Purpose

Lumbar paraspinal muscle dysfunction and low back pain are strongly correlated. Muscle atrophy is common in LBP and is recognised by MRI scan. Corticosteroid injections and physical rehabilitation programs are advocated for treatment of LBP.

The purpose is to evaluate efficacy of specific lumbar multifidus muscle retraining exercises and perifacet multifidus injections in treatment of Low Back Pain (LBP) and referred leg pain.

Purpose: To evaluate the changes in lumbar spine kinematics and clinical outcomes of patients with spinal stenosis 2 years after implantation of the X Stop interspinous decompression device.

Methods: 10 patients (6 males; 4 females) underwent X Stop procedure. Age ranged from 57 years to 71 years. 15 levels were operated (5 single levels: L_2-3 - 1, L_4-5 - 4; 5 double levels: L_3-4 +L_4-5 – 4; L_4-5+L₅S₁ – 1). A 0.6 Tesla Upright MRI scanner was used to acquire images in seated (flexion, extension, and neutral) and erect postures at preoperative, 6 months, and 2 years after surgery. The total range of motion of the lumbar spine and the operated segments were measured, along with changes in disc height, areas of the exit foramens, and dural sac. Clinical outcomes were assessed by Zurich Claudication Questionnaire before and 3, 6, 12, and 24 months after surgery.

Results: Mean Zurich Claudication Scores (n=10)

At 6 months, there was a significant increase in the spinal canal and foraminal dimension. However at 2 years there was a reduction in these dimensions such that there was no significant difference from the preop-erative measurements.

Conclusion: The results of this prospective observational study indicate that X Stop offers significant short-term improvement. It is a safe, effective, and less invasive alternative for treatment of lumbar spinal stenosis. The maximum clinical benefit and mechanical efficacy seems to be realized in the early stages postoperatively with gradual reduction thereafter over 2 years. Co-existing co-morbidities such as obesity and osteoarthritis in the lower limbs may influence the clinical results.

Introduction: This prospective observational study reports on the clinical efficacy of a complete case series of patients who have had X STOP interspinous device insertion for the treatment of lumbar spinal stenosis.

Methods: 60 patients were enrolled and asked to complete the ZCQ, ODI, SF-36 and VAS questionnaire’s pre-operatively, and at 3-, 6- and 12 months post-operatively. Clinical significance with the ZCQ is accepted as improvement in 2 of the 3 domains (where the changes correspond to a mean decrease of 0.42 or 0.46 for symptom severity or physical function respectively, or there is a mean patient satisfaction score of 2.4 or less). Changes in ZCQ were measured at each time point and compared to pre-operative levels.

Results: The mean age was 70 (range 54–90), M:F 29:30. Two of the 59 patients were withdrawn due to intra-operative spinous process fracture and unrelated death. 60% underwent single level and 40% double level insertion.

The ZCQ, ODI, SF-36 and VAS were completed preoperatively and at 12 months by 54, 50, 52, 52 respectively.

Thirty-nine patients completed all questionnaires at all time points and the maximal clinical efficacy was evident 3 months post-operatively. Clinical significant improvement was maintained at the 6- and 12 month post-operative follow-ups despite a minimal loss of clinical efficacy in absolute mean values.

Overall, clinically significant response was achieved in 65%. Seventy-one per cent of double level patients and 61% of single level patients as determined by the ZCQ, had a clinically significant response. Corresponding changes were seen in VAS and ODI and SF-36.

Ten patients (18%) required caudal epidural for recurrence of symptoms and 1 patient required perifacet injections for back pain.

Conclusion: X STOP offers a safe reversible treatment for symptomatic spinal stenosis. Clinically significant improvement is present at three months and is maintained at 12 months.

Purpose: We present the early results of a pilot study of 10 patients evaluating the basic safety and performance of an in situ polymerising protein hydrogel used in discectomy to prevent recurrent nuclear herniation, reduce motion segment instability and preserve disc height.

Method: Patients with radicular symptoms due to a MRI scan proven disc herniation, failed at least 3 months of conservative therapy, and had mild to moderate disc space narrowing. A standard open discectomy was performed to create a cavity for the implant, which was injected into the void through the annulotomy. The implant polymerised within 2 minutes. All patients had standard post-operative care for open discectomy.

The patients were assessed pre-operatively and post-operatively at 6 weeks, 3, and 6 months using Visual Analogue pain scale (VAS), Oswestry Disability index (ODI), SF-36 Health Survey (SF-36) and positional MRI scan in sitting (flexion, extension and neutral), erect and supine positions. To date, seven patients have a six-month follow up.

Results: Six females and 4 males were implanted into either the L4/L5 (5 patients) or L5/S1 (5 patients) level. The mean age of the patients was 40.6 years with a range of 19–57 years. ODI decreased from a mean of 49.2 pre-operatively to a mean of 11 at 6 months, and numerical pain score from of 5.86 to 1.62. Physical Component Score improved from a mean of 28.52 pre-operatively to 48.10 at 6 months. Two patients have suffered recurrent herniation, male (L5/S1) at 10 days, and a female (L5/S1) at 8 months, both requiring surgery.

Conclusion: Early clinical results indicate that the material can be used to fill the nuclear void following discectomy. Long-term data will be collected and evaluated to determine its efficacy in reducing spinal segment instability and preserving disc height.

Introduction: The effect of the X-STOP on sagittal kinematics and spinal canal and neural foraminal area are reported when this interspinous device is used for the treatment of neurogenic claudication.

Methods: Patients underwent Positional MRI scanning pre-operatively and 6 months post-operatively in the erect, flexed seated and extended and neutral positions. Anterior and posterior disc heights were measured on the erect images, endplate angle and the L1S1 angle on flexion and extension images at the operated and adjacent levels. Spinal canal and neural foraminal area were measured on all images. Measurements were made using the Osiris 4.17 program and statistical analysis using the Wilcoxon sign rank test.

Results: Fifty-two patients were enrolled. M:F 26:26. Single level: Double level insertion 29:20. Three patients withdrawn, one died of unrelated causes, one intra-operative spinous process fracture, one lost to follow-up.

Single Level: Spinal canal and neural foramina areas were increased in all positions with canal area significantly increased on standing (p=0.024) and sitting neutral (p=0.036). There was no significant effect on endplate angle, segmental range of movement, L1S1 angle or disc height.

Double Level: Spinal canal area was significantly increased in the cranial segment on standing (p=0.002) and extension (p=0.016) and the caudal segment in extension (p=0.016). Foraminal area was significantly increased at the right cranial (p=0.019) and caudal (p= 0.045) segments in flexion and left cranial (p=0.017) and caudal segments (p=0.004) in extension. A significant change was observed at the endplate angles in flexion (p=0.028) and extension (p=0.026) at the upper level. The L1S1 angle was significantly reduced in extension (p=0.017). The caudal anterior disc height was reduced (p=0.023). There was no significant effect on segmental range of movement or sagittal kinematics at adjacent levels.

Conclusion: X-STOP insertion has minimal effect on the sagittal kinematics of the lumbar spine but does increase canal and neural foraminal area.

Purpose: To measure the effect of the X-Stop interspinous distraction device on spinal canal, exit foramina, and disc height dimensions at the operated level; and adjacent segment endplate angle, and lumbar spine movement in patients with symptomatic lumbar spinal stenosis using upright MRI.

Methods /Results: 14 patients (9 M;5 F) were scanned before and six months after operation. Age ranged from 57 to 88 years. All had symptomatic lumbar spinal stenosis- single level- 9 (L2/3-1; L3/4-1; L4/5-7); double level 5 (L3/4, L4/5).

Images were taken in sitting flexed, extended, neutral, and standing. The total range of motion of the lumbar spine and of the individual segments were measured, along with changes in disc height, areas of the exit foramina, and dural sac.

The mean area of the dural sac at the operated levels increased from 62.46mm2 to 77.69mm2 (p=0.004) in the standing posture and from 70.85mm2 to 94.62mm2 (p=0.019) in extension postoperatively. The area of the exit foramina in extension increased from 83.57mm2 to 107.88mm2 (p=0.002) on the left side and from 83.77mm2 to 108.69mm2 (p=0.012) on the right. The overall changes in the range of movement of the individual segments or of the lumbar spine were statistically insignificant.

Conclusions: This is the first study carried out using an upright MRI scanner in patients with lumbar spinal stenosis. The X-Stop device increases the cross-sectional area of the spinal canal and exit foramina by distracting the spinous processes of the operated level without significantly affecting overall posture of the lumbar spine.

Purpose Of The Study: This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Material-Method-Results: All the 25 patients, with chronic back pain, had discography preoperatively a positional MRI scans pre-op and nine months postoperatively in different postures.

The patients were divided into two groups. The Group-A with 14 patients in which only Dynesys was used and Group-B with 11 patients in which Dynesys was combined with fused levels.

The operated levels were 51, 13 of which were fused. The results showed that the mean range of movement of the lumbosacral angle reduced by 10.28° (Preop=39.21°, Postop=28.93°) (p=0.016) in group-A. In group-B it reduced by 13.73° (Preop=36.18°, Postop=22.45°) (p=0.02).

The range of movement of the end plate angle at the instrumented segments in group-A reduced by 2.96° (Preop=5.56°, Postop=2.60°) (p=0.016) while in group-Bit reduced by 4.23° (Preop=6.69°, Postop=2.46°)(p=0.008).

The mean range of movement of the end plate angle at adjacent level in group-A reduced by 1.58° (Preop=8.7°, Postop=7.21°)(p=0.427) while in group-B it increased by 1.73° (Preop=6.91°, Postop=8.64°) (p=0.149)

The mean anterior disc height in group-A reduced by 1.18mm (Preop=10.05mm, Postop=8.87mm) (p< 0.005), and the posterior one was increased by 0.6mm (Preop=6.51mm, Postop=8.87mm) (p=0.013). In group-B, the anterior disc height was reduced by 1.11mm (Preop= 10.44mm, Postop=9.33mm) (p=0.049) and the posterior one by 0.16mm (Preop=6.98mm Postop=6.82mm) (p=0.714)

Conclusion: Dynesys stabilizing system allows movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the more the anterior annulus than to distract the posterior.

Introduction Conventional MRI scanners require the patient to lie in a supine position within the bore of the magnet; positional MRI (pMRI) scanners allow patients to be scanned in any position. This is of particular value when patients have postural dependent symptoms.

Here we discuss the evaluation of two spinal devices: Dynesys, a spinal stabilisation system for back pain, and X STOP, an interspinous process distraction device for spinal stenosis.

Materials, Methods & Results For each device, patients underwent pre and post-operative scans in standing, lying and seated in neutral, flexed and extended positions and the ranges of movement at the operated levels and across the whole lumbar were measured.

For Dynesys, 30 patients with lower back pain were recruited. The first 20 patients have completed their 9 month scan, and the results show that the device reduces the range of movement at the operated segments, with a small increase in movement at adjacent segments and an overall reduction in the range of movement of the lumbar spine.

For X STOP, the first 10 of 45 have reached their second scan at 6 months post surgery. The scans demonstrate a net increase in the cross-section of the spinal canal of 21% when flexed to 35% whilst standing, and an increase in the surface area of the exit foramen of 23% flexed and 51% standing at operated levels.

Conclusion These studies demonstrate the value of pMRI for the evaluation of lumbar spine prosthesis. pMRI allows for the assessment of the devices in their functional (i.e. upright) position.