The biomechanical influence of transtibial Bone-Anchored limbs during walking

Individuals with unilateral transtibial amputation (TTA) using socket prostheses demonstrate asymmetric joint biomechanics during walking, which increases the risk of secondary comorbidities (e.g., low back pain (LBP), osteoarthritis (OA)). Bone-anchored limbs are an alternative to socket prostheses, yet it remains unknown how they influence multi-joint loading. Our objective was to determine the influence of bone-anchored limb use on multi-joint biomechanics during walking. Motion capture data (kinematics, ground reaction forces) were collected during overground walking from ten participants with unilateral TTA prior to (using socket prostheses) and 12-months after bone-anchored limb implantation. Within this year, each participant completed a rehabilitation protocol that guided progression of loading based on patient pain response and optimized biomechanics. Musculoskeletal models were developed at each testing timepoint (baseline or 12-months after implantation) and used to calculate joint kinematics, internal joint moments, and joint reaction forces (JRFs). Analyses were performed during three stance periods on each limb. The between-limb normalized symmetry index (NSI) was calculated for joint moments and JRF impulses. Discrete (range of motion (ROM), impulse NSI) dependent variables were compared before and after implantation using paired t-tests with Bonferroni-Holm corrections while continuous (ensemble averages of kinematics, moments, JRFs) were compared using statistical parametric mapping (p < 0.05). When using a bone-anchored limb, frontal plane pelvic (residual: pre = 9.6 ± 3.3°, post = 6.3 ± 2.5°, p = 0.004; intact: pre = 10.2 ± 3.9°, post = 7.9 ± 2.6°, p = 0.006) and lumbar (residual: pre = 15.9 ± 7.0°, post = 10.6 ± 2.5°, p = 0.024, intact: pre = 17.1 ± 7.0°, post = 11.4 ± 2.8°, p = 0.014) ROM was reduced compared to socket prosthesis use. The intact limb hip extension moment impulse increased (pre = -11.0 ± 3.6 Nm*s/kg, post = -16.5 ± 4.4 Nm*s/kg, p = 0.005) and sagittal plane hip moment impulse symmetry improved (flexion: pre = 23.1 ± 16.0 %, post = -3.9 ± 19.5 %, p = 0.004, extension: pre = 29.2 ± 20.3 %, post = 8.7 ± 22.9 %, p = 0.049). Residual limb knee extension moment impulse decreased compared to baseline (pre = 15.7 ± 10.8 Nm*s/kg, post = 7.8 ± 3.9 Nm*s/kg, p = 0.030). These results indicate that bone-anchored limb implantation alters multi-joint biomechanics, which may impact LBP or OA risk factors in the TTA population longitudinally.

Daily steps and stepping cadence increase one-year following prosthesis osseointegration in people with lower-limb amputation

PURPOSE

People with lower-limb loss participate in less physical activity than able-bodied individuals, which increases the mortality risk and incidence of metabolic syndromes. This study evaluated the effect of lower-limb prosthesis osseointegration on physical activity, including daily steps and stepping cadence.

METHODS

Free-living walking activity was assessed from 14 patients scheduled to undergo prosthesis osseointegration at two time points (within 2 weeks prior to osseointegration surgery and 12-months following). Daily step count, stepping time, number of walking bouts, average step cadence per bout, maximum step cadence per bout, and time spent in bands of step cadence were compared before and after osseointegration.

RESULTS

Twelve months after prosthesis osseointegration, participants increased daily steps, daily stepping time, average step cadence, and maximum cadence per walking bout compared to pre-osseointegration.

CONCLUSIONS

Participants engaged in more daily steps, higher stepping cadence, and longer bouts at higher cadence one year following osseointegration compared to when using a socket prosthesis. As a novel intervention that is becoming more common, it is important to understand walking activity outcomes as these are critical for long-term health.

The Amputated Limb Gluteus Medius is Biomechanically Disadvantaged in Patients with Unilateral Transfemoral Amputation

Patients with transfemoral amputation (TFA) are at an increased risk of secondary musculoskeleteal comorbidities, primarily due to asymmetric joint loading. Amputated limb muscle weakness is also prevalent in the TFA population, yet all factors that contribute to muscle strength and thus joint loading are not well understood. Our objective was to bilaterally compare gluteus medius (GMED) muscle factors (volume, fatty infiltration, moment arm) that all contribute to joint loading in patients with TFA. Quantitative magnetic resonance (MR) images of the hip were collected from eight participants with unilateral TFA (2M/6F; age: 47.3 ± 14.7 y/o; BMI: 25.4 ± 5.3 kg/m2; time since amputation: 20.6 ± 15.0 years) and used to calculate normalized GMED muscle volume and fatty infiltration. Six participants participated in an instrumented gait analysis session that collected whole-body kinematics during overground walking. Subject-specific musculoskeletal models were used to calculate bilateral GMED (anterior, middle, posterior) moment arms and frontal plane hip joint angles across three gait cycles. Differences in volume, fatty infiltration, hip adduction-abduction angle, and peak moment arms were compared between limbs using paired Cohen's d effect sizes. Volume was smaller by 36.3 ± 18.8% (d = 1.7) and fatty infiltration was greater by 6.4 ± 7.8% (d = 0.8) in the amputated limb GMED compared to the intact limb. The amputated limb GMED abduction moment arms were smaller compared to the intact limb for both overground walking (anterior: d = 0.9; middle: d = 0.1.2) and during normal range of motion (anterior: d = 0.8; middle: d = 0.8) while bilateral hip adduction-abduction angles were similar during overground walking (d = 0.5). These results indicate that in patients with TFA, the amputated limb GMED is biomechanically disadvantaged compared to the intact limb, which may contribute to the etiology of secondary comorbidities. This population might benefit from movement retraining to lengthen the amputated limb GMED abduction moment arm during gait.

How Comprehensive and Efficient Are Patient-Reported Outcome Measures for Individuals with Lower Extremity Amputation Undergoing Implantation of Osseointegrated Bone Anchored Limbs?

» Patient-reported outcome measures (PROMs) are essential for measuring quality and functional outcomes after implantation of osseointegrated bone anchored limbs for patients with lower extremity amputation.» Using a novel assessment criterion with 8 domains, this study assessed all commonly used PROMs for their efficiency and comprehensiveness.» Comprehensiveness was scored according to the presence or absence of PROM questions related to these 8 domains (maximum score = 60): mobility (15 items), prosthesis (14 items), pain (10 items), psychosocial status (10 items), independence/self-care (4 items), quality of life/satisfaction (4 items), osseoperception (1 item), general information (1 item), and vitality (1 item).» The efficiency scores were calculated by dividing the comprehensiveness score by the total number of questions answered by the patients with higher scores being deemed more efficient.» The most comprehensive PROMs were Orthotics and Prosthetics User's Survey-Lower Extremity Functional Status (OPUS-LEFS) (score = 36), Prosthesis Evaluation Questionnaire (PEQ) (score = 31), and Questionnaire for Persons with a Transfemoral Amputation (score = 27).» The most efficient PROMs were the OPUS-LEFS (score = 1.8) and European Quality of Life (score = 1.4).

Social Media and Digital Footprints in Orthopaedic Trauma: An Analysis of 1465 Orthopaedic Trauma Association Members

OBJECTIVES

The purpose of this study was to quantify social media usage among Orthopaedic Trauma Association (OTA) members.

METHODS

All active OTA members were searched for involvement among common social media platforms. Surgeons were then classified as "active" on any given social media site if they posted within the past 6 months. Surgeons were also identified by the region they practiced in, sex, and their practice setting (academic vs. private). Finally, a surgeon's score and number of reviews from common physician review websites were examined.

RESULTS

A total of 1465 OTA members were included in the analysis. Most surgeons were male (89.1% [n = 1305]) and practiced in a private setting (54.5% [n = 799]). A total of 590 surgeons (40.3%) had at least one form of social media account. Social media sites most used were LinkedIn with 48.7% (n = 713) and ResearchGate with 29.2% (n = 428). Academic surgeons were more likely to have a ResearchGate, LinkedIn, and Twitter account while private surgeons were more likely to have a personal website ( P < 0.05). Finally, there was no correlation between surgeons more active on social media and average scores on Vitals.com or Healthgrade.com ( P > 0.05).

CONCLUSIONS

Most orthopaedic trauma surgeons do not have professional social media accounts. Although social media may help spread scholarship, having a professional social media account does not correlate with better online physician reviews or increased online reviews among orthopaedic trauma surgeons.

Prophylactic Intrawound Antibiotics Significantly Reduce the Risk of Deep Infections in Fracture Fixation: Subgroup Meta-analyses of the Type of Fracture, Antibiotics, and Organism

OBJECTIVES

To analyze the efficacy of subgroups of various intrawound local antibiotics in reducing the rate of fracture-related infections.

DATA SOURCES AND STUDY SELECTION

PubMed, MEDLINE via Ovid, Web of Science, Cochrane database, and Science Direct were searched for articles in English on July 5, 2022, and December 15, 2022.

STUDY SELECTION

All clinical studies comparing the incidence of fracture-related infection between the administration of prophylactic systemic and topical antibiotics in fracture repair were analyzed.

DATA EXTRACTION

Cochrane collaboration's assessment tool and the methodological bias and the methodological index for nonrandomized studies were used to detect bias and evaluate the quality of included studies, respectively.

DATA SYNTHESIS

RevMan 5.3 software (Nordic Cochrane Centre, Denmark) was used to conduct the meta-analyses and generate forest plots.

CONCLUSIONS

From 1990 to 2021, 13 studies included 5309 patients. Nonstratified meta-analysis showed that intrawound administration of antibiotics significantly decreased the overall incidence of infection in both open and closed fractures, regardless of the severity of open fracture and antibiotics class [OR = 0.58, ( P = 0.007)] [OR = 0.33, ( P < 0.00001)], respectively. The stratified analysis revealed that prophylactic intrawound antibiotics significantly lowered infection rate in open fracture patients with Gustilo-Anderson type I (OR = 0.13, P = 0.004), type II (OR = 0.29, P = 0.0002), type III (OR = 0.21, P < 0.00001), when either tobramycin PMMA beads (OR = 0.29, P < 0.00001) or vancomycin powder (OR = 0.51, P = 0.03) was applied. This study demonstrates prophylactic administration of intrawound antibiotics significantly decreases the overall incidence of infection in all subgroups of surgically fixated fractures but does not affect the patient's length of hospital stay.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Recombinant human DNase-I improves acute respiratory distress syndrome via neutrophil extracellular trap degradation

BACKGROUND

Respiratory failure is the primary cause of death in patients with COVID-19, whereas coagulopathy is associated with excessive inflammation and multiorgan failure. Neutrophil extracellular traps (NETs) may exacerbate inflammation and provide a scaffold for thrombus formation.

OBJECTIVES

The goal of this study was to determine whether degradation of NETs by recombinant human DNase-I (rhDNase), a safe, Food and Drug Administration-approved drug, reduces excessive inflammation, reverses aberrant coagulation, and improves pulmonary perfusion after experimental acute respiratory distress syndrome (ARDS).

METHODS

Intranasal poly(I:C), a synthetic double-stranded RNA, was administered to adult mice for 3 consecutive days to simulate a viral infection, and these subjects were randomized to treatment arms, which received either an intravenous placebo or rhDNase. The effects of rhDNase on immune activation, platelet aggregation, and coagulation were assessed in mice and donor human blood.

RESULTS

NETs were observed in bronchoalveolar lavage fluid and within regions of hypoxic lung tissue after experimental ARDS. The administration of rhDNase mitigated peribronchiolar, perivascular, and interstitial inflammation induced by poly(I:C). In parallel, rhDNase degraded NETs, attenuated platelet-NET aggregates, reduced platelet activation, and normalized the clotting time to improve regional perfusion, as observed using gross morphology, histology, and microcomputed tomographic imaging in mice. Similarly, rhDNase reduced NETs and attenuated platelet activation in human blood.

CONCLUSION

NETs exacerbate inflammation and promote aberrant coagulation by providing a scaffold for aggregated platelets after experimental ARDS. Intravenous administration of rhDNase degrades NETs and attenuates coagulopathy in ARDS, providing a promising translational approach to improve pulmonary structure and function after ARDS.

Unilateral transfemoral osseointegrated prostheses improve joint loading during walking

People with unilateral transfemoral amputation using socket prostheses are at increased risk for developing osteoarthritis in both the residual hip and intact lower-limb joints. Osseointegrated prostheses are a surgical alternative to socket prostheses that directly attach to the residual femur via a bone-anchored implant, however their multi-joint loading effect is largely unknown. Our objective was to establish how osseointegrated prostheses influence joint loading during walking. Motion capture data (kinematics, ground reaction forces) were collected from 12 participants at baseline, with socket prostheses, and 12-months after prosthesis osseointegration during overground walking at self-selected speeds. Subject-specific musculoskeletal models were developed at each timepoint relative to osseointegration. Internal joint moments were calculated using inverse dynamics, muscle and joint reaction forces (JRFs) were estimated with static optimization. Changes in internal joint moments, JRFs, and joint loading-symmetry were compared using statistical parametric mapping (p≤ 0.05) before and after osseointegration. Amputated limb hip flexion moments and anterior JRFs decreased during terminal stance (p = 0.002, <0.001; respectively), while amputated limb hip abduction moments increased during mid-stance (p < 0.001), amputated hip rotation moment changed from internal to external throughout early stance (p < 0.001). Intact limb hip extension and knee flexion moments (p = 0.028, 0.032; respectively), superior and resultant knee JRFs (p = 0.046, 0.049; respectively) decreased during the loading response following prosthesis osseointegration. These results may indicate that the direct loading transmission of these novel prostheses create a more typical mechanical environment in bilateral joints, which is comparable with loading observed in able-bodied individuals and could decrease the risk of development or progression of osteoarthritis.

The risk of hospital readmission, revision, and intra- and postoperative complications between direct anterior versus posterior approaches in primary total hip arthroplasty: a stratified meta-analysis and a probability based cost projection

INTRODUCTION

This study presents stratified meta-analysis and projected cost per case analysis of direct anterior approach (DAA) versus posterior approach (PA) in total hip arthroplasty (THA) to determine the best surgical approach and guarantee hip joint longevity.

METHODS

Several online databases were searched for clinical trials comparing DAA and PA in primary THA. The stratified analysis was conducted to test for confounding and biases across the different types of included trials. The average cost and probability were used to determine projected added costs of medical and surgical management for complications.

RESULTS

30 clinical trials included 11,562 patients who underwent THA. Almost 50% of these patients performed DAA. As compared to PA, both non-stratified and stratified analyses demonstrated that DAA has a significant higher incidence of the overall intra- and postoperative complications (non-stratified, OR 1.64; p = 0.003) (stratified, OR 4.12; p = 0.005), nerve injury (non-stratified, OR 22.0; p < 0.00001) (stratified, OR 0.28; p < 0.00001), higher rate of revision surgery (non-stratified; OR 1.54; p = 0.01) (stratified, OR 7.37; p = 0.006), and higher incidence of surgical wound complications (non-stratified; OR 1.67; p = 0.002) as compared to PA following primary THA. In addition, DAA demonstrated higher trends of incidence (non-statistically significant) of femur fracture (Non-stratified, OR 1.32, p = 0.10) and thrombo-embolic complications (Retrospective studies, OR 1.39, p = 0.69). However, PA demonstrated higher trends of incidence (non-statistically significant) of hip joint dislocation, as compared to DAA. (Stratified RCTs, OR 0.63, p = 0.65]. Collectively, this amounts a $421,068.68 surplus in DAA complication costs.

CONCLUSIONS

PA may provide a more lucrative, safer approach to those undergoing THA given its comparable postoperative outcomes, reduced complication rates, and lower overall cost relative to DAA.

Sub-chondroplasty Reduces Pain, Improves Function and Delays the Conversion to Arthroplasty in Patients with Advanced Knee Osteoarthritis: A Stratified Meta-analysis and Quality Assessment

There is an ongoing interest in alternatives to total knee arthroplasty, as a means to delay inevitable replacement. A possible, minimally invasive, alternative is a sub-chondroplasty, involving interosseous injection of bone substitute materials such as calcium phosphate (CaPo4), platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC) or Injectable demineralized bone matrix (iDBM) into the subchondral bone. Eleven clinical trials were found, investigating the effectiveness of sub-chondroplasties performed using CaPo4, PRP, BMAC, and iDBM. A non-stratified and stratified meta-analysis of the included studies were conducted to test for confounding variables across the trials. Non-stratified analysis, regardless of injectable type, revealed a significant improvement in the average Visual Analog Scale (VAS) score and postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients post sub-chondroplasty, as compared to baseline. This analysis demonstrates that the sub-chondroplasty procedure reduces pain, improves function, and has lower risk of conversion to arthroplasty. (Journal of Surgical Orthopaedic Advances 32(2):065-074, 2023).

Neuraxial Anesthesia Significantly Reduces 30-Day Venous Thromboembolism Rate and Length of Hospital Stay in Primary Total Hip Arthroplasty: A Stratified Propensity Score-Matched Cohort Analysis

BACKGROUND

General anesthesia (GA) has been the commonly used protocol for total hip arthroplasty (THA); however, neuraxial anesthesia (NA) has been increasingly performed. Our purpose was to compare NA and GA for 30-day postoperative outcomes in United States veterans undergoing primary THA.

METHODS

A large veteran's database was utilized to identify patients undergoing primary THA between 1999 and 2019. A total of 6,244 patients had undergone THA and were included in our study. Of these, 44,780 (79.6%) had received GA, and 10,788 (19.2%) had received NA. Patients receiving NA or GA were compared for 30-day mortalities, cardiovascular, respiratory, and renal complications, and wound infections and hospital lengths of stay (LOS). Propensity score matching, multivariate regression analyses, and subgroup analyses by American Society of Anesthesiology classification were performed to control for selection bias and patient baseline characteristics.

RESULTS

Upon propensity-adjusted multivariate analyses, NA was associated with decreased risks for deep venous thrombosis (odds ratio [OR] = 0.63; 95% CI = 0.4-0.9; P = .02), any respiratory complication (OR = 0.63; 95% CI = 0.5-0.9; P = .003), unplanned reintubation (OR = 0.51; 95% CI = 0.3-0.9; P = .009), and prolonged LOS (OR = 0.78; 95% CI = 0.72-0.84; P < .001). Subgroup analyses by American Society of Anesthesiology classes showed NA decreased 30-day venous thromboembolism rate in low-risk (class I/II) patients and decreased respiratory complications in high-risk (class III/IV) patients.

CONCLUSION

Using a patient cohort obtained from a large national database, NA was associated with reduced risk of 30-day adverse events compared to GA in patients undergoing THA. Postoperative adverse events were decreased with NA administration with similar decreases observed across all patient preoperative risk levels. NA was also associated with a significant decrease in hospital LOS.

Opioid-Related Genetic Polymorphisms of Cytochrome P450 Enzymes after Total Joint Arthroplasty: A Focus on Drug-Drug-Gene Interaction with Commonly Coprescribed Medications

Pharmacogenomic testing, together with the early detection of drug-drug-gene interactions (DDGI) before initiating opioids, can improve the selection of dosage and reduce the risk of adverse drug interactions and therapeutic failures following Total Joint Arthroplasty. The variants of CYP genes can mediate DDGI. Orthopedic surgeons should become familiar with the genetic aspect of opioid use and abuse, as well as the influence of the patient genetic makeup in opioid selection and response, and polymorphic variants in pain modulation.

Coronavirus pandemic in the Nordic countries: Health policy and economy trade-off

Background

Countries making up the Nordic region – Denmark, Finland, Iceland, Norway, and Sweden – have minimal socioeconomic, cultural, and geographical differences between them, allowing for a fair comparative analysis of the health policy and economy trade-off in their national approaches towards mitigating the impact of the COVID-19 pandemic.

Methods

This study utilized publicly available COVID-19 data of the Nordic countries from January 2020 to January 3, 2021. COVID-19 epidemiology, public health and health policy, health system capacity, and macroeconomic data were analysed for each Nordic country. Joinpoint regression analysis was performed to identify changes in temporal trends using average monthly percent change (AMPC) and average weekly percent change (AWPC).

Results

Sweden’s health policy, being by far the most relaxed response to COVID-19, was found to have the largest COVID-19 incidence and mortality, and the highest AWPC increases for both indicators (13.5, 95% CI = 5.6, 22.0, P < 0.001; 6.3, 95% CI = 3.5, 9.1, P < 0.001). Denmark had the highest number of COVID-19 tests per capita, consistent with their approach of increased testing as a preventive strategy for disease transmission. Iceland had the second-highest number of tests per capita due to their mass-testing, contact tracing, quarantine and isolation response. Only Norway had a significant increase in unemployment (AMPC = 2.8%, 95% CI = 0.7-4.9, P < 0.009) while the percentage change in real Gross Domestic Product (GDP) was insignificant for all countries.

Conclusions

There was no trade-off between public health policy and economy during the COVID-19 pandemic in the Nordic region. Sweden’s relaxed and delayed COVID-19 health policy response did not benefit the economy in the short term, while leading to disproportionate COVID-19 hospitalizations and mortality.

Current Guidelines and Practice Recommendations to Prevent Hospital-Acquired Conditions After Major Orthopaedic Surgeries

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In 2016, a total of 48,771 hospital-acquired conditions (HACs) were reported in U.S. hospitals. These incidents resulted in an excess cost of >$2 billion, which translates to roughly $40,000 per patient with an HAC.

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Current guidelines for the prevention of venous thromboembolism and surgical site infection consist primarily of antithrombotic prophylaxis and antiseptic technique, respectively.

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The prevention of catheter-associated urinary tract infection (CA-UTI) and in-hospital falls and trauma is done best via education. In the case of CA-UTI, this consists of training staff about the indications for catheters and their timely removal when they are no longer necessary, and in the case of in-hospital falls and trauma, advising the patient and family about the patient's fall risk and communicating the fall risk to the health-care team.

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Blood incompatibility is best prevented by implementation of a pretransfusion testing protocol. Pressure ulcers can be prevented via patient positioning, especially during surgery, and via postoperative skin checks.

Closed‐incision negative pressure therapy at −125 mmHg significantly reduces surgical site complications following total hip and knee arthroplasties: A stratified meta‐analysis of randomized controlled trials

Background

Closed‐incision negative pressure wound therapy (ciNPT) has shown promising effects for managing infected wounds. This meta‐analysis explores the current state of knowledge on ciNPT in orthopedics and addresses whether ciNPT at −125 mmHg or −80 mmHg or conventional dressing reduces the incidence of surgical site complications in hip and knee arthroplasty.

Methods

This meta‐analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta‐analysis (PRISMA) guidelines and Cochrane Handbook. Prospective randomized controlled trials (RCTs) with ciNPT use compared to conventional dressings following hip and knee surgeries were considered for inclusion. Non‐stratified and stratified meta‐analyses of six RCTs were conducted to test for confounding and biases. A P value less than .05 was considered statistically significant.

Results

The included six RCTs have 611 patients. Total hip and knee arthroplasties were performed for 51.7% and 48.2% of the included population, respectively. Of 611 patients, conventional dressings were applied in 315 patients and 296 patients received ciNPT. Two ciNPT systems have been used across the six RCTs; PREVENA Incision Management System (−125 mmHg) (63.1%) and PICO dressing (−80 mmHg) (36.8%). The non‐stratified analysis showed that the ciNPT system had a statistically significant, lower risk of persistent wound drainage as compared to conventional dressing following total hip and knee arthroplasties (OR = 0.28; P = .002). There was no difference between ciNPT and conventional dressings in terms of wound hematoma, blistering, seroma, and dehiscence. The stratified meta‐analysis indicated that patients undergoing treatment with high‐pressure ciNPT (120 mmHg) displayed significantly fewer overall complications and persistent wound drainage (P = .00001 and P = .002, respectively) when compared to low‐pressure ciNPT (80 mmHg) and conventional dressings. In addition, ciNPT is associated with shorter hospital stays. (P = .005).

Conclusion

When compared to conventional wound dressing and −80 mmHg ciNPT, the use of −125 mmHg ciNPT is recommended in patients undergoing total joint arthroplasty.

Stimulation of angiotensin II receptor 2 preserves cognitive function and is associated with an enhanced cerebral vascular density after stroke

Angiotensin signaling is known to be sexually dimorphic. Although it is a well-studied target for intervention in stroke and cognitive impairment, female studies are rare. With females suffering a disproportionately greater negative impact of stroke and dementia vs. males, effective interventions are of utmost urgency. The aim of the current study was to determine the impact of activation of the angiotensin II type 2 receptor (AT2R) with the agonist compound 21 (C21) on the development of post-stroke cognitive impairment, after experimental ischemic stroke. Ovariectomized (OVX) spontaneously hypertensive rats (SHRs) were subjected to 1 h of middle cerebral artery occlusion (MCAO). At 24 h, rats with a significant neurologic deficit were randomized to receive either saline or C21 (0.03 mg/kg/day) intraperitoneally (IP) for 5 days, then orally (0.12 mg/kg/day) for a total of 6 weeks. Cognitive function, brain structure by MRI and vascular architecture by microCT angiography were measured. C21 preserved cognitive function, specifically spatial memory, and improved vascular density in the ischemic hemisphere at 6 weeks, reflecting both arteriogenesis and angiogenesis. In conclusion, C21 prevented cognitive impairment after stroke, likely through a mechanism involving vascular protection and restoration.

Hospital-Acquired Conditions: A Review of Classical and Novel Risk Factors Following Total Hip and Knee Arthroplasties

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In 2016, a total of 48,771 hospital-acquired conditions (HACs) were reported in U.S. hospitals. These incidents resulted in an excess cost of >$2 billion, which translates to roughly $41,000 per patient per HAC.

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In the settings of total hip arthroplasty (THA) and total knee arthroplasty (TKA), increased age, a body mass index of >35 kg/m2, male sex, diabetes mellitus, electrolyte disturbances, and a history of anemia increase the likelihood of surgical site infections.

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Institution-specific (surgical) risk factors such as increased tourniquet time, an operative time of >130 minutes, bilateral procedures, a femoral nerve block, and general anesthesia increase the risk of HACs in the settings of THA and TKA.

Direct anterior approach has short-term functional benefit and higher resource requirements compared with the posterior approach in primary total hip arthroplasty : a meta-analysis of functional outcomes and cost

AIMS

It has been suggested that the direct anterior approach (DAA) should be used for total hip arthroplasty (THA) instead of the posterior approach (PA) for better early functional outcomes. We conducted a value-based analysis of the functional outcome and associated perioperative costs, to determine which surgical approach gives the better short-term outcomes and lower costs.

METHODS

This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the Cochrane Handbook. Several online databases were searched. Non-stratified and stratified meta-analyses were conducted to test the confounding biases in the studies which were included. The mean cost and probability were used to determine the added costs of perioperative services.

RESULTS

The DAA group had significantly longer operating times (p < 0.001), reduced length of hospital stay by a mean of 13.4 hours (95% confidence interval (CI) 9.12 to 18; p < 0.001), and greater blood loss (p = 0.030). The DAA group had significantly better functional outcome at three (p < 0.001) and six weeks (p = 0.006) postoperatively according to the Harris Hip Score (HHS). However, there was no significant difference between the groups for the HHS at six to eight weeks (p = 0.230), 12 weeks (p = 0.470), six months (p = 0.740), and one year (p = 0.610), the 12-Item Short Form Survey (SF-12) physical score at six weeks (p = 0.580) and one year (p = 0.360), SF-12 mental score at six weeks (p = 0.170) and one year (p = 0.960), and University of California and Los Angeles (UCLA) activity scale at 12 weeks (p = 0.250). The mean non-stratified and stratified difference in costs for the operating theatre time and blood transfusion were $587.57 (95% CI 263.83 to 1,010.29) to $887.04 (95% CI 574.20 to 1,298.88) and $248.38 (95% CI 1,003.40 to 1,539.90) to $1,162.41 (95% CI 645.78 to 7,441.30), respectively, more for the DAA group. However, the mean differences in costs for the time in hospital were $218.23 and $192.05, respectively, less for the DAA group.

CONCLUSION

The use of the DAA, rather than the PA, in THA has earlier benefits for function and pain. However, these are short-lasting, with no significant differences seen at later intervals. In addition the limited benefits were obtained with higher cumulative costs for DAA. Cite this article: Bone Joint J 2021;103-B(6):1078-1087.

Dysregulation of epigenetic related genes in Diabetic Trigger finger Patients; preliminary analysis of Patient-Derived Samples

BACKGROUND

Trigger finger (TF), a painful condition involving a finger flexor tendon, is a common problem with a prevalence of ~2-3% in the general population. However, the TF prevalence is higher among diabetic patients-ranges from 6.7% to 10%. We have analyzed the expression of the extracellular matrix, inflammation, and epigenetic related genes in diabetic and non-diabetes TF. We hypothesized that Diabetes condition induces alter the expression of epigenetic modification genes in diabetic patients and one of the underlying determinants for more prevalence of TF in diabetic patients.

METHOD

Tissues from the fingers of patients with symptomatic trigger fingers were collected. We had three groups: carpal tunnel syndrome (as a control), trigger finger, and diabetic trigger finger. A quantitative real-time polymerase chain reaction was performed. The gene expression of Extracellular matrix (ECM) components [COL-I, COL-II, COL-X, Aggrecan], DNA methyltransferases enzymes (DNMT1, DNMT3), growth factors (TGF-b, IGF), and Histone deacetylase enzymes (HDAC1, HDAC2) were evaluated in all groups.

RESULTS

The mRNA expression of COL-I, COL-II, Aggrecan was significantly higher in the pully A1 of diabetic patients (p= 0.0164, p=0.0351, p=0.0399, respectively) as compared to non-diabetic TF patients. Diabetes was associated with a significant increase in the DNMT3 expression compared to non-diabetic TF patients (p=0.0485). HDAC1 and HDAC2 gene expression were up-regulated in diabetic TF than non-diabetic TF.

CONCLUSION

The chronic state of hyperglycemia induces epigenetic modification of gene expressions in trigger fingers. This seems to have a significant impact on the development, recurrence, and progression of trigger finger in diabetic patients.

Homemade Glove Retrieval Bag in Laparoscopic Complete Excision of Benign Ovarian Teratoma with Ovarian Tissue Preservation in Children: A Case Series

STUDY OBJECTIVE

To present our experience of laparoscopic resection of pediatric benign ovarian teratomas with gonadal preservation, using a homemade glove retrieval bag. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Review of all girls with benign ovarian teratomas who were managed with laparoscopic ovarian-sparing surgery (OSS) at our hospital between January 2013 and December 2018.

RESULTS

Eleven patients were included for analysis with a mean age of 6.1 years. Ten patients received elective surgery, whereas 1 patient received emergency surgery because of ovarian torsion. Main indication for OSS was the existence of a dissection plane between tumor margins and healthy ovarian tissue. Postoperative outcome and follow-up were uneventful with a median follow-up of 30.1 months (range; 12-60 months).

CONCLUSION

Laparoscopic OSS can be safely performed for these tumors. Laparoscopic magnification with energy devices are excellent tools in such procedures. The homemade glove bag can be used to retrieve the tumor effectively in countries with limited resources.

Role of dendritic cell-mediated immune response in oral homeostasis: A new mechanism of osteonecrosis of the jaw

Dendritic cells are an important link between innate and adaptive immune response. The role of dendritic cells in bone homeostasis, however, is not understood. Osteoporosis medications that inhibit osteoclasts have been associated with osteonecrosis, a condition limited to the jawbone, thus called medication-related osteonecrosis of the jaw. We propose that disruption of the local immune response renders the oral microenvironment conducive to osteonecrosis. We tested whether zoledronate (Zol) treatment impaired dendritic cell (DC) functions and increased bacterial load in alveolar bone in vivo and whether DC inhibition alone predisposed the animals to osteonecrosis. We also analyzed the role of Zol in impairment of differentiation and function of migratory and tissue-resident DCs, promoting disruption of T-cell activation in vitro. Results demonstrated a Zol induced impairment in DC functions and an increased bacterial load in the oral cavity. DC-deficient mice were predisposed to osteonecrosis following dental extraction. Zol treatment of DCs in vitro caused an impairment in immune functions including differentiation, maturation, migration, antigen presentation, and T-cell activation. We conclude that the mechanism of Zol-induced osteonecrosis of the jaw involves disruption of DC immune functions required to clear bacterial infection and activate T cell effector response.

Short-Term Acute Exercise Preconditioning Reduces Neurovascular Injury After Stroke Through Induced eNOS Activation

Physical exercise is known to reduce cardiovascular risk but its role in ischemic stroke is not clear. It was previously shown that an acute single bout of exercise reduced increased eNOS activation in the heart and reduced myocardial infarction. However, the impact of a single bout or short-term exercise on eNOS-induced neuroprotection after stroke was not previously studied. Accordingly, this study was designed to test the hypothesis that short-term acute exercise can provide "immediate neuroprotection" and improve stroke outcomes through induced eNOS activation. Male Wistar rats (300 g) were subjected to HIIT treadmill exercise for 4 days (25 min/day), break for 2 days, and then one acute bout for 30 min. Exercised animals were subjected to thromboembolic stroke 1 h, 6 h, 24 h, or 72 h after the last exercise session. At 24 h after stroke, control (sedentary) and exercised rats were tested for neurological outcomes, infarct size, and edema. The expression of active eNOS (p-S1177-eNOS) and active AMPK (p-T172-AMPK) was measured in the brain, cerebral vessels, and aorta. In an additional cohort, animals were treated with the eNOS inhibitor, L-NIO (I.P, 20 mg/kg), and stroked 1 h after exercise and compared with non-exercise animals. Acute exercise significantly reduced infarct size, edema, and improved functional outcomes, and significantly increased the expression of peNOS and pAMPK in the brain, cerebral vessels, and aorta. eNOS inhibition abolished the exercise-induced improvement in outcomes. Short-term acute preconditioning exercise reduced the neurovascular injury and improved functional outcomes after stroke through eNOS activation.

Monomethylfumarate protects against ovariectomy-related changes in body composition

Osteoporosis, low bone mass that increases fracture susceptibility, affects approximately 75 million individuals in the United States, Europe and Japan, with the number of osteoporotic fractures expected to increase by more than 3-fold over the next 50 years. Bone mass declines with age, although the mechanisms for this decrease are unclear. Aging enhances production of reactive oxygen species, which can affect bone formation and breakdown. The multiple sclerosis drug Tecfidera contains dimethylfumarate, which is rapidly metabolized to monomethylfumarate (MMF); MMF is thought to function through nuclear factor erythroid-derived-2-like-2 (Nrf2), a transcription factor activated by oxidative stress which induces the expression of endogenous anti-oxidant systems. We hypothesized that MMF-elicited increases in anti-oxidants would inhibit osteopenia induced by ovariectomy, as a model of aging-related osteoporosis and high oxidative stress. We demonstrated that MMF activated Nrf2 and induced anti-oxidant Nrf2 target gene expression in bone marrow-derived mesenchymal stem cells. Sham-operated or ovariectomized adult female mice were fed chow with or without MMF and various parameters monitored. Ovariectomy produced the expected effects, decreasing bone mineral density and increasing body weight, fat mass, bone marrow adiposity and serum receptor activator of nuclear factor-kappa-B ligand (RANKL) levels. MMF decreased fat but not lean mass. MMF improved trabecular bone microarchitecture after adjustment for body weight, although the unadjusted data showed few differences; MMF also tended to increase adjusted cortical bone and to reduce bone marrow adiposity and serum RANKL levels. Because these results suggest the possibility that MMF might be beneficial for bone, further investigation seems warranted.

Serum C-terminal cross-linking telopeptide level as a predictive biomarker of osteonecrosis after dentoalveolar surgery in patients receiving bisphosphonate therapy: Systematic review and meta-analysis

BACKGROUND

The authors' aim in this systematic review was to evaluate the validity of using preoperative serum C-terminal cross-linking telopeptide (CTX) levels as a predictive factor of increased risk of developing medication-related osteonecrosis of the jaw (MRONJ) in patients receiving bisphosphonate (BP) therapy who underwent invasive dental procedures.

TYPES OF STUDIES REVIEWED

The authors searched PubMed, MEDLINE, and Web of Science and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The authors conducted a meta-analysis on the risk ratio. The authors used the methodological index for nonrandomized studies and Quality Appraisal of Reliability Studies checklist to assess quality.

RESULTS

The authors included 18 clinical trials involving 2,301 patients. Most patients received alendronate or risedronate for an average of 62.14 months. The average serum CTX level in patients who received BP before surgery was 198.25 picograms per milliliter. Meta-analysis results showed that the cutoff in CTX level (150 pg/mL) was not predictive of MRONJ risk. The sensitivity of CTX values lower than 150 pg/mL was 34.26%, and the specificity was 77.08%.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The use of CTX levels to diagnose MRONJ risk after dental procedures in patients receiving BP is not justified. The cutoff of 150 pg/mL in serum CTX levels is not predictive of MRONJ. Further studies are needed to develop other reliable biomarkers.

What doesn't kill you makes you stranger: Dipeptidyl peptidase-4 (CD26) proteolysis differentially modulates the activity of many peptide hormones and cytokines generating novel cryptic bioactive ligands

Dipeptidyl peptidase 4 (DPP4) is an exopeptidase found either on cell surfaces where it is highly regulated in terms of its expression and surface availability (CD26) or in a free/circulating soluble constitutively available and intrinsically active form. It is responsible for proteolytic cleavage of many peptide substrates. In this review we discuss the idea that DPP4-cleaved peptides are not necessarily inactivated, but rather can possess either a modified receptor selectivity, modified bioactivity, new antagonistic activity, or even a novel activity relative to the intact parent ligand. We examine in detail five different major DPP4 substrates: glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide tyrosine-tyrosine (PYY), and neuropeptide Y (NPY), and stromal derived factor 1 (SDF-1 aka CXCL12). We note that discussion of the cleaved forms of these five peptides are underrepresented in the research literature, and are both poorly investigated and poorly understood, representing a serious research literature gap. We believe they are understudied and misinterpreted as inactive due to several factors. This includes lack of accurate and specific quantification methods, sample collection techniques that are inherently inaccurate and inappropriate, and a general perception that DPP4 cleavage inactivates its ligand substrates. Increasing evidence points towards many DPP4-cleaved ligands having their own bioactivity. For example, GLP-1 can work through a different receptor than GLP-1R, DPP4-cleaved GIP can function as a GIP receptor antagonist at high doses, and DPP4-cleaved PYY, NPY, and CXCL12 can have different receptor selectivity, or can bind novel, previously unrecognized receptors to their intact ligands, resulting in altered signaling and functionality. We believe that more rigorous research in this area could lead to a better understanding of DPP4's role and the biological importance of the generation of novel cryptic ligands. This will also significantly impact our understanding of the clinical effects and side effects of DPP4-inhibitors as a class of anti-diabetic drugs that potentially have an expanding clinical relevance. This will be specifically relevant in targeting DPP4 substrate ligands involved in a variety of other major clinical acute and chronic injury/disease areas including inflammation, immunology, cardiology, stroke, musculoskeletal disease and injury, as well as cancer biology and tissue maintenance in aging.

Value of pre-operative CTX serum levels in the prediction of medication-related osteonecrosis of the jaw (MRONJ): a retrospective clinical study

OBJECTIVES

The low incidence yet severe presentation of medication-related osteonecrosis of the jaw (MRONJ) makes it necessary to develop reliable predictive and preventive strategies. This study explored the value of pre-operative carboxy-terminal collagen crosslinks (CTX) serum level in the prediction of osteonecrosis-related complications in patients on bisphosphonate therapy.

PATIENTS AND METHODS

We examined patient records over 4 years (a total of 137 patients). Biometric data were extracted, in addition to type of treatment, CTX levels, drug holiday, procedure, complications, and co-morbidities. Non-parametric Wilcoxon two-sample tests were used to test the effect of initial CTX level in IV or PO and whether it was predictive of complications. Two independent proportion tests were used for testing the two different complication incident rates before or after the drug holiday.

RESULTS

A total of 93 patients were included in the study, of whom 88.17% were female. A total of 11 patients were receiving IV bisphosphonates at the time of initial presentation, 82 oral bisphosphonates. Out of 64 patients who underwent invasive dental procedure (IDP) before a drug holiday, eight were on IV bisphosphonates. Three patients in this group experienced osteonecrosis-related complications (37.5%). Out of the remaining 56 patients on oral bisphosphonates, four (7.14%) developed complications, significantly lower than the IV bisphosphonate group (p = 0.0364). On the other hand, of the 34 patients placed on a drug holiday prior to IDP, only one subject developed complications related to osteonecrosis. Five subjects who had operations both before and after drug holiday did not experience any complications. No statistical difference was detected in complication rates based on initial CTX level (above versus below 150 pg/ml), gender, comorbidities, or total duration of bisphosphonate treatment (p = 0.2675). The sensitivity and specificity of CTX cutoff of 150 pg/ml in predicting osteonecrosis were 37.5% and 57.7, respectively.

CONCLUSIONS

Serum levels of CTX by itself are not reliable as a predictive or preventive measure for such complications. Our data also suggested that a drug holiday of 5 months was not helpful in preventing osteonecrosis-related complications in patients on intravenous bisphosphonates. Further studies are urgently needed to develop adequate predictive and preventive strategies of MRONJ.

The use of vascularized fibula flap in mandibular reconstruction; A comprehensive systematic review and meta-analysis of the observational studies

BACKGROUND

Vascularized fibular flaps are considered the gold standard for the reconstruction of segmental defects in the mandible. This review compares the complication and success rates of these techniques between primary and secondary reconstruction, as well as between lateral and antero-lateral defects.

TYPE OF STUDIES REVIEWED

A systematic review and meta-analysis were conducted according to PRISMA protocol and the Cochrane Handbook for Systematic Reviews of Interventions. The authors performed an independent comprehensive search using PubMed, Ovid MEDLINE, Web of Science, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and COS Conference Papers Index according to established inclusion and exclusion criteria. The methodological index for nonrandomized studies (MINORS) was used to assess the quality of the included studies. Meta-analysis was conducted to compare the type of reconstruction and location of the defect.

RESULTS

Seventy-eight studies, involving 2461 patients, were eligible. 83.7% of the included patient received primary reconstruction with vascularized fibular flap. The overall flap success rate was 93%. There was improvement in MINORS quality score over time with positive correlation with the publication year (r = 0.5549, P < 0.0001, CI 0.3693 to 0.6979). Meta-analysis indicated no significant association in flap success between primary and secondary reconstruction, or lateral and antero-lateral defects.

CONCLUSION

Based on the available studies, this review found no evidence of difference in success or complication rates between primary and secondary reconstruction or between lateral and anterolateral defects. High-quality clinical studies are required to analyze the outcome of these techniques, especially regarding the impact of chemotherapy, radiation therapy, implant-supported dental prostheses, and preoperative planning, on the outcome of reconstruction.

Current insights on use of growth factors as therapy for Intervertebral Disc Degeneration

Chronic low back pain is a critical health problem and a leading cause of disability in aging populations. A major cause of low back pain is considered to be the degeneration of the intervertebral disc (IVD). Recent advances in therapeutics, particularly cell and tissue engineering, offer potential methods for inhibiting or reversing IVD degeneration, which have previously been impossible. The use of growth factors is under serious consideration as a potential therapy to enhance IVD tissue regeneration. We reviewed the role of chosen prototypical growth factors and growth factor combinations that have the capacity to improve IVD restoration. A number of growth factors have demonstrated potential to modulate the anabolic and anticatabolic effects in both in vitro and animal studies of IVD tissue engineering. Members of the transforming growth factor-β superfamily, IGF-1, GDF-5, BMP-2, BMP-7, and platelet-derived growth factor have all been investigated as possible therapeutic options for IVD regeneration. The role of growth factors in IVD tissue engineering appears promising; however, further extensive research is needed at both basic science and clinical levels before its application is appropriate for clinical use.

Removal of matrix-bound zoledronate prevents post-extraction osteonecrosis of the jaw by rescuing osteoclast function

Unlike other antiresorptive medications, bisphosphonate molecules accumulate in the bone matrix. Previous studies of side-effects of anti-resorptive treatment focused mainly on systemic effects. We hypothesize that matrix-bound bisphosphonate molecules contribute to the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this study, we examined the effect of matrix-bound bisphosphonates on osteoclast differentiation in vitro using TRAP staining and resorption assay, with and without pretreatment with EDTA. We also tested the effect of zoledronate chelation on the healing of post-extraction defect in rats. Our results confirmed that bisphosphonates bind to, and can be chelated from, mineralized matrix in vitro in a dose-dependent manner. Matrix-bound bisphosphonates impaired the differentiation of osteoclasts, evidenced by TRAP activity and resorption assay. Zoledronate-treated rats that underwent bilateral dental extraction with unilateral EDTA treatment showed significant improvement in mucosal healing and micro-CT analysis on the chelated sides. The results suggest that matrix-bound bisphosphonates are accessible to osteoclasts and chelating agents and contribute to the pathogenesis of BRONJ. The use of topical chelating agents is a promising strategy for the prevention of BRONJ following dental procedures in bisphosphonate-treated patients.

Chronic Remote Ischemic Conditioning Is Cerebroprotective and Induces Vascular Remodeling in a VCID Model

Vascular contributions to cognitive impairment and dementia (VCID) make up 50% of the cases of dementia. The purpose of this study was to determine the effect of chronic remote ischemic conditioning (C-RIC) on improving long-term (6 months) outcomes and cerebral blood flow (CBF) and collateral formation in a mouse model of VCID. Adult C57BL/6J male mice (10 weeks) were randomly assigned to four different groups: (1) sham-bilateral carotid artery stenosis (BCAS), (2) BCAS + sham RIC, (3) BCAS+C-RIC for 1 month (1MO), and (4) BCAS+C-RIC-4 months (4MO). CBF, cognitive impairment, and functional outcomes were performed up for 6 months after BCAS surgery. The expression of CD31, α-SMA, and myelin basic protein (MBP) was assessed by immunohistochemistry (IHC). Additional set of mice were randomized to sham, BCAS, and BCAS+C-RIC. The cerebrovascular angioarchitecture was studied with micro-CT. RIC therapy for either 1 or 4 months significantly improved CBF, new collateral formation, functional and cognitive outcomes, and prevented white matter damage. There was no difference between C-RIC for 1 or 4 months; IHC studies at 6 months showed an increase in brain CD31 and α-SMA expression indicating increased angiogenesis and MBP indicating preservation of white matter in animals receiving RIC. One month of daily RIC is as effective as 4 months of daily RIC in improving CBF, angiogenesis, and long-term functional outcomes (6 months) in a VCID model. This suggests that 1 month of RIC is sufficient to reduce cognitive impairment and induce beneficial cerebrovascular remodeling.