Background-

Health care is best delivered face to face, doctor to patient. However, in some places like Scotland, patients can be in remote areas, far from the nearest health care provider. Medical video conferencing (VC) enables patients and doctors to meet for consultations from wherever they may be without the need for travel, and is already used widely in countries like Australia and Canada.

Introduction:

Isolated Weber B lateral malleolus fractures heal uneventfully, but concern that late subluxation may occur due to unrecognised medial ligament tearing, despite an intact mortice on initial radiographs, often results in overtreatment. The aim of this study was to determine the incidence of late talar shift with nonoperative management in a cohort of patients with no initial talar shift, and also record functional outcomes at 16–28 months following injury.

We compared the postoperative wound discharge rates and 3 months clinical results of three types of wound closure and dressing – 2-octylcyanoacrylate with Opstie (G+O), 2-octylcyanoacrylate with Tegaderm (G+T), and Opsite without 2-octylcyanoacrylate (O) in patients having primary total hip arthroplasty.

We randomised 141 patients scheduled for primary total hip arthroplasty into 3 arms of this study- G+O, G+T, or O. The extent of wound discharge was recorded on a diagrammatic representation of the dressing in situ on paper and graded each day. Dressings were left in-situ provided the extent of wound discharge allowed for this. The patient was clinically reviewed at 3 months to assess their scar length, cosmesis, scar discomfort, and evidence of superficial or deep wound sepsis.

A greater number of patients dressings remained dry on day 1 postoperatively in the two groups with 2-octylcyanoacrylate compared to the no glue group p=0.001. G+T group had a significantly lower proportion of patients with increased leakage of wounds on 2^nd postoperative day p=0.044. At 3 months review, there was no statistical difference in the Hollander score or scar discomfort.

In patients who have had primary total hip arthroplasty, usage of 2-octylcyanoacrylate for wound closure along with Tegaderm dressing reduces wound discharge. The same effect is not noted in glue with Opsite group. Whilst dressing changes required in the non-glue group compared from the two glue groups did not reach statistical significance, this may have clinical relevance for patients and nursing staff. No effect on postoperative length of stay, or wound complications was noted.

A consensus regarding management of calcaneal fractures eludes orthopaedic surgeons. While operative treatment has gained more acceptance, surgical morbidity remains high. We undertook a retrospective review of early complications and radiological outcomes following internal fixation of calcaneal fractures in our unit over 15 months.

A consecutive series of 33 patients who underwent fixation of the Calcaneus was selected. Patient records, X-rays and scans were reviewed.

37 fractures in 33 patients underwent fixation. 81 % were male. Mean age at surgery was 37yrs (19 -59yrs). 35 % were operated within 1 wk of injury and 13% after 2 wks of injury. 43% were Sanders' type III, 18% type II and 13% tuberosity avulsion fractures. 63% had a reversed/zero Bohler's angle. Mean post-op Bohler's angle was 32 degrees. Overall complication rate was 32%, with a combined deep infection rate of 8%. All patients with infection were male, and 70% were smokers. 86% were above 40yrs of age (mean 47yrs). The deep infection rate for intra-articular fractures was 3% and for tuberosity avulsion fractures 40%. Majority of patients with wound complications had been operated within 7 days of injury.

Males over 40yrs and smokers seem to be at most risk of wound complications. Time to surgery/delay in surgery up to 2 wks did not seem to have any adverse consequences. Complications increase with fracture complexity and avulsion fractures have highest risk of wound breakdown. Near anatomical restoration of the articular surface is possible in most.

Background: The Calcaneus is the largest of the tarsal bones. 2% of all adult and 60 % of all tarsal fractures involve the Calcaneus. A true consensus regarding the management of these fractures still eludes orthopaedic surgeons. While operative treatment for displaced fractures has gained more acceptance in the last decade, surgical morbidity still remains high.

Aim: A retrospective review of the early complications and radiological outcomes following open reduction and internal fixation of displaced calcaneal fractures in our unit over the last 15 months.

Methods: A consecutive series of 33 patients who underwent surgical fixation of the Calcaneus was selected. Patient records, X rays and scans were reviewed. Mode and nature of injury, life style factors, surgical complications and Bohler’s angles were analysed.

Results: 37 fractures in 33 patients underwent operative fixation. 81 % were male. Mean age at surgery was 37yrs (range19–59). 35 % were operated within 1 week of the injury and 13% after 2 weeks of injury. 43% were Sanders’ type III, 18% type II and 13% tuberosity avulsion fractures. 63% of patients had a reversed or zero Bohler’s angle. Mean post-op Bohler’s angle was 32 degrees. Overall complication rate was 32%, with a combined deep infection rate of 8%. All patients with infection were male, and 70% were smokers. 86% were above 40yrs of age (mean 47yrs). The deep infection rate for intra-articular fractures was 3% and for tuberosity avulsion fractures 40%. Majority of patients with wound complications had been operated within 7 days of injury. 4 patients had persisting pain requiring removal of metal work.

Discussion: Our study highlights that there are significant risks associated with operative management of calcaneal fractures. Male patients over the age of 40yrs who are smokers seem to be at most risk of wound complications. Time to surgery or delay in surgery up to 2 weeks did not seem to have any adverse consequences. Complications increase with fracture complexity, and avulsion fractures have a high risk of wound breakdown. Near anatomical restoration of the articular surface is possible in most cases.

Aim: To assess the kinematic changes that occur within the lumbar spine 2 years following insertion of the Dynesys Spinal stabilisation implant.

Materials and Methods: Twenty patients who were treated with Dynesys surgical stabilisation for dominant lower back pain underwent positional MRI scanning before and two years following surgery.

The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.

Results: The results of the pMRI measurements showed that the range of movement (ROM) of the L1/S1 angle in Group A reduced by 11.8o{pre-op=37.9o, postop=26.1o(p=0.085)} while in Group-B reduced by 12.3o {pre-op=37.8o, postop=25.5o(p=0.017)}.

The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72^o to 1.44^o{difference 4.28^o(p=0.005)} and in Group B reduced from 6.00^o to 2.17^o,{difference 3.83^o(p=0.001)}.

The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2^o to 5.1^o {reduction 3.1^o(p=0.085)}, while in group-B increased from 7.3^o to 7.5^o, a difference of 0.2^o (p=0.877).

The mean anterior disc height in Group A reduced by 2.1mm (p< 0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)

Discussion: This study shows that the Dynesys stabilisation system allows some movement at the operated segment two years following surgery. The study also confirms that the adjacent segment hypermobility often seen following spinal fusion surgery is eliminated.

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.

Aim: To assess the kinematic changes that occur within the lumbar spine 2 years following insertion of the Dynesys Spinal stabilisation implant.

Materials and Methods: Twenty patients who were treated with Dynesys surgical stabilisation for dominant lower back pain underwent positional MRI scanning before and two years following surgery.

The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.

Results: The results of the pMRI measurements showed that the range of movement (ROM) of the L1/S1 angle in Group A reduced by 11.8o{pre-op=37.9o, postop=26.1o(p=0.085)} while in Group-B reduced by 12.3o {pre-op=37.8o, postop=25.5o(p=0.017)}.

The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72^o to 1.44^o{difference 4.28^o(p=0.005)} and in Group B reduced from 6.00^o to 2.17^o,{difference 3.83^o(p=0.001)}.

The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2^o to 5.1^o {reduction 3.1^o(p=0.085)}, while in group-B increased from 7.3^o to 7.5^o, a difference of 0.2^o (p=0.877).

The mean anterior disc height in Group A reduced by 2.1mm (p< 0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)

Discussion: This study shows that the Dynesys stabilisation system allows some movement at the operated segment two years following surgery. The study also confirms that the adjacent segment hypermobility often seen following spinal fusion surgery is eliminated.

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.

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.

Purposes Of The Study-Background Data: Dynesys is claimed that allows motion in the operative levels. This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Thirty patients with were treated with Dynesys system. All had discography and positional MRI preoperatively and nine months post-operatively.

The patients were divided in to two groups. The first in which only Dynesys was used and the second in which Dynesys was used with fusion.

Results: The operated levels were 63. The results of the pMRI measurements showed that the range of movement(ROM) of the L1/S1 angle in group-A reduced by 11.89^o{pre-op=39.26^o,postop=27.37^o(p=0.008)} while in group-B reduced by 13.73^o {preop=36.18^o,po stop=22.45^o(p=0.002)}.

The ROM of the end plate angle at the instrumented segments in group-A reduced from 5.24^o to 2.18^o{difference 3.06^o(p< 0.005)} and in group-B reduced from 6.69^o to 2.46^o,{difference 4.23^o(p=0.008)}. The ROM of the end plate angle at adjacent level in group-A changed from 8.26^o to 7.0^o {reduction 1.26^o(p=0.388)},while in group-B increased from 6.91^o to 8.64^o, {difference 1.73^o(p=0.149)}

The mean anterior disc height in-group A reduced by 1.43mm (p< 0.005) from 9.75mm to 8.32mm, and the posterior one was increased from 6.27mm to 6.77mm {difference of 0.5mm,(p=0.008)}. In group-B the anterior disc height reduced by 1.11mm (pre-op=10.44mm,post-op= 9.33mm,p=0.049) and the posterior one by 0.16mm (pre-op 6.98mm to post-op 6.82mm,p=0.714).

Conclusion: This study shows that in the Dynesys stabilizing system allows small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus.

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 Symptoms of neurogenic intermittent claudication in spinal stenosis are explained by the narrowing of the spinal canal in the extended (upright) position and widening in the sitting (flexed) position. The XStop inter-spinous process distraction device is a new product that is designed to hold the affected segments in a flexed posture. This prospective study looks at the changes in the lumbar spine in a variety of postures from pre- to post insertion.

Methods Using a positional magnetic resonance imaging (pMRI) scanner, patients were scanned before and six months after the insertion of the device. Images were taken in sitting flexed and extended, and standing positions. The change in the total range of movement of the lumbar spine and in the individual operated segments was measured along with changes in the surface areas of the exit foramen, the dural sac, and the disc height.

Results 12 patients with 17 levels distracted have been scanned and measured. The cross sectional area of the dural sac at the level of the stenosis has increased from a mean of 77.8 mm² to 93.4 mm² in the standing position (p=0.006) and from 84.56mm² to 107.35mm² on extension (p=0.008). There were no statistically significant changes in the range of movement of the whole lumbar spine, or at levels adjacent to the device.

Discussion This study demonstrates that the X Stop device increases the cross sectional surface area of the spinal canal at the stenosed level, without causing extensive changes in the posture of the lumbar spine.

Introduction The Dynesys device uses transpedicular screws linked by a cord and spacers. It is claimed that the advantage is that it allows some motion, in all directions, in the operative levels. In vitro laboratory biomechanical studies show that the movement permitted is similar to rigid fusions.

This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Material-method In our study 20 patients with dominant low back pain, with or without leg pain, were treated with Dynesys system. Stress discography was made to evaluate the symptomatic level

All had a positional MRI preoperatively and nine months post-operatively in flexion-extension-lateral bending.

The patients were divided in to two groups:

Group(A) with 8 patients in which Dynesys was used with fusion (disc-height< 40 %)

Group(B) with 12 patients was the Dynesys-only group (disc-height=40–90%).

Results The operated levels were 42, 10 of those were fused levels. The results showed that there was a statistically significant difference in flexion-extension range of movement of the whole lumbar spine (mean= −13.45)(p< 0.005), but it wasn’t significant in the level above (mean=0.056)(p=0.972) and at a single instrumented segment was (mean=−4.06°)(p< 0.05)

The changes in the anterior disc height was (mean= −1.18)(p< 0.05) and to the posterior (mean=0.37)(p=0.134). In bending were (mean=−0.87°)(p=0.18) for left and (mean=−0.24°)(p=0.75) for the right

Discussion This study shows that in the Dynesys stabilizing system allows small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus

Introduction Symptoms of neurogenic intermittent claudication in spinal stenosis are explained by the narrowing of the spinal canal in the extended (upright) position and widening in the sitting (flexed) position. The X-Stop® inter-spinous process distraction device (St. francis Medical Technologies) is a new product designed to hold the affected segments in a flexed posture. This prospective study looks at the changes in the lumbar spine in a variety of postures from pre- to post-insertion.

Method Using positional MRI (pMRI), patients were scanned before and six months after operation. Images were taken in sitting flexed, extended, neutral, and standing positions. The total range of motion of the lumbar spine and of the individual operated segments were measured, along with changes in disc height, areas of the exit foramina, and dural sac.

21 patients (11 males; 10 females) were included in the study. Age ranged from 57 – 88 years. All had symptomatic lumbar spinal stenosis- single level- 13 (L2/3-1; L3/4-3; L4/5-9); double level 8(L3/4, L4/5 – 7; L4/5, L5/ S1 – 1).

Results The mean area of the dural sac at the operated levels increased from 89.25mm2 to 108.96mm2 (p< 0.001) in the standing posture and from 103.96mm2 to 124.94mm2 (p< 0.001) in extension postoperatively. The area of the exit foramina in extension increased from 79.15mm2 to 100.41mm2 (p< 0.001) on the left side and from 80.86mm2 to 98.74mm2 (p< 0.001) on the right side. The overall changes in the range of movement of the individual segments or of the lumbar spine were statistically insignificant.

Discussion Previous, radiologic (Willen J, et al; Spine 1997) and cadaveric studies have demonstrated reduction in area of the dural sac and exit foramina as the lumbar spine moves from flexion into extension. Our study is the first to quantify these changes in symptomatic patients with lumbar spinal stenosis using postional MRI. This study supports previous studies using positional MRI scanner in patients with lumbar spinal stenosis and also demonstrates that 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.

Introduction The Dynesys® stabilisation system (Zimmer Spine) uses transpedicular screws linked by a cord and spacers; the advantage claimed is that it allows some motion, in all directions, in the operated levels. In vitro laboratory biomechanical studies show that the movement permitted is similar to rigid fixation systems.

This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device. Methods In our study 25 patients with dominant low back pain, with or without leg pain, were treated with Dynesys system, 14 females and 11 males with mean age 43.5 yrs. Discography was done to evaluate the symptomatic painful level. All patients had a positional magnetic resonance imaging (pMRI) scans preoperatively and nine months post-operatively in standing; sitting flexion and extension, and left and right bending postures. The patients were initially divided into two groups. The first (Group A) with 14 patients in which only Dynesys was used (disc height 40–90%) and the second (group B) with 11 patients in which Dynesys was used with fusion (disc height < 40 %).

Results The operated levels were 51, 13 of which were fused. The results of the pMRI measurements showed that the mean range of movement of the lumbosacral angle reduced by 10.3° from pre-op of 39.2° to postop. of 28.9° (p= 0.016) in group A while in group B it reduced by 13.7° from 36.2° preop. to 22.5° postoperatively (p= 0.02).

The range of movement of the end plate angle at the instrumented segments in group A reduced from 5.6° preoperatively to 2.6° with a difference of 3.0° (p=0.016) while in group B it reduced from 6.7° to 2.5° postoperatively with a difference of 4.2°(p=0.008). The range of movement of the end plate angle at adjacent level in group A changed from 8.8° preop. to 7.2° with a reduction of 1.6° (p=0.427) while in group B it increased from 6.9° to 8.6°, difference of 1.7° (p=0.149)

The mean anterior disc height in group A reduced by 1.2mm (p< 0.005) from 10.1mm to 8.9mm postoperatively, and the posterior one was increased from 6.5mm to 8.9mm with a difference of 0.6mm (p= 0.013). In group B the anterior disc height was reduced by 1.1mm (pre-op 10.4mm to post-op 9.3mm; p=0.049) and the posterior one by 0.16mm (pre-op 6.98mm to post-op 6.82mm; p=0.714)

Discussion This study shows that in the Dynesys stabilising system allows a small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus more than to distract the posterior annulus.