Biomedical subjects

James F Zucherman

Publications and source records attributed to James F Zucherman.

9 recordsLinked to original sources

PubMed2006

Interspinous process decompression with the X-STOP device for lumbar spinal stenosis: a 4-year follow-up study.

X-STOP is the first interspinous process decompression device that was shown to be superior to nonoperative therapy in patients with neurogenic intermittent claudication secondary to spinal stenosis in the multicenter randomized study at 1 and 2 years. We present 4-year follow-up data on the X-STOP patients. Patient records were screened to identify potentially eligible subjects who underwent X-STOP implantation as part of the FDA clinical trial. The inclusion criteria for the trial were age of at least 50 years, leg, buttock, or groin pain with or without back pain relieved during flexion, being able to walk at least 50 feet and sit for at least 50 minutes. The exclusion criteria were fixed motor deficit, cauda equina syndrome, previous lumbar surgery or spondylolisthesis greater than grade I at the affected level. Eighteen X-STOP subjects participated in the study. The average follow-up was 51 months and the average age was 67 years. Twelve patients had the X-STOP implanted at either L3-4 or L4-5 levels. Six patients had the X-STOP implanted at both L3-4 and L4-5 levels. Six patients had a grade I spondylolisthesis. The mean preoperative Oswestry score was 45. The mean postoperative Oswestry score was 15. The mean improvement score was 29. Using a 15-point improvement from baseline Oswestry Disability Index score as a success criterion, 14 out of 18 patients (78%) had successful outcomes. Our results have demonstrated that the success rate in the X-STOP interspinous process decompression group was 78% at an average of 4.2 years postoperatively and are consistent with 2-year results reported by Zucherman et al previously and those reported by Lee et al. Our results suggest that intermediate-term outcomes of X-STOP surgery are stable over time as measured by the Oswestry Disability Index.

Aged↗

PubMed2006

Measurement of in vivo lumbar intervertebral disc pressure during spinal manipulation: a feasibility study.

This paper presents the first reported measurements of lumbar intervertebral disc pressure in vivo during spinal manipulation. A pressure transducer was inserted into the nucleus pulposus of one normal-appearing lumbar disc in an asymptomatic adult volunteer. Pressures were recorded during several body positions and maneuvers, then during spinal manipulation, and lastly during a repetition of the preintervention body positions. Baseline pressures in the prone and side-lying positions measured 110 kPa and 150 kPa, respectively. During the manipulation, pressure rose to a peak of 890 kPa over 250 ms. Immediately following, pressures in the prone and side-lying positions measured 150 kPa and 165 kPa, respectively. These data do not support the hypotheses that manipulation can reduce a herniation by decreasing intradiscal pressure, or cause a herniation by raising pressure to failure levels. Further work may lead to a better understanding of this treatment method.

Adult↗

PubMed2006

Quality of life of lumbar stenosis-treated patients in whom the X STOP interspinous device was implanted.

OBJECT: This study was conducted to compare the quality of life (QOL) in patients with neurogenic intermittent claudication (NIC) secondary to lumbar spinal stenosis (LSS). Using the 36-Item Short Form (SF-36) questionnaire, the authors compared the results obtained in patients treated with the X STOP Interspinous Process Decompression (IPD) System with those obtained in patients who underwent nonoperative therapies. METHODS: Patients with LSS were enrolled in a prospective 2-year multicenter study and randomized either to the X STOP or nonoperative group. The SF-36 survey was used to assess the QOL before treatment and at 6 weeks, 6 months, 1 year, and 2 years posttreatment. An analysis of variance was used to compare individual pre- and posttreatment mean SF-36 domain scores between the two groups and within each treatment group. At all posttreatment time points, the authors observed the following: (1) mean domain scores in X STOP-treated patients were significantly greater than those in patients treated nonoperatively, with the exception of the mean General Health (GH), Role Emotional, and Mental Component Summary scores at 2 years; and (2) mean posttreatment domain scores documented in X STOP-treated patients were significantly greater than mean pretreatment scores, with the exception of mean GH scores at 6, 12, and 24 months. CONCLUSIONS: The results of this study demonstrate that the X STOP device is significantly more effective than nonoperative therapy in improving the QOL in patients with LSS. The results are comparable with those reported in other studies involving traditional decompressive techniques for LSS and suggest that the X STOP implant can provide an effective treatment compared with nonoperative and conventional surgical therapies.

Aged↗

PubMed2005

A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results.

STUDY DESIGN: A randomized, controlled, prospective multicenter trial comparing the outcomes of neurogenic intermittent claudication (NIC) patients treated with the interspinous process decompression system (X STOP) with patients treated nonoperatively. OBJECTIVE: To determine the safety and efficacy of the X STOP interspinous implant. SUMMARY OF BACKGROUND DATA: Patients suffering from NIC secondary to lumbar spinal stenosis have been limited to a choice between nonoperative therapies and decompressive surgical procedures, with or without fusion. The X STOP was developed to provide an alternative therapeutic treatment. METHODS.: 191 patients were treated, 100 in the X STOP group and 91 in the control group. The primary outcomes measure was the Zurich Claudication Questionnaire, a patient-completed, validated instrument for NIC. RESULTS: At every follow-up visit, X STOP patients had significantly better outcomes in each domain of the Zurich Claudication Questionnaire. At 2 years, the X STOP patients improved by 45.4% over the mean baseline Symptom Severity score compared with 7.4% in the control group; the mean improvement in the Physical Function domain was 44.3% in the X STOP group and -0.4% in the control group. In the X STOP group, 73.1% patients were satisfied with their treatment compared with 35.9% of control patients. CONCLUSIONS: The X STOP provides a conservative yet effective treatment for patients suffering from lumbar spinal stenosis. In the continuum of treatment options, the X STOP offers an attractive alternative to both conservative care and decompressive surgery.

Aged↗

PubMed2005

The use of an interspinous implant in conjunction with a graded facetectomy procedure.

STUDY DESIGN: The range of motion (ROM) of lumbar cadaver spines was measured during flexion, extension, axial rotation, and lateral bending following graded facetectomies and implantation of an X STOP interspinous spacer implant. OBJECTIVE: The study was performed undertaken to understand better the influence of the interspinous spacer implant on the kinematics of the lumbar spine following graded facetectomies. SUMMARY OF THE BACKGROUND DATA: Lateral lumbar spinal stenosis is often treated with a unilateral or bilateral facetectomy procedure. Previous biomechanical research has shown that a facetectomy may increase the ROM during flexion and axial rotation. METHODS: Seven cadaver spines (L2-L5) were tested in flexion, extension, axial rotation, and lateral bending, and the individual ROM of each motion segment was measured. Specimens were tested intact and following 3 graded facetectomies (i.e., unilateral medial facetectomy [UMF], unilateral total facetectomy [UTF], and bilateral total facetectomy [BTF]), with and without the X STOP. RESULTS: A BTF caused a significant increase in ROM during flexion and axial rotation but not extension and lateral bending. The UMF and UTF did not affect the ROM during any of the 4 motions. The interspinous implant: (1) significantly decreased the flexion ROM for the intact, UMF, UTF, and BTF treatments; (2) significantly decreased the extension ROM for the intact, UMF, and BTF treatments but not the UTF (P < 0.13); (3) had no significant effect on the axial rotation ROM; and (4) significantly increased the lateral bending ROM for the UMF, UTF, and BTF treatments. CONCLUSIONS: The results suggest that the implant may be used in conjunction with a UMF or UTF. However, the X STOP should not be used in conjunction with BTF.

Biomechanical Phenomena↗

PubMed2005

Insertion loads of the X STOP interspinous process distraction system designed to treat neurogenic intermittent claudication.

An interspinous process implant has been developed to treat patients suffering from neurogenic intermittent claudication secondary to lumbar spinal stenosis. As most patients who suffer from spinal stenosis are over the age of 50 and may have weaker bones, it is imperative to know how bone mineral density (BMD) correlates with lateral spinous process strength. The study was undertaken to characterize the lateral failure loads of the spinous process, correlate the failure loads to BMD, and compare the failure loads to the loads required to insert an interspinous process implant. Spinous process lateral failure loads were assessed, correlated to BMD, and compared to the loads required to insert an interspinous process implant. Mean spinous process failure loads were significantly greater than the lateral insertion load of the interspinous process implant. There was a significant relationship between the BMD and spinous process failure load. The technique used to insert the interspinous implant poses little risk to spinous process failure. There is ample margin of safety between the insertion loads and spinous process failure loads. The significant relationship between BMD and spinous process failure load suggests that patients with lower BMD must be approached with more caution during the implant insertion procedure.

Biomechanical Phenomena↗

PubMed2003

The effects of an interspinous implant on the kinematics of the instrumented and adjacent levels in the lumbar spine.

STUDY DESIGN: Measurement of the kinematics of the lumbar spine after insertion of an interspinous spacer in vitro. OBJECTIVES: To understand the kinematics of the instrumented and adjacent levels due to the insertion of this interspinous implant. SUMMARY OF BACKGROUND DATA: An interspinous spacer (X Stop, SFMT, Concord, California) has been developed to treat neurogenic intermittent claudication by placing the stenotic segment in slight flexion and preventing extension. This restriction of motion by the interspinous implant may affect the kinematics of levels adjacent to the instrumented level. METHODS: Seven lumbar spines (L2-L5) were tested in flexion-extension, lateral bending, and axial rotation. Images were taken during each test to determine the kinematics of each motion segment. The interspinous implant was placed at the L3-L4 level, and the test protocol was repeated. RESULTS: The flexion-extension range of motion was significantly reduced at the instrumented level. Axial rotation and lateral bending ranges of motion were not affected at the instrumented level. The range of motion in flexion-extension, axial rotation, and lateral bending at the adjacent segments was not significantly affected by the implant. CONCLUSIONS: The implant does not significantly alter the kinematics of the motion segments adjacent to the instrumented level.

Adolescent↗

PubMed2003

The effects of an interspinous implant on intervertebral disc pressures.

STUDY DESIGN: Measurement of intradiscal pressure was performed after placement of an interspinous implant in a cadaver model. OBJECTIVE: To understand the likelihood of accelerated adjacent-level disc degeneration as a result of the implant. SUMMARY OF BACKGROUND DATA: An interspinous implant has been developed to treat lumbar neurogenic claudication secondary to spinal stenosis that places the stenotic segment in slight flexion and prevents extension. Previous biomechanical studies demonstrated that fusing one level may significantly increase the intradiscal pressures at adjacent levels. Moreover, clinical studies have reported an increased incidence of adjacent-level degeneration after lumbar spinal fusion. METHODS: Eight cadaver lumbar specimens (L2-L5) were loaded in flexion, neutral, and extension. A pressure transducer measured intradiscal pressure and annular stresses during each of the three positions at each of the three disc levels. An appropriately sized implant was placed at L3-L4, and the pressure measurements were repeated. RESULTS: The pressures at the adjacent discs were not significantly affected by the interspinous implant insertion. There was a significant decrease in intradiscal pressure at the L3-L4 disc in the posterior annulus and nucleus in the neutral and extended positions. CONCLUSIONS: The implant does not significantly change the intradiscal pressures at the adjacent levels, yet it significantly unloads the intervertebral disc at the instrumented level in the neutral and extended positions. On the basis of the current findings, it does not appear that the implant causes accelerated disc degeneration at the adjacent levels.

Aged↗

PubMed2002

Gadopentetate dimeglumine as an intradiscal contrast agent.

STUDY DESIGN: Magnetic resonance discography using gadolinium as an intradiscal contrast agent was investigated in a prospective study. OBJECTIVE: To evaluate the utility of magnetic resonance discography using gadolinium as an intradiscal contrast agent, as compared with the current standard of computed tomographic discography using intradiscal iodinated contrast agent. SUMMARY OF BACKGROUND DATA: Magnetic resonance arthrography with gadolinium has been used to evaluate shoulder, elbow, wrist, hip, knee, and other joints. Gadolinium has not been used as an intradiscal contrast agent. The authors' preliminary results using gadolinium as an intradiscal contrast agent for magnetic resonance discography were reported previously. They report the results of their completed study. METHODS: For this study, 42 disc levels were studied in 13 patients. Water-soluble iodinated contrast and gadopentetate dimeglumine were injected at each disc level. After discography, anteroposterior and lateral radiographs, computed tomography scans, and T1-weighted magnetic resonance imaging were performed. Six physicians interpreted the results from each disc level in a blinded fashion. Interscan and interobserver interpretation variability was determined for magnetic resonance discography and computed tomographic discography using the Pearson correlation-coefficient (r) test. RESULTS: Interscan variability was highly correlated between computed tomographic discography and magnetic resonance discography when used to determine disc normality (r = 0.87), general degeneration (r = 0.87), anular fissure (r = 0.89), disc herniation (r = 0.92), and contrast leakage (r = 0.77). Interscan variability was assessed by the Pearson test, and all values of r for all the readers were noted to be statistically significant at P values less than 0.01. Interobserver variability was significantly correlated among the four more experienced readers (neuroradiologists and spine surgeons), but not among the spine fellows. Interobserver variability was also significantly correlated by computed tomographic (CT) and magnetic resonance imaging (MRI) discography for disc normality (CT r = 0.60; MRI r = 0.56), general degeneration (CT r = 0.76; MRI r = 0.71), anular fissure (CT r = 0.79; MRI r = 0.84), and disc herniation (CT r = 0.63; MRI r = 0.64). The readings for contrast leakage did not reach statistical significance for computed tomographic or magnetic resonance discography. CONCLUSIONS: The high interscan and interobserver correlation rates obtained for magnetic resonance discography using gadolinium, as compared with the standard computed tomographic discography technique, indicate that magnetic resonance discography may be an acceptable substitute for the imaging of disc pathology. Magnetic resonance discography with gadolinium can be recommended for patients allergic to iodinated contrast agents and for patients who wish to limit their radiation exposure.

Contrast Media↗