Standard versus short stem cemented Exeter® when used for primary total hip arthroplasty: a survivorship analysis

AIMS

The aims were to compare the survival of the cemented standard (150 mm) with the short (DDH [35.5 mm offset or less], number 1 short stem [125 mm options of 37.5 mm, 44 mm, 50 mm offset] and revision [44/00/125]) Exeter® V40 femoral stems when used for primary total hip arthroplasty (THA).

METHODS

Patients were retrospectively identified from an arthroplasty database. A total of 664 short stem Exeter® variants were identified, of which 229 were DDH stems, 208 number 1 stems and 227 revision stems were implanted between 2011 and 2020. A control group of 698 standard Exeter® stems used for THA was set up, and were followed up for a minimum of 10 years follow-up (implanted 2011). All-cause survival was assessed for THA and for the stem only. Adjusted analysis was undertaken for age, sex and ASA grade.

RESULTS

The median survival time for the short stems varied according to design: DDH had a survival time of 6.7 years, number 1 stems 4.1 years, and revision stems 7.2 years. Subjects in the short stem group (n = 664) were significantly younger (mean difference 5.1, P < 0.001) and were more likely to be female (odds ratio 1.89, 95% CI 1.50 to 2.39, P < 0.001), compared to the standard group. There were no differences in THA (P = 0.26) or stem (P = 0.35) survival at 5 years (adjusted THA: 98.3% vs. 97.2%; stem 98.7% vs. 97.8%) or 10 years (adjusted THA 97.0% vs. 96.0 %; stem 96.7% vs. 96.2%) between standard and short stem groups, respectively. At 5 years no differences were found in THA (DDH: 96.7%, number 1 97.5%, revision 97.3%, standard 98.6%) or stem (DDH: 97.6%, number 1 99.0%, revision 97.3%, standard 98.2%) survival between/among the different short stems or when compared to the standard group.

CONCLUSION

The Exeter® short stems offer equivocal survival when compared to the standard stem at 5- to 10-year follow-up, which does not seem to be influenced by the short stem design.

Short- vs long-term assessment of heart rate variability: Clinical significance in Dravet Syndrome

PURPOSE

Heart rate variability (HRV) is a promising prognostic biomarker in Dravet Syndrome (DS), but different studies are not always comparable, limiting its clinical application. In fact, multiple HRV parameters, analyzed over different timescales and in different states are reported. The aim of this study was to assess which HRV parameter is more reproducible and clinically significant, analyzing differences between wake and sleep.

METHOD

Patients with DS, with available 24 h-ECG Holter-derived HRV, were screened to evaluate if they had EEG-derived ECG traces available within one month before/after the Holter. A 5-minute period in the awake and sleep state were analyzed and correlated with the 24 h-HRV. Several relevant clinical features such as age, a recent history of status epilepticus (SE), and frequent generalized tonic-clonic seizures (GTCS) were correlated to HRV parameters with multiple linear regression models.

RESULTS

Thirty-oneawake recordings and 22 sleep recordings were included. HF was the parameter with the highest correlation in awake (Rho 0.745, p < 0.001) and in sleep (Rho 0.727, p < 0.001). Age was a significant factor in simple models for most of the parameters except RMSSD. A recent history of SE was associated with a significant reduction of HRV, both in simple and multiple regressions for all parameters except for awake LF and for sleep RMSSD and PNN50. Frequent GTCS were associated with a significant decrease in sleep RMSSD, HF, and LF, also when correcting for the effect of age and history of SE. When compared pairwise, a significant increase in sleep was seen for HF (median + 24.45 ms2, IQR -7.51/+172.18 ms2, p = 0.036; increase in 15/22 patients).

CONCLUSION

A moderate degree of correlation between long- and short-term HRV was seen both in sleep and in awake, and a strong correlation for awake HF. HF, both in awake and sleep, was significantly associated with high seizure burden, including SE and frequent GTCS.

How is hip anatomy reconstruction and inlay wear associated up to 10 years after primary THA using ceramic on highly crosslinked polyethylene bearings?

INTRODUCTION

Conventional polyethylene (PE) wear has been reported to be associated with femoral offset reconstruction and cup orientation after THA. Thus, the present study aimed (1) to determine the polyethylene wear rate of 32 mm ceramic heads with highly cross-linked polyethylene (HXLPE) inlays up to 10 years postoperatively and (2) to identify patient and surgery-related factors affecting the wear rate.

METHODS

A prospective cohort study was performed, investigating 101 patients with 101 cementless THAs and ceramic (32 mm) on HXLPE bearings after 6-24 months, 2-5 years and 5-10 years postoperatively. The linear wear rate was determined using a validated software (PolyWare®, Rev 8, Draftware Inc, North Webster, IN, USA) by two reviewers, blinded to each other. A linear regression model was used to identify patient and surgery-related factors on HXLPE -wear.

RESULTS

After an initial bedding-in phase of 1 year after surgery, the mean linear wear rate was 0.059 ± 0.031 mm/y at ten years (mean 7.7 years; SD 0.6 years, range 6-10), being below the osteolysis relevant threshold of 0.1 mm/year. The regression analysis demonstrated that age at surgery, BMI, cup inclination or anteversion and the UCLA score were not associated with the linear HXLPE-wear rate. Only increased femoral offset showed a significant correlation with an increased HXLPE-wear rate (correlation coefficient of 0.303; p = 0.003) with a moderate clinical effect size (Cohen's f²=0.11).

CONCLUSION

In contrast to conventional PE inlays, hip arthroplasty surgeons may be less concerned about osteolysis-related wear of the HXLPE if the femoral offset is slightly increased. This allows focusing on joint anatomy reconstruction, hip stability and leg length.

Spatial distribution of short birth interval and associated factors among reproductive age women in Ethiopia: spatial and multilevel analysis of 2019 Ethiopian mini demographic and health survey

BACKGROUND

Short Birth Interval negatively affects the health of both mothers and children in developing countries. Studies conducted in Ethiopia on the spatial variation and determinants of individual and community-level factors about short birth intervals were limited. Thus, this study was intended to assess the spatial variation of the short birth interval and its determinants in Ethiopia.

METHODS

This study is a secondary analysis of the Ethiopian Demographic and Health Survey (mini EDHS 2019). A total of 1784 reproductive-age women were included in the analysis. The global spatial autocorrelation (Global Moran's I) and the Getis-Ord statistics tool were used to detect the presence of clustering and the high/low hotspot areas of SBI respectively. Ordinary kriging was used to interpolate short birth intervals, and spatial scan statistics were employed to identify spatial clusters with high and low SBI. A multilevel multivariable model was used to identify predictors of a short birth interval.

RESULTS

The prevalence of SBI was 62.89% (95%CI: 59.3, 69.7) in Ethiopia. High clustering of SBI was observed in all parts of Somali, in Afar (zones 1, 3, 4, &5), Oromia (Guje, Bale, & West Harerge), and northern Tigray. The most likely significant primary cluster was observed in the Somali region. Women who lived in the primary cluster were 24% more likely to have a short birth interval than those who lived outside the window. In the multilevel mixed-effect analysis age 25-34 [(AOR = 0.40, 95% CI: 0.35, 0.45)], 35-49 [(AOR = 0.44, 95% CI: 0.38, 0.51)], Muslim religion follower [(AOR = 3.5, 95% CI: 2.7, 4.69)], no formal education [(AOR = 0.5, 95% CI: 0.37, 0.70)], primary education[(AOR = 0.4, 95%CI: 0.28, 0.53)], and secondary education [(AOR = 0.3, 95% CI: 0.24, 0.48)], middle [(AOR: 1.3, 95% CI: 1.2, 1.52)], rich wealth status [(AOR: 1.4, 95% CI: 1.3, 1.68)], female sex children [(AOR: 1.2, 95% CI: 1.09, 1.42)], and two or fewer ideal number of children [(AOR = 0.2, 95% CI: 0.25, 0.32)] were found to be significant predictors of SBI.

CONCLUSION

Overall, SBI was high and significantly clustered across the region of Ethiopia. Age, religion, education, wealth status, the sex of the indexed child, and the ideal number of children were found to be significantly associated with short birth intervals. Hence, the government should design a health promotion strategy and public health awareness in the identified hotspot areas of SBI and should scale up family planning and the wealth status of reproductive-age women.

Cementless curved endoprosthesis stem for distal femoral reconstruction in a Chinese population: a combined anatomical & biomechanical study

Background

The endoprosthetic knee reconstruction using a current universal femoral stem might not be suitable for local population due to the anatomical difference between Chinese and Western populations. We measured the anatomical parameters of Chinese femurs as reference for stem design, and proposed a cementless, curved, short endoprosthesis stem for the reconstruction of distal femur. This study analyzed the biomechanical performance of the newly designed stem aimed at the identification of better operative strategy.

Methods

The CT–scanning data of femurs derived from 96 healthy Chinese volunteers were imported into the Mimics software, and a segmental measurement strategy was applied to evaluate the radius of curvature (ROC) of the femoral medullary cavity. Then, 4 kinds of endoprosthetic replacement models were created based on the measurement results. Model A: the distal tumor resected femora + straight stem A; Model B: the distal tumor resected femora + curved stem B; Model C: the distal tumor resected femora + curved stem C; Model D: the distal tumor resected femora + curved stem D. Finally, the mechanical difference among these models were compared by finite element analysis.

Results

The mean femoral ROC of Segment_{1, 2, 3, 4, 5} measured in the present study was 724.5 mm, 747.5 mm, 1016.5 mm, 1286.5 mm, and 1128 mm, respectively. Based on the femoral ROC of Segment_2, the stem ROC of the curved stem B, C, and D was designed as 475 mm, 700 mm, and 1300 mm, respectively. Generally, all endoprosthetic replacement models showed a normal–like stress distribution on the femurs. However, compared to the straight stem, the biomimetic curved stem showed better biomechanical performance both in terms of reducing the extent of the stress shielding of the femur and in terms of minimizing the stress distribution of the implant.

Conclusions

The uncemented, curved, short stem with suitable ROC can perfectly match the Chinese femoral canal morphology which has better mechanical properties than the conventional femoral stem. Thus, this newly designed femoral stem might be an optimized method for treatment of malignant femoral tumours in the Chinese populations in the case that the numerical results are supported by future experimental studies.

Short versus standard implants at sinus augmented sites: a systematic review and meta-analysis

BACKGROUND

Short implants are proposed as a less invasive alternative with fewer complications than standard implants in combination with sinus lift. The aim of this systematic review and meta-analysis was to state the efficacy of placing short implants (≤ 6 mm) compared to standard-length implants (≥ 8 mm) performing sinus lift techniques in patients with edentulous posterior atrophic jaws. Efficacy will be evaluated through analyzing implant survival (IS) and maintenance of peri-implant bone (MBL).

METHODS

Screening process was done using the National Library of Medicine (MEDLINE by PubMed), EMBASE, the Cochrane Oral Health, and Web of Science (WOS). The articles included were randomized controlled trials. Risk of bias was evaluated according to The Cochrane Collaboration's tool. Weighted means were calculated. Heterogeneity was determined using Higgins (I²). A random-effects model was applied. Secondary outcomes such as surgical time, patient satisfaction, mucositis and peri-implantitis, pain, and swelling were analyzed.

RESULTS

Fourteen studies (597 patients and 901 implants) were evaluated. IS was 1.02 risk ratio, ranging from 1.00 to 1.05 (CI 95%) (p = 0.09), suggesting that IS was similar when both techniques were used. MBL was higher in patients with standard-length implants plus sinus lift elevation (p = 0.03). MBL was 0.11 (0.01-0.20) mm (p = 0.03) and 0.23 (0.07-0.39) mm (p = 0.005) before and after 1 year of follow-up, respectively, indicating that the marginal bone loss is greater for standard-length implants.

DISCUSSION

Within the limitations of the present study, as relatively small sample size, short dental implants can be used as an alternative to standard-length implants plus sinus elevation in cases of atrophic posterior maxilla. Higher MBL was observed in the groups where standard-length implants were used, but implant survival was similar in both groups. Moreover, with short implants, it was observed a reduced postoperative discomfort, minimal invasiveness, shorter treatment time, and reduced costs.

CLINICAL CLINICAL RELEVANCE

The low MBL promoted by short implants does contribute to a paradigm shift from sinus grafting with long implants to short implants. Further high-quality long-term studies are required to confirm these findings.

Term spontaneous trial of labor in nulliparous women of short stature: A hospitals-based cohort study

OBJECTIVES

To study the mode of delivery in a well selected cohort of short nulliparous women.

STUDY DESIGN

Hospitals-based cohort study between 2010-2018. The threshold (150 cm, i.e 2,3°p), for the short stature was chosen before the analysis by corresponding to - 2SD of the average population size distribution of all women who delivered over the same period: 2010-2018. Were included nulliparous women with a heigh ≤ 150 cm in term spontaneous labor with a single livung fetus in vertex presentation without malformation. Exclusion criteria were: multiparous, scarred uterus, twin pregnancy, induced labor, preterm delivery (< 37 W P), non-vertex pregnancy, medical termination of pregnancy, stillbirth, severe fetal malformations, pre-labor cesarean, and late dating ultrasound. The main outcome was the mode of delivery. Univariate and multivariate analysis adjusted on potential confounding variable were performed to investigate the risk of intrapartum CS.

RESULTS

178 nulliparous women were included. The mean height was 148 cm. The rate of spontaneous vaginal delivery, operative vaginal delivery a nd intrapartum CS were :35,4 %, 35,4 % and 29,2 % respectively. Intrapartum CS was performed during the first stage labor in 15 (28, 8 %) women and during the second stage in 37 (71, 2 %) women. An arrest of labor was significantly more frequent in the active labor than the early labor stage: 62,1 % vs. 33.3 % (p = 0, 02). In univarate analysis were associated with intrapartum CS : Gestational diabetes, birthweight> 3,5 kg, individual adjusted birthweight >90°p, occiput posterior, oxytocin use, cephalic circumference. After adjustment on birthplace and overweight (BMI over 25), only a birthweight > 3,5 kg remains associated with the risk of intrapartum CS (aOR4.3 ;95 %CI 1.96-10.2).

CONCLUSION

An attempt of vaginal birth is a reasonable option for short stature women. Maternal height could be included in the selection criteria for planned birth center or home birth. The customized gestational-related optimal weigh could be useful to identify large of gestational age fetus.

Evaluating hierarchical items of the geriatric depression scale through factor analysis and item response theory

Background

Geriatric depression scale (GDS) is a common screening tool for measuring depression among older adults. It employs a multi-factor structure and some differential item functioning (DIF) allowing different versions of GDS across cultures. The present study aimed to identify the short version of the hierarchical scale of GDS in which all items comprised the invariant item ordering, and items without DIF.

Methods

Participants and Measurement: A total of 803 participants, 70% female, with a mean age of 69.24 years (SD = 6.88) were enrolled from three geriatric units of tertiary care hospitals. All completed the 15-item GDS. Three methods of confirmatory factor analysis (CFA) with multiple indicators, multiple cause model, Mokken analysis and Rasch analysis were applied.

Results

Item 9 (prefer to stay at home) showed poor discriminatory power among all three methods. After removing DIF items due to sex and age, nine items remained suitable for the shortened version by CFA. When Mokken and Rasch analysis were applied, only six items remained for the hierarchical scale. Compared with other related shortened version of GDS, the new GDS-6 proved to have a comparable ability to detect depression as did the original 15-item GDS.

Limitation

The new GDS-6 needs to be investigated for test-retest reliability to ensure temporal stability of the scale. This cross-sectional analysis needs replication.

Conclusion

The GDS-6 derived from IRT had measurement properties and met criteria related to unidimensionality and ability to separate levels of depression. It was shown to be equal to or better in predicting performance compared with the original 15-item GDS.

Fifty-six percent of proximal femoral cortical hypertrophies 6 to 10 years after Total hip arthroplasty with a short Cementless curved hip stem - a cause for concern?

Background

Thigh pain and cortical hypertrophies (CH) have been reported in the short term for specific short hip stem designs. The purpose of the study was to investigate 1) the differences in clinical outcome, thigh pain and stem survival for patients with and without CHs and 2) to identify patient and surgery-related factors being associated with the development of CHs.

Methods

A consecutive series of 233 patients with 246 hips was included in the present retrospective diagnostic cohort study, who had received a total hip arthroplasty (THA) between December 2007 and 2009 with a cementless, curved, short hip stem (Fitmore, Zimmer, Warsaw, IN, USA). Clinical and radiographic follow-up, including the radiographic parameters for hip geometry reconstruction, were prospectively assessed 1, 3, and 6 to 10 years after surgery.

Results

Cortical hypertrophies were observed in 56% of the hips after a mean of 7.7 years, compared to 53% after 3.3 years being mostly located in Gruen zone 3 and 5. There was no significant difference for the Harris Hip Score and UCLA score for patients with and without CHs. Only one patient with a mild CH in Gruen zone 5 and extensive heterotopic ossifications around the neck of the stem reported thigh pain. The Kaplan Meier survival rate after 8.6 years was 99.6% (95%-CI; 97.1–99.9%) for stem revision due to aseptic loosening and no association with CHs could be detected. Postoperative increase in hip offset was the only risk factor being associated with the development of CHs in the regression model (ΔHO; OR 1.1 (1.0–1.2); p = 0.001).

Conclusions

The percentage of cortical hypertrophies remained almost constant in the mid-term compared to the short-term with the present cementless short hip stem design. The high percentage of cortical hypertrophies seems not be a cause for concern with this specific implant in the mid-term.

Level of evidence

Diagnostic Level IV

Uncemented, curved, short endoprosthesis stem for distal femoral reconstruction: early follow-up outcomes

Background

Uncemented endoprosthetic knee replacement has become a mainstream treatment for malignant tumours of the distal femur. Most femoral stems, however, are straight and therefore poorly fit the anteriorly bowed curvature of the femur. To address this issue, we used a short, curved, uncemented press-fit femoral stem and evaluated its short-term outcomes after reconstruction of the distal femur.

Methods

Forty-two patients underwent distal femur replacement using curved press-fit stem. To assess the interface, we measured the axial length of the press-fit area and the perpendicular distance of the radiolucent area between the stem and bone on digital images obtained using tomosynthesis with Shimadzu Metal Artefact Reduction Technology (T-SMART). Postoperative complications and oncological outcomes were monitored at each follow-up visit.

Results

Of the 42 patients enrolled in the study, two had cancer-related deaths and one had local tumour recurrence. The minimum follow-up time of the surviving patients was 24 months, with no incidence of aseptic loosening or mechanical failure of the prosthesis. The average effective contact length between the press-fit stem and bone was 74.0 mm, with nearly undetectable radiolucent gaps between the implant and the bone on medial-lateral and anteroposterior views.

Conclusions

Over the short term, uncemented, curved, short stem provides a stable bone-prosthesis interface without any aseptic loosening.

Prediction of virus-host protein-protein interactions mediated by short linear motifs

BACKGROUND

Short linear motifs in host organisms proteins can be mimicked by viruses to create protein-protein interactions that disable or control metabolic pathways. Given that viral linear motif instances of host motif regular expressions can be found by chance, it is necessary to develop filtering methods of functional linear motifs. We conduct a systematic comparison of linear motifs filtering methods to develop a computational approach for predicting motif-mediated protein-protein interactions between human and the human immunodeficiency virus 1 (HIV-1).

RESULTS

We implemented three filtering methods to obtain linear motif sets: 1) conserved in viral proteins (C), 2) located in disordered regions (D) and 3) rare or scarce in a set of randomized viral sequences (R). The sets C,D,R are united and intersected. The resulting sets are compared by the number of protein-protein interactions correctly inferred with them - with experimental validation. The comparison is done with HIV-1 sequences and interactions from the National Institute of Allergy and Infectious Diseases (NIAID). The number of correctly inferred interactions allows to rank the interactions by the sets used to deduce them: D∪R and C. The ordering of the sets is descending on the probability of capturing functional interactions. With respect to HIV-1, the sets C∪R, D∪R, C∪D∪R infer all known interactions between HIV1 and human proteins mediated by linear motifs. We found that the majority of conserved linear motifs in the virus are located in disordered regions.

CONCLUSION

We have developed a method for predicting protein-protein interactions mediated by linear motifs between HIV-1 and human proteins. The method only use protein sequences as inputs. We can extend the software developed to any other eukaryotic virus and host in order to find and rank candidate interactions. In future works we will use it to explore possible viral attack mechanisms based on linear motif mimicry.

Comparison of Short vs Long Anti-rotation in Treating Trochanteric Fractures

Introduction: A comparative evaluation of the surgical treatment and outcome of patients with pertrochanteric fractures treated with short versus long proximal femoral nail antirotation.

Materials and methods: A retrospective review was conducted of patients with pertrochanteric fractures treated between January 2011 and June 2012. In all 80 patients were enrolled in the study, of which 40 were treated with short PFNA and the remaining with long PFNA. Comparative analyses of demographic data, peri-operative outcome and complications were carried out.

Results: There was no significant difference noted in the two groups with regards to Arbeitsgemeinschaft fur Osteosynthesefragen (AO) fracture classification, time from injury to surgery, blood transfusion post surgery and hospital stay. The surgical duration for a short PFNA procedure was significantly less (58 minutes) when compared to that of a long PFNA (87 minutes). Similarly intra-operative blood loss was significantly higher in the long PFNA group as compared to the short PFNA.

Conclusions: A relatively quicker surgical time of just under an hour , lesser blood loss and better learning curve with trainee surgeons make short PFNA a better implant choice in the treatment of pertrochanteric fractures.

The Prevalence and Diagnostic Validity of Short-Duration Hypomanic Episodes and Major Depressive Episodes

Current diagnostic criteria for a hypomanic episode, as outlined in both the fourth and fifth editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and DSM-5), require a minimum duration of four consecutive days of symptoms of mood elevation. The 4-day criterion for duration of hypomania has been challenged as arbitrary and lacking empirical support, with many arguing that shorter-duration hypomanic episodes are highly prevalent and that those experiencing these episodes are clinically more similar to patients with bipolar disorder than to those with unipolar major depressive disorder. We review the current evidence regarding the prevalence, diagnostic validity, and longitudinal illness correlates of shorter-duration hypomanic episodes and summarize the arguments for and against broadening the diagnostic criteria for hypomania to include shorter-duration variants. Accumulating findings suggest that patients with major depressive episodes and shorter-duration hypomanic episodes represent a complex clinical phenotype, perhaps best conceptualized as being on the continuum between those with unipolar depressive episodes alone and those with DSM-5-defined bipolar II disorder. Further investigation is warranted, ideally involving large prospective, controlled studies, to elucidate the diagnostic and treatment implications of depression with shorter-duration hypomanic episodes.

Symmetrically biased T/R switches for NMR and MRI with microsecond dead time

For direct NMR detection and imaging of compounds with very short coherence life times the dead time between radio-frequency (RF) pulse and reception of the free induction decay (FID) is a major limiting factor. It is typically dominated by the transient and recovery times of currently available transmit-receive (T/R) switches and amplification chains. A novel PIN diode-based T/R switch topology is introduced allowing for fast switching by high bias transient currents but nevertheless producing a very low video leakage signal and insertion loss (0.5dB). The low transient spike level in conjunction with the high isolation (75dB) prevent saturation of the preamplifier entirely which consequently does not require time for recovery. Switching between transmission and reception is demonstrated within less than 1μs in bench tests as well as in acquisitions of FIDs and zero echo time (ZTE) images with bandwidths up to 500kHz at 7T. Thereby the 2kW switch exhibited a rise-time of 350ns (10-99%) producing however a total video leakage of below 20mV peak-to-peak and less than -89dBm in-band. The achieved switching time renders the RF pulse itself the dominant contribution to the dead time in which a coherence cannot be observed, thus making pulsed NMR experiments almost time-optimal even for compounds with very short signal life times.

Minimal inframammary incision for breast augmentation

The inframammary approach in breast augmentation, still the most popular technique among plastic surgeons, has always been hampered by the undesirable appearance of its scar. The present paper describes a modified approach to inframammary augmentation with saline-filled prostheses. This approach uses a very short incision, thus resulting in a much less noticeable scar. The surgical technique is easy to learn, simple to execute, does not necessitate any special equipment and gives consistent results. Decreasing the scar length to an absolute minimum ensures higher patient and surgeon satisfaction.