Introduction: Forward slip of the above vertebra may compromise the exit foramen and produce nerve root signs. Conservative management should be attempted first. However in 10–15% surgical procedures are required to control symptoms of backpain and radiculopathy.

In this cohort study, we compare the functional outcome of Dynesys in patients with degenerative spondylolisthesis categorised in three subgroups.

Material & Methods: Seventy eight patients with degenerative spondylolisthesis were treated with Dynesys. Patients were sub-grouped into Dynesys alone (group 1 n=31), Adjunct fusion (group 2 n=34) and Adjunct decompression (group 3 n=13). Three main outcome parameters were reviewed; ODI, VAS and the need for further surgeries. Patients follow up was arranged at 2 weeks, 3 months, 6 months, 12 months then annually.

Results: Average follow up was 53 months, 47 months & 55 months in groups 1, 2 & 3 respectively.

Patients with Dynesys alone had initial good improvement in ODI & VAS but this was not maintained. Secondary surgery was needed in 32% at 28.2 months.

Dynesys with adjunct PLIF showed clinically & statistically maintained ODI & VAS outcome. Secondary surgery rate was 11.7% at 26 months.

Dynesys with adjunct decompression group was favoured by clinically & statistically improved functional outcome. Second surgery was necessary in 7.6%.

Discussion: Dynesys stands as an innovative device for the treatment of backpain. However, its clinical indications were not refined. Patients with degenerative spondylolisthesis require decompression with instrumented stabilisation.

Conclusion: Dynesys alone is not recommended for degenerative spondylolisthesis.

Conflicts of Interest: None

Source of Funding: Zimmer Spine sponsored research fellowship at the Conquest hospital between 2005–2007. The funds were paid direct to the hospital for follow up and maintenance of Dynesys database. No researcher received direct fund by the company.

Introduction: In this study we have studied the range of motion within Dynesys treated discs and levels adjacent to flexible stabilisation.

Dynesys was designed to offer physiological motion at the lumbar spine. An advantage which is superior to abolishing movements through spinal fusion.

Methods: A cohort of 75 post-Dynesys patients had weight-bearing lateral lumbar spine x rays in flexion/extension positions. Evaluation was done through PACS™ digital software. Flexibility at individual disc level was measured as the differences between flexion/extension angles accurate to within 1°. Motion was evaluated at the index and immediate adjacent levels.

Results: Patients with single level Dynesys had an average ROM of (3+/−4.7) at L5-S1 and (5.1+/−2.9) at the immediate adjacent level. Two levels Dynesys was associated with a ROM of 5+/−3.6 at L5-S1 & L4–5 and 3.5+/−1.8 at their immediate neighbour disc. Across three levels, Dynesys favoured a ROM of 5.3+/−2.5 at the operated sites and 1.6+/− 2 at the adjacent level.

Discussion & Conclusion: This study is the first radiological research to confirm the flexibility of Dynesys. Controlled motion at the dynesys treated disc levels share to distribute global spinal movements. This will advantage the next disc segments and protects them from risk of developing “accelerated adjacent segment disease”.

Introduction: In this study we report our experience with the clinical outcomes following Dynesys. Our objectives are to revalidate the most suitable indication(s) of Dyne-sys in patients with backpain.

Method: A prospective cohort study on 374 consecutive patients who had Dynesys for backpain from September 2000 to-present. Average age of patients was 57 years and male to female ratio were (40%:60%). Preoperative assessment involved ODI, SF36, VAS for leg and backpain and the diagnosis was confirmed with physical examination, x rays, spinal probe and lumbar spine MRI. Regular follow up was arranged at 2 weeks, 3, 6 and 12 months then on annual intervals.

In our cohort, clinical indications were:

t-test was used for comparison between preoperative and postoperative scores and p-value was used to show the significance.

Results: Overall outcome assessment revealed significant improvement in ODI, SF36 and VAS in comparison with preoperative status (p-value < 0.05). Improvement was greatest in DDD group and average for ASD.

Patients with stenosis performed better when the procedure involved adjunct decompression. Similarly, results of decompression and fusion were better than Dynesys alone in patients with spondylolisthesis.

Discussion and Conclusion:

Dynesys was successfully controlled symptoms of DDD in the intermediate term.

Introduction: In this study we describe Modic changes within treated-lumbar disc levels and levels adjacent-to-Dynamic Neutralisation System for the Spine (Dynesys).

Modic changes(M) have been described in association to Degenerative Disc Disease(DDD). Type-I represents the inflammatory phase whereas Type-II describes fatty changes within the vertebral marrow and endplate. Type-III is more advanced degeneration and it indicates marked sclerosis adjacent to endplates.

Material & Methods: Postoperative MRI has been compared to preoperative scan in 28 symptomatic patients treated with Dynesys. Parameters assessed were Modic changes within treated disc levels and their adjacent segments. Average time to postoperative MRI was 36 months with a range of 17–66 months.

Results: Within Dynesys-treated levels; 16 levels had no Modic change preoperatively of which 13 remained unchanged while 3 developed M2 with treatment. 15 had M2, of which, 7 worsen to M3, 6 continued as M2 and 2 improved to M0. 12 had M3, of which 1 improved to M1 and the rest did not change.

Adjacent endplate levels showed worsening of M0 to M2 in 11 patients while no change was seen in 35 levels. Only 4 levels with M2 were seen, of which 3 levels did not change and 1 level continued to M3. 2 M3 improved to M2.

Discussion & Conclusion: Compared to recently published studies by Danish group, Modic changes have the tendancy to worsen on conservative treatment. In this study we could show that following Dynesys progress of Modic changes at the treated level(s) was not remarkable though few cases continued with the process of degeneration.

Introduction: ACDF involves cancellation of the diseased spinal motion segment, the neighboring spinal segments take the burden of excessive compensatory spinal movements and strain resulting in early degeneration.

Adjacent segment degeneration with new, symptomatic radiculopathy occurs after ACDF in 2–3% of patients per year on cumulative basis. An estimated 15% of patients ultimately require a secondary procedure at an adjacent level.

An alternative to fusion is total disc arthroplasty (TDA). The key advantage of this promising technology is restoration and maintenance of normal physiological motion rather than elimination of motion.

We describe 4 patients with a serious complication observed following implantation of the Bryan disc prosthesis in our cohort of 48 patients.

Material and Results:

Patient #1: 43 M, with neck pain & left brachalgia, with left C6 dermatome signs, with MRI findings of C5/6 disc prolapse with left C6 root impingement, undergoing C5/6 Bryan TDA in April 2004, with treatment recommendation of C3/4 and C6/7 Bryan TDA in January 2006.

Discussion & Conclusions: Bryan TDR did not prevent the development of accelerated ASD. Evidence from in vivo X ray studies suggested that the range of motion across the operated levels did not match the physiological ROM.

Despite the MRI images preoperatively, it is difficult to exclude the natural progression of degeneration as a reason for ASD.

Introduction: In this study, we report interobserver reliability of X-ray for the interpretation of pedicle screw osteointegration based on the diagnosis of “Halo zone” surrounding the screw.

Dynamic stabilisation system for the spine relies on titanium screw purchase within the pedicle. Decision on osteointegration is important especially when the patient becomes symptomatic following initial good outcome. From our cohort of 420 Dynesys patients, over all incidence of screw loosening was 17%. Only 35% were symptomatic.

Method: Lumbar spine X-ray images of 50 patients in two views (AP and lateral) randomly selected from our cohort of 420 Dynesys patients. The images were deployed in a CD-ROM. The authors were asked to review the images and state whether or not each pedicle screw is loose (total of 258 pedicle screws).

Seven observers composed of two expert orthopaedic spine consultant surgeons and one spine expert consultant radiologist and four Specialist Registrars in orthopaedics and radiology.

Data gathered were distributed and presented in tables in the form of descriptive statistics. The evaluation of interobserver agreement was performed by obtaining a Kappa (K) index. For continuous variables comparison, the t test was employed, with a significance level of 0.05.

Results: Kappa Index among three experts was 0.2198 at 95% CI (−0.0520, 0.4916) while for all 7 assessors (3 Experts & 4 SpR), KI was 0.1462 at 95% CI (0.0332, 0.2592)

Discussion & Conclusion: Kappa Index among expert assessors was 0.2 which means X-ray is unreliable for the assessment of pedicle screw osteointegration. Validity of X-ray is not applicable as it is unreliable.

We are planning to evaluate a 3D computer reconstruction model based on 2 X-ray views at 45 degree angle to each other which might be sensitive to detect screw loosening.

Introduction: In this study, we report interobserver reliability of X-ray for the interpretation of pedicle screw osteointegration based on the diagnosis of “Halo zone” surrounding the screw.

Dynamic stabilisation system for the spine relies on titanium screw purchase within the pedicle. Decision on osteointegration is important especially when the patient becomes symptomatic following initial good outcome. From our cohort of 420 Dynesys patients, over all incidence of screw loosening was 17%. Only 35% were symptomatic.

Method: Lumbar spine X-ray images of 50 patients in two views (AP and lateral) randomly selected from our cohort of 420 Dynesys patients. The images were deployed in a CD-ROM. The authors were asked to review the images and state whether or not each pedicle screw is loose (total of 258 pedicle screws).

Seven observers composed of two expert orthopaedic spine consultant surgeons and one spine expert consultant radiologist and four Specialist Registrars in orthopaedics and radiology.

Data gathered were distributed and presented in tables in the form of descriptive statistics. The evaluation of interobserver agreement was performed by obtaining a Kappa (K) index. For continuous variables comparison, the t test was employed, with a significance level of 0.05.

Results: Kappa Index among three experts was 0.2198 at 95% CI (−0.0520, 0.4916) while for all 7 assessors (3 Experts & 4 SpR), KI was 0.1462 at 95% CI (0.0332, 0.2592)

Discussion & Conclusion: Kappa Index among expert assessors was 0.2 which means X-ray is unreliable for the assessment of pedicle screw osteointegration. Validity of X-ray is not applicable as it is unreliable.

We are planning to evaluate a 3D computer reconstruction model based on 2 X-ray views at 45 degree angle to each other which might be sensitive to detect screw loosening.

Introduction: We report a series of 10 cases from a cohort of 421 Dynesys procedures in which evidence of Accelerated Adjacent Disc Disease (AASDD).

Spinal fusion for degenerative disc disease is known to have inconsistent outcomes. One concern is the possibility of AASDD as a result of the altered kinematics. The Dynamic Neutralisation System (Dynesys) appears to offer an advantage in that it restricts, rather than abolishes movement at the treated segment, and should thereby reduce the problem of AASDD, In the event of failure, it can in addition be removed, returning the spine to the former status quo. Various biomechanical studies confirmed flexibility of Dynesys.

Method: Ten patients developed new and symptomatic disc disease within segments adjacent to Dynesys. The average age of patients was 49 year with range between 36–70 years. Average post Dynesys to secondary surgery for ASD was 24.7 months. Previous discography and MRI in all cases had shown no evidence of disc disease within these adjacent segements prior to Dynesys. All patients were evaluated preoperatively using Oswestry Disability Index, SF 36 and Visual Analogue Scores together with plain x ray imaging, MRI scanning and discography. Of this cohort Dynesys was indicated to treat single disc level in 7 and two levels in 3

Results: Incidence of AASDD associated with Dynesys was 2.1%. Further surgical intervention included:

Extension of Dynesys10

There was no caudal ASD in our cohort.

Discussion & Conclusions: Dyensys did not prevent the development of accelerated ASD. Evidence from Aylott cadaver studies suggests that Dynesys instrumentation alters the Kinematics of the adjacent segment and increases the excursion. It is unclear whether the small number of AASDD reported here is other than the natural progression of degenerative change. 95.7 cases did not progress.

Background: Tuberculosis continues to increase in England, Wales and Northern Ireland. The London region accounted for a substantial proportion of cases in 2005 (43%) and had the highest rate of disease (46.3 per 100,000). Skeleton is a common site of predilection. However, diagnostic evaluation of vertebral TB is hampered by the difficulty of MRI interpretation and failing to keep a high index of suspicion.

Methods: Cross sectional sampling of all patients with confirmed vertebral TB between the years of 1999–2006 in two large London hospitals covering; Royal London Hospital and King George Hospital. Various dermographic parameters were evaluated. The mode of presentation, surgical procedures and outcome of patients were highlighted.

Results: One hundred and twenty three patients were identified with a Mean age of thirty four years. Male and female was 55%, 45% respectively. Asians represent the highest immigrant group followed by Afrocarbian at 63%, 28% respectively. White British represents only 6.5%. The dorsal spine was the most commonly affected site at 45%, then lumbar spine in 33% followed by multiple regions in 11%. Delayed diagnosis was made in 34% of patients, 44% of them over six months.

Back pain/neck pain was the presenting complaint in 100% whereas neurological signs were found in 37% and systemic manifestations present in 38%. To control the disease, spinal surgical procedures was needed in 44% of cases. Approximately 30% of them had partial recovery and 9% had complete recovery.

Conclusions: The incidence of vertebral TB is on the increase. A high index of suspecion is required to avoid delay in the diagnosis. Knowledge of the patients’ background may help making approperiate early referral for MRI especially among Asian groups.

Background: Spinal fusion for degenerative disc disease remains a controversial issue due to adjacent segment disease. Several alternatives have been evaluated; including Dynamic Neutralisation System for Spine and artificial disc arthroplasty. In our cohort study, we are highlighting advantages of DYNESYS over TDA and fusion as being a simple and reversible procedure if removal of implants is necessary.

Materials and Methods: Prospective cohort study on 415 patients underwent DYNESYS. The implant has to be removed in 43 patients. Patients were evaluated preoperatively using Oswestry Disability Index, SF 36 and Visual Analogue Scores together with plain imaging and MRI scanning. Preoperative discography was performed in 81% of patients. Questionnaires were evaluated on subsequent follow up at 3 & 6 months, 1 year then at annual intervals.

Results: Average treatment period was 26 months with a range from 3/12 to 60/12. The main reason for DYNE-SYS removal was screws’ failure or loosening followed by infections. The implant was used to treat single disc space in 20.9%, two spaces in 67.4% and three disc spaces in 9.3%. 81% of the screws were not Hydroxy-appetite coated. No loosening was detected among HA coated screws.

Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.

Conclusions: DYNESYS can maintain disc height and restricts movements exceeding physiological limits. HA coated screws have superior biomechanical characteristics in preventing screw loosening and subsequent spinal spasms. If necessary, removal of implants is a simple procedure.

Tuberculosis continues to increase in England. London accounted for a substantial proportion of cases in 2005 (43%) and had the highest rate of disease. Spinal TB is the most common skeletal manifestation. The diagnostic evaluation of spinal TB is hampered by the difficulty of MRI interpretation and failing to keep a high index of suspicion.

The mode of presentation of spinal tuberclosis, surgical procedures and outcome of patients were highlighted. Various dermographic parameters were evaluated.

A prospective cohort study was conducted. Cross sectional sampling of patients presented with spinal TB between the years of 1999–2006 in two main hospitals covering large population of East London, Royal London Hospital and King George Hospital.

One hundred and twenty three patients (mean age: 34 years) were identified. Asians represent the highest group affected (63%), then appear Afrocarribean (28%). White British represent only 6.5%. Frequency of occurence was as follows: dorsal spine 45%, lumbar spine 33%, multiple regions 11%. Delayed diagnosis was made in 34% of patients, 44% of whom were over 6/12.

Backpain or neckpain was the presenting complaint in all of the patients (100%), whereas neurological signs were found in 37%. Systemic manifestations presented in 38%. Spinal surgical procedures were needed in 44% of cases. Approximately 30% of them had partial recovery and 9% had complete recovery.

The incidence of spinal TB is on the increase. A high index of suspecion is required to avoid delay in the diagnosis. Knowledge of the patients’ background may help making appropriate early referral for MRI.

Background: Spinal fusion for degenerative disc disease remains a controversial issue due to adjacent segment disease. Several alternatives have been evaluated; including Dynamic Neutralisation System for Spine and artificial disc arthroplasty. In our cohort study, we are highlighting advantages of DYNESYS over TDA and fusion as being a simple and reversible procedure if removal of implants is necessary.

Material & Methods: Prospective cohort study on 415 patients underwent DYNESYS. The implant has to be removed in 43 patients. Patients were evaluated preoperatively using Oswestry Disability Index, SF 36 and Visual Analogue Scores together with plain imaging and MRI scanning. Preoperative discography was performed in 81% of patients. Questionnaires were evaluated on subsequent follow up at 3/12, 6/12 then at annual intervals.

Results: Average treatment period was 26 months with a range from 3/12 to 60/12. The main reason for DYNE-SYS removal was screws’ failure or loosening followed by infections. The implant was used to treat single disc space in 20.9%, two spaces in 67.4% and three disc spaces in 9.3%. 81% of the screws were not Hydroxy Appetite coated. No loosening was detected among HA coated screws.

Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.

Conclusions: DYNESYS can maintain disc height and restricts movements exceeding physiological limits. HA coated screws have superior biomechanical characteristics in preventing screw loosening and subsequent spinal spasms. If necessary, removal of implants is a simple procedure.