Clinical and radiological results of TLIF surgery with titanium-coated PEEK or uncoated PEEK cages: a prospective single-centre randomised study

BACKGROUND

A comparison of fusion rates and clinical outcomes of instrumented transforaminal interbody fusion (TLIF) between polyetheretherketone (PEEK) and titanium-coated PEEK (Ti-PEEK) cages is not well documented.

METHODS

A single-centre, prospective, randomised study included patients who underwent one-level TLIF between L3-S1 segments. Patients were randomised into one of two groups: TLIF surgery with the PEEK cage and TLIF surgery with the Ti-PEEK cage. Clinical results were measured. All patients were assessed by repeated X-rays and 3D CT scans. Cage integration was assessed using a modified Bridwell classification. The impact of obesity and smoking on fusion quality was also analysed. Patients in both groups were followed up for 2 years.

RESULTS

Altogether 87 patients were included in the study: of these 87 patients, 81 (93.1%) completed the 2-year follow-up. A significant improvement in clinical outcome was found in the two measurements scales in both groups (RM: p = 0.257, VAS: p = 0.229). There was an increase in CobbS and CobbL angle in both groups (p = 0.172 for CobbS and p = 0.403for CobbL). Bony fusion was achieved in 37 of 40 (92.5%) patients in the TiPEEK group and 35 of 41 (85.4%) in the PEEK group (p = 0.157). Cage subsided in 2 of 40 patients (5%) in the TiPEEK group and 11 of 41 (26.8%) in the PEEK group (p = 0.007). Body mass index > 30 and smoking were not predictive factors of bony fusion achievement.

CONCLUSION

There is no significant advantage of TiPEEK cages over PEEK cages in clinical outcome and fusion rate 2 years after surgery.

Raman scattering yields cubic crystal grain orientation

The paper proposes a fully optical method for determination of a cubic crystal grain orientation in a sample inspected by a Raman microscope. The method is based on a universal and strong polarisation anisotropy of the Raman scattering by doubly degenerate optic phonon modes and it only requires a standard Raman microscope equipped with a polarisation analysis. Explicit formulas for the orientation of the crystal grain are derived. The feasibility of the approach is demonstrated by comparing grain orientations in a polycrystalline cubic lacunar spinel GaV₄S₈ determined independently using electron backscatter diffraction and Raman scattering methods.

Ultrasonographic examination of the ruptured cord after collagenase treatment or needle fasciotomy for Dupuytren's contracture

Local treatment of Dupuytren's contracture, either by collagenase or needle fasciotomy, allows disruption of the pathological cord during forced extension. The purpose of this study was to investigate the cord before and after both treatments by ultrasound. A total of 39 patients with a minimum of 20° contracture in the metacarpophalangeal joint were included and randomized to treatment with either collagenase (20 patients) or needle fasciotomy (19 patients). The distance between the distal and the proximal parts of the ruptured cord was measured by ultrasound and the difference in passive joint movement before and after treatment was measured with a goniomenter. There were no significant differences between the collagenase and needle fasciotomy groups in the size of the rupture or gain of mobility. Most cords treated with collagenase and subsequent forced extension had the same ultrasonographic appearance as cords disrupted mechanically by needle fasciotomy.

LEVEL OF EVIDENCE

III.

A multiferroic material to search for the permanent electric dipole moment of the electron

We describe the first-principles design and subsequent synthesis of a new material with the specific functionalities required for a solid-state-based search for the permanent electric dipole moment of the electron. We show computationally that perovskite-structure europium barium titanate should exhibit the required large and pressure-dependent ferroelectric polarization, local magnetic moments and absence of magnetic ordering at liquid-helium temperature. Subsequent synthesis and characterization of Eu(0.5)Ba(0.5)TiO(3) ceramics confirm the predicted desirable properties.

Coexistence of the phonon and relaxation soft modes in the terahertz dielectric response of tetragonal BaTiO3

The dielectric response to infrared waves polarized along the tetragonal axis of a ferroelectric single-domain crystal of BaTiO3 was determined by time-domain THz spectroscopy and Fourier-transform infrared reflectivity techniques. In addition to the three well-known polar lattice modes, the experiment shows an additional mode of the relaxation type in the THz spectral region, which accounts for the Curie-Weiss behavior of the c-axis dielectric constant. A comparison of experimental results with ab initio based effective-Hamiltonian simulations allows us to elucidate its relation to the order-disorder model of Comes, Lambert, and Guinier [Solid State Commun. 6, 715 (1968)10.1016/0038-1098(68)90571-1].

Internal bleaching with 10% carbamide peroxide in vitro

This in vitro study assessed the efficacy of 10% carbamide peroxide to internally bleach discolored teeth. Following pulp removal, 38 tooth crowns were stained with erythrocytes and bleached 3 times over 14 days using either 10% carbamide peroxide or 30% H2O2 and sodium perborate. The pulp chambers were subsequently filled, and the tooth crowns stored for 3 months. The shades of the crowns were measured using reflectance spectroscopy prior to and at several time points following bleaching. Using statistical analysis, the authors determined that both materials significantly improved the shade of the crowns, and that 10% carbamide peroxide could be utilized clinically to internally bleach nonvital discolored teeth.

Increased lesion-induced sprouting of corticospinal fibres in the myelin-free rat spinal cord

Myelin contains potent inhibitors of neurite growth which have been implicated in the failure of long-distance regeneration of nerve fibres within the CNS. These myelin-associated neurite growth inhibitors may also be involved in the stabilization of neural connections by suppressing sprouting and fibre growth. After lesions of the CNS in neonatal animals, extensive rearrangements of the remaining fibre systems have been observed. In the rat, this plasticity of neuronal connections is severely restricted following the first few weeks of postnatal life, coincident with the progression of myelination of the nervous system. A well-studied example of postnatal plasticity is the sprouting of one corticospinal tract (CST) into the denervated half of the spinal cord after unilateral motor cortex or pyramidal lesions. In the hamster and rat, significant CST sprouting is restricted to the first 10 postnatal days. Here we show that very extensive sprouting of corticospinal fibres occurs after deafferentations as late as P21 if myelination is prevented by neonatal X-irradiation in the rat lumbar spinal cord. Sprouted fibres from the intact CST cross the midline and develop large terminal arbors in the denervated spinal cord, suggesting the establishment of synaptic connections. Our results suggest that myelin and its associated neurite growth inhibitors play an important role in the termination of neurite growth permissive periods during postnatal CNS development. Corticospinal sprouting subsequent to lesions early in life, i.e. in the absence of myelin-associated neurite growth inhibitors may explain the frequent occurrence of mirror movements in patients with hemiplegic cerebral palsy.

Phase Transition in K3Na(MoO4)2 and Determination of the Twinned Structures of K3Na(MoO4)2 and K2.5Na1.5(MoO4)2 at Room Temperature

The room-temperature phases of sodium potassium molybdates K3Na(MoO4)2 and K2.5Na1.5(MoO4)2 are isostructural with the monoclinic low-temperature phases of KaNa(SeO4)2 and K3Na(CrO4)2, which are twinned distorted glaserite structures. In the molybdates there are two crystallographically independent potassiums and their environment slightly differs from those in K3Na(SeO4)2 and K3Na(CrO4)2. The excessive Na in K2.5Na1.5(MoO4)2 occupies the position of the more firmly bound potassium. A reversible phase transition at 513 K was discovered in KaNa(MoO4)2 by DSC (differential scanning calorimetry), but no such transition in K2.5Na1.5(MoO4)2 was detected. Both samples used in the diffractometer experiment were found to be composed of six domains being related by twinning operations of the point group 6. The twinning may be considered as a combination of a merohedral and a pseudo-merohedral twinning with two- and threefold rotations as twinning operations, respectively. However, a reversible domain switching, which is observable in the related ferroelastic crystals of KaNa(SeO4)2 and K3Na(CrO4)2, was not observed either in K3Na(MoO4)2 or in K2.5Na1.5(MoO4)2, either due to semitransparency of the samples or high ferroelastic distortion. This distortion is manifested by the values of the atomic displacement vectors which are about twice as large as those in the selenate or the chromate.

Detection of DNA breaks in apoptotic cells utilizing the DNA binding domain of poly(ADP-ribose) polymerase with fluorescence microscopy

The DNA binding domain (DBD) of poly(ADP-ribose) polymerase (PARP) has proved to be a novel, highly sensitive probe for detecting DNA breaks in intact cells undergoing apoptosis. A recombinant peptide spanning the DNA binding domain of PARP was expressed, purified and used to detect DNA strand breaks in fixed cells. Fluorescence microscopy with this probe followed by detection with anti-PARP antisera initially revealed an increased binding following treatment of cells with DNA strand-breaking agents (such asN-methyl-N'-nitro-N-nitrosoguanidine) and, subsequently, using biotinylated PARP DBD, during the later stages of apoptosis in several cell systems, when internucleosomal strand breaks became evident. This procedure was found to be at least as sensitive and required fewer steps to detect DNA strand breaks than those utilizing Klenow incorporation of biotinylated nucleotides.