C1 Lateral Mass-C2 Intralaminar Fixation

2017 ◽  
Vol 7 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Nitin Bhatia ◽  
Asheen Rama ◽  
Brandon Sievers ◽  
Ryan Quigley ◽  
Michelle H. McGarry ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Axial Rotation ◽  
Biomechanical Properties ◽  
Lateral Mass ◽  
Intact State ◽  
Flexion Extension ◽  
Fixation Techniques ◽  
Rotation Stiffness ◽  
Biomechanical Evaluation ◽  
C2 Fixation

Study Design: Biomechanical, cadaveric study. Objectives: To compare the relative stiffness of unilateral C1 lateral mass-C2 intralaminar fixation to intact specimens and bilateral C1 lateral mass-C2 intralaminar constructs. Methods: The biomechanical integrity of a unilateral C1 lateral mass-C2 intralaminar screw construct was compared to intact specimens and bilateral C1 lateral mass-C2 intralaminar screw constructs. Five human cadaveric specimens were used. Range of motion and stiffness were tested to determine the stiffness of the constructs. Results: Unilateral fixation significantly decreased flexion/extension range of motion compared to intact ( P < .001) but did not significantly affect axial rotation ( P = .3) or bending range of motion ( P = .3). There was a significant decrease in stiffness in extension for both unilateral and bilateral fixation techniques compared to intact ( P = .04 and P = .03, respectively). There was also a significant decrease in stiffness for ipsilateral rotation for the unilateral construct compared to intact ( P = .007) whereas the bilateral construct significantly increased ipsilateral rotation stiffness compared to both intact and unilateral fixation ( P < .001). Conclusion: Bilateral constructs did show improved biomechanical properties compared to the unilateral constructs. However, unilateral C1-C2 fixation using a C1 lateral mass and C2 intralaminar screw-rod construct decreased range of motion and improved stiffness compared to the intact state with the exception of extension and ipsilateral rotation. Hence, a unilateral construct may be acceptable in clinical situations in which bilateral fixation is not possible, but an external orthosis may be necessary to achieve a fusion.

scholarly journals Experimentally-induced and real-world acute anxiety have no effect on goal-directed behaviour

2019 ◽  
Author(s):  
CM Gillan ◽  
MM Vaghi ◽  
FH Hezemans ◽  
Grothe S van Ghesel ◽  
J Dafflon ◽  
...  
Keyword(s):  
Individual Differences ◽  
Anxiety Disorders ◽  
Healthy Volunteers ◽  
Real World ◽  
Real Life ◽  
Stressful Events ◽  
Panic Attacks ◽  
Healthy Individuals ◽  
Correlational Design ◽  
Acute Anxiety

AbstractCompulsivity is associated with failures in goal-directed control, an important cognitive faculty that protects against developing habits. But might this effect be explained by co-occurring anxiety? Previous studies have found goal-directed deficits in other anxiety disorders, and to some extent when healthy individuals are stressed, suggesting this is plausible. We carried out a causal test of this hypothesis in two experiments (between-subject N=88; within-subject N=50) that used the inhalation of hypercapnic gas (7.5% CO2) to induce an acute state of anxiety in healthy volunteers. In both experiments, we successfully induced anxiety, assessed physiologically and psychologically, but this did not affect goal-directed performance. In a third experiment (N=1413), we used a correlational design to test if real-life anxiety-provoking events (panic attacks, stressful events) impair goal-directed control. While small effects were observed, none survived controlling for individual differences in compulsivity. These data suggest that anxiety has no meaningful impact on goal-directed control.

scholarly journals Evaluation of ubiquitin C-terminal hydrolase-L1 enzyme levels in patients with epilepsy

2020 ◽  
Vol 78 (7) ◽  
pp. 424-429
Author(s):  
Ibrahim Halil YASAK ◽  
Mustafa YILMAZ ◽  
Murat GÖNEN ◽  
Metin ATESCELIK ◽  
Mehtap GURGER ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Epileptic Seizure ◽  
Epileptic Seizures ◽  
Healthy Individuals ◽  
Roc Curve Analysis ◽  
Remission Period ◽  
Significant Difference ◽  
Epileptic Attack ◽  
Patients With Epilepsy

ABSTRACT Objective: Ubiquitin C-terminal Hydrolase-L1 (UCH-L1) enzyme levels were investigated in patients with epilepsy, epileptic seizure, remission period, and healthy individuals. Methods: Three main groups were evaluated, including epileptic seizure, patients with epilepsy in the non-seizure period, and healthy volunteers. The patients having a seizure in the Emergency department or brought by a postictal confusion were included in the epileptic attack group. The patients having a seizure attack or presenting to the Neurology outpatient department for follow up were included in the non-seizure (remission period) group. Results: The UCH-L1 enzyme levels of 160 patients with epilepsy (80 patients with epileptic attack and 80 patients with epilepsy in the non-seizure period) and 100 healthy volunteers were compared. Whereas the UCH-L1 enzyme levels were 8.30 (IQR=6.57‒11.40) ng/mL in all patients with epilepsy, they were detected as 3.90 (IQR=3.31‒7.22) ng/mL in healthy volunteers, and significantly increased in numbers for those with epilepsy (p<0.001). However, whereas the UCH-L1 levels were 8.50 (IQR=6.93‒11.16) ng/mL in the patients with epileptic seizures, they were 8.10 (IQR=6.22‒11.93) ng/mL in the non-seizure period, and no significant difference was detected (p=0.6123). When the UCH-L1 cut-off value was taken as 4.34 mg/mL in Receiver Operating Characteristic (ROC) Curve analysis, the sensitivity and specificity detected were 93.75 and 66.00%, respectively (AUG=0.801; p<0.0001; 95%CI 0.747‒0.848) for patients with epilepsy. Conclusion: Even though UCH-L1 levels significantly increased more in patients with epilepsy than in healthy individuals, there was no difference between epileptic seizure and non-seizure periods.

scholarly journals The application of C2 transpedicular screw, C1 laminar hook fixation and bone graft in the atlantoaxial instability

2021 ◽  
Vol 38 (2) ◽  
pp. 94-98
Author(s):  
Şükrü ORAL
Keyword(s):  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Surgical Techniques ◽  
Atlantoaxial Instability ◽  
Posterior Arch ◽  
X Rays ◽  
Advantages And Disadvantages ◽  
Transpedicular Screw ◽  
Flexion Extension ◽  
Laminar Hooks

Traumatic atlantoaxial instability usually results from a motor vehicle accident, falls and motorcycle accidents. Atlantoaxial instability can lead to spinal cord compression and neck pain, but, spasticity and radicular symptoms as well. The purpose of surgery is to remove the compression and stabilize the joint permanently. To date, several surgical techniques have been described to remedy C1-C2 instability. In this study, the clinical and radiological outcomes of patients who operated with the C1 (Atlas bone) laminar hooks fixation and bilateral C2 (Axis bone) trans-pedicular screw technique were shown. Also, the advantages and disadvantages of this technique are discussed. From March 2010 to December 2017, 12 patients who have atlantoaxial instability were surgically treated by modified fixation technique which consists C1 laminar hooks fixation and bilateral C2 transpedicular screw. Twelve patients were operated with this procedure from March 2010 to December 2017. All the patients were checked with flexion-extension x-rays at the end of the twelfth week. The posterior bony fusion formation was observed on imaging in all patients. C2 bilateral pedicle screw combined with C1 laminar hook system is a good method for atlantoaxial instability in the conditions which is not convenient for insertion of C1 lateral mass and C2 trans-articular screw. However, this method may not be available in some cases such as traumatic, infection, neoplastic or degenerative pathologies in which the posterior arch of the atlas is damaged.

Modification of Pelvic Orientation after Total Hip Replacement in Primary Osteoarthritis

2009 ◽  
Vol 19 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Elhadi Sariali ◽  
Jean Yves Lazennec ◽  
Frederic Khiami ◽  
Michel Gorin ◽  
Yves Catonne
Keyword(s):  
Healthy Volunteers ◽  
Range Of Motion ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Sacral Slope ◽  
X Rays ◽  
Acetabular Anteversion ◽  
Total Hip ◽  
Pelvic Inclination ◽  
Primary Osteoarthritis

The acetabular anteversion angle varies according to the position of the pelvis. The objective goal of our study was to investigate changes in pelvic orientation after total hip replacement for primary osteoarthritis. We studied 89 patients who underwent total hip replacement for primary unilateral osteoarthritis. Lateral pelvic X-rays that included the hips were performed pre-operatively and one year post-operatively. Reference values were calculated by carrying out the same analysis in 100 asymptomatic healthy volunteers. Pelvic orientation was analyzed using the sacral slope. Patients having surgery for osteoarthritis had a decreased pelvic range of motion pre-operatively and post-operatively when compared to healthy volunteers. Post-operatively, this range of motion increased by 3° but remained lower than the norm. Compared to asymptomatic healthy volunteers, patients affected by osteoarthritis had a posterior pelvic extension that decreased post-operatively but did not return to norm. This post-operative pelvic inclination generates a significant decrease in the final cup anteversion and thus may predispose to posterior dislocation. As this post-operative alteration to pelvic orientation cannot be anticipated, computer-aided surgery for cup positioning may not improve the accuracy of the acetabular anteversion in some patients.

Sign in / Sign up

Export Citation Format

Share Document