Introduction

Isolated U-shaped sacral fractures are rare entities, mostly seen in polytraumatized patients, and hence, they are difficult to diagnose. While the pelvic ring remains intact across S2/S3, the U-shaped fracture around S1 leads to marked instability between the base of the spine and the pelvis. As severe neurological deficits can occur, timely treatment of these fractures is crucial. We present a novel technique of percutaneous reduction and trans-sacral screw fixation in U-shaped fractures.

Posterior internal fixation systems undergo internal constraints resulting in high load bearing requirement for the pedicular screw/bone interface. Only few studies deal with the impact of the vertebral augmentation on the migration of pedicular screws. In this study, the impact of the pedicular screw augmentation has been investigated under physiological load for osteoporotic vertebras. The data have been proceeded to reduce the influence of vertebral geometry, which generally leads to results devoid of statistical meaning

In 8 osteoporotic vertebrae, two screws have been inserted in each vertebra: a non-augmented on one side and an augmented one on the contralateral side.

Compression tests have been performed (two consecutive 50 cycles load steps -100N and 200N-) to observe the displacement of the screw’s head. Two different setups have been employed: a free connection (FC) and a blocked connection (BC). A load step is successful if the migration between two consecutive cycles tends to zero. To reduce the impact of the vertebras’ geometry, the screws’ migration have been compared contra-laterally using the migration ratio (MR). MR of vertebrae is defined as the division of the augmented screw’s migration with the non-augmented screw’s migration.

All the augmented screws survived both test setups whereas the non-augmented failed the 200N FC load step. Significant differences are observable only for the highest successful load steps for each test setup: T-tests (P=0.039 and P=0.007 respectively) put into evidence that the results are statistically smaller than one. It is observable as well, that the BC induced fewer loads into the vertebrae: even non-augmented screw can withstand 200N load step.

As expected, augmentation of pedicular perforated screws increases their stability in osteoporotic vertebras undergoing large physiological load. This could be explained by the fact that the presence of PMMA increases the load transfer interface improving screw/PMMA complex bearing capacity. Smaller loads induce only small differences that are not significant.

Minimal-invasive augmentation techniques have been advocated to treat osteoporotic vertebral body fractures (VBFs). Kyphoplasty is designed to address both fracture-related pain as well as the kyphotic deformity usually associated with the fracture. Previous studies have indicated the potential of the technique for immediate pain relief and reduction of vertebral height, but whether this is a lasting effect, has not been well investigated. The current prospective study reports on our experience and the one-year results in 27 kyphoplasty procedures in 24 patients with PMMA for osteoporotic VBFs.

Pain was assessed on a 0–10 VAS. Deformity and reduction of the vertebral body was measured as the angulation between the two endplates on standing lateral radiographs. All parameters were taken pre-op, one day and two months post-operatively and after one year. Multiple regression analysis was conducted to determine the importance of independent factors as predictors of the achieved fracture reduction.

All but one patient experienced pain relief directly following the procedure with a lasting effect after 2 months and also one year in 25 cases. An average vertebral kyphosis reduction of 47.7% was achieved with no loss of reduction after one year. Pain relief was not related to the amount of reduction. The potential for reduction was related to pre-op kyphosis, level treated, and fracture age, but not to the age of the patient.

In this series, kyphoplasty was an effective treatment of VBFs in terms of pain relief and durable reduction of deformity. However, whether spinal realignment results in an improved long-term clinical outcome remains to be investigated.

Aims: To determine whether certain motion parameters could be linked to clinical signs and symptoms of instability in a group of chronic LBP patients. Methods: Thirty-four patients enrolled for an external þxation (ESF) test performed active ßexion-extension, axial rotation, and lateral bending motions, during which the relative motion between marker carriers attached to the Schanz screws was measured with an optoelectronic camera. The rotations of the vertebrae were analysed with special reference to ranges of motion, motion asymmetries, and coupled motions. Studentñs t-test was used to determine whether these parameters were signiþ cantly different between the patient groups that did and did not receive pain relief from the stabilization of the suspected painful segment/s. Results: The improvement of the patientñs functional status during the external þxation as well as after subsequent lumbar fusion surgery was signiþcantly correlated with the extension ROM (p=0.049 and p=0.036), and the ratio of extension to ßexion ROM (p=0.035 and p=0.044) at the index levels before surgery. No signiþcant correlations with the other motion pattern parameters were observed. Conclusions: In case of a positive ESF test, preserved motion at the symptomatic level/s before the surgery seemed to predict a favorable fusion outcome. On the other hand, abnormal patterns of asymmetry and coupled motion did not seem to be associated with pain relief after stabilization of the suspected painful segment/s.

Osteoporosis and osteoporotic fractures represent a growing medical and socioeconomic problem and the spine is the most common site for this kind of fracture. Back pain is the leading symptom with progressive loss of stature and restricted physical activity as a consequence. Vertebroplasty – percutaneous cement reinforcement of osteoporotic vertebrae - represents a new treatment alternative.

During a three year period, 512 vertebrae in 180 patients were reinforced for osteoporotic fractures with low viscosity PMMA. One to eight levels were treated per time, and 8ml (2–18ml) of PMMA per vertebra were injected. The patients’ pain (VAS) was prospectively monitored before surgery, one day, 3 months and one and two years postoperatively. Furthermore, X-rays were analysed 3, 12 and 24 months postoperatively.

One out of 180 patients suffered from an L2 root irritation due to cement leakage that subsided after steroid infiltration. 52 patients with 144 levels treated and a minimal follow up of two years showed a significant (p< 0.02) and lasting pain reduction from 7.7 to 2.8 points at two years. 6 patients were treated a 2nd time for a new fracture. The reinforced vertebrae remained stable without further sintering.

Vertebroplasty is efficient for the treatment of osteoporotic vertebral fractures. The injection technique used is safe, easy and fast. An unsolved problem remains the question about the importance of prophylactic reinforcement of non-fractured vertebrae.