Comparison of short-stem versus conventional stem for hip arthroplasty in patients younger than 60 years: 7-14 years follow-up.

PURPOSE: Short-stem prostheses in hip arthroplasty have emerged as an alternative to conventional stems, especially in younger patients. The purpose of this study was to compare functional and radiological results of a short metaphyseal fitting cementless stem versus a conventional stem implant, in patients younger than 60 years. METHODS: All patients operated from January 2006 to April 2013 were included, obtaining a minimum follow-up of 7 years. Harris Hip Score (HHS) and SF-36 (quality of life) questionnaires were applied and the presence of "thigh pain" was specifically assessed. We also compared complication rate, revision rate and average prosthesis survival. Femoral stress shielding (Gruen scale), stem subsidence, varus-valgus tilt and implant stability (Engh scale) were also compared. RESULTS: A total of 101 short-stem and 74 conventional arthroplasties were included, with an average follow-up of 9.82 (7-14) years. HHS functional score and SF-36 were excellent in both implants and no significant difference between them (p > 0.05) was found. However, "thigh pain" was present in 7 patients with conventional stems and none with short-stems (p < 0.001). The survival rate at 13 years was 99%, for both implants, and no significant differences were found between them (χ2(2) = 0.178; p = 0.673). Conventional stems had stress shielding at the greater trochanter in 72% of the cases and 43% at the calcar, being statistically superior (p < 0.001) to the stress shielding observed in the short stems. CONCLUSION: According to our results, this short-stem seems to allow preservation of bone stock, with decreased stress shielding and also a lower incidence of thigh pain compared to conventional stems. LEVEL OF EVIDENCE: Level III retrospective comparative study.

The segmental and chain relaxation modes in high-cis-polyisoprene as studied by thermally stimulated currents.

The technique of Thermally Stimulated Currents is used to study the slow molecular mobility in a series of poly (1,4-cis-isoprene) samples with different molecular weights, Mw, and low polydispersity. The technique revealed a high resolution power, particularly useful in the study of the lower molecular weight samples where the chain and the segmental relaxations strongly overlap. The dynamic crossover that is reported for the normal mode by varying the molecular weight is clearly revealed by the thermally stimulated depolarization currents results through the temperature location, TMn, of the normal mode peak, the values of the relaxation time at TMn, τ(TMn), and the value of the fragility index of the normal mode, mn. The kinetic features of the glass transition relaxation of polyisoprene have also been determined.

TSDC and DSC Investigation on the Molecular Mobility in the Amorphous Solid State and in the Glass Transformation Region of Two Benzodiazepine Derivatives: Diazepam and Nordazepam.

In this work we study the molecular mobility in the amorphous solid state and in the glass transformation region of two compounds, diazepam and nordazepam; these are two benzodiazepines, a family of psychotropic drugs with sedative, anxiolytic and muscle-relaxing properties. The experimental techniques used are thermostimulated currents (TSC) and differential scanning calorimetry (DSC). TSC is a time-dependent technique recognized for its high resolving power; the use of this technique in the depolarization and polarization modes (TSDC and TSPC respectively), provides results that confirm and complement results of dielectric relaxation spectroscopy (DRS) published recently. On the other hand, the variation with the heating rate of the temperature position of the DSC glass transition signal also allowed the estimation of the activation energy at Tg and of the dynamic fragility of the two glass formers.

Shoulder Arthroplasty Options for Glenohumeral Osteoarthritis in Young and Active Patients (<60 Years Old): A Systematic Review.

Aim: This study aims to describe the shoulder arthroplasty options for young and active patients (<60 years old) with glenohumeral osteoarthritis. Methods: A systematic review of the literature was conducted by searching on Pubmed database. Studies that reported outcomes of patients with glenohumeral arthritis, younger than 60 years, that underwent shoulder arthroplasty [(Hemiarthroplasty (HA), Hemiarthroplasty with biological resurfacing (HABR), Total shoulder arthroplasty (TSA), Reversed total shoulder arthroplasty (RSA)] were included. Data include patient characteristics, surgical technique, range of motion, pain relief, outcome scores, functional improvement, complications, need for and time to revision. Results: A total of 1591 shoulders met the inclusion criteria. Shoulder arthroplasty provided improvements in terms of ROM on the 3 plains, forward flexion (FF), abduction (Abd) and external rotation (ER), in different proportions for each type of implant. Patients submitted to RSA had lower preoperative FF (p = 0.011), and the highest improvement (Δ) in Abd, but the worst in terms of ER (vsTSA, p = 0.05). HA had better ER postoperative values (vsRSA p = 0.049). Pain scores improved in all groups but no difference between them (p = 0.642). TSA and RSA groups had the best CS Δ (p = 0.012). HA group had higher complication rates (21.7%), RSA (19.4%, p = 0.034) and TSA (19.4%, p = 0.629) groups the lowest, and HABR had the highest rate of revisions (34.5%). Conclusions: HA had the highest rate of complications and HABR unacceptable rates of revision. These implants have been replaced by modern TSAs, with RSA reserved for complex cases. Surgeons should be aware of the common pitfalls of each option.

Thermal behavior and molecular mobility studies in the supercooled liquid and glassy states of carvedilol and loratadine.

The thermal behavior of carvedilol and loratadine was studied by differential scanning calorimetry (DSC). The glass-forming ability, as well as the the tendency for crystallization from the glass (glass stability) and from the metastable and equilibrium melt were also investigated by DSC. In addition this technique was also used to characterize the glass transition of carvedilol and loratadine by determining the activation energy of the structural relaxation, the dynamic fragility, and the heat capacity jump associated with the glass transformation. Different aspects of the molecular mobility in carvedilol and loratadine were analyzed by Thermally Stimulated Depolarization Currents (TSDC), while in carvedilol the Dielectric Relaxation Spectroscopy (DRS) technique was also used. Carvedilol stands out for its high values of specific heat jump and dynamic fragility, which has been attributed to the particular mobility of this glass-former in the glass transformation region, a consequence of specific characteristics of its molecular structure. These molecular features are also at the origin of a relaxation above Tg that has been detected and characterized by TSDC; the DRS investigation allowed to better understand the molecular dynamics in carvedilol in the amorphous solid, in the metastable liquid state and in the glass transformation region. Finally, the secondary relaxations in loratadine were studied by TSDC, while those in carvedilol were studied by the two dielectric techniques and the results were compared and discussed.

Isolated traumatic posterior dislocation of the radial head in an adult, a rare injury: New case report.

Isolated radial head dislocations are rare in adults with only 23 cases published in 45 years. The diagnosis may be easily missed on radiographs and a CT-scan is often required. If managed promptly patient can restore normal range of motion and elbow function. Authors report a new case of a 67-year-old female presenting a posttraumatic isolated posterior dislocation of the radial head. Treatment consisted of closed reduction followed by immobilization for four weeks in a plaster cast with the elbow flexed at 90°, followed by active mobilization and physiotherapy. At 18 months of follow-up, functional outcome is excellent with no differences between both sides.

Tuberosity Healing after Reverse Shoulder Arthroplasty for Proximal Humerus Fractures: Is there Clinical Improvement?

Objective To compare the functional results of patients with complex proximal humerus fracture submitted to total shoulder reverse arthroplasty with and without tuberosity healing. The secondary goal was to know the tuberosity healing rate after reverse shoulder arthroplasty with our surgical technique. Methods A retrospective, cohort type study, with a prospective database collection. In total, 28 patients fulfilled the inclusion criteria: age ≥ 65 years, reverse shoulder arthroplasty for complex proximal humerus fracture (type-3 or -4, according to Neer), and a minimum of 24 months of follow-up. At six months of follow-up, all of the patients were evaluated radiographically for tuberosity, and then they were divided into 2 groups: those with healed tuberosities and those with non-healed tuberosities. A clinical evaluation using the Constant score, active range of motion and the Visual Analog Scale (VAS) at the last follow-up was also performed. Results Tuberosity healing occurred in 21 patients (76.3%). There were statistically significant differences in the Constant scoring system ( p < 0.001), forward elevation ( p = 0.020), internal rotation ( p = 0.001) and external rotation ( p = 0.003) when comparing the group of healed tuberosities with the group of non-healed tuberosities. No differences were found regarding the VAS score. Conclusion Tuberosity healing results in an improvement of the functional outcomes of patients submitted to reverse shoulder arthroplasty as a treatment for complex proximal humeral fractures in the elderly.

Thermal Behavior and Slow Relaxation Dynamics in Amorphous Efavirenz: A Study by DSC, XRPD, TSDC, and DRS.

The analysis of the thermal behavior of efavirenz showed a high glass-forming ability and good glass stability of this glass-forming liquid at room temperature. No polymorphic forms were formed either by cold crystallization or by recrystallization from solvent acetone. The determination of the dynamic fragility by the differential scanning calorimetry, thermally stimulated depolarization currents (TSDC), and dielectric relaxation spectroscopy (DRS) techniques is unanimous in suggesting efavirenz as a moderately fragile liquid. With DRS, secondary relaxations were detected, however, with weak intensities that did not allow the respective kinetic analysis; in contrast, TSDC allows clearly resolving the components of the secondary ß-relaxation below Tg, with activation energies distributed between about 75 and 90 kJ mol-1 and Arrhenius prefactors of the order of 10-13 s. In this regard, the TSDC technique proved to be more effective compared to DRS in characterizing the secondary relaxation. The glass forming ability and glass stability found for efavirenz have been discussed in terms of various thermodynamic and kinetic parameters such as the reduced glass transition temperature, Tgred, the dynamic fragility, m, the stretching exponent, ßKWW, the melting entropy, ΔSfus, and the molecular stiffness. The exceptionally low value of efavirenz fusion entropy was highlighted as a key feature of the thermal behavior of this glass-forming liquid.

Relaxation behaviour of D(-)-salicin as studied by Thermally Stimulated Depolarisation Currents (TSDC) and Differential Scanning Calorimetry (DSC).

Thermally Stimulated Depolarisation Currents (TSDC) measurements on D(-)-salicin have been carried out in the temperature region from -165 degrees C up to 150 degrees C. The slow molecular mobility was characterised in the crystal and in the glassy state. The value of the steepness index or fragility (T(g)-normalized temperature dependence of the relaxation time) was obtained by Differential Scanning Calorimetry (DSC) from the analysis of the scanning rate dependency of T(g). The existence of an unknown polymorph of salicin is also reported.

Slow molecular mobility in the crystalline and amorphous solid states of pentitols: a study by thermally stimulated depolarisation currents and by differential scanning calorimetry.

The molecular mobility of the pentitol isomers (xylitol, adonitol, D-arabitol and L-arabitol) was studied by thermally stimulated depolarisation currents (TSDC) in the crystalline and in the amorphous solid states. Differential scanning calorimetry (DSC) was used to characterise the phase transformations, to detect polymorphism and to analyse the dynamics of the structural relaxation in the glassy state (from the heating rate dependence of the onset temperature of the glass transition signal). The mobility in crystalline xylitol and adonitol displays features that are different compared with crystalline arabitols. No difference of the dynamic behaviour seems to emerge from our results on the primary and secondary relaxations in the amorphous isomeric pentitols. The values of the steepness index or fragility obtained in this work by TSDC and DSC are compared with the values reported in the literature obtained from other experimental techniques, and with values predicted by empirical formulae.