Injury to the syndesmosis occurs in 10–13% of all operative ankle fractures and there is evidence that both incomplete treatment and malreduction of the syndesmosis can lead to poor clinical outcomes. Much attention has been given to post–operative malreduction documented by computer tomography (CT), however, there is limited data about the intact positioning and relative motion of the native syndesmosis. The aim of this study is to elucidate more detailed information on the position of the fibula in the syndesmosis during simulated weight–bearing in intact state, with sequential ligament sectioning and following two reconstructive techniques.

Fourteen paired, fresh–frozen human cadaveric limbs were mounted in a weight–bearing simulation jig. CT scans were obtained under simulated foot–flat loading (75 N) and in single–legged stance (700 N), in five foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantarflexion. The elements of the syndesmosis and the deltoid ligament were sequentially sectioned. One limb of each pair was then reconstructed via one of two methods: Achilles autograft and peroneus longus ligamentoplasty. The specimens were rescanned in all 5 foot positions following each ligament resection and reconstruction. Measurements of fibular diastasis, rotation and anterior–posterior translation were performed on the axial cuts of the CT scans, 1 cm proximal to the roof of the plafond.

Multiple measurements were made to define the position of the fibula in the incisura. Clinically relevant deformity patterns were produced. The deformity at the incisura was consistent with clinical injury, and the degree of displacement in all ligament states was dependent on the foot position. The most destructive state resulted in the most deformity at the syndesmosis. Differences between the intact and reconstructed states were found with all measurements, especially when the foot was in external rotation and dorsiflexion. There was no significant difference with direct comparison of the reconstructions.

This study has detailed the motion of the fibula in the incisura and its variation with foot position. Neither reconstruction was clearly superior and both techniques had difficulty in the externally rotated and dorsiflexed foot positions. This study design can serve as a model for future ex–vivo testing of reconstructive techniques.

Introduction: Lumbar spinal stenosis (LSS) is a condition involving the narrowing of either the spinal canal or neural foramina and may lead to intermittent neurogenic claudication (INC). Traditionally LSS is been treated by conservative therapy followed by decompression and, if required, stabilizing of the lumbar spine for non-responders. Current results indicate that decompression may lead to increase of biomechanical stresses at levels adjacent to the operated level causing degenerative disorders.

In the last years dynamic devices represent an alternative for the more invasive decompression surgery.

Currently a registry is maintained to collect data on patients implanted with the X STOP.

Methods: Patients who were diagnosed with LSS and planned for an implantation of the X STOP were included in the study. Diagnosis was confirmed by CT or MRI scans. Outcome was measured by the Zurich Claudication Questionnaire measuring symptom severity (SS), physical function (PF), and patient satisfaction (PS). An analysis was performed for the patient who completed the pre-operative and either the 1-year follow-up or 2-year follow-up assessment.

Results: 283 patients participated in the study by completing either the questionnaires by the patient or data forms by the specialist. From these 89 patients completed the pre-operative and 1-year assessment and 20 completed the pre-operative and 2-year assessment.

The results showed a clinical significant change for the domains SS and PF for both 1-year follow-up and 2-year follow-up. For the domain PS the mean score is 1.81 (very satisfied = 1, somewhat satisfied = 2).

The clinically significant success rate based on clinically improvement in 2 of the 3 domains is 71.9% and 65.0 % after respectively 1-year and 2-year follow-up.

Discussion: Our results suggest that intermediate term clinical outcomes of X STOP IPD surgery are stable over time although it may indicate that over time a decrease in clinical significant improvement may be observed. As INC caused by LSS is an ongoing degenerative disease, this may be explained by the ongoing degenerative process.