Objective: This study investigates whether fixation down to lumbar spine only can prevent pelvic tilt compared to pelvic fixation, in the surgical treatment of Duchenne Muscular Dystrophy (DMD). Design: Retrospective and prospective clinical outcome study, with long-term follow up. Materials and Methods: Nineteen cases of DMD with scoliosis had early stabilisation (mean age 11.5 years, range 9–16) with sublaminar wires and rods, and pedicle screws up to the lumbar spine. This cohort was followed up for a mean 4.2 years (3–10 years). 31 cases in another centre had late stabilisation (mean age 14.5 years, range 10–17), with Luque rod and sublaminar wire fixation, and pelvic fixation using L-rod (22 cases) configuration or Galveston technique (9 cases) and were followed up for 4.6 years (0.5–11.5 years). Post-op morbidity, Cobb angle correction and pelvic obliquity data were collected retrospectively and prospectively for comparison. Results: In the lumbar fixation group FVC was 58%, the mean Cobb angle and pelvic obliquity were 19.8° and 9° preoperative, 3.2° and 2.2° direct postoperative, and 5.2° and 2.9° at final follow up respectively. The mean estimated blood loss was 3.3 litres and average hospital stay 7.7 days. In the pelvic fixation group FVC was 44%, the mean Cobb angle and pelvic obliquity were 48° and 19.8° preoperative, 16.7° and 7.2° direct postoperative, and 22° and 11.6° at final follow up respectively. The mean blood loss (4.1 litres) and the average hospital stay (17 days) were significantly higher (p< 0.05) compared to the lumbar fixation group. The pelvic fixation group had higher complication rate at the lower end of fixation. No progression of the pelvic obliquity was noted in the lumbar fixation group during follow up. Conclusion: Lumbar fixation may be adequate for scoliosis in DMD, if the stabilisation is performed early, before the pelvis becomes tilted, and scoliosis becomes significant. The caudal pedicular fixation in the lumbar spine stops rotation of the spine around the rods, and prevent pelvic tilt to occur. Pelvic fixation may be necessary in presence of established pelvic obliquity and larger scoliosis, but is associated with higher morbidity and complications

Study Design: We describe innovative minimally invasive Israeli made Expandable Spinal Fusion System for lumbar spinal fusion, in patients with all caused of mechanical back pain: Degenerative Disc Disease (DDD) at one or two levels from L2–S1, up to Grade l spondylolysthesis. The purpose of the study was to provide a preliminary evaluation of the safety and efficacy of the Expandable Spinal Fusion System in establishing vertebral stability and fusion, and in improving the quality of life of the patients.

The relatively large diameter of currently used cages dictates extensive manipulations, damaging structures that are crucial for spinal stability.

The Expandable Spinal Fusion System, is 5 mm in diameter in closed configuration, applied in a minimally invasive technique, through a 6mm entering opening by an open or percutaneous posterior procedures. Once in position, its dimensions are increased to a precut size in a controlled procedure. Thus, this system maintains the integrity of facet joints, with no or minimal laminectomy, and minimal damage to the surrounding tissues.

Methods: Data were collected in a series of 60 patients with DDD in levels L3–S1. The patients wee operated in the open posterior approach with or without Pedicle Screws and percutaneous posterolateral. Both end-plates faces were treated by special curettes and partially removed. Posterior iliac bone graft was used and 2 tubes device were introduced to the inter-somatic space under direct vision controlled by X-rays C-Arm intensifying magnification.

Data: The implantation approach was posterior in 52 patients, anterior in 2 and percutaneous in 6 patients. Maximal follow up period is 12 months. Patients follow up was completed according to investigational protocol mandate follow up visit at 1.5, 3, 6, 12 months postoperatively. The main at the time of the surgery was 52 years old. 57 underwent surgery at one level as follows: 3 at L3-L4, 32 at L4-L5, and 21 at L5-S1, and 3 underwent surgery at two levels.

Patient questionnaire pain and quality of life was evaluated using the Oswestry questionnaire and VAS measurement. The patient fill those pre-operatively and at each follow up visit.

Results: Although follow up period is short according to preliminary data, the Expandable Spinal Fusion System has proved to be safe, effective, as well as easy to handle for treating all cases of mechanical back pain: DDD. There was no neurological injury, no infection, no death and no worsening of clinical symptoms. There was no breakage or migration of the implant at the last follow-up. Flexion-Extension X-ray show good stability. VAS score for pain dropped from 8 pre op to 2.6 in average 3 months post-op.

Introduction: Mechanical complications following lumbar fixation are due to the combination of various factors related to morphology, pathology, and surgery. The aim of this study was to provide a patient-specific Finite Element Model of the lumbar spine for the simulation of surgical strategies, and to use it as a predictive tool aiming to detect and reduce preoperatively the risks of mechanical complications. Materials & Methods: A pre-existing 3D personalized FEM of the lumbar spine was used. Posterior implants and main degenerative pathologies were also modelled. After in vitro validation based on 24 specimens and 4 different instrumentations, the model was used to simulate real cases. Applied loads were based on patient characteristics (weight, imbalance). Simulation results included mechanical stresses in the discs and within the implants. Clinical consistency of the simulations was tested through the gathering of clinical data for 66 patients instrumented with lumbo-sacral rigid screw-rod systems. Two subsets were considered: “mechanical successes” (53), and “mechanical failures” (13, including 11 screw breakage and 2 screw loosening). Blind comparison was then performed between these observed clinical outcomes and numerical simulations results. Results & Discussion: Among the 66 patients, simulation results highlighted specific behaviours for 9 patients for which mechanical loads on implants were significantly higher. All of these 9 patients were actual “mechanical failures”. None of the actual “mechanical successes” were associated with “abnormal” simulation results. Conclusion: This is the first time finite element simulations helped predicting 9 failures out of 13 observed among a total of 66 patients. This is a promising step towards the possibility to use FEM as a clinically relevant simulation tool for surgery planning

Introduction The unacceptably low fusion rate with stand-alone ALIF cages led to the practice of combining ALIF with posterior instrumentation. Recently ALIF combined with anterior lumbar plate fixation has been promoted to obviate the need for additional posterior surgery. The purpose of this study is to compare the multidirectional flexibility of ALIF combined with posterior instrumentation (either translaminar facet screws or pedicle screws) to that combined with anterior plate fixation. Methods Ten human lumbar cadaveric motion segments were tested in the following sequence: (i) intact, (ii) stand alone ALIF cages, (iii) ALIF and anterior lumbar plate, (iv) ALIF with translaminar facet screws, (v) ALIF with pedicle screws. In each condition, the specimens were tested under bending moments of 0–8 Nm flexion, 0–6 Nm extension, 0–6 Nm lateral bending and 0–5 Nm axial rotation. 3D motions were measured using an optoelectronic motion monitoring system. Results The ALIF cages decreased the ROM in the sagittal and frontal planes (p< 0.05). Their effectiveness improved in the sagittal plane with the combination of either anterior plate or posterior fixation (p< 0.05). There was no statistical difference between the ALIF/ Plate and translaminar screws or pedicle screws in flexion-extension and axial rotation ROM. There was a difference in the lateral bending ROM between the ALIF with anterior plate and ALIF with either translaminar facet screws or ALIF with pedicle screws (p< 0.05) favouring posterior fixation. However there was no statistical difference between the combined ROM for ALIF/Plate and translaminar screws or pedicle screws. Discussion This study shows that the stability achieved with the combination of ALIF with an anterior plate is comparable to that achieved with posterior instrumentation with translaminar facet screws or pedicle screws. This suggests that sufficient segmental stability may be provided by anterior plating, obviating the need for a concomitant posterior approach