Does hydrogen peroxide application to the dermis following surgical incision affect Cutibacterium acnes cultures in total shoulder arthroplasty in male patients? A randomized controlled trial

BACKGROUND

Periprosthetic joint infections occur in 1%-4% of primary total shoulder arthroplasties (TSAs). Cutibacterium acnes is the most commonly implicated organism and has been shown to persist in the dermis despite use of preoperative antibiotics and standard skin preparations. Studies have shown decreased rates of cultures positive for C acnes with use of preoperative benzoyl peroxide or hydrogen peroxide (H2O2), but even with this positive deep cultures remain common. We sought to determine whether an additional application of H2O2 directly to the dermis following skin incision would further decrease deep culture positivity rates.

METHODS

We performed a randomized controlled trial comparing tissue culture results in primary TSA in patients who received a standard skin preparation with H2O2, ethanol, and ChloraPrep (CareFusion, Leawood, KS, USA) vs. an additional application of H2O2 to the dermis immediately after skin incision. Given the sexual dimorphism seen in the shoulder microbiome regarding C acnes colonization rates, only male patients were included. Bivariable and multivariable analyses were performed to compare rates of positive cultures based on demographic and surgical factors.

RESULTS

Dermal cultures were found to be positive for C acnes at similar rates between the experimental and control cohorts for the initial (22% vs. 28%, P = .600) and final (61% vs. 50%, P > .999) dermal swabs. On bivariable analysis, the rate of positive deep cultures for C acnes was lower in the experimental group, but this difference was not statistically significant (28% vs. 44%, P = .130). However, patients who underwent anatomic TSA were found to have a significantly greater rate of deep cultures positive for C acnes (57% vs. 28%, P = .048); when controlling for this on multivariable analysis, the experimental cohort was found to be associated with significantly lower odds of having positive deep cultures (odds ratio, 0.37 [95% confidence interval, 0.16-0.90], P = .023). There were no wound complications in either cohort.

CONCLUSIONS

An additional H2O2 application directly to the dermis following skin incision resulted in a small but statistically significant decrease in the odds of having deep cultures positive for C acnes without any obvious adverse effects on wound healing. Given its cost-effectiveness, use of a post-incisional dermal decontamination protocol may be considered as an adjuvant to preoperative use of benzoyl peroxide or H2O2 to decrease C acnes contamination.

Does the stemless reverse arthroplasty compare to a conventional stemmed implant? Clinical and radiographic evaluation at 2 years' minimum follow-up

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a well-recognized treatment for many shoulder conditions, including rotator cuff arthropathy, primary glenohumeral joint arthritis, and rheumatoid arthritis, and can be used in both trauma and revision settings. Over the past 10 years, its popularity in New Zealand has been increasing, with a 6%-7% annual growth rate during this period. Stemless RSA designs have the following proposed advantages: They can preserve humeral bone stock, they can limit periprosthetic fractures, and they can be indicated in patients with abnormal diaphyseal humeral anatomy. To date, only 1 study has evaluated the outcomes of the Lima SMR Stemless implant. We present our data with an aim to report how the stemless reverse arthroplasty compares to a conventional stemmed implant.

METHODS

We performed a retrospective review of a consecutive series of patients treated at a single institution between 2015 and 2020. The endpoint was defined as final follow-up at a minimum of 2 years. Patients were excluded from the final analysis if they underwent revision. Thirty-three patients were identified as having undergone stemless RSA. Thirty patients had patient-reported outcome measures and radiographs at a minimum of 2 years' follow-up. Three patients had undergone revision within 2 years. The same sample size of stemmed RSAs (n = 33) was selected for comparison.

RESULTS

A total of 60 patients were included in the final analysis, of whom 30 underwent stemless RSA and 30 underwent stemmed RSA. The demographic characteristics of the 2 groups were comparable except age at operation, which showed a statistically significant difference (P = .001): 77 years (stemmed) vs. 65 years (stemless). The mean Oxford Shoulder Score was 40.1 in the stemless group vs. 40 in the stemmed group. The mean American Shoulder and Elbow Surgeons score was 72.9 in the stemless group vs. 79 in the stemmed group. Patient-reported outcome measures, pain scores, and satisfaction ratings were not statistically significantly different between the 2 groups. In terms of radiographic data, subsidence was observed in 2 patients in the stemless RSA group but the patients had no clinical symptoms. Also in the stemless RSA group, 1 patient had an acromial stress fracture and 1 patient had a superficial wound infection successfully treated with oral antibiotics. In terms of revisions in the stemless RSA group, 1 patient underwent revision owing to chronic infection, 1 underwent revision as a result of a periprosthetic fracture after a fall, and 1 underwent revision for gross instability.

CONCLUSIONS

The early results of sRSA are promising, and the stemless implant shows similar outcomes to a conventional stemmed implant.

Reverse and Anatomic Shoulder Arthroplasty Regional Usage and Open Payment Analysis Using the Centers for Medicare and Medicaid Services Database

Background

This retrospective review aimed to assess if open payments made by industry arthroplasty companies to physicians and hospital systems were significantly affected by implant type and geographic variation.

Methods

Data was obtained from the Centers for Medicare and Medicaid Services (CMS) publicly available open payment datasets (2016-2019). Geographic locations were identified using regions as defined by the US Census Bureau. A linear regression was calculated to predict the open payment made based on the created variable region, the most used implant type (reverse vs anatomic, n > 30 to be included), and their hypothesized interaction.

Results

A significant regression equation was found for the hypothesized interaction between implant and region, F(13,11 186) = 3.446, P < .0001, with an R2 of 0.005. Within the regression, the implant type alone was not significantly related to the open payment (P = .070) but only became significant when paired with the region in the South (US$5807; P < .0001) and West (US$5638; P = .0012) compared to the Northeast.

Discussion

Our multivariate linear regression model revealed that reverse total shoulder implants were associated with higher open payments, but only within the South and West regions. This indicates that the contributions made by industry arthroplasty companies are a function of both implant and region.

[Corrigendum] Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P‑gp and MRP‑1

Following the publication of the above article, an interested reader drew to the authors' attention that, in Fig. 2 on p. 1408, the microscopic images shown for the light scope images (upper row) and the green fluorescence images (lower row) appeared to be overlapping, such that these images appeared to have been derived from the same original sources even though they were intended to portray the results from differently performed experiments. After having re‑examined their figures, the authors realized that this figure was assembled incorrectly. The revised version of Fig. 2, showing the correct data for all four experimental panels, is shown below. Note that the errors made during the assembly of these figures did not affect the overall conclusions reported in the paper. All the authors agree with the publication of this corrigendum, and are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this. They also apologize to the readership for any inconvenience caused. [International Journal of Molecular Medicine 37: 1405‑1411, 2016; DOI: 10.3892/ijmm.2016.2539].

Associations between radiographic parameters in the reverse shoulder arthroplasty and patient outcomes

Background

Various radiological parameters have been measured in the Reverse Shoulder Arthroplasty (RSA) and correlated to patient outcomes, to determine best baseplate position. Results remain unclear with respect to certain parameters such as inferior baseplate tilt. We have investigated our series of patients to clarify the relationship between radiological parameters and patient outcomes.

Methods

We conducted a UK based bi-centre retrospective review of 156 prostheses. Critical shoulder angle (CSA), RSA angle (RSAA), Overhang and Deltoid Lever Arm (DLA) were measured on preoperative and postoperative radiographs. Range of motion and Oxford Shoulder Score (OSS) (range 1-8 years) were obtained. We assessed for scapular notching at minimum 1 year follow up (n = 138).

Results

Decreased postoperative CSA and increased DLA were associated with higher OSSs (P = 0.001 and 0.019). Increased overhang and DLA were associated with increased flexion (P = 0.033 and 0.024 respectively). Multivariate analysis showed that CSA and DLA affected notching rate (P = 0.002 and 0.007).

Conclusions

Baseplate tilt in relation to the acromion (CSA) and DLA are the most predictive parameters for notching and OSS. We recommend considering a maximum CSA of 26 degrees to decrease notching rate and improve OSS. We recommend considering an Overhang of at least 6 mm to improve FF.

Reversing and modulating cellular senescence in beta cells, a new field of opportunities to treat diabetes

Diabetes constitutes a world-wide pandemic that requires searching for new treatments to halt its progression. Cellular senescence of pancreatic beta cells has been described as a major contributor to development and worsening of diabetes. The concept of reversibility of cellular senescence is critical as is the timing to take actions against this "dormant" senescent state. The reversal of cellular senescence can be considered as rejuvenation of the specific cell if it returns to the original "healthy state" and doesn't behave aberrantly as seen in some cancer cells. In rodents, treatment with senolytics and senomorphics blunted or prevented disease progression, however their use carry drawbacks. Modulators of cellular senescence is a new area of research that seeks to reverse the senescence. More research in each of these modalities should lead to new treatments to stop diabetes development and progression.

Continence criteria of 193 618 patients after open, laparoscopic, and robot-assisted radical prostatectomy

OBJECTIVES

To apply a new evidence-gathering methodology, called reverse systematic review (RSR), to analyse the influence of different continence classification criteria on urinary continence rates among open retropubic radical prostatectomy (RRP), laparoscopic RP (LRP) and robot-assisted RP (RARP).

MATERIALS AND METHODS

A search was carried out in eight databases between 2000 and 2020 through systematic reviews (SRs) studies referring to RRP, LRP or RARP (80 SRs). All references used in these SRs were captured referring to 910 papers in an overall database called the 'EVIDENCE Database'. A total of 422 studies related to post-RP urinary continence were selected for the final analysis, totalling 782 reports referring to 193 618 patients.

RESULTS

Overall, 206 (26.4%) reports for RRP, 243 (31.0%) reports for LRP, and 333 (42.6%) reports for RARP were found. Mean overall continence rates, respectively for RRP, LRP and RARP, were: 42%, 34% and 42% at 1 month; 62%, 64% and 65% at 3 months; 73, 77 and 79% at 6 months; and 81%, 85% and 86% at 12 months. The most used criterion was 'No pad' (53.3%), followed by 'Safety pad' (19.3%), 'Not described' (10.6%), and 'No leak' (9.9%). 'No pad' showed the lowest discrepancy in continence rates in each period compared to the overall average for each technique, demonstrating less ability to influence the final results favouring any of the techniques.

CONCLUSION

The RSR demonstrated that the 'No pad' criterion was the most used in the literature and showed the lowest bias capable of influencing the results and favouring any of the techniques and is the fairest option for future comparisons.

Trends in Cause-Specific Injury Mortality in China in 2005-2019: Longitudinal Observational Study

BACKGROUND

Over the last few decades, although the age-standardized mortality rate (ASMR) of injury has shown a significant declining trend in China, this pattern has dramatically reversed recently.

OBJECTIVE

We aimed to elucidate the geographical, demographic, and temporal trends of cause-specific injuries, the reversal phenomenon of these trends, and the fluctuations of injury burden from 2005 to 2019 in China.

METHODS

A longitudinal observational study was performed using the raw data of injury deaths in the National Cause-of-Death surveillance data provided by the disease surveillance points system in 2005-2019. The cause-specific injuries were divided into disparate subgroups by sex, age, urban/rural region, and eastern/central/western areas of China. The burden of injury was assessed using potential years of life lost (PYLL), average years of life lost (AYLL), and PYLL rate (PYLLR). Temporal trends of mortality rates and burden were evaluated using best-fitting joinpoint models.

RESULTS

Injury deaths accounted for 7.51% (1,156,504/15,403,835) of all-cause deaths in China in 2005-2019. The crude mortality rate of all-cause injury was 47.74 per 100,000 persons. The top 3 injury types (traffic accident, falls, and suicide) accounted for 70.57% (816,145/1,156,504) of all injury-related deaths. The ASMR of all-cause injury decreased (P=.003), while the crude mortality rate remained unchanged (P=.52) during 2005-2019. A significant reverse trend in ASMR of all-cause injury was observed in urban older adults since 2013, mainly due to the inverted trend in injuries from falls. A reverse trend in ASMR of suicide was observed among individuals aged 10-24 years, with notable increases by 35.18% (annual percentage change 15.4%, 95% CI 4.1%-28.0%) in men since 2017. The AYLL and PYLLR of all-cause injury among older adults showed consistent ascending trends from 2005 to 2019 (average annual percentage change [AAPC] 6.1%, 95% CI 5.4%-6.9%, 129.04% increase for AYLL; AAPC 5.4%, 95% CI 2.4%-8.4%, 105.52% increase for PYLLR). The AYLL due to suicide for individuals aged 10-24 years showed a considerable upswing tendency (AAPC 0.5%, 95% CI 0.4%-0.7%, 8.02% increase).

CONCLUSIONS

Although the ASMR of all-cause injury decreased in China from 2005 to 2019, the trend in suicide among adolescents and young adults and falls among older adults has been on the rise in recent years. Interventions should be encouraged to mitigate the cause-specific burdens of injury death.

Simplified soft tissue coverage of the distal lower extremity: The reverse sural flap

Soft tissue defects involving the distal lower extremity present challenging problems for orthopaedic surgeons to manage. Historically, wounds not amenable to primary closure have necessitated assistance from multidisciplinary teams using plastic surgeons to obtain adequate soft tissue coverage through rotational flap or free tissue transfer procedures. Techniques related to soft tissue rearrangement and local rotational flap coverage have advanced over the years with a growing knowledge of local anatomy and vasculature. The reverse sural flap may be performed to cover soft tissue defects within 10 cm of the foot or ankle region, negating the need for microvascular intervention. The simplistic nature of the reverse sural flap is appealing to orthopaedic surgeons as a means to provide timely patient care without additional support because it does not require microvasculature work or the need for intraoperative microscopes and has been popularized among orthopaedic trauma surgeons as a necessary tool to possess. Here, we discuss the reverse sural flap to include history, relevant anatomy, clinical indications, and a description of the technique for application.

Is reverse cholesterol transport regulated by active cholesterol?

This review considers the hypothesis that a small portion of plasma membrane cholesterol regulates reverse cholesterol transport in coordination with overall cellular homeostasis. It appears that almost all of the plasma membrane cholesterol is held in stoichiometric complexes with bilayer phospholipids. The minor fraction of cholesterol that exceeds the complexation capacity of the phospholipids is called active cholesterol. It has an elevated chemical activity and circulates among the organelles. It also moves down its chemical activity gradient to plasma HDL, facilitated by the activity of ABCA1, ABCG1, and SR-BI. ABCA1 initiates this process by perturbing the organization of the plasma membrane bilayer, thereby priming its phospholipids for translocation to apoA-I to form nascent HDL. The active excess sterol and that activated by ABCA1 itself follow the phospholipids to the nascent HDL. ABCG1 similarly rearranges the bilayer and sends additional active cholesterol to nascent HDL, while SR-BI simply facilitates the equilibration of the active sterol between plasma membranes and plasma proteins. Active cholesterol also flows downhill to cytoplasmic membranes where it serves both as a feedback signal to homeostatic ER proteins and as the substrate for the synthesis of mitochondrial 27-hydroxycholesterol (27HC). 27HC binds the LXR and promotes the expression of the aforementioned transport proteins. 27HC-LXR also activates ABCA1 by competitively displacing its inhibitor, unliganded LXR. § Considerable indirect evidence suggests that active cholesterol serves as both a substrate and a feedback signal for reverse cholesterol transport. Direct tests of this novel hypothesis are proposed.

Early clinical outcomes following navigation-assisted baseplate fixation in reverse total shoulder arthroplasty: a matched cohort study

BACKGROUND

Accurate placement of the glenoid baseplate is an important technical goal of reverse total shoulder arthroplasty (RSA). The use of computer navigated instrumentation has been shown to improve the accuracy and precision of intraoperative execution of preoperative planning. The purpose of this study was to compare early clinical outcomes of patients undergoing navigated RSA vs. a non-navigated matched cohort.

METHODS

A retrospective review of a prospectively collected shoulder arthroplasty database was used to identify 113 patients from a single institution who underwent navigated primary RSA with a minimum 2-year follow-up. A matched cohort of 113 non-navigated RSAs was created based on sex, age, follow-up, and preoperative diagnosis. Preoperative and postoperative range of motion, functional outcome scores, and complications were reported.

RESULTS

A total of 226 shoulders with a mean age of 71 years were evaluated after navigated (113) or non-navigated (113) RSAs. The mean follow-up was 32.8 months (range: 21-54 months). At the final postoperative follow-up, the navigated group had better active forward elevation (135° vs. 129°, P = .023), active external rotation (39° vs. 32°, P = .003), and Constant scores (71.1 vs. 65.5, P = .003). However, when comparing improvements from the preoperative state, there was no statistically significant difference in range of motion or functional outcome scores between the groups. Complications occurred in 1.8% (2) of patients undergoing navigated RSA compared with 5.3% (6) in the non-navigated group (P = .28). Scapular notching (3.1% vs. 8.0%, P = .21) and revision surgery (0.9% vs. 3.5%, P = .37) were more common in non-navigated shoulders.

CONCLUSION

At early follow-up, navigated and non-navigated RSAs yielded similar rates of improvement in range of motion and functional outcome scores. Notching and reoperation was more common in non-navigated shoulders, but did not reach statistical significance. Longer follow-up and larger cohort size are needed to determine if intraoperative navigation lengthens the durability of RSA results and reduces the incidence of postoperative complications.

Aseptic Glenoid Baseplate Loosening after Reverse Total Shoulder Arthroplasty with a Single Prosthesis

INTRODUCTION

Early reverse total shoulder arthroplasty (rTSA) designs had high failure rates, mainly from loosening of the glenoid baseplate. The purpose of this study is to determine the incidence of aseptic glenoid baseplate loosening after primary rTSA using a contemporary medialized glenoid/lateralized humeral system and identify significant risk factors associated with loosening.

METHODS

7,162 primary rTSA were treated with a single platform rTSA system between April 2007 and August 2021, from which 3,127 primary rTSA patients with a minimum 2-year follow-up were identified. Patients with aseptic glenoid baseplate loosening were compared to all other primary rTSA without loosening. Univariate and multivariate analyses were performed to compare these cohorts and identify the demographic, comorbidities, operative, and implants associated aseptic glenoid loosening after rTSA. Odds ratios were calculated for each significant risk factor and for multiple combinations of risk factors.

RESULTS

Irrespective of minimum follow-up, fifty-three (31F/22M) of 7,162 primary rTSA shoulders experienced aseptic glenoid loosening, for an overall rate of 0.74%. At latest 2-year minimum follow-up, thirty of 3,127 patients experienced aseptic glenoid loosening and had significantly lower clinical scores, function, active ROM, and higher pain scores as compared to patients without loosening. Univariate analysis identified that patients with rheumatoid arthritis (RA, p=0.029, OR = 2.74) and diabetes (p=0.028, OR=1.84) and multivariate analysis identified Walch glenoid types B2 (p=0.002, OR= 4.513) and B3 (p=0.002, OR=14.804), use of expanded lateralized glenospheres (p=0.025, OR=2.57) and use of augmented baseplates (p=0.001, OR=2.50) as significant risk factors for aseptic glenoid loosening after rTSA.

CONCLUSION

The incidence of aseptic glenoid baseplate loosening was 0.74% for this medialized glenoid/lateralized humeral rTSA system. Numerous risk factors for aseptic loosening were identified, including: RA, diabetes, Walch B2 and B3 glenoids, posterior/superior augmented baseplates, and expanded lateralized glenospheres. Finally, analysis of multiple combinations of risk factors identified patients and implant configurations with the greatest risk of aseptic glenoid loosening.

Reverse Atrial Remodeling in Heart Failure With Recovered Ejection Fraction

Background Heart failure with recovered ejection fraction (HFrecEF) has been a newly recognized entity since 2020. However, the concept has primarily focused on left ventricular ejection fraction improvement, with less focus on the recovery of the left atrium. In this study, we investigated changes in left atrial (LA) echocardiographic indices in HFrecEF. Methods and Results An inpatient cohort with heart failure with reduced ejection fraction (HFrEF) was identified retrospectively and followed up prospectively in a single tertiary hospital. The enrolled patients were classified into HFrecEF and persistent HFrEF groups. Alternations in LA parameters by echocardiography were calculated. The primary outcome was a composite of cardiovascular death or heart failure rehospitalization. A total of 699 patients were included (HFrecEF: n=228; persistent HFrEF: n=471). Compared with persistent HFrEF, the HFrecEF group had greater reductions in LA diameter, LA transverse diameter, LA superior-inferior diameter, LA volume, and LA volume index but not in LA sphericity index. Cox regression analysis showed that the HFrecEF group experienced lower risks of prespecified end points than the persistent HFrEF group after adjusting for confounders. Additionally, 136 (59.6%) and 62 (13.0%) patients showed LA reverse remodeling (LARR) for the HFrecEF and persistent HFrEF groups, respectively. Among the HFrecEF subgroup, patients with LARR had better prognosis compared with those without LARR. Multivariate logistic analysis demonstrated that age and coronary heart disease were 2 independent negative predictors for LARR. Conclusions In HFrecEF, both left ventricular systolic function and LA structure remodeling were improved. Patients with HFrecEF with LARR had improved clinical outcomes, indicating that the evaluation of LA size provides a useful biomarker for risk stratification of heart failure.

Does glenohumeral offset affect clinical outcomes in a lateralized reverse total shoulder arthroplasty?

BACKGROUND

Reverse total shoulder arthroplasty (rTSA) exhibits high rates of success and low complication rates. rTSA has undergone numerous design adaptations over recent years, and lateralization of implant components provides theoretical and biomechanical benefits in stability and range of motion (ROM) as well as decreased rates of notching. However, the magnitude of implant lateralization and its effect on these outcomes is less well understood. The purpose of this study was to evaluate how increasing glenohumeral offset affects outcomes after rTSA, specifically in a lateralized humerus + medialized glenoid implant model.

METHODS

Primary rTSA using a lateralized humeral + medialized glenoid implant model performed at a single academic institution between 2012 and 2018 were retrospectively reviewed. Patient-reported outcome (PRO) parameters and clinical outcomes including ROM were evaluated both pre- and postoperatively. Pre- and postoperative radiographs were analyzed for measurement of glenohumeral offset, defined as the acromial-tuberosity offset (ATO) distance on the anteroposterior radiograph.

RESULTS

A total of 130 rTSAs were included in the analysis, with a mean follow-up of 35 mo. The mean postoperative absolute ATO was 16 mm, and the mean delta ATO (difference from pre- to postoperatively) was 4.6 mm further lateralized. Among all study patients, improvements in all ROM parameters and all PROs were observed from pre- to postoperative assessments. When assessing for the effects of lateralization on these outcomes, multivariate analysis failed to reveal a significant effect from the absolute postoperative ATO or the delta ATO on any outcome parameter.

CONCLUSIONS

rTSA using a lateralized humeral + medialized glenoid implant model exhibits excellent clinical outcomes in ROM and PROs. However, the magnitude of lateralization as measured radiographically by the ATO did not significantly affect these outcomes; patients exhibited universally good outcomes irrespective of the degree of offset restoration.

Origin and Reversion of Omicron Core Mutations in the Evolution of SARS-CoV-2 Genomes

Genetic analyses showed nearly 30 amino acid mutations occurred in the spike protein of the Omicron variant of SARS-CoV-2. However, how these mutations occurred and changed during the generation and development of Omicron remains unclear. In this study, 6.7 million (all publicly available data from 2020/04/01 to 2022/04/01) SARS-CoV-2 genomes were analyzed to track the origin and evolution of Omicron variants and to reveal the genetic pathways of the generation of core mutations in Omicron. The haplotype network visualized the pre-Omicron, intact-Omicron, and post-Omicron variants and revealed their evolutionary direction. The correlation analysis showed the correlation feature of the core mutations in Omicron. Moreover, we found some core mutations, such as 142D, 417N, 440K, and 764K, reversed to ancestral residues (142G, 417K, 440N, and 764N) in the post-Omicron variant, suggesting the reverse mutations provided sources for the emergence of new variants. In summary, our analysis probed the origin and further evolution of Omicron sub-variants, which may add to our understanding of new variants and facilitate the control of the pandemic.

A Systematic Review of the Utility of Intraoperative Navigation During Total Shoulder Arthroplasty

Total shoulder arthroplasty (TSA) has been demonstrated to successfully recover function to shoulders impaired by arthrosis and rotator cuff insufficiency. Long-term survival depends on the correct positioning of glenoid components and secure bone fixation. Computed tomography (CT)-based intraoperative navigation has proven to be an effective technique for successful TSA procedures. This paper presents a review of CT-based intraoperative navigation considering its advantages and disadvantages. The crucial factors that contribute to the success of this technique are glenoid component positioning, operative duration, and screw selection, which are detailed in this review.

Routine immediate postoperative radiographs rarely identify unknown complications after shoulder arthroplasty

BACKGROUND

Intraoperative complications after shoulder arthroplasty (SA) are uncommon, yet surgeons continue to obtain immediate postoperative radiographs despite prior literature questioning the efficacy of these images. There is a paucity of literature describing the role of immediate postoperative radiographs in revision SA. This study aimed to evaluate the utility of immediate postoperative radiographs in identifying intraoperative complications leading to a change in care after primary or revision SA. We hypothesized that routine postoperative ("survey") radiographs would not provide a high diagnostic yield in identifying early complications requiring a change in postoperative management.

METHODS

A retrospective review of 4063 SAs (1298 primary anatomic total shoulder arthroplasties [aTSAs], 2162 primary reverse shoulder arthroplasties [RSAs], 129 revision aTSAs, and 474 revision RSAs) was performed from a multi-institutional arthroplasty database. All shoulders were evaluated with a single immediate postoperative (survey) radiograph that was read by a musculoskeletal radiologist and by the treating orthopedic surgery team. The radiology reports of all 4063 immediate postoperative radiographs were reviewed to determine whether complications had been identified. For patients in whom complications were identified, the medical record was then reviewed to determine whether the survey radiograph resulted in a return to the operating room or a change in management between the surgical procedure and the first postoperative clinic visit with radiographic evaluation.

RESULTS

Complications were reported by a radiologist on the basis of immediate postoperative radiographs in 10 of 4063 shoulders (0.2%, or 1 of every 500 arthroplasties). Complications were reported after 4 primary RSAs, 4 revision aTSAs, and 2 revision RSAs; no complication was reported after any of the primary aTSAs. Of the 10 complications, only 3 were unknown to the treating surgeon following the operation and none altered immediate postoperative management. Early complications were reported at a rate of 1% after revision arthroplasty vs. 0.1% after primary arthroplasty (P = .001). Additionally, revision aTSA was found to have a higher rate of complications reported on radiographs, with a rate of 3.1%, compared with revision RSA, at 0.4% (P = .021).

CONCLUSION

The radiology reports of routine immediate postoperative radiographs rarely identified postoperative complications (0.2%). In all cases, postoperative management remained unaltered until the time of the first postoperative visit. The value and medicolegal implications of immediate postoperative radiographs may inform the decision to abandon obtaining these studies routinely.

Obesity does not associate with 5-year surgical complications following anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty

BACKGROUND

Although obesity has been shown to increase the risk of short-term medical complications following total shoulder arthroplasty (TSA), evidence is lacking on the influence of obesity on longer-term surgical complications such as revision. The purpose of this study was to assess the association of increasing obesity with 2- and 5-year all-cause revision, periprosthetic joint infection (PJI), aseptic loosening, and manipulation under anesthesia (MUA) among patients undergoing reverse total shoulder arthroplasty (RTSA) or TSA.

METHODS

Patients who underwent RTSA or TSA with a minimum 5-year follow-up were identified in a national claims database (PearlDiver Technologies). Patients with obesity (body mass index [BMI] ≥30) were compared to patients who are normal or overweight (18.5 ≤ BMI < 30). Those with obesity were further stratified to those with class I or II obesity (30 ≤ BMI < 40) and those with class III obesity (BMI ≥ 40). Outcomes for comparison included all-cause revision, PJI, aseptic loosening, and MUA within 2 or 5 years. These cohorts were compared using univariate and multivariable analysis.

RESULTS

Patients with obesity had no significant difference in any surgical complication within 2 or 5 years for both those who underwent TSA or RTSA. After stratifying by class I or II obesity and class III obesity, there was still no significant difference in surgical complications with 2 or 5 years for both TSA patients and RTSA patients.

DISCUSSION

Obesity, when other major comorbidities are controlled for, was not associated with increased risk of long-term surgical complications after shoulder replacement surgery.

Targeting mTOR Complex 2 in Castration-Resistant Prostate Cancer with Acquired Docetaxel Resistance

PURPOSE

Mammalian Target of rapamycin (mTOR) plays a central role in regulating cell growth, proliferation, and cell cycle. The key component of mTORC2 is highly expressed in docetaxel-resistant prostate cells. However, the underlying molecular effects on prostate cells remain unclear.

METHODS

A docetaxel-resistant human prostate cell line (PC-3/DTX) was constructed to investigate the role of mTORC2 in docetaxel resistance. The lentivirus was transfected into cells to knock down the expression of Rictor, and cell viability was measured by Cell Counting Kit 8 (CCK-8). Flow cytometry was used to analyze the cell cycle, and the changes in related signal cascades were assessed by immunohistochemistry (IHC) staining and Western blot.

RESULTS

Docetaxel showed the lowest IC50 (50% inhibitory concentration) in PC-3/DTX cells with sh-RNA. Decreased Rictor expression resulted in a larger proportion of arrested cells in the G0/G1 phase in PC-3/DTX cells. The IC50 values of the AZD8055 group were lower than in the Rapamycin group when treated with docetaxel again. Furthermore, a larger proportion of PC-3/DTX cells were arrested in the G0/G1 phase in the AZD8055 group compared to the Rapamycin group. The IHC results of the prostate cancer tissues from a CRPC patient revealed the over expression of Rictor only, while Raptor expression was unaffected.

CONCLUSION

We investigated the role of mTORC2 signaling on the acquired docetaxel -resistant PC-3 cells to identify potential methods for clinical treatment. MTORC2 expression is essential for docetaxel drug resistance of PC-3 cells. The mTORC1/2 inhibitor AZD8055 caused more significant disruption of mTORC2 kinase activity than the mTORC1 inhibitor Rapamycin, which lead to decreased docetaxel-mediated resistance. Therefore, reversing docetaxel resistance, may become a therapeutic option in the treatment of mCRPC patients.

Total shoulder replacement stems in osteoarthritis-short, long, or reverse? An analysis of the impact of crosslinked polyethylene

BACKGROUND

The 2021 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) report indicated that total shoulder replacement using both midhead (TMH) length humeral components and reverse arthroplasty (RTSA) had a lower revision rate than stemmed humeral components in anatomic total shoulder arthroplasty (aTSA)-for all prosthesis types and diagnoses. However, there are many factors that affect the outcome of total shoulder replacement, including stem length and polarity, polyethylene type, and glenoid fixation (cemented vs. cementless). The aim of this study was to assess the impact of these variables in the various primary total arthroplasty alternatives for osteoarthritis (OA) in the shoulder.

METHODS

Data from a large national arthroplasty registry were analyzed for the period April 2004 to December 2020. The study population included all primary aTSA, RTSA, and TMH shoulder arthroplasty procedures undertaken for OA using either crosslinked polyethylene (XLPE) or noncrosslinked polyethylene (non-XLPE). Because of the previously documented and reported higher revision rate compared with other anatomic total shoulder replacement options, those using cementless metal-backed glenoid components were excluded. The rate of revision was determined by Kaplan-Meier estimates, with comparisons by Cox proportional hazard models. Reasons for revision were also assessed.

RESULTS

For a primary diagnosis of OA, aTSA with a cemented XLPE glenoid component had the lowest revision rate, with a 12-year cumulative revision rate of 4.7%, compared with aTSA with cemented non-XLPE glenoid component at 8.7% and RTSA at 6.8%. The revision rate for TMH (with XLPE or non-XLPE) was lower than aTSA with cemented non-XLPE but was similar to the other implants at the same length of follow-up. The reason for revision of cemented aTSR was most commonly component loosening, not rotator cuff deficiency.

CONCLUSION

Long-stem humeral components matched with XLPE in aTSA achieve a lower revision rate compared with shorter stems, long stems with conventional polyethylene, and RTSA when used to treat shoulder OA. In all these cohorts, loosening, not rotator cuff failure, was the most common diagnosis for revision.

Reverse Foster Kennedy Syndrome Caused by an Intra-axial Tumor

We present a case of a 23-year-old male complaining of painless loss of vision in right eye for 1 year and rapidly progressing vision loss in left eye with bilateral lateral rectus palsy. His fundoscopy revealed optic atrophy on the right side and papilledema on the left. Magnetic resonance imaging (MRI) showed intra-axial contrast-enhancing left frontal tumor. We discuss this first case of reverse Foster-Kennedy syndrome in the English literature with emphasis on the clinico-radiological and clinico-histopathological correlation.

Reverse total shoulder arthroplasty in patients 80 years and older: a national database analysis of complications and mortality

BACKGROUND

Although reverse total shoulder arthroplasty (RSA) is considered a safe surgical option in elderly patients, large-scale analyses of complications and mortality after RSA in patients 80 years and older are scarce. The goals of the current study were to identify revision, complication, and early mortality rates after RSA in patients 80 years and older and compare these to younger patients.

METHODS

The PearlDiver Database, which contains services rendered to Medicare, Medicaid, and commercial insurance patients, was queried for patients undergoing RSA using International Classification of Diseases, Ninth/Tenth Revision (ICD-9/ICD-10) procedure codes. Patients were separated into 2 groups based on their age: 80 years and older and <80 years of age. The incidence of revision arthroplasty, medical, and surgical complications after RSA were extracted. Multivariate regression was used to compare revision arthroplasty and complication rates between groups. Statistical significance was set at P <.05.

RESULTS

A total of 29,430 cases of RSA were included, with 486 cases in patients 80 years and older (median age, 80 years; age range, 2 years). Patients 80 years and older had 1- and 2-year revision rates of 3.9% and 5.1%, compared with the younger cohort at 3.0% and 3.1%, respectively. In patients 80 years and older, there were higher rates of deep venous thrombosis (DVT) (odds ratio [OR] 2.87, 95% CI 1.5-4.97), urinary tract infection (OR 1.42, 95% CI 1.01-1.94), acute renal failure (OR 2.18, 95% CI 1.44-3.17), and pneumonia (OR 1.75, 95% CI 1.09-2.68) within 90 days postoperatively. Ninety-day surgical complications were similar between the cohorts; however, younger patients experienced higher rates of dislocation, stiffness, periprosthetic fracture, and implant complications 1 year postoperatively. Patients 80 years and older had a significantly higher 90-day mortality rate at 2.7% compared with 1.5% in younger patients (P = .002).

CONCLUSIONS

RSA is a generally safe procedure even in patients 80 years and older, with low complication and revision rates. Patients 80 years and older had higher early mortality and medical complication rates, including DVT, renal failure, and pneumonia than patients <80 years of age. However, patients 80 years and older had lower rates of dislocation, periprosthetic fracture, and implant-related complication at 1 year postoperatively.

Lateralized glenosphere reverse shoulder arthroplasty: inlay and onlay designs have similar clinical outcomes in patients with glenohumeral osteoarthritis

BACKGROUND

Whether or how the position of the humeral tray (inlay or onlay) in reverse shoulder arthroplasty (RSA) affects outcomes is unclear. Our goal was to compare the clinical and radiographic results of RSA systems with inlay vs. onlay designs but with similar neck shaft angles (NSAs) and lateralized glenospheres.

METHODS

We screened the institutional database at our tertiary academic center for patients who underwent primary RSA (with a lateralized glenosphere and a 135° NSA) from 2009 through 2017. The indication for surgery was glenohumeral osteoarthritis with glenoid bone loss (Walch classification A2, B2, B3, or C) and an intact rotator cuff. All patients were followed for a minimum of 2 years (mean, 47 months; range, 24-123 months). The humeral tray design was inlay for 79 patients and onlay for 71. All patients underwent preoperative and postoperative evaluations, including physical examination, radiography, and patient-reported outcome measures (visual analog scale for pain, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and Western Ontario Osteoarthritis of the Shoulder index).

RESULTS

Compared with preoperative values, both groups achieved minimal clinically important differences in range of motion and patient-reported outcomes at the final follow-up. We found no significant differences between groups in any of these measures at the final follow-up. Rates of revision (inlay, 3.8% vs. onlay, 1.4%), scapular notching (inlay, 5.1% vs. onlay, 7.0%), acromial stress fracture (inlay, 0% vs. onlay, 2.8%), and tuberosity resorption (inlay, 25% vs. onlay, 27%) were not significantly different between groups (all, P > .05).

CONCLUSION

For patients with glenohumeral osteoarthritis with glenoid bone loss and an intact rotator cuff who underwent RSA using a lateralized glenosphere prosthesis with a 135° NSA, there were no significant differences between the inlay and onlay groups for range of motion, patient-reported outcomes, or complication rates. These findings are limited to this off-label indication for RSA.

A validated preoperative risk prediction tool for discharge to skilled nursing or rehabilitation facility following anatomic or reverse shoulder arthroplasty

BACKGROUND

As bundled payment models continue to spread, understanding the primary drivers of cost excess helps providers avoid penalties and ensure equal health care access. Recent work has shown discharge to rehabilitation and skilled nursing facilities (SNFs) to be a primary cost driver in total joint arthroplasty, and an accurate preoperative risk calculator for shoulder arthroplasty would not only help counsel patients in clinic during shared decision-making conversations but also identify high-risk individuals who may benefit from preoperative optimization and discharge planning.

METHODS

Anatomic and reverse total shoulder arthroplasty cohorts from 2 geographically diverse, high-volume centers were reviewed, including 1773 cases from institution 1 (56% anatomic) and 3637 from institution 2 (50% anatomic). The predictive ability of a variety of candidate variables for discharge to SNF/rehabilitation was tested, including case type, sociodemographic factors, and the 30 Elixhauser comorbidities. Variables surviving parameter selection were incorporated into a multivariable logistic regression model built from institution 1's cohort, with accuracy then validated using institution 2's cohort.

RESULTS

A total of 485 (9%) shoulder arthroplasties overall were discharged to post-acute care (anatomic: 6%, reverse: 14%, P < .0001), and these patients had significantly higher rates of unplanned 90-day readmission (5% vs. 3%, P = .0492). Cases performed for preoperative fracture were more likely to require post-acute care (13% vs. 3%, P < .0001), whereas revision cases were not (10% vs. 10%, P = .8015). A multivariable logistic regression model derived from the institution 1 cohort demonstrated excellent preliminary accuracy (area under the receiver operating characteristic curve [AUC]: 0.87), requiring only 11 preoperative variables (in order of importance): age, marital status, fracture, neurologic disease, paralysis, American Society of Anesthesiologists physical status, gender, electrolyte disorder, chronic pulmonary disease, diabetes, and coagulation deficiency. This model performed exceptionally well during external validation using the institution 2 cohort (AUC: 0.84), and to facilitate convenient use was incorporated into a freely available, online prediction tool. A model built using the combined cohort demonstrated even higher accuracy (AUC: 0.89).

CONCLUSIONS

This validated preoperative clinical decision tool reaches excellent predictive accuracy for discharge to SNF/rehabilitation following shoulder arthroplasty, providing a vital tool for both patient counseling and preoperative discharge planning. Further, model parameters should form the basis for reimbursement legislation adjusting for patient comorbidities, ensuring no disparities in access arise for at-risk populations.

The outcomes of shoulder arthroplasty in those aged ≥70 years with glenohumeral arthritis: a New Zealand Joint Registry study

INTRODUCTION

Reverse total shoulder arthroplasty (RTSA) was traditionally reserved for the patient with rotator cuff tear arthropathy. As the indications for RTSA continue to expand, the role of RTSA in patients aged >70 years with glenohumeral arthritis and an intact rotator cuff remains unclear.

AIM

To study the New Zealand Joint Registry (NZJR) and compare the outcomes of a primary Total Shoulder Arthroplasty (TSA), a primary RSA and an RSA performed for revision of a failed TSA in patients aged >70 years, to determine if there is clear evidence to support a primary RSA in those aged >70 years instead of a primary TSA METHOD: This is a retrospective study of the NZJR from 2000 to 2018. We included all primary TSAs, primary RTSAs, and those RTSAs that were performed for the revision of a failed TSA. We excluded those RTSAs that were performed for the revision of an RTSA or hemiarthroplasty. The primary outcome was the Oxford Shoulder Score (OSS) at 6 months and 5 years, with a secondary outcome being the subsequent revision rate.

RESULTS

A total of 3449 primary TSAs, 4681 primary RTSAs, and 104 revision RTSAs were identified. The mean OSSs at 6 months for a primary TSA, a primary RTSA, and a revision RTSA were 39.5 ± 9.0, 35.5 ± 9.4, and 32.5 ± 9.7, respectively (P < .001, primary TSA vs. primary RSTA; P <.001, primary TSA vs. revision RTSA; P = .0252 primary RTSA vs. revision RTSA). The mean OSSs at 5 years for a primary TSA and a primary RTSA were 42.1 ± 7.5 vs. 39.8 ± 8.4, respectively (P < .001), with no results available for revision RTSA. The secondary outcome was the revision rate for those aged >70 years with osteoarthritis as their primary indication for surgery. The revision rates for a primary TSA and a primary RTSA were 0.53/100 component-years (95% confidence interval [CI] 0.38-0.72) and 0.51/100 component-years (95% CI 0.31-0.79), respectively (P = .193), which was not statistically significant.

CONCLUSION

The TSA remains the gold standard for primary shoulder arthroplasty. For those individuals aged >70 years with osteoarthritis as their primary diagnosis, a primary TSA is associated with a higher OSS than and similar revision rates to a primary RTSA's. However, these patients must be counseled regarding the risk of subsequent cuff failure, as the outcomes from a revision RTSA are significantly inferior than those from a primary RTSA.

Comparison of Glenoid Bone Grafting versus Augmented Glenoid Baseplates in Reverse Shoulder Arthroplasty: A Systematic Review

BACKGROUND

Management of bone loss and glenoid deformity can present a significant challenge to surgeons. The purpose of this review was to compare outcomes of reverse shoulder arthroplasty (RSA) using either bone graft or augmented baseplates for the management of glenoid bone loss and deformity.

METHODS

A comprehensive search of MEDLINE, Embase, Cochrane indices was performed for studies reporting clinical outcomes following primary RSA with bone grafting or use of augmented baseplates. Pooled and frequency-weighted means were calculated where applicable. Between-group comparison was also performed.

RESULTS

Overall, 19 studies and 652 patients were included in the study. There were no significant differences in age or gender between the bone grafting (70.3 years; 47.8% female) and augmented baseplate (72.9 years; 59.0% female) groups (p=0.166; p=0.659). Overall complication and revision rates were similar for reverse shoulder arthroplasty (RSA) using either bone graft (11.7% complication rate; 4.5% revision rate) or augmented baseplates (11.8% complication rate; 3.7% revision rate) for the management of glenoid bone loss and deformity (p=0.968; p=0.562). Furthermore, range of motion as well as patient-reported and functional outcome scores were similar between both techniques. However, infections (0.7% augmented baseplate; 1.9% bone grafting) and notching (4.7% augmented baseplate; 24.6% bone grafting) were found to be more common in the bone grafting group (p=0.012; p=0.018).

CONCLUSIONS

Glenoid bone grafting and augmented baseplates have similar overall clinical outcomes, complication rates, and revision rates. However, there were some significant differences between groups with respect to notching and infections which deserve consideration and further exploration.

Appropriate patient selection for outpatient shoulder arthroplasty: a risk prediction tool

BACKGROUND

The transition from inpatient to outpatient shoulder arthroplasty critically depends on appropriate patient selection, both to ensure safety and to counsel patients preoperatively regarding individualized risk. Cost and patient demand for same-day discharge have encouraged this transition, and a validated predictive tool may help decrease surgeon liability for complications and help select patients appropriate for same-day discharge. We hypothesized that an accurate predictive model could be created for short inpatient length of stay (discharge at least by postoperative day 1), potentially serving as a useful proxy for identifying patients appropriate for true outpatient shoulder arthroplasty.

METHODS

A multicenter cohort of 5410 shoulder arthroplasties (2805 anatomic and 2605 reverse shoulder arthroplasties) from 2 geographically diverse, high-volume health systems was reviewed. Short inpatient stay was the primary outcome, defined as discharge on either postoperative day 0 or 1, and 49 patient outcomes and factors including the Elixhauser Comorbidity Index, sociodemographic factors, and intraoperative parameters were examined as candidate predictors for a short stay. Factors surviving parameter selection were incorporated into a multivariable logistic regression model, which underwent internal validation using 10,000 bootstrapped samples.

RESULTS

In total, 2238 patients (41.4%) were discharged at least by postoperative day 1, with no difference in rates of 90-day readmission (3.5% vs. 3.3%, P = .774) between cohorts with a short length of stay and an extended length of stay (discharge after postoperative day 1). A multivariable logistic regression model demonstrated high accuracy (area under the receiver operator characteristic curve, 0.762) for discharge by postoperative day 1 and was composed of 13 variables: surgery duration, age, sex, electrolyte disorder, marital status, American Society of Anesthesiologists score, paralysis, diabetes, neurologic disease, peripheral vascular disease, pulmonary circulation disease, cardiac arrhythmia, and coagulation deficiency. The percentage cutoff maximizing sensitivity and specificity was calculated to be 47%. Internal validation showed minimal loss of accuracy after bias correction for overfitting, and the predictive model was incorporated into a freely available online tool to facilitate easy clinical use.

CONCLUSIONS

A risk prediction tool for short inpatient length of stay after shoulder arthroplasty reaches very good accuracy despite requiring only 13 variables and was derived from an underlying database with broad geographic diversity in the largest institutional shoulder arthroplasty cohort published to date. Short inpatient length of stay may serve as a proxy for identifying patients appropriate for same-day discharge, although perioperative care decisions should always be made on an individualized and holistic basis.

Cemented versus uncemented reverse shoulder arthroplasty for acute proximal humeral fractures

BACKGROUND

The purposes of this study were (1) to compare postoperative range of motion (ROM) and functional outcomes in patients with proximal humeral fractures operated on with cemented or uncemented reverse shoulder arthroplasty (RSA), (2) to compare the rate of tuberosity healing between cemented and uncemented stems, (3) to determine whether there are significant differences in functional outcomes between patients with healed tuberosities and those with unhealed tuberosities, and (4) to compare complications and revision rates in patients with cemented RSA and uncemented RSA.

METHODS

A cemented RSA was performed early in the study period, which represented a historical cohort (January 2015 to January 2017), followed by a transition to the uncemented RSA later in the study period (February 2017 to February 2019). We excluded 22 cases from postoperative evaluation because of fracture sequelae, age < 65 years, death, and institutionalization; 3 patients were lost to follow-up. The remaining 67 cases (32 cemented and 35 uncemented) underwent clinical and radiographic evaluation by 2 independent fellowship-trained shoulder surgeons. Patients were assessed regarding ROM and the visual analog scale for pain, American Shoulder and Elbow Surgeons score, Constant score, and Single Assessment Numeric Evaluation score. All intraoperative and postoperative complications were recorded.

RESULTS

The mean follow-up period was 41 months (range, 24-72 months), and the mean age was 74 years (range, 65-84 years). Mean postoperative active elevation, internal rotation, external rotation in abduction, and external rotation in adduction were 130° (±15°), 27° (±5°), 28° (±10°), and 16° (±6°), respectively. The mean postoperative visual analog scale, American Shoulder and Elbow Surgeons, Constant, and Single Assessment Numeric Evaluation scores were 1.8 (±0.8), 74 (±6), 58 (±11), and 74% (±8), respectively. There were no significant differences in final ROM and functional scores between the cemented and uncemented groups. The rate of tuberosity healing did not vary significantly in relation to whether the stem was cemented. The subgroup of patients with tuberosity healing presented significantly better active elevation, external rotation, and Constant scores than the subgroup without tuberosity healing. There were 5 complications (7%) and no cases of aseptic humeral stem loosening.

CONCLUSION

In the short term (mean, 41 months), there were no significant differences in postoperative ROM, functional outcomes, complications, and revisions between patients operated on with cemented RSA and those operated on with uncemented RSA for proximal humeral fractures. Patients with healed tuberosities presented significantly better ROM and functional scores than patients without tuberosity healing. The cementation of the stem did not significantly affect the rate of tuberosity healing.

Deltoid fatigue part 2: a longitudinal assessment of anatomic total shoulder arthroplasty over time

BACKGROUND

Gradual loss of overhead range of motion (ROM) has been observed after reverse shoulder arthroplasty (RSA). It remains unclear if this is caused by the effect of RSA design on muscle fiber lengthening or is part of the natural aging process of the shoulder musculature. Although studies have attempted to evaluate deltoid fatigue after RSA, there is a paucity of literature evaluating this effect after anatomic shoulder arthroplasty (aTSA), which would be expected to occur due to aging alone. The purpose of this study is to evaluate the effect of time on overhead ROM after aTSA and compare this with previous data on a similar cohort of RSAs. We hypothesized that overhead ROM would decrease gradually over time in both groups without differences between prosthesis types.

METHODS

A retrospective review of 384 aTSAs without complications was performed over a 10-year period. All shoulders were treated for primary osteoarthritis using a single implant system. Patients were evaluated longitudinally at multiple postoperative time points. At least 1 follow-up visit was between 1 and 2 years postoperatively and another at least 5 years after surgery. ROM and patient reported outcome measures (PROMs) were evaluated using linear-mixed models for repeated measures. These results were compared with a previously evaluated cohort of 165 well-functioning RSAs analyzed using the same methodology.

RESULTS

Primary aTSA shoulders were observed to lose 0.7° of abduction per year starting 1 year postoperatively (P = .001). Smaller losses were observed in external rotation (-0.3°/yr, P = .06) and internal rotation (-0.04/yr, P < .001). However, no significant losses were observed in forward elevation (P = .8). All PROMs diminished slowly over time, but these changes did not exceed the minimally clinically important difference when modeled over 10 years (Simple Shoulder Test -0.08/yr, P < .001; American Shoulder Elbow Surgeons -0.5/yr, P < .001; University of California Los Angeles Shoulder Score -0.2/yr, P < .001). When compared with a similarly analyzed cohort of RSAs, overhead ROM decreased at a slower rate in the aTSA cohort (abduction -0.7° vs. -0.8°/yr, P = .9; FE -0.06° vs. -0.8°/yr, P = .05).

DISCUSSION

In the well-functioning aTSA, gradual loss of ROM occurs in all planes of motion except forward elevation. However, these losses are small and have little meaningful impact relative to minimally clinically important difference thresholds on PROMs. Progressive loss of abduction seen in both aTSA and RSA is likely secondary to aging of the periscapular and rotator cuff musculature. When compared with RSA, loss of motion after aTSA was statistically similar, calling into question the belief that RSA-induced deltoid fatigue leads to loss of overhead motion over time.

Characteristics and risk factors for 90-day readmission following shoulder arthroplasty

BACKGROUND

Anatomic total shoulder arthroplasty (TSA) and reverse TSA are the standard of care for end-stage shoulder arthritis. Advancements in implant design, perioperative management, and patient selection have allowed shorter inpatient admissions. Unplanned readmissions remain a significant complication. Identification of risk factors for readmission is prudent as physicians and payers prepare for the adoption of bundled care reimbursement models. The purpose of this study was to identify characteristics and risk factors associated with readmission following shoulder arthroplasty using a large, bi-institutional cohort.

METHODS

A total of 2805 anatomic TSAs and 2605 reverse TSAs drawn from 2 geographically diverse, tertiary health systems were examined for unplanned inpatient readmissions within 90 days following the index operation (primary outcome). Forty preoperative patient sociodemographic and comorbidity factors were tested for their significance using both univariable and multivariable logistic regression models, and backward stepwise elimination selected for the most important associations for 90-day readmission. Readmissions were characterized as either medical or surgical, and subgroup analysis was performed. A short length of stay (discharge by postoperative day 1) and discharge to a rehabilitation or skilled nursing facility were also examined as secondary outcomes. Parameters associated with increased readmission risk were included in a predictive model.

RESULTS

Within 90 days of surgery, 175 patients (3.2%) experienced an unanticipated readmission, with no significant difference between institutions (P = .447). There were more readmissions for surgical complications than for medical complications (62.9% vs. 37.1%, P < .001). Patients discharged to a rehabilitation or skilled nursing facility were significantly more likely to be readmitted (13.1% vs. 8.8%, P = .049), but a short inpatient length of stay was not associated with an increased rate of 90-day readmission (42.9% vs. 41.3%, P = .684). Parameter selection based on predictive ability resulted in a multivariable logistic regression model composed of 16 preoperative patient factors, including reverse TSA, revision surgery, right-sided surgery, and various comorbidities. The area under the receiver operator characteristic curve for this multivariable logistic regression model was 0.716.

CONCLUSION

Risk factors for unplanned 90-day readmission following shoulder arthroplasty include reverse shoulder arthroplasty, surgery for revision and fracture, and right-sided surgery. Additionally, there are several modifiable and nonmodifiable risk factors that can be used to ascertain a patient's readmission probability. A shorter inpatient stay is not associated with an increased risk of readmission, whereas discharge to post-acute care facilities does impose a greater risk of readmission. As scrutiny around health care cost increases, identifying and addressing risk factors for readmission following shoulder arthroplasty will become increasingly important.

Bit-Level Automotive Controller Area Network Message Reverse Framework Based on Linear Regression

Modern intelligent and networked vehicles are increasingly equipped with electronic control units (ECUs) with increased computing power. These electronic devices form an in-vehicle network via the Controller Area Network (CAN) bus, the de facto standard for modern vehicles. Although many ECUs provide convenience to drivers and passengers, they also increase the potential for cyber security threats in motor vehicles. Numerous attacks on vehicles have been reported, and the commonality among these attacks is that they inject malicious messages into the CAN network. To close the security holes of CAN, original equipment manufacturers (OEMs) keep the Database CAN (DBC) file describing the content of CAN messages, confidential. This policy is ineffective against cyberattacks but limits in-depth investigation of CAN messages and hinders the development of in-vehicle intrusion detection systems (IDS) and CAN fuzz testing. Current research reverses CAN messages through tokenization, machine learning, and diagnostic information matching to obtain details of CAN messages. However, the results of these algorithms yield only a fraction of the information specified in the DBC file regarding CAN messages, such as field boundaries and message IDs associated with specific functions. In this study, we propose multiple linear regression-based frameworks for bit-level inversion of CAN messages that can approximate the inversion of DBC files. The framework builds a multiple linear regression model for vehicle behavior and CAN traffic, filters the candidate messages based on the decision coefficients, and finally locates the bits describing the vehicle behavior to obtain the data length and alignment based on the model parameters. Moreover, this work shows that the system has high reversion accuracy and outperforms existing systems in boundary delineation and filtering relevant messages in actual vehicles.

Emerging Significance of Ginsenosides as Potentially Reversal Agents of Chemoresistance in Cancer Therapy

Chemoresistance has become a prevalent phenomenon in cancer therapy, which alleviates the effect of chemotherapy and makes it difficult to break the bottleneck of the survival rate of tumor patients. Current approaches for reversing chemoresistance are poorly effective and may cause numerous new problems. Therefore, it is urgent to develop novel and efficient drugs derived from natural non-toxic compounds for the reversal of chemoresistance. Researches in vivo and in vitro suggest that ginsenosides are undoubtedly low-toxic and effective options for the reversal of chemoresistance. The underlying mechanism of reversal of chemoresistance is correlated with inhibition of drug transporters, induction of apoptosis, and modulation of the tumor microenvironment(TME), as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (NRF2)/AKT, lncRNA cancer susceptibility candidate 2(CASC2)/ protein tyrosine phosphatase gene (PTEN), AKT/ sirtuin1(SIRT1), epidermal growth factor receptor (EGFR)/ phosphatidylinositol 3-kinase (PI3K)/AKT, PI3K/AKT/ mammalian target of rapamycin(mTOR) and nuclear factor-κB (NF-κB). Since the effects and the mechanisms of ginsenosides on chemoresistance reversal have not yet been reviewed, this review summarized comprehensively experimental data in vivo and in vitro to elucidate the functional roles of ginsenosides in chemoresistance reversal and shed light on the future research of ginsenosides.

Short stay after shoulder arthroplasty does not increase 90-day readmissions in Medicare patients compared with privately insured patients

BACKGROUND

As of January 1, 2021, total shoulder arthroplasty was removed from the Medicare inpatient-only list, reflecting a growing belief in the potential merits of same-day discharge regardless of insurance type. It is yet unknown whether Medicare populations, which frequently have more severe comorbidity burdens, would experience higher complication rates relative to privately insured patients, who are often younger with fewer comorbidities. Given the limited number of true outpatient cohorts available to study, discharge at least by postoperative day 1 may serve as a useful proxy for true same-day discharge, and we hypothesized that these Medicare patients would have increased 90-day readmission rates compared with their privately insured counterparts.

METHODS

Data on 4723 total shoulder arthroplasties (anatomic in 2459 and reverse in 2264) from 2 large, geographically diverse health systems in patients having either Medicare or private insurance were collected. The unplanned 90-day readmission rate was the primary outcome, and patients were stratified into those who were discharged at least by postoperative day 1 (short inpatient stay) and those who were not. Patients with private insurance (n = 1845) were directly compared with those with Medicare (n = 2878), whereas cohorts of workers' compensation (n = 198) and Medicaid (n = 58) patients were analyzed separately. Forty preoperative variables were examined to compare overall health burden, with the χ² and Wilcoxon rank sum tests used to test for statistical significance.

RESULTS

Medicare patients undergoing short-stay shoulder arthroplasty were not significantly more likely than those with private insurance to experience an unplanned 90-day readmission (3.6% vs. 2.5%, P = .14). This similarity existed despite a substantially worse comorbidity burden in the Medicare population (P < .05 for 26 of 40 factors). Furthermore, a short inpatient stay did not result in an increased 90-day readmission rate in either Medicare patients (3.6% vs. 3.4%, P = .77) or their privately insured counterparts (2.5% vs. 2.4%, P = .92). Notably, when the analysis was restricted to a single insurance type, readmission rates were significantly higher for reverse shoulder arthroplasty compared with total shoulder arthroplasty (P < .001 for both), but when the analysis was restricted to a single procedure (anatomic or reverse), readmission rates were similar between Medicare and privately insured patients, whether undergoing a short or extended length of stay.

CONCLUSIONS

Despite a substantially more severe comorbidity profile, Medicare patients undergoing short-stay shoulder arthroplasty did not experience a significantly higher rate of unplanned 90-day readmission relative to privately insured patients. A higher incidence of reverse shoulder arthroplasty in Medicare patients does increase their overall readmission rate, but a similar increase also appears in privately-insured patients undergoing a reverse indicating that Medicare populations may be similarly appropriate for accelerated-care pathways.

Development and assessment of 3-dimensional computed tomography measures of proximal humeral bone density: a comparison to established 2-dimensional measures and intraoperative findings in patients undergoing shoulder arthroplasty

Background

The purpose of this study was to develop novel three-dimensional (3D) measures of bone density from computed tomography (CT) scans and to compare them with validated two-dimensional (2D) radiographic assessments of bone density. Patient demographic data were also analyzed to see if there were any predictors of bone density (age, sex, etiology).

Methods

The study group consisted of 290 consecutive patients undergoing primary shoulder arthroplasty surgery (total anatomic, reverse, and hemiarthroplasty). All underwent preoperative CT imaging. Three 3D CT measurements (metaphysis cancellous, metaphysis cortical, and proximal diaphysis) were developed and automated into software. The developed 3D measurements were compared with validated 2D measures (Tingart and Gianotti Index). Patient demographic data were correlated with these measurements. The difference between the size of the final sounder and of the final stem was calculated as Delta.

Results

There was moderately strong correlation between Tingart and Gianotti measures (0.674, P < .001), as well as between 3D metaphysis cancellous measurements and Tingart (0.645, P < .001). Decreased bone density was highly correlated with female sex. Tingart (area under the curve [AUC]: 0.87, 95% confidence interval [CI]: 0.82-0.91) and 3D metaphysis cancellous (AUC: 0.78, 95% CI: 0.72-0.84) had the highest correlation. These were significantly more than other measures of bone density (P < .01). Decreased bone density measured with Tingart also had moderate correlation with advanced age (AUC: 0.67, 95% CI: 0.6-0.73), but less so for etiology (AUC: 0.62, 95% CI: 0.55-0.69). The 3D metaphysis cancellous measure had lower correlation with age (AUC: 0.59, 95% CI: 0.52-0.66) and etiology (AUC: 0.59, 95% CI: 0.52-0.65). The highest correlation with Delta (the difference between the final sounder and the stem size) was with the 3D metaphysis cancellous measure (AUC: 0.67, 95% CI: 0.59-0.73), followed by Tingart (AUC: 0.647, 95% CI: 0.57-0.671). A multiple regression model to predict Delta demonstrated the stronger prediction using 3D metaphysis cancellous (analysis of variance F-ratio of 42.6, P < .001) than Tingart (35.9, P < .001).

Conclusion

This study demonstrates that automated measures of bone density can be obtained from 3D CT scans. Of the three novel 3D measurements of bone density, the humeral metaphysis cancellous measurement was most correlated to the known 2D measures and most correlated to the intraoperative assessment of bone density (delta).

Exogenous Citrulline and Glutamine Contribute to Reverse the Resistance of Salmonella to Apramycin

Antibiotic resistance is an increasing concern for human and animal health worldwide. Recently, the concept of reverting bacterial resistance by changing the metabolic state of antibiotic-resistant bacteria has emerged. In this study, we investigated the reversal of Apramycin resistance in Salmonella. First, non-targeted metabonomics were used to identify key differential metabolites of drug-resistant bacteria. Then, the reversal effect of exogenous substances was verified in vivo and in vitro. Finally, the underlying mechanism was studied. The results showed that the metabolites citrulline and glutamine were significantly reduced in Apramycin-resistant Salmonella. When citrulline and glutamine were added to the culture medium of drug-resistant Salmonella, the killing effect of Apramycin was restored markedly. Mechanistic studies showed that citrulline and glutamine promoted the Tricarboxylic acid cycle, produced more NADH in the bacteria, and increased the proton-motive force, thus promoting Apramycin entry into the bacterial cells, and killing the drug-resistant bacteria. This study provides a useful method to manage infections by antibiotic-resistant bacteria.

Preoperative factors associated with loss of range of motion after reverse shoulder arthroplasty

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is a successful procedure, often allowing patients to achieve better range of motion (ROM) compared with their preoperative baseline. However, there is a subset of patients who either fail to improve or lose ROM postoperatively. These patients are at increased risk of poor satisfaction and patient-reported outcomes. To date, characteristics of this subset of patients have not been well described. The purpose of this study is to determine risk factors associated with loss of ROM after primary RTSA.

METHODS

A retrospective review using a commercial international RTSA database (Exactech Inc., Gainesville, FL, USA) of patients who underwent primary RTSA between 2007 and 2017 was performed. A total of 123 (7.7%) shoulders lost ≥10° of forward elevation (FE) (group 1, P₁) and 183 (11.4%) lost ≥10° of external rotation (ER) (group 2, P₂). Univariate and multivariate analyses were performed comparing these patients with control cohorts to evaluate risk factors for loss of motion.

RESULTS

Better preoperative abduction, FE, ER, and internal rotation were each associated with greater loss of FE (P₁ < .001) and ER (P₂ < .001) postoperatively. Higher preoperative Simple Shoulder Test (P₁ < .001, P₂ < .001), Constant (P₁ < .001, P₂ < .001), Shoulder Pain and Disability Index (P₁ < .001, P₂ < .001), American Shoulder Elbow Surgeons (P₁ < .001), and University of California at Los Angeles (P₁ < .001) scores were also strongly associated with loss of ROM postoperatively. Other factors associated with a higher risk of losing ROM included a diagnosis of irreparable rotator cuff tear (P₁ = .038), rotator cuff arthropathy (P₁ = .017, P₂ ≤ .001), and inflammatory arthropathy (P₁ = .021). After multivariate analysis, higher preoperative FE (P₁ < .001), internal rotation (P₁ = -.018), and weight (P₁ = .008) remained significant predictors of loss of FE. Better preoperative FE (P₂ = .003), ER (P₂ < .001), and University of California at Los Angeles score (P₂ < .001) remained significant predictors of loss of ER. Patients who lost FE or ER were more likely to report lower satisfaction scores than their counterparts who did not lose ROM (P₁ < .001, P₂ < .001).

CONCLUSION

Patients with greater preoperative shoulder ROM or higher patient-reported outcomes are at higher risk of losing ROM after primary RTSA. They are also at higher risk of reporting lower postoperative satisfaction, though the majority were still satisfied. Surgeons should strongly counsel patients with well-preserved preoperative function on the risk of loss of ROM.

Concept and simulation of an alternative design for an orthopaedic shoulder implant

For a first-time glenohumeral arthritis patient, total shoulder arthroplasty (TSA) is an option where the shoulder joint is replaced with an artificial humeral head that articulates against a cup attached to the glenoid. A patient with rotator cuff deficiency can undergo reverse total shoulder arthroplasty (RTSA) where the components are switched. Presented here is a concept design at simulation stage which offers a platform-based implant where either a system can be assembled and implanted for TSA or a reverse system for RTSA. Platform components and the glenoid baseplate have been designed as part of this concept stage. Modular components are also described as part of the concept, which can influence a patient's range of motion (ROM), as well as the effect of implant positioning within the patient. A 42 mm hemisphere is used as the articulating component providing a good balance between ROM, joint load and deltoid force. The most suitable material concluded for the concept design TSA was as follows: grade 5 Ti-6Al-4V for the humeral stem and baseplate and CoCrMo with cross-linked polyethylene (XLPE) for the metal-on-polymer bearing surface. Finite element analysis concluded that the concept prosthesis is able to withstand an impact force of six times bodyweight from a forward fall. A dynamic fatigue test concluded that the expected lifetime of the concept polymer bearing surface is 33 years.

Effects of dissociative anesthesia opioid-free protocols combined with local anesthesia, with or without flumazenil or atipamezole postoperatively, for orchiectomy in cats

OBJECTIVE

To evaluate the anesthetic effects of two drug combinations with local anesthesia, with or without postoperative antagonists, for orchiectomy in cats.

STUDY DESIGN

Prospective, randomized blinded clinical study.

ANIMALS

A total of 64 healthy cats.

METHODS

Cats were assigned to four equal groups: ketamine (5 mg kg^-1) and dexmedetomidine (10 μg kg^-1) were administered intramuscularly (IM), followed postoperatively with intravenous (IV) saline (5 mL; group KDS) or atipamezole (50 μg kg^-1; group KDA); and ketamine (14 mg kg^-1) with midazolam (0.5 mg kg^-1) and acepromazine (0.1 mg kg^-1) IM, with postoperative IV saline (5 mL; group KMAS) or flumazenil (0.1 mg kg^-1; group KMAF). Lidocaine (2 mg kg^-1) was divided between subcutaneous and intratesticular injection. Physiologic variables were recorded at time points during anesthesia. Ketamine rescue dose was recorded. The degree of sedation and the quality of recovery were evaluated postoperatively.

RESULTS

Time to loss of pedal reflex was longer in groups KMAS and KMAF than in groups KDS and KDA (p = 0.010). Total rescue dose of ketamine was higher in KMAS and KMAF than in KDS and KDA (p = 0.003). Heart rate (HR) during anesthesia was higher in KMAS and KMAF than in KDS and KDA (p = 0.001). Times to head up (p = 0.0005) and to sternal recumbency (p = 0.0003) were shorter in KDA than in KDS, KMAS and KMAF. Lower sedation scores were assigned sooner to KDA than KDS, KMAS and KMAF (p < 0.001). Recovery quality scores were good in all groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Both anesthetic protocols allowed the performance of orchiectomy. Groups KMAS and KMAF required higher rescue doses of ketamine before injecting lidocaine. HR and oscillometric systolic pressure were minimally changed in groups KD and tachycardia was recorded in groups KMA. Only atipamezole shortened the anesthetic recovery.

Downregulation of miRNA-14669 Reverses Vincristine Resistance in Colorectal Cancer Cells through PI3K/AKT Signaling Pathway

BACKGROUND

Vincristine (VCR) is a chemotherapeutic drug commonly used in the treatment of Colorectal Cancer (CRC). However, VCR drug resistance may result in reduced efficacy and even failure of chemotherapy in CRC treatment. MiRNA has been demonstrated to be associated with the sensitivity of tumor cells to chemotherapy.

OBJECTIVE

This study aimed to identify a novel miRNA-14669 that can reverse vincristine resistance and sensitize drug-resistant colorectal cancer cells.

METHODS

High-throughput sequencing was performed to screen miRNAs that are associated with VCR drug resistance, and qRT-PCR was used for further validation. The miRNA mimic and inhibitor were designed and transfected into HCT-8，HCT-116 and HCT-8/VCR cells. Wound healing test examined the effect of the miRNA on the migration of colorectal cancer cells. Flow cytometry was used to evaluate cell apoptosis of HCT-8 cells. Survivin, Bcl-2, GST3, MDR1 and MRP1 expressions were detected by Western blot.

RESULTS

The expression of miRNA-14669 in HCT-8/VCR cells was 1.925 times higher than that of the HCT-8 cells. After transfecting with mimic miRNA, HCT-8 and HCT-116 cells showed an increased survival rate. The survival rate of HCT-8/VCR cells decreased by transfection of inhibitor. The inhibitor also sensitized HCT-8 and HCT-116 cells to VCR or 5-Fluorouracil (5-FU). The migratory ability of HCT-8 and HCT-116 cells increased by miRNA mimic while reduced by miRNA inhibitor. Overexpression of miRNA-14669 reduced apoptosis, while downregulation of miRNA-14669 increased cell apoptosis in HCT-8 cells. The mechanism of the miRNA involved in drug resistance may be attributed to apoptosis of tumor cells, detoxification of GST3 and drug efflux induced by MDR1 and MRP1. PI3K / AKT is the signaling pathway related to drug resistance.

CONCLUSION

We identified a novel miRNA-14669 that may be associated with the chemotherapeutic resistance in CRC cells.

Bilateral total shoulder arthroplasty: A systematic review of clinical outcomes

BACKGROUND

The purpose of this study was to describe the clinical outcomes following bilateral total shoulder arthroplasty (TSA).

METHODS

A systematic search of the PubMed, Embase, and Cochrane Library databases following PRISMA guidelines was performed. English-language literature published from 2010 to 2018 analyzing bilateral TSA (anatomic and/or reverse) with a minimum one-year follow-up was reviewed by two independent reviewers. Study quality was evaluated with the Modified Coleman Methodology Score and the methodological index for non-randomized studies score.

RESULTS

Eleven studies (1 Level II, 3 Level III, 7 Level IV) with 292 patients were included. Two studies reported on bilateral anatomic TSA (n = 54), six reported on bilateral reverse TSA (RTSA; n = 168), two reported on anatomic TSA with contralateral RTSA (TSA/RTSA; n = 31), and one compared bilateral anatomic TSA (n = 26) and bilateral RTSA (n = 13). Among studies, mean revision rate ranged from 0% to 10.53% and mean complication rate ranged from 4.9% to 31.3%. At final follow-up, patients experienced significant overall improvements in range of motion and patient-reported outcome score measurements. However, bilateral anatomic TSA resulted in greater improvements in external rotation compared to bilateral RTSA. Overall patient satisfaction was 91.0%.

CONCLUSION

The available data indicate that bilateral TSA allows for functional and pain improvements and result in high patient satisfaction.

LEVEL OF EVIDENCE

IV.

Clinical and radiographic outcomes of cementless reverse total shoulder arthroplasty for proximal humeral fractures

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) has demonstrated successful outcomes in the treatment of both acute and chronic proximal humeral fractures (PHFs). The traditional RTSA surgical technique uses a methyl methacrylate cemented humeral component to restore and maintain both humeral height and retroversion. However, use of humeral bone cement has been associated intraoperatively with cardiopulmonary risk, increased operative cost, and postoperatively with difficulty if revision arthroplasty is required. We report the clinical and radiographic outcomes of a completely cementless RTSA technique for PHF surgery.

METHODS

Between 2013 and 2018, 60 consecutive patients underwent surgical management of a PHF with cementless RTSA. All surgical procedures were performed by a single senior shoulder surgeon using a modified deltopectoral approach and a completely uncemented RTSA technique. Fractures were defined as either acute or chronic based on a 4-week injury-to-surgery benchmark. The mean age was 67 years (range, 47-85 years). There were 18 acute and 42 chronic fractures. The mean time from injury to surgery was 2 weeks (range, 0.4-4 weeks) for acute fractures and 60 months (range, 1-482 months) for chronic fractures. We excluded 17 cases from postoperative evaluation because of revision and/or loss to follow-up. The remaining 43 cases underwent clinical and radiographic evaluation by 2 independent fellowship-trained shoulder surgeons at a mean of 21 months (range, 10-46 months) postoperatively. Independent statistical analysis was performed using the paired t test and Wilcoxon signed rank test.

RESULTS

At final review, mean active anterior elevation was 157° (range, 100°-170°); active external rotation, 52° (range, 6°-80°); and active internal rotation, 66° (range, 0°-80°). Improvements were seen in the visual analog scale pain score (from 6 to 0.2, P < .001), Simple Shoulder Test score (from 9 to 93, P < .001), American Shoulder and Elbow Surgeons score (from 19 to 91, P < .001), and Single Assessment Numeric Evaluation score (from 21% to 89%, P < .001). Overall, 39 of 43 greater tuberosities (91%) demonstrated osseous healing to the humeral shaft. No significant differences in clinical and radiographic outcomes were found in acute vs. chronic cases, as well as cases with minimum follow-up of 1 year vs. 2 years. Overall, there were 4 major complications necessitating surgical revision (6.7%) and no cases of aseptic humeral stem loosening.

CONCLUSION

Cementless RTSA for acute and chronic PHFs demonstrates clinical and radiographic outcomes similar to those after traditional cemented RTSA. The successful greater tuberosity healing and absence of humeral stem loosening in this short-term cohort are encouraging for the continued long-term success of this technique. By avoiding cemented humeral implants, surgeons may minimize intraoperative complications, operative cost, and postoperative revision difficulty.

An update on reverse total shoulder arthroplasty: current indications, new designs, same old problems

Reverse total shoulder arthroplasty (RTSA) was originally developed because of unsatisfactory results with anatomic shoulder arthroplasty options for the majority of degenerative shoulder conditions and fractures.

After initial concerns about RTSA longevity, indications were extended to primary osteoarthritis with glenoid deficiency, massive cuff tears in younger patients, fracture, tumour and failed anatomic total shoulder replacement.

Traditional RTSA by Grammont has undergone a number of iterations such as glenoid lateralization, reduced neck-shaft angle, modular, stemless components and onlay systems.

The incidence of complications such as dislocation, notching and acromial fractures has also evolved.

Computer navigation, 3D planning and patient-specific implantation have been in use for several years and mixed-reality guided implantation is currently being trialled.

Controversies in RTSA include lateralization, stemless humeral components, subscapularis repair and treatment of acromial fractures.

Cite this article: EFORT Open Rev 2021;6:189-201. DOI: 10.1302/2058-5241.6.200085

The effect of body mass index on internal rotation and function following anatomic and reverse total shoulder arthroplasty

BACKGROUND

The exact relationship between body mass index (BMI) and internal rotation (IR) before and after total shoulder arthroplasty has not been studied to date. The purpose of this study was to determine the effects of BMI on the preoperative and postoperative shoulder range of motion and function in anatomic (aTSA) and reverse total shoulder arthroplasty (rTSA), and specifically how IR affects patient ability to perform IR-related activities of daily living (ADLs).

METHODS

Patients from a prospective multicenter international shoulder arthroplasty registry who underwent primary rTSA (n=1171) and primary aTSA (n=883) were scored preoperatively and at latest follow-up (2-10 years, mean = 3 years) using the Simple Shoulder Test, University of California-Los Angeles shoulder score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Constant score, and Shoulder Pain and Disability Index patient-reported outcome measures (PROMs). Measured active abduction, forward flexion, IR, and active and passive external rotation were recorded, and BMI was evaluated as a predictor of motion and patient-reported outcomes. Patient responses to questions regarding the difficulty level of IR-related ADLs were studied. The relationships between BMI, IR, and ability to perform IR-related ADLs were quantified through analysis of variance with post hoc comparisons by Tukey honestly significant difference tests, where significance was denoted as P < .05.

RESULTS

BMI was found to be inversely correlated with IR in patients undergoing both aTSA and rTSA, both preoperatively (P < .001 and P = .002) and postoperatively (P < .001 and P < .001). BMI affected the range of motion parameters of forward flexion abduction and external rotation but to a lesser extent than that of IR. Nonobese patients demonstrated significantly greater IR than overweight, obese, and morbidly obese patients postoperatively for aTSA (P < .001). For rTSA, nonobese patients had a significantly greater postoperative IR than obese and morbidly obese patients (P < .001 and P = .011, respectively). For both aTSA and rTSA patients, mean IR scores significantly differed between patients reporting normal function vs. patients reporting slight difficulty, considerable difficulty, or inability to perform IR-related ADLs. Increasing IR demonstrated a significant, positive correlation with all PROMs for both aTSA and rTSA patients (Pearson correlation, P < .001).

CONCLUSIONS

BMI is an independent predictor of IR, even when controlling for age, gender, glenosphere size, and subscapularis repair. BMI was inversely correlated with the degree of IR, and decreased IR significantly negatively affected the ability to perform IR-related ADLs.

CLINICAL RELEVANCE

Increasing BMI adversely affects shoulder ROM, particularly IR. IR is correlated with the ability to perform ADLs requiring IR in both aTSA and rTSA patients.

Valproic acid reverses sorafenib resistance through inhibiting activated Notch/Akt signaling pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common lethal human malignancies worldwide. Sorafenib is the first-line drug approved by the United States Food and Drug Administration for HCC. However, the acquired resistance to sorafenib reduces its beneficial effects and limits clinical use. In this study, we established a sorafenib-resistant HCC cell line HepG2-SR by low-concentration gradient induction. Compared with the parental cell HepG2, the proliferation and anti-apoptosis were increased in drug-resistant cell HepG2-SR. Thorough comparisons of the molecular changes between parental HepG2 and sorafenib-resistant HepG2-SR cells indicated that the Notch signaling pathway and PI3K/Akt signaling pathway were associated with sorafenib resistance mechanisms. Notch1 and Akt were upregulated in sorafenib-resistant cells. However, we surprisingly found that valproic acid (VPA) combined with sorafenib could enhance the sensitivity of drug-resistant cells and reverse the increased levels of Notch1 and Akt in sorafenib-resistant HCC cells. Moreover, Akt inhibitor could suppress Notch1 expression, whereas the level of Akt phosphorylation decreased along with increasing dose of Notch inhibitor. Besides, we found that knockdown of Akt resulted in Notch1 reduction, whereas Notch1 reduction also led to a significant reduction in the phosphorylation of Akt. Collectively, our results indicated that Notch1 and Akt might play vital roles in sorafenib resistance in HCC cells and VPA might overcome the drug resistance to enhance the sensitivity of HCC cells to sorafenib through suppressing Notch/Akt signaling pathway. VPA combined with sorafenib may provide a potential targeting therapeutic regimen for clinically to solve the problem of sorafenib resistance.

The incidence of shoulder arthroplasty: rise and future projections compared with hip and knee arthroplasty

BACKGROUND

There remains a paucity of epidemiologic data from recent years on the incidence of shoulder arthroplasty. We aimed to examine the recent trends and predict future projections of hemiarthroplasty (HA), anatomic (aTSA), and reverse shoulder arthroplasty (RSA), as well as compare these predictions to those for total hip (THA) and knee arthroplasty (TKA).

METHODS

The National Inpatient Sample was queried from 2011 to 2017 for HA, aTSA, and RSA, as well as TKA and THA. Linear and Poisson regression was performed to project annual procedural incidence and volume to the year 2025.

RESULTS

Between 2011 and 2017, the number of primary shoulder arthroplasties increased by 103.7%. In particular, RSA increased by 191.3%, with 63,845 RSAs performed in 2017. All projection models demonstrated significant increases in shoulder arthroplasty volume and incidence from 2017 to 2025. By 2025, the linear model predicts that shoulder arthroplasty volume will increase by 67.2% to 174,810 procedures whereas the Poisson model predicts a 235.2% increase, to 350,558 procedures by 2025. These growth rate projections outpace those of THA and TKA.

CONCLUSIONS

The number of shoulder arthroplasties has been increasing in recent years, largely because of the exponential increases in RSA. The overall incidence is increasing at a greater rate than TKA or THA, with projections continuing to rise over the next decade. These data and projections can be used by policy makers and hospitals to drive initiatives aimed at meeting these projected future demands.

An Evolution of Shoulder Periprosthetic Infections Management: MicroDTTect, Bioactive Glass and Tantalum Cones Employment

Periprosthetic joint infections of the shoulder (PJIS) are the major cause for revision within the first two post-operative years, and are challenging both to diagnose and treat. Success depends on early identification of microorganisms, appropriate surgical procedures and efficient antibiotic administration. The peculiar microbiology of the shoulder may render the criteria for hip/knee PJI management inappropriate. In addition, later cases with clinically subtle signs often present diagnostic challenges. In recent years, specific issues of PJIS have been managed through the use of new instruments, such as MicroDTTect in pathogen detection and Bioactive Glass and tantalum cones in humeral bone loss. In the literature to date, no reports have been found that discuss the application in shoulder revisions and infections. The early identification of the microorganisms that cause infection may help improve both treatment strategies and the efficacy of therapy. MicroDTTect proved to be more efficient than swab collection for bacterial identification in orthopedic surgery, thus reducing analysis costs. The increasing number of shoulder arthroplasties is associated with an increase in the number of revisions. In cases of massive metaphyseal humeral bone loss, several techniques have been described; no reports have been reported regarding tantalum in humeral bone loss management. In some cases the tantalum cones required adaptation for femoral diaphysis in the augmentation of the humerus metaphysis and bone loss management improvement. Obtaining stable osseointegration of prosthetic implants is one of the greatest issues in orthopedic surgery, and even more crucial in revisions. Bioactive glasses demonstrated good regenerative and osseointegration properties, and an excellent candidate as a bone graft, scaffold and antibiotics deliverer. The Bioactive glasses were used to increase prosthesis-bone interface stability and fill bone defects in PJIS revision surgeries, contributing to the prevention of re-infection. Longer-term follow-up will be necessary to determine if construction durability is improved in the long term.

Comparison of reconstructive techniques following oncologic intraarticular resection of proximal humerus

INTRODUCTION

The proximal humerus is a common site of primary and metastatic disease in the upper extremity. Historically, the goal of a hemiarthroplasty reconstruction was to provide a stable platform for hand and elbow function, with limited shoulder function. Techniques utilizing a reverse endoprosthesis (endoprosthetic replacement [EPR]) and allograft-prosthetic composite (APC) have been developed; however, there is a paucity of comparative studies.

METHODS

A total of 83 (42 females, 41 males) patients undergoing an intraarticular resection of the humerus were reviewed. Reconstructions included 30 reverse and 53 hemiarthroplasty; including hemiarthroplasty EPR (n = 36) and APC (n = 17), and reverse EPR (n = 20) and APC (n = 10).

RESULTS

Reverse reconstructions had improved forward elevation (85° vs. 44°, p < .001) and external rotation (30° vs. 21°; p < .001) versus a hemiarthroplasty. Reverse reconstructions had improved American Shoulder and Elbow Surgeons scores (65 vs. 57; p = .01) and Musculoskeletal Tumor Society 93 scores (72 vs. 63; p < .001) versus hemiarthroplasty. Subluxation of the reconstruction was a common (n = 23, 27%), only occurring in hemiarthroplasty patients (EPR [n = 13, 36%] and APC [n = 10, 59%]).

CONCLUSION

The current series highlights the improved functional outcome in patients undergoing reconstruction with a reverse arthroplasty compared to the traditional hemiarthroplasty. Currently reverse shoulder arthroplasty (APC or EPR) is our preferred methods of reconstruction in this patient population.

Distal clavicle autograft augmentation for glenoid bone loss in revision shoulder arthroplasty: results and technique

BACKGROUND

Structural bone graft for reconstruction of glenoid bone stock is often necessary in the setting of revision shoulder arthroplasty. This study introduces a new structural autograft technique using the distal clavicle for treatment of glenoid bone loss in the setting of revision shoulder arthroplasty.

METHODS

This is a retrospective, single-surgeon study of patients with significant glenoid bone loss requiring revision shoulder arthroplasty with autologous distal clavicle bone grafting to the glenoid. Twenty patients with failed shoulder arthroplasty who underwent revisions of their glenoid components between 2015 and 2019 were retrospectively identified. Sixteen patients were available with follow-up of greater than 1 year. Patient records and radiographs were reviewed for intraoperative and postoperative complications. Preoperative and postoperative function were evaluated by physical examination and patient-reported outcome surveys.

RESULTS

There were no observed intraoperative complications relating to the distal clavicle autograft harvest or placement. There were no iatrogenic nerve injuries or intraoperative instability. One of the 16 patients developed postoperative loosening and subsequent failure of the glenoid baseplate, requiring revision. One additional patient demonstrated increased elevation of the coracoclavicular interval postoperatively, likely related to the distal clavicle autograft harvest. At a mean follow-up of 25 months, 15 of 16 glenoid implants remained well fixed (93.4%), with no evidence of infection, or impingement demonstrated radiographically or clinically. Average patient age was 69 years at the time of surgery. Forward elevation improved from 76° to 123° at final follow-up (P = .0002). The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score improved from an average of 35.8 to 67.8 at mean follow-up (P = .001). The visual analog scale score improved from an average of 5.9 to 2 at mean follow-up, though not statistically significant (P = .068). There was no significant change in external rotation following surgery (P = .319).

CONCLUSION

Osteolysis and bone loss of the glenoid poses a challenging problem in revision shoulder arthroplasty. Distal clavicle autograft augmentation is a viable and reproducible technique to manage structural glenoid defects.

Mutagenic Analysis of Hazara Nairovirus Nontranslated Regions during Single- and Multistep Growth Identifies both Attenuating and Functionally Critical Sequences for Virus Replication

Hazara nairovirus (HAZV) is a member of the family Nairoviridae in the order Bunyavirales and closely related to Crimean-Congo hemorrhagic fever virus, which is responsible for severe and fatal human disease. The HAZV genome comprises three segments of negative-sense RNA, named S, M, and L, with nontranslated regions (NTRs) flanking a single open reading frame. NTR sequences regulate RNA synthesis and, by analogy with other segmented negative-sense RNA viruses, may direct activities such as virus assembly and innate immune modulation. The terminal-proximal nucleotides of 3' and 5' NTRs exhibit extensive terminal complementarity; the first 11 nucleotides are strictly conserved and form promoter element 1 (PE1), with adjacent segment-specific nucleotides forming PE2. To explore the functionality of NTR nucleotides within the context of the nairovirus multiplication cycle, we designed infectious HAZV mutants bearing successive deletions throughout both S segment NTRs. Fitness of rescued viruses was assessed in single-step and multistep growth, which revealed that the 3' NTR was highly tolerant to change, whereas several deletions of centrally located nucleotides in the 5' NTR led to significantly reduced growth, indicative of functional disruption. Deletions that encroached upon PE1 and PE2 ablated virus growth and identified additional adjacent nucleotides critical for viability. Mutational analysis of PE2 suggest that its signaling ability relies solely on interterminal base pairing and is an independent cis-acting signaling module. This study represents the first mutagenic analysis of nairoviral NTRs in the context of the infectious cycle, and the mechanistic implications of our findings for nairovirus RNA synthesis are discussed.IMPORTANCE Nairoviruses are a group of RNA viruses that include many serious pathogens of humans and animals, including one of the most serious human pathogens in existence, Crimean-Congo hemorrhagic fever virus. The ability of nairoviruses to multiply and cause disease is controlled in major part by nucleotides that flank the 3' and 5' ends of nairoviral genes, called nontranslated regions (NTRs). NTR nucleotides interact with other virus components to perform critical steps of the virus multiplication cycle, such as mRNA transcription and RNA replication, with other roles being likely. To better understand how NTRs work, we performed the first comprehensive investigation of the importance of NTR nucleotides in the context of the entire nairovirus replication cycle. We identified both dispensable and critical NTR nucleotides, as well as highlighting the importance of 3' and 5' NTR interactions in virus growth, thus providing the first functional map of the nairovirus NTRs.