First-line management of distal humerus fracture by total elbow arthroplasty in geriatric traumatology: Results in a 21-patient series at a minimum 2years' follow-up

INTRODUCTION

Total elbow arthroplasty (TEA) is one option in distal humerus fracture in elderly osteoporotic patients.

HYPOTHESIS

The study hypothesis was that, in patients aged 70years or more, TEA provides functional results and ranges of motion compatible with everyday activity, with a complications rate equal to or lower than with internal fixation, and no loss of autonomy or cognitive impairment.

MATERIAL AND METHODS

In this retrospective study, 21 patients receiving TEA for distal humerus fracture were included. Mean follow-up was 3.2years, with functional (Quick DASH and MEPS), cognitive (MMSE), autonomy-related (ADL) and radiological assessment (Morrey).

RESULTS

Mean MEPS was 84 and QuickDASH 32.4. Mean extension deficit was 22°, and mean flexion 125°. There was no loss of autonomy or cognitive impairment. The complications rate was 9.5%. There were no revision surgeries.

DISCUSSION

TEA proved reliable in comminuted distal humerus fracture in elderly patients. Functional results were comparable to those in the literature, and the complications rate was lower. Long-term implant survival needs confirmation to validate this option as a treatment of choice in these indications in geriatric traumatology.

TYPE OF STUDY

Retrospective non-comparative, single-center.

LEVEL OF EVIDENCE

4.

Titanium-titanium modular neck for primary THA. Result of a prospective series of 170 cemented THA with a minimum follow-up of 5 years

BACKGROUND

Although they have been in use since the end of the 1980s, modular titanium neck components are associated with a risk of wear or fracture, and their safety has recently become a subject of debate and has never been evaluated in a consecutive series of patients. The goal of this study was to evaluate: revision-free survival of these implants after a minimum follow-up of 5 years; clinical and radiographic results; and the potential complications associated with the use of modular titanium neck components.

HYPOTHESIS

The use of titanium modular neck on cemented titanium THA is safe at a minimum follow-up of 5 years.

PATIENTS AND METHODS

Between January 2006 and December 2008, we prospectively followed 170 patients (170 hips) who underwent primary anatomical THA with a modular cemented titanium stem design implant. The indications were unilateral THA for primary (n=160) or secondary (n=10) hip osteoarthritis (aseptic osteonecrosis of the femoral head or hip dysplasia). Mean age of patients was 75.4±5.8 years old (52-85), and mean BMI was 26.1±4.5 kg/m(2) (16.6-42.1). Patients were operated on by a modified Watson-Jones anterolateral approach based on preoperative 2D planning. All patients underwent annual clinical and radiological follow-up by an independent observer.

RESULTS

At a mean follow-up of 71±8 months (60-84), 5 patients died and 7 were lost to follow-up. There was no revision of THA after a maximum follow-up of 84 months. The Harris score improved significantly from 50.4±11.3 (0-76) preoperatively to 84.5±15.2 (14-100) at the final follow-up. There was no difference in postoperative femoral offset or the position of the center of rotation compared to the opposite side. On the other hand, the neck-shaft angle (NSA) and limb length were corrected (2±5° [-11 to +14°] and 2.16±3.6 mm [-7.4 to +12.7 mm]) respectively. Fifteen patients (9%) had limb length discrepancies of more than 5 mm and 4 patients (2%) of more than 10 mm. There were no complications due to the modular implant design.

DISCUSSION

Our study suggests that the use of cemented titanium implants with a modular titanium stem is safe at a follow-up of 5 years. The modular design does not prevent limb length discrepancies but restores femoral offset.

LEVEL OF EVIDENCE

IV: prospective, non-comparative study.

Partial or total replacement of a unicompartmental knee prosthesis by another unicompartmental knee prosthesis: a reasonable option? About 22 cases

Twenty-two patients who received primary unicompartmental knee arthroplasties (21 medial and 1 lateral) were reoperated between 2001 and 2010 for partial or total replacement of their implant without using a TKA. Of the 21 patients (1 bilateral) reoperated for PE insert wear (11), PE fracture (3), infection (2), and loosening or malposition (6), 3 patients died and 2 were lost to follow up. The remaining 17 cases had their clinical scores significantly improved. Only one re-revision occurred and consisted of a simple change of PE insert at 9 years, on a very heavy and very active patient. It therefore seems possible and reasonable for now to continue partial or total replacement of unicompartmental knee arthroplasty by another unicompartmental knee arthroplasty without using a TKA.

Validation of HPLC method for quantitative determination of Tinosorb S and three other sunscreens in a high protection cosmetic product

A chromatographic method (high performance liquid chromatography) with a diode array detector was developed for simultaneous assay of Tinosorb S (bis-ethylhexyloxyphenol methoxyphenyl triazine) with three other sunscreen agents [benzophenone-3, butyl methoxydibenzoylmethane (avobenzone) and ethylhexyl methoxycinnamate] in high protection sunscreen. Separations were performed on a RP-18 Nucleodur Gravity column (150 x 4.6 mm, 5 mum) eluted with a ternary gradient mixture constituted of tetrahydrofuran, acetonitrile and an aqueous solution of acetic acid. The quantitative analysis was achieved with internal calibration performed with octyl dimethyl para-aminobenzoate (PABA) at 330 nm. In accordance with the analytical references (SFSTP, ICH, ISO...), the accuracy of the method was evaluated using a statistical approach of the validation parameters (specificity, response function, linearity, precision and trueness). For each studied ultraviolet filter, an accuracy profile was determined on a predicted range. These profiles show a graphical representation of the recovery percentage and confidence limits centred on 100%. The method is validated and can be used for analysis in cosmetic sunscreen products.

[Sensory syndrome and aphasia after left insular infarct]

INTRODUCTION

Sensorial impairment without hemiplegia is usually caused by a thalamic lesion.

CASE REPORT

A 28-year-old woman presented with hemianesthesia associated with aphasia following a left insular lesion, subsequent to subarachnoid hemorrhage. Brain MRI Flair sequence revealed a high intensity signal in the left insular and frontal subcortical regions. Insular infarct was diagnosed, associated with hemorrhagic sequelae.

DISCUSSION/CONCLUSION

Study of the normal and pathologic insular cortex suggest several implications of the region in somatosensory and language functions. However, the insular cortex has been mainly associated with central pain. Lasting objective hypoesthesia has been very rarely documented. The left insular cortex has also been implicated in speech apraxia but our patient presented with fluent aphasia mostly affecting the rhythm of speech, as it has been observed in thalamic aphasia.

L-arginine-induced vasodilation in healthy humans: pharmacokinetic-pharmacodynamic relationship

AIMS

Administration of L-arginine by intravenous infusion or via oral absorption has been shown to induce peripheral vasodilation in humans, and to improve endothelium-dependent vasodilation. We investigated the pharmacokinetics and pharmacokinetic-pharmacodynamic relationship of L-arginine after a single intravenous infusion of 30 g or 6 g, or after a single oral application of 6 g, as compared with the respective placebo, in eight healthy male human subjects.

METHODS

L-arginine levels were determined by h.p.l.c. The vasodilator effects of L-arginine were assessed non-invasively by blood pressure monitoring and impedance cardiography. Urinary nitrate and cyclic GMP excretion rates were measured as non-invasive indicators of endogenous NO production.

RESULTS

Plasma L-arginine levels increased to (mean +/- s.e.mean) 6223+/-407 (range, 5100-7680) and 822+/-59 (527-955) micromol l(-1) after intravenous infusion of 30 g and 6 g L-arginine, respectively, and to 310+/-152 (118-1219) micromol l(-1) after oral ingestion of 6 g L-arginine. Oral bioavailability of L-arginine was 68+/-9 (51-87)%. Clearance was 544+/-24 (440-620), 894+/-164 (470-1190), and 1018+/-230 (710-2130) ml min(-1), and elimination half-life was calculated as 41.6+/-2.3 (34-55), 59.6+/-9.1 (24-98), and 79.5+/-9.3 (50-121) min, respectively, for 30 g i.v., 6 g i.v., and 6 g p.o. of L-arginine. Blood pressure and total peripheral resistance were significantly decreased after intravenous infusion of 30 g L-arginine by 4.4+/-1.4% and 10.4+/-3.6%, respectively, but were not significantly changed after oral or intravenous administration of 6 g L-arginine. L-arginine (30 g) also significantly increased urinary nitrate and cyclic GMP excretion rates by 97+/-28 and 66+/-20%, respectively. After infusion of 6 g L-arginine, urinary nitrate excretion also significantly increased, (nitrate by 47+/-12% [P<0.05], cyclic GMP by 67+/-47% [P= ns]), although to a lesser and more variable extent than after 30 g of L-arginine. The onset and the duration of the vasodilator effect of L-arginine and its effects on endogenous NO production closely corresponded to the plasma concentration half-life of L-arginine, as indicated by an equilibration half-life of 6+/-2 (3.7-8.4) min between plasma concentration and effect in pharmacokinetic-pharmacodynamic analysis, and the lack of hysteresis in the plasma concentration-versus-effect plot.

CONCLUSIONS

The vascular effects of L-arginine are closely correlated with its plasma concentrations. These data may provide a basis for the utilization of L-arginine in cardiovascular diseases.

Assessment of coronary blood flow in humans using phase difference MR imaging. Comparison with intracoronary Doppler flow measurement

Coronary blood flow quantification provides essential information on the hemodynamic significance of coronary artery stenoses. Recently, magnetic resonance (MR) flow mapping has emerged as a new promising method to noninvasively determine flow velocity and flow volume within the coronary arteries. The aim of this study was to compare phase difference (PD) MR flow quantification with intracoronary Doppler flow measurements in 15 patients with suspected or known coronary artery disease. Flow quantification was attempted before and after systemic application of 5mg Isosorbiddinitrate (ISDN) in order to determine possible alterations in coronary flow volume. PD MR flow mapping was performed successfully in 13 of the 15 patients. For flow velocities and flow volume values, a close correlation between PD MR and Doppler flow measurements was found (r = 0.79 and r = 0.90, respectively). However, average flow measured by PD MR was significantly lower than the invasively obtained values (9.0 +/- 4.4 cm/sec vs. 11.7 +/- 4.9 cm/sec; p < 0.001 and 46.3 +/- 28.7 ml/min vs. 53.4 +/- 32.8 ml/min; p < 0.05). Although the mean flow volume remained constant in the entire patient group after ISDN application, individual changes (increase in 6, decrease in 4 cases) could be documented with PD MR imaging and showed a good correlation to the Doppler method (r = 0.82). In conclusion, PD MR flow mapping is a promising method for the noninvasive quantification of coronary blood flow and therefore offers the potential of assessing coronary artery stenoses. However, technical improvements are mandatory in order to increase accuracy of the method.

Differential inhibition of human platelet aggregation and thromboxane A2 formation by L-arginine in vivo and in vitro

We compared the effects of L-arginine (L-ARG), the precursor of endogenous NO, on platelet aggregation and thromboxane A2 formation in vivo and in vitro. Human platelet-rich plasma (PRP) was anticoagulated with citrate (which decreases extracellular Ca2+) or with recombinant hirudin (which does not affect extracellular Ca2+). Two groups of 10 healthy male volunteers received intravenous infusions of L-ARG (30 g or 6 g, 30 min) or placebo. Blood was collected immediately before and at the end of the infusions for aggregation by ADP or collagen. Infusion of L-ARG inhibited ADP-induced aggregation in PRP anticoagulated with citrate by 37.5+/-6.3% (P < 0.05). In PRP anticoagulated with hirudin, aggregation was inhibited by 33.6+/-16.0% (P < 0.05). L-ARG infusion also inhibited platelet TXB2 formation and slightly, but not significantly decreased the urinary excretion rate of 2,3-dinor-TXB2; cGMP concentrations in PRP were significantly elevated during L-arginine infusion. In vitro preincubation with L-ARG (10 microM-2.5 mM) inhibited platelet aggregation in PRP anticoagulated with rhirudin, but not citrate. This effect was stereospecific for L-arginine, as D-arginine had no effect. It was dependent upon NO synthase activity, as indicated by increased cGMP levels in PRP. Moreover, both the NOS inhibitor L-NMMA and the inhibitor of soluble guanylyl cyclase ODQ antagonized the effects of L-ARG. Haemoglobin, an extracellular scavenger of NO, partly antagonized the antiplatelet effects of L-ARG. 8-Br-cyclic GMP and the exogenous NO donor linsidomine inhibited aggregation in PRP anticoagulated with citrate or r-hirudin. The inhibitory effects of L-ARG on platelet aggregation in vitro were paralleled by increased cyclic GMP levels; L-ARG also inhibited platelet TXB2 formation in PRP anticoagulated with r-hirudin, but not citrate. We conclude that the L-arginine/NO pathway is present in human platelets as a Ca2+-dependent anti-aggregatory pathway. In vivo the formation of NO from L-ARG by endothelial cells may contribute to the platelet-inhibitory effects of L-ARG. NO-releasing compounds like linsidomine inhibit platelet aggregation in vitro independent of extracellular Ca2+.

Dose-related effect of intravenous L-arginine on muscular blood flow of the calf in patients with peripheral vascular disease: a H215O positron emission tomography study

1. Endothelium-derived nitric oxide (NO) contributes to the regulation of vascular tone and blood pressure. Infusion of L-arginine produces systemic vasodilatation via stimulation of endogenous NO formation. Vasodilatation is accompanied by an increase in peripheral arterial blood flow. However, it is not known whether capillary nutritive blood flow increases as well. The time course and dose-response pattern of this effect remain to be elucidated. 2. Two groups of ten patients with peripheral vascular disease (PVD) received an intravenous infusion of 8 g or 30 g of L-arginine over a period of 40 min. Blood pressure and heart rate were monitored non-invasively. Muscular blood flow (MBF) of the calf was determined at 0, 20, 40, 60, 80 min by positron emission tomography with H215O as flow tracer. Plasma L-arginine and cyclic GMP (cGMP) levels were determined at the same time points. 3. L-arginine induced a dose-related decrease in blood pressure during the infusion period. MBF and plasma cGMP levels during and after the infusion of 8 g of L-arginine did not change significantly. In the patients receiving 30 g of L-arginine, MBF was enhanced significantly from 1.56 +/- 0.14 to 2.09 +/- 0.21 ml min-1 100 ml-1 at 40 min and 2.23 +/- 0.15 ml min-1 100 ml-1 after 80 min (+43.0%). The increase in MBF was paralleled by an increase in plasma cGMP from 4789.8 +/- 392.2 nmol/l at baseline to 9223.2 +/- 1233.6 nmol/l at 40 min. 4. We conclude that intravenous L-arginine enhances nutritive capillary MBF in patients with PVD via the NO-cGMP pathway in a dose-related manner. This effect might be therapeutically beneficial in patients with PVD.