The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform

Yoram Folman - One of the best experts on this subject based on the ideXlab platform.

  • B-twin expandable Spinal Spacer for posterior lumbar interbody stabilization: mechanical testing.
    Journal of surgical orthopaedic advances, 2006
    Co-Authors: Yoram Folman, S. Shabat, R. Gepstein
    Abstract:

    Posterior lumbar interbody fusion is an accepted surgical technique to treat disabling lower back pain due to degenerative disc disease. In the techniques that prevail, installation of large fixed-size twin cages dictate the sacrifice of the posterior stabilizing structures. Moreover, excessive retraction of the dural sac imposes potential neurological hazard. The authors present a novel technique based on a Spacer capable of threefold expansion once it has been installed in the disc space. The Spacer was laboratory tested under controlled loading conditions. Strength and fatigue tests of an isolated Spacer were performed using an artificial model. Pullout resistance and ultimate compression strength of the surgical construct were evaluated using a cadaveric specimen. The yield force and the ultimate force for the single Spacer averaged 2660 +/- 483 N and 4313 +/- 420 N, respectively, while the endurance limit at 5 million cycles averaged 931 N. The single-Spacer resistance to pullout averaged 556 +/- 207 N, while the ultimate compressive strength of bone-Spacer interface averaged 3399 +/- 136 N for a pair of Spacers. The results of the study indicate that the B-twin ESS is expected to withstand the loads imposed upon it during everyday activity and resist migration or significant subsidence until fusion is achieved.

  • Percutaneous posterior lumbar interbody fusion using the B-twin expandable Spinal Spacer.
    Minimally invasive neurosurgery : MIN, 2005
    Co-Authors: R. Gepstein, D. Werner, S. Shabat, Yoram Folman
    Abstract:

    Sixty-two suitable subjects (mean age: 49.3 years) underwent percutaneous posterior lumbar interbody fusion (PPLIF) using the B-Twin expandable Spinal Spacer (B-Twin ESS) and were followed thereafter for 2 years or longer. The clinical outcome was expressed by the change in pain intensity as scored on a visual analogue scale and the change in degree of disability as scored by the Oswestry Disability Index. The results were compared with those of a previous trial of PLIF using the B-Twin ESS in which the latter was introduced via the open surgical approach (OPLIF). Mean duration of operation was 103 minutes. Blood loss was negligible. No operative difficulties or complications were encountered. No participant was lost to follow-up. Disc space height had increased by a mean of 10 %. At that time there were no radiographic signs of non-union in any patient. The mean pain intensity and disability scores decreased by 66 % and 61 %, respectively, as compared to those on admission. The clinical outcome of the percutaneous method was comparable to that of the open procedure using the B-Twin ESS; however, the results can be interpreted as favoring the former in the context of minimal invasiveness. Should this outcome be validated in further trials, the technique may be adopted in selective cases.

  • Posterior lumbar interbody fusion for degenerative disc disease using a minimally invasive B-twin expandable Spinal Spacer: a multicenter study.
    Journal of spinal disorders & techniques, 2003
    Co-Authors: Yoram Folman, Sang-ho Lee, Jose Raul Silvera, R. Gepstein
    Abstract:

    Acquired degenerative disc disease causes gradual disc space collapse, concurrent discogenic or facet-induced pain, and possible compression radiculopathy. Surgical treatment aims to re-expand the intervertebral space and stabilize the involved segment in balanced alignment until fusion is complete. The prevailing methods make use of a twin cage device of predetermined size. Their implantation requires extensive exposure, entailing the sacrifice of posterior stabilizing structures. The procedure also results in significant traction on the dural sac and the cauda equina and is thereby a potential source of neurologic damage. The new expandable Spinal Spacer (ESS) was designed to mitigate all the shortcomings alluded to above. A prospective multicenter clinical study was conducted of 87 patients with chronic low back pain due to degenerative disc disease, treated by posterior lumbar interbody fusion (PLIF) using a newly designed ESS. The study protocol was approved by the ethics committees of all the participating institutions. The objective was to test the safety and efficacy of the device. Each participant was followed periodically for >1 postoperative year. The ongoing record included intraoperative difficulties and complications, if any, radiologic evidence of fusion and clinical outcome as scored by pre- and postoperative questionnaires pertaining to pain intensity and degree of disability. No dural lacerations or neurologic deficit occurred. There were no mechanical failures of the Spacer. Radiologic study demonstrated fusion in all but one patient. Disc space height that averaged 7.53 +/- 2.42 mm before surgery increased to 10.03 +/- 2.00 mm at the time of surgery and stabilized at 9.47 +/- 2.10 mm upon final follow-up. Visual Analog Scale and Oswestry Index decreased by 60% and 58%, respectively. PLIF using the ESS achieves the same ultimate outcome as do other methods currently in use but does not share the handicaps and hazards and is more user-friendly to the surgeon.

R. Gepstein - One of the best experts on this subject based on the ideXlab platform.

  • B-twin expandable Spinal Spacer for posterior lumbar interbody stabilization: mechanical testing.
    Journal of surgical orthopaedic advances, 2006
    Co-Authors: Yoram Folman, S. Shabat, R. Gepstein
    Abstract:

    Posterior lumbar interbody fusion is an accepted surgical technique to treat disabling lower back pain due to degenerative disc disease. In the techniques that prevail, installation of large fixed-size twin cages dictate the sacrifice of the posterior stabilizing structures. Moreover, excessive retraction of the dural sac imposes potential neurological hazard. The authors present a novel technique based on a Spacer capable of threefold expansion once it has been installed in the disc space. The Spacer was laboratory tested under controlled loading conditions. Strength and fatigue tests of an isolated Spacer were performed using an artificial model. Pullout resistance and ultimate compression strength of the surgical construct were evaluated using a cadaveric specimen. The yield force and the ultimate force for the single Spacer averaged 2660 +/- 483 N and 4313 +/- 420 N, respectively, while the endurance limit at 5 million cycles averaged 931 N. The single-Spacer resistance to pullout averaged 556 +/- 207 N, while the ultimate compressive strength of bone-Spacer interface averaged 3399 +/- 136 N for a pair of Spacers. The results of the study indicate that the B-twin ESS is expected to withstand the loads imposed upon it during everyday activity and resist migration or significant subsidence until fusion is achieved.

  • Percutaneous posterior lumbar interbody fusion using the B-twin expandable Spinal Spacer.
    Minimally invasive neurosurgery : MIN, 2005
    Co-Authors: R. Gepstein, D. Werner, S. Shabat, Yoram Folman
    Abstract:

    Sixty-two suitable subjects (mean age: 49.3 years) underwent percutaneous posterior lumbar interbody fusion (PPLIF) using the B-Twin expandable Spinal Spacer (B-Twin ESS) and were followed thereafter for 2 years or longer. The clinical outcome was expressed by the change in pain intensity as scored on a visual analogue scale and the change in degree of disability as scored by the Oswestry Disability Index. The results were compared with those of a previous trial of PLIF using the B-Twin ESS in which the latter was introduced via the open surgical approach (OPLIF). Mean duration of operation was 103 minutes. Blood loss was negligible. No operative difficulties or complications were encountered. No participant was lost to follow-up. Disc space height had increased by a mean of 10 %. At that time there were no radiographic signs of non-union in any patient. The mean pain intensity and disability scores decreased by 66 % and 61 %, respectively, as compared to those on admission. The clinical outcome of the percutaneous method was comparable to that of the open procedure using the B-Twin ESS; however, the results can be interpreted as favoring the former in the context of minimal invasiveness. Should this outcome be validated in further trials, the technique may be adopted in selective cases.

  • Posterior lumbar interbody fusion for degenerative disc disease using a minimally invasive B-twin expandable Spinal Spacer: a multicenter study.
    Journal of spinal disorders & techniques, 2003
    Co-Authors: Yoram Folman, Sang-ho Lee, Jose Raul Silvera, R. Gepstein
    Abstract:

    Acquired degenerative disc disease causes gradual disc space collapse, concurrent discogenic or facet-induced pain, and possible compression radiculopathy. Surgical treatment aims to re-expand the intervertebral space and stabilize the involved segment in balanced alignment until fusion is complete. The prevailing methods make use of a twin cage device of predetermined size. Their implantation requires extensive exposure, entailing the sacrifice of posterior stabilizing structures. The procedure also results in significant traction on the dural sac and the cauda equina and is thereby a potential source of neurologic damage. The new expandable Spinal Spacer (ESS) was designed to mitigate all the shortcomings alluded to above. A prospective multicenter clinical study was conducted of 87 patients with chronic low back pain due to degenerative disc disease, treated by posterior lumbar interbody fusion (PLIF) using a newly designed ESS. The study protocol was approved by the ethics committees of all the participating institutions. The objective was to test the safety and efficacy of the device. Each participant was followed periodically for >1 postoperative year. The ongoing record included intraoperative difficulties and complications, if any, radiologic evidence of fusion and clinical outcome as scored by pre- and postoperative questionnaires pertaining to pain intensity and degree of disability. No dural lacerations or neurologic deficit occurred. There were no mechanical failures of the Spacer. Radiologic study demonstrated fusion in all but one patient. Disc space height that averaged 7.53 +/- 2.42 mm before surgery increased to 10.03 +/- 2.00 mm at the time of surgery and stabilized at 9.47 +/- 2.10 mm upon final follow-up. Visual Analog Scale and Oswestry Index decreased by 60% and 58%, respectively. PLIF using the ESS achieves the same ultimate outcome as do other methods currently in use but does not share the handicaps and hazards and is more user-friendly to the surgeon.

S. Shabat - One of the best experts on this subject based on the ideXlab platform.

  • B-twin expandable Spinal Spacer for posterior lumbar interbody stabilization: mechanical testing.
    Journal of surgical orthopaedic advances, 2006
    Co-Authors: Yoram Folman, S. Shabat, R. Gepstein
    Abstract:

    Posterior lumbar interbody fusion is an accepted surgical technique to treat disabling lower back pain due to degenerative disc disease. In the techniques that prevail, installation of large fixed-size twin cages dictate the sacrifice of the posterior stabilizing structures. Moreover, excessive retraction of the dural sac imposes potential neurological hazard. The authors present a novel technique based on a Spacer capable of threefold expansion once it has been installed in the disc space. The Spacer was laboratory tested under controlled loading conditions. Strength and fatigue tests of an isolated Spacer were performed using an artificial model. Pullout resistance and ultimate compression strength of the surgical construct were evaluated using a cadaveric specimen. The yield force and the ultimate force for the single Spacer averaged 2660 +/- 483 N and 4313 +/- 420 N, respectively, while the endurance limit at 5 million cycles averaged 931 N. The single-Spacer resistance to pullout averaged 556 +/- 207 N, while the ultimate compressive strength of bone-Spacer interface averaged 3399 +/- 136 N for a pair of Spacers. The results of the study indicate that the B-twin ESS is expected to withstand the loads imposed upon it during everyday activity and resist migration or significant subsidence until fusion is achieved.

  • Percutaneous posterior lumbar interbody fusion using the B-twin expandable Spinal Spacer.
    Minimally invasive neurosurgery : MIN, 2005
    Co-Authors: R. Gepstein, D. Werner, S. Shabat, Yoram Folman
    Abstract:

    Sixty-two suitable subjects (mean age: 49.3 years) underwent percutaneous posterior lumbar interbody fusion (PPLIF) using the B-Twin expandable Spinal Spacer (B-Twin ESS) and were followed thereafter for 2 years or longer. The clinical outcome was expressed by the change in pain intensity as scored on a visual analogue scale and the change in degree of disability as scored by the Oswestry Disability Index. The results were compared with those of a previous trial of PLIF using the B-Twin ESS in which the latter was introduced via the open surgical approach (OPLIF). Mean duration of operation was 103 minutes. Blood loss was negligible. No operative difficulties or complications were encountered. No participant was lost to follow-up. Disc space height had increased by a mean of 10 %. At that time there were no radiographic signs of non-union in any patient. The mean pain intensity and disability scores decreased by 66 % and 61 %, respectively, as compared to those on admission. The clinical outcome of the percutaneous method was comparable to that of the open procedure using the B-Twin ESS; however, the results can be interpreted as favoring the former in the context of minimal invasiveness. Should this outcome be validated in further trials, the technique may be adopted in selective cases.

Manuela L Ferreira - One of the best experts on this subject based on the ideXlab platform.

  • surgical options for lumbar Spinal stenosis
    Cochrane Database of Systematic Reviews, 2016
    Co-Authors: Gustavo C Machado, Paulo H Ferreira, Ian A Harris, Marina B Pinheiro, Maurits W Van Tulder, Magdalena Rzewuska, Christopher G Maher, Bart W Koes, Manuela L Ferreira
    Abstract:

    Background Hospital charges for lumbar Spinal stenosis have increased significantly worldwide in recent times, with great variation in the costs and rates of different surgical procedures. There have also been significant increases in the rate of complex fusion and the use of Spinal Spacer implants compared to that of traditional decompression surgery, even though the former is known to incur costs up to three times higher. Moreover, the superiority of these new surgical procedures over traditional decompression surgery is still unclear. Objectives To determine the efficacy of surgery in the management of patients with symptomatic lumbar Spinal stenosis and the comparative effectiveness between commonly performed surgical techniques to treat this condition on patient-related outcomes. We also aimed to investigate the safety of these surgical interventions by including perioperative surgical data and reoperation rates. Search methods Review authors performed electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, AMED, Web of Science, LILACS and three trials registries from their inception to 16 June 2016. Authors also conducted citation tracking on the reference lists of included trials and relevant systematic reviews. Selection criteria This review included only randomised controlled trials that investigated the efficacy and safety of surgery compared with no treatment, placebo or sham surgery, or with another surgical technique in patients with lumbar Spinal stenosis. Data collection and analysis Two reviewers independently assessed the studies for inclusion and performed the 'Risk of bias' assessment, using the Cochrane Back and Neck Review Group criteria. Reviewers also extracted demographics, surgery details, and types of outcomes to describe the characteristics of included studies. Primary outcomes were pain intensity, physical function or disability status, quality of life, and recovery. The secondary outcomes included measurements related to surgery, such as perioperative blood loss, operation time, length of hospital stay, reoperation rates, and costs. We grouped trials according to the types of surgical interventions being compared and categorised follow-up times as short-term when less than 12 months and long-term when 12 months or more. Pain and disability scores were converted to a common 0 to 100 scale. We calculated mean differences for continuous outcomes and relative risks for dichotomous outcomes. We pooled data using the random-effects model in Review Manager 5.3, and used the GRADE approach to assess the quality of the evidence. Main results We included a total of 24 randomised controlled trials (reported in 39 published research articles or abstracts) in this review. The trials included 2352 participants with lumbar Spinal stenosis with symptoms of neurogenic claudication. None of the included trials compared surgery with no treatment, placebo or sham surgery. Therefore, all included studies compared two or more surgical techniques. We judged all trials to be at high risk of bias for the blinding of care provider domain, and most of the trials failed to adequately conceal the randomisation process, blind the participants or use intention-to-treat analysis. Five trials compared the effects of fusion in addition to decompression surgery. Our results showed no significant differences in pain relief at long-term (mean difference (MD) -0.29, 95% confidence interval (CI) -7.32 to 6.74). Similarly, we found no between-group differences in disability reduction in the long-term (MD 3.26, 95% CI -6.12 to 12.63). Participants who received decompression alone had significantly less perioperative blood loss (MD -0.52 L, 95% CI -0.70 L to -0.34 L) and required shorter operations (MD -107.94 minutes, 95% CI -161.65 minutes to -54.23 minutes) compared with those treated with decompression plus fusion, though we found no difference in the number of reoperations (risk ratio (RR) 1.25, 95% CI 0.81 to 1.92). Another three trials investigated the effects of interspinous process Spacer devices compared with conventional bony decompression. These Spacer devices resulted in similar reductions in pain (MD -0.55, 95% CI -8.08 to 6.99) and disability (MD 1.25, 95% CI -4.48 to 6.98). The Spacer devices required longer operation time (MD 39.11 minutes, 95% CI 19.43 minutes to 58.78 minutes) and were associated with higher risk of reoperation (RR 3.95, 95% CI 2.12 to 7.37), but we found no difference in perioperative blood loss (MD 144.00 mL, 95% CI -209.74 mL to 497.74 mL). Two trials compared interspinous Spacer devices with decompression plus fusion. Although we found no difference in pain relief (MD 5.35, 95% CI -1.18 to 11.88), the Spacer devices revealed a small but significant effect in disability reduction (MD 5.72, 95% CI 1.28 to 10.15). They were also superior to decompression plus fusion in terms of operation time (MD 78.91 minutes, 95% CI 30.16 minutes to 127.65 minutes) and perioperative blood loss (MD 238.90 mL, 95% CI 182.66 mL to 295.14 mL), however, there was no difference in rate of reoperation (RR 0.70, 95% CI 0.32 to 1.51). Overall there were no differences for the primary or secondary outcomes when different types of surgical decompression techniques were compared among each other. The quality of evidence varied from 'very low quality' to 'high quality'. Authors' conclusions The results of this Cochrane review show a paucity of evidence on the efficacy of surgery for lumbar Spinal stenosis, as to date no trials have compared surgery with no treatment, placebo or sham surgery. Placebo-controlled trials in surgery are feasible and needed in the field of lumbar Spinal stenosis. Our results demonstrate that at present, decompression plus fusion and interspinous process Spacers have not been shown to be superior to conventional decompression alone. More methodologically rigorous studies are needed in this field to confirm our results.

Kyu-cheol Shin - One of the best experts on this subject based on the ideXlab platform.

  • a biomechanical analysis on disc pressure distribution changes with interspinous Spinal Spacer insertion for lumbar Spinal stenosis
    The Journal of The Korean Orthopaedic Association, 2007
    Co-Authors: Soon-yong Kwon, Sung-chul Jun, Soo-jung Moon, Gye-rae Tack, Sung Jae Lee, Kyu-cheol Shin
    Abstract:

    Purpose: To assess the biomechanical effects and effectiveness of an interspinous Spinal Spacer (ISS) on the intradiscal pressure using in vitro biomechanical tests. Materials and Methods: Six calf spine specimens (less than 2 weeks of age, L1-L5) were divided to two groups the intact and the surgery groups (n=3 each). For the surgery group, an ISS made from PMMA (Greek pi=12-mm) were inserted into the space between the spinous processes of L3-L4. The intradiscal pressures at the various regions of the annulus (anterior, posterior, and posterolateral locations) and the nucleus pulposus were measured using the four pressure transducers under pure compression (700 N) and extension loads (700 N+7.5 Nm). Results: An increase in pressure was observed from neutral to extension at the posterior and posterolateral annulus. After inserting the ISS, the changes in pressure at the adjacent disc levels (L2-L3, L4-L5) were negligible regardless of the loading conditions (p>0.05). However, at the implanted level (L3-L4) statistically significant changes in the pressure were found under extension loading at the nucleus pulposus, posterior and posterolateral regions of the annulus with a pressure drop from 1.48 MPa, 1.42 MPa, 1.71 MPa to 1.11 MPa, 0.961 MPa, 1.08 MPa, at the respective locations (p<0.05). The relative percentage decrease were 25%, 31.7%, and 36.8%. Conclusion: On the implanted level, these results showed that the insertio n of the ISS with PMMA can effectively reduce the intradiscal pressures by at least 25% quite uniformly over the intraver- tebral disc during extension. More effective reduction was observed at the posterolateral location. The pressure changes at the adjacent levels were negligible in contrast to the abnormal pressure changes that are frequently reported after conventional rigid fusion. This suggests that the likelihood of adjacent level degeneration after surgery can be minimized using the ISS insertion.

  • A Biomechanical Analysis on Disc Pressure Distribution Changes with Interspinous Spinal Spacer Insertion for Lumbar Spinal Stenosis
    The Journal of the Korean Orthopaedic Association, 2007
    Co-Authors: Soon-yong Kwon, Sung-chul Jun, Soo-jung Moon, Gye-rae Tack, Sung Jae Lee, Kyu-cheol Shin
    Abstract:

    Purpose: To assess the biomechanical effects and effectiveness of an interspinous Spinal Spacer (ISS) on the intradiscal pressure using in vitro biomechanical tests. Materials and Methods: Six calf spine specimens (less than 2 weeks of age, L1-L5) were divided to two groups the intact and the surgery groups (n=3 each). For the surgery group, an ISS made from PMMA (Greek pi=12-mm) were inserted into the space between the spinous processes of L3-L4. The intradiscal pressures at the various regions of the annulus (anterior, posterior, and posterolateral locations) and the nucleus pulposus were measured using the four pressure transducers under pure compression (700 N) and extension loads (700 N+7.5 Nm). Results: An increase in pressure was observed from neutral to extension at the posterior and posterolateral annulus. After inserting the ISS, the changes in pressure at the adjacent disc levels (L2-L3, L4-L5) were negligible regardless of the loading conditions (p>0.05). However, at the implanted level (L3-L4) statistically significant changes in the pressure were found under extension loading at the nucleus pulposus, posterior and posterolateral regions of the annulus with a pressure drop from 1.48 MPa, 1.42 MPa, 1.71 MPa to 1.11 MPa, 0.961 MPa, 1.08 MPa, at the respective locations (p