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: 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.