A meta-analysis and review on the effectiveness and safety of renal denervation in managing heart failure with reduced ejection fraction.

OBJECTIVE: This study aimed to systematically evaluate the effectiveness and safety of renal denervation (RDN) in managing heart failure with reduced ejection fraction (HFrEF). METHODS: A comprehensive search was done in multiple databases: Cochrane Library, PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database for Chinese Technical Periodicals. All clinical trials investigating RDN treatment for HFrEF through 15 March 2024 were gathered. The quality of the included studies was evaluated utilizing the Cochrane risk assessment tool. The pertinent data were gathered, and a meta-analysis was done using Review Manager 5.3, accompanied by sensitivity and publication bias analyses. RESULTS: After applying the inclusion and exclusion criteria, eight randomized controlled trials (RCTs) were selected for analysis, encompassing 314 patients; 154 patients underwent RDN treatment during hospitalization, while 150 were randomized to the control group to receive medication therapy. The meta-analysis demonstrated that compared to medication therapy, RDN contributed to a 9.59% increase in left ventricular ejection fraction (LVEF) (95% CI: 7.92-11.27, Z = 11.20, p < 0.01); a decrease in brain natriuretic peptide (BNP) (95% CI: -364.19--191.75, Z = 6.32, p < 0.01); a decrease in N-terminal pro B-type natriuretic peptide (NT-proBNP) (95% CI: -1300.15--280.95, Z = 3.04, p < 0.01); a decrease in the New York Heart Association (NYHA) classification (95% CI: -1.58--0.34, Z = 3.05, p < 0.01); a 90.00-m increase in 6-min walk test (6MWT) (95% CI: 68.24-111.76, Z = 8.11, p < 0.01); a reduction of 4.05 mm in left ventricular end-diastolic diameter (LVEDD) (95% CI: -5.65--2.48, Z = 5.05, p < 0.01); a decrease of 4.60 heart beats·min-1 (95% CI: -8.83--0.38, Z = 2.14, p < 0.05); and a 4.67-mm reduction in left atrial diameter (LAD) (95% CI: -6.40--2.93, Z = 5.27, p < 0.01). Left ventricular end-systolic diameter (LVESD) and systolic/diastolic blood pressure (OSBP/ODBP) were similar between groups (p > 0.01). As the safety indicator, estimated glomerular filtration rate (eGFR) improved by 7.11 in the RDN group [ml/(min·1.73 m2)] (95% CI: 1.10-13.12, Z = 2.32, p < 0.05). LVEF, BNP, 6MWT, LVEDD, LAD and eGFR were meta-analyzed using a fixed-effects model, the other indicators a random-effects model. CONCLUSION: RDN significantly ameliorated cardiac function in HFrEF patients while exhibiting commendable safety.

The Total Denervation of the Ischemic Kidney Induces Differential Responses in Sodium Transporters' Expression in the Contralateral Kidney in Goldblatt Rats.

The Goldblatt model of hypertension (2K-1C) in rats is characterized by renal sympathetic nerve activity (rSNA). We investigated the effects of unilateral renal denervation of the clipped kidney (DNX) on sodium transporters of the unclipped kidneys and the cardiovascular, autonomic, and renal functions in 2K-1C and control (CTR) rats. The mean arterial pressure (MAP) and rSNA were evaluated in experimental groups. Kidney function and NHE3, NCC, ENaCß, and ENaCγ protein expressions were assessed. The glomerular filtration rate (GRF) and renal plasma flow were not changed by DNX, but the urinary (CTR: 0.0042 ± 0.001; 2K-1C: 0.014 ± 0.003; DNX: 0.005 ± 0.0013 mL/min/g renal tissue) and filtration fractions (CTR: 0.29 ± 0.02; 2K-1C: 0.51 ± 0.06; DNX: 0.28 ± 0.04 mL/min/g renal tissue) were normalized. The Na+/H+ exchanger (NHE3) was reduced in 2K-1C, and DNX normalized NHE3 (CTR: 100 ± 6; 2K-1C: 44 ± 14, DNX: 84 ± 13%). Conversely, the Na+/Cl- cotransporter (NCC) was increased in 2K-1C and was reduced by DNX (CTR: 94 ± 6; 2K-1C: 144 ± 8; DNX: 60 ± 15%). In conclusion, DNX in Goldblatt rats reduced blood pressure and proteinuria independently of GRF with a distinct regulation of NHE3 and NCC in unclipped kidneys.

[Construction of a predictive model for postoperative pain relief after microscopic spermatic cord surgery for spermatic cord pain].

OBJECTIVE: To explore the relevant factors affecting the efficacy of microscopic spermatic cord surgery and build a predictive model for postoperative pain relief. METHODS: A retrospective analysis was conducted on the clinical data of 324 patients with spermatic cord pain who visited the Department of Urology at Peking University People's Hospital between October 2015 and April 2023. This cohort included 212 patients with varicocele-related spermatic cord pain and 112 patients with idiopathic spermatic cord pain. All the patients underwent microsurgical procedures: varicocele-related pain was treated with microsurgical varicocelectomy, and idiopathic pain was treated with microsurgical denervation of the spermatic cord. The patients were categorized into effective and ineffective groups based on whether their pain had decreased by more than 50% six months post-surgery compared with pre-surgery levels. Baseline data were preliminarily screened for clinical indicators using t tests and univariate analysis. Clinical predictor variables [age, duration of pain, diameter of varicocele, patient health questionnaire-9 (PHQ-9) score, generalized anxiety disorder-7 (GAD-7) score] were selected using Lasso regression. A clinical prediction model for effective pain relief following microscopic spermatic cord surgery was constructed using Logistic regression and presented as a nomogram. The model's internal validation was performed using the bootstrap method. Its predictive power and clinical utility were evaluated through the concor-dance index, the area under the receiver operating characteristic curve, and calibration plots. RESULTS: Post-microscopic varicocele ligation, 156 patients (73.58%) experienced significant pain relief, as did 94 patients (83.93%) following microscopic denervation. Independent predictors for postoperative outcomes included age, PHQ-9 score, GAD-7 score, chronic pain duration, and varicocele diameter, differing slightly between varicocele-related and idiopathic pain groups. The models demonstrated excellent predictive ability, with areas under the curve of 0.909 and 0.913 for varicocele and idiopathic groups, respectively, and high concordance indices. CONCLUSION: The postoperative efficacy prediction model based on age, pain duration, PHQ-9 score, GAD-7 score, and varicocele diameter has good predictive ability and clinical applicability, and can be used in clinical practice.

Effectiveness and cost-effectiveness of radiofrequency denervation versus placebo for chronic and moderate to severe low back pain: study protocol for the RADICAL randomised controlled trial.

INTRODUCTION: Low back pain (LBP) is the leading global cause of disability. Patients with moderate to severe LBP who respond positively to a diagnostic medial nerve branch block can be offered radiofrequency denervation (RFD). However, high-quality evidence on the effectiveness of RFD is lacking. METHODS AND ANALYSIS: RADICAL (RADIofrequenCy denervAtion for Low back pain) is a double-blind, parallel-group, superiority randomised controlled trial. A total of 250 adults listed for RFD will be recruited from approximately 20 National Health Service (NHS) pain and spinal clinics. Recruitment processes will be optimised through qualitative research during a 12-month internal pilot phase. Participants will be randomised in theatre using a 1:1 allocation ratio to RFD or placebo. RFD technique will follow best practice guidelines developed for the trial. Placebo RFD will follow the same protocol, but the electrode tip temperature will not be raised. Participants who do not experience a clinically meaningful improvement in pain 3 months after randomisation will be offered the alternative intervention to the one provided at the outset without disclosing the original allocation. The primary clinical outcome will be pain severity, measured using a pain Numeric Rating Scale, at 3 months after randomisation. Secondary outcomes will be assessed up to 2 years after randomisation and include disability, health-related quality of life, psychological distress, time to pain recovery, satisfaction, adverse events, work outcomes and healthcare utilisation. The primary statistical analyses will be by intention to treat and will follow a prespecified analysis plan. The primary economic evaluation will take an NHS and social services perspective and estimate the discounted cost per quality-adjusted life-year and incremental net benefit of RFD over the 2-year follow-up period. ETHICS AND DISSEMINATION: Ethics approval was obtained from the London-Fulham Research Ethics Committee (21/LO/0471). Results will be disseminated in open-access publications and plain language summaries. TRIAL REGISTRATION NUMBER: ISRCTN16473239.

Does Patellar Denervation with Electrocautery Benefits for Total Knee Arthroplasty without Patellar Resurfacing: A Meta-analysis of Randomized Controlled Trails.

To investigate the effects of patellar denervation (PD) and non-patellar denervation (NPD) after primary total knee arthroplasty (TKA) without patellar resurfacing, this study conducted systematic electronic searches in November 2023 using PubMed, Embase, Web of Science, Cochrane, and Scopus, adhering to Cochrane Collaboration recommendations. Only randomized controlled trials (RCTs) were included. Additionally, a manual search was performed to identify potentially eligible studies from the reference lists of review articles. Two researchers independently conducted literature reviews, data extraction, and risk of bias assessments. The outcome analysis encompassed the incidence of anterior knee pain (AKP), visual analogue scale (VAS), range of motion (ROM), American Knee Society Score (KSS), Oxford Knee Score (OKS), patellar score (PS), complications, and reoperations. Meta-analysis was executed using RevMan 5.3 software. To enhance the credibility of the study, TSA v0.9 software was utilized to perform power analysis on the overall efficacy of primary and secondary outcomes. Twelve studies involving 1745 patients (1587 knees) were included, with 852 undergoing PD and 893 undergoing NPD. Results indicated a superior reduction in AKP incidence in the PD group compared to the NPD group. Statistically significant differences were observed between PD and NPD in KSS, OKS, and PS. However, the upper limit of the 95% confidence interval for each outcome fell below the minimal clinically important difference (MCID). No significant differences were found in VAS and ROM between PD and NPD. Additionally, PD was not associated with an increased incidence of complications or reoperations. Within 12 months and beyond, PD was proven to be a beneficial intervention in reducing AKP following TKA without patellar resurfacing, achieved without an increase in complications or reoperations. Regarding KSS, OKS, and PS, the minimal advantage achievable through PD may not be clinically significant.

Renal Denervation Ameliorates Cardiomyocyte Apoptosis in Myocardial Ischemia-Reperfusion Injury Through Regulating Mitochondria-Endoplasmic Reticulum Contact.

BACKGROUND: Myocardial ischemia-reperfusion injury (I/R) has been improved with drugs and effective reperfusion, but it still cannot be prevented. METHODS: To investigate whether renal denervation (RDN) reduces cardiomyocyte apoptosis by ameliorating endoplasmic reticulum stress, 60 male specific pathogen-free (SPF) Wistar rats were randomly divided into 6 groups (n = 6). We established the I/R rat model by ligating the left anterior descending artery. The I/R+ angiotensin receptor neprilysin inhibitors (ARNI) group received ARNIs for 2 weeks until euthanasia. RESULTS: The I/R+RDN and I/R+ARNI groups have significantly ameliorated left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) and reversed expansion of the left ventricular end-systolic diameter (LVSD) and left ventricular end diastolic diameter (LVDD) compared to the I/R group. The levels of norepinephrine (NE), angiotensin II, and aldosterone (ALD) increased significantly in the I/R group, but decreased significantly after RDN and ARNI intervention. In the I/R+RDN and I/R+ARNI groups, the myocardial tissue edema was alleviated. The infarct size was smaller in the I/R+RDN and I/R+ARNI groups compared to the I/R group. Apoptosis of cardiomyocytes and fibroblasts in myocardial tissue increased significantly in the I/R group, which was greatly diminished by RDN and ARNI. The expression of Bax, caspase-3, CHOP, PERK, and ATF4 protein was significantly increased in the I/R group, which compared to other groups, and the level of CHOP, PERK, and ATF4 gene expression increased. After RDN intervention, these expression levels recovered to varying degrees. CONCLUSION: The effect of RDN may be associated with regulating the endoplasmic reticulum stress PERK/ATF4 signaling pathway.

Effect of repeated sciatic nerve crush on the conditioning lesion response: Generating an experimental animal model to prolong the denervation period while maintaining peripheral nerve continuity.

Peripheral nerves exhibit long-term residual motor dysfunction following injury. The length of the denervation period before nerve and muscle reconnection is an important factor in motor function recovery. We aimed to investigate whether repeated nerve crush injuries to the same site every 7 days would preserve the conditioning lesion (CL) response and to determine the number of nerve crush injuries required to create an experimental animal model that would prolong the denervation period while maintaining peripheral nerve continuity. Rats were grouped according to the number of sciatic nerve crushes. A significant decrease in the soleus muscle fiber cross-sectional area was observed with increased crushes. After a single crush, macrophage accumulation and macrophage chemotaxis factor CCL2 expression in dorsal root ganglia were markedly increased, which aligned with the gene expression of Ccl2 and its receptor Ccr2. Macrophage numbers, histological CCL2 expression, and Ccl2 and Ccr2 gene expression levels decreased, depending on the number of repeated crushes. Histological analysis and gene expression analysis in the group with four repeated crushes did not differ significantly when compared with uninjured animals. Our findings indicated that repeated nerve crushes at the same site every 7 days sustained innervation loss and caused a loss of the CL response. The experimental model did not require nerve stump suturing and is useful for exploring factors causing prolonged denervation-induced motor dysfunction. SIGNIFICANCE STATEMENT: This study elucidates the effects of repeated nerve crush injury to the same site on innervation and conditioning lesion responses and demonstrates the utility of an experimental animal model that recapitulates the persistent residual motor deficits owing to prolonged denervation without requiring nerve transection and transection suturing.

Patient reported and functional outcome measures after surgical salvage procedures for posttraumatic radiocarpal osteoarthritis - a systematic review.

BACKGROUND: Posttraumatic wrist osteoarthritis is an irreversible and often progressive condition. Many surgical treatments, used in (daily) practice, aim to relieve symptoms like pain and restore function. The aim of this systematic review is to assess the patient reported and functional outcomes of the most common surgical interventions in patients with posttraumatic wrist osteoarthritis. This overview can help clinicians select the best treatment and manage patient's expectations. METHODS: A literature search was performed in Pubmed, Embase and Cochrane for articles published between 1990 and November 2022 according to the PRISMA guidelines. The study protocol has been registered in the PROSPERO database (CRD42017080427). Studies that describe patient reported outcomes (pain and Disability of Arm, Shoulder and Hand (DASH) -score) and functional outcomes (range of motion (ROM) and grip strength) after surgical intervention with a minimal follow-up of 1 year were included. The identified surgical procedures included denervation, proximal row carpectomy, interpositional- and total arthroplasty, and midcarpal-, radiocarpal- and total arthrodesis. The pre-and postoperative outcomes were pooled and presented per salvage procedure. RESULTS: Data from 50 studies was included. Pain score improved after all surgeries except denervation. Flexion/extension decreased after radiocarpal arthrodesis, did not show significant changes after proximal row carpectomy, and improved for all other surgeries. DASH score improved after arthroplasty, proximal row carpectomy and midcarpal arthrodesis. Grip strength improved after interposition arthroplasty and partial arthrodesis. CONCLUSION: Evidence from this review did not support the indication for denervation in this particular patient population. In patients with SLAC/SNAC II, proximal row carpectomy might be favourable to a midcarpal arthrodesis solely based on better FE ROM of the radiocarpal joint after proximal row carpectomy. In terms of radiocarpal mobility, total wrist arthroplasty might be preferred to radiocarpal arthrodesis in patients with osteoarthritis after a distal radius fracture. More uniform measurements of outcomes would improve the understanding of the effect of surgical treatments of the posttraumatic osteoarthritic wrist.

Anatomical study of the motor branches of the tibial nerve and incision design for hyperselective neurectomy.

PURPOSE: Selective tibial neurotomy (STN) is a surgical procedure for treating spastic equinovarus foot. Hyperselective neurectomy (HSN) of tibial nerve is a modified STN procedure, which was rarely discussed. This study aimed to describe the branching patterns of the tibial nerve and propose an optimal surgical incision of HSN for treatment of spastic equinovarus foot. METHODS: Sixteen lower limbs were dissected to determine the various branching patterns of the tibial nerve and categorized according to these branching patterns. The mean distances from the nerve entry points to the tip of femur's medial epicondyle were measured, as well as their percentage to the overall length of the leg. The surgical incision was designed according to the range of these nerve entry points. RESULTS: The tibial nerve sent out proximal and distal motor branches based on their position relative to the soleus muscle's tendinous arch. For proximal motor branches, the branches innervating the medial gastrocnemius, lateral gastrocnemius and proximal soleus were categorized into types I (9/16), II (5/16) and III (2/16). Measurements from the medial epicondyle to the nerve entry points into the medial gastrocnemius, lateral gastrocnemius and proximal soleus ranged from 14 to 33 mm (4-9% of leg length), 22-45 mm (6-12%) and 35-81 mm (10-22%), respectively. Distal motor branches including the distal soleus, posterior tibialis, flexor digitorum longus and flexor hallucis longus, were classified as types A (8/14), B (4/14) and C (2/14), with the distances from their respective terminal points to the medial epicondyle were 67-137 mm (19-39%), 74-125 mm (20-35%), 116-243 mm (33-69%) and 125-272 mm (35-77%). CONCLUSIONS: The motor branches of tibial nerve were classified into two groups and each subdivided into three types. Detailed location parameters may serve as an anatomical basis for designing incision of HSN.

Identification of compounds that cause axonal dieback without cytotoxicity in dorsal root ganglia explants and intervertebral disc cells with potential to treat pain via denervation.

Low back pain, knee osteoarthritis, and cancer patients suffer from chronic pain. Aberrant nerve growth into intervertebral disc, knee, and tumors, are common pathologies that lead to these chronic pain conditions. Axonal dieback induced by capsaicin (Caps) denervation has been FDA-approved to treat painful neuropathies and knee osteoarthritis but with short-term efficacy and discomfort. Herein, we propose to evaluate pyridoxine (Pyr), vincristine sulfate (Vcr) and ionomycin (Imy) as axonal dieback compounds for denervation with potential to alleviate pain. Previous literature suggests Pyr, Vcr, and Imy can cause undesired axonal degeneration, but no previous work has evaluated axonal dieback and cytotoxicity on adult rat dorsal root ganglia (DRG) explants. Thus, we performed axonal dieback screening using adult rat DRG explants in vitro with Caps as a positive control and assessed cytotoxicity. Imy inhibited axonal outgrowth and slowed axonal dieback, while Pyr and Vcr at high concentrations produced significant reduction in axon length and robust axonal dieback within three days. DRGs treated with Caps, Vcr, or Imy had increased DRG cytotoxicity compared to matched controls, but overall cytotoxicity was minimal and at least 88% lower compared to lysed DRGs. Pyr did not lead to any DRG cytotoxicity. Further, neither Pyr nor Vcr triggered intervertebral disc cell death or affected cellular metabolic activity after three days of incubation in vitro. Overall, our findings suggest Pyr and Vcr are not toxic to DRGs and intervertebral disc cells, and there is potential for repurposing these compounds for axonal dieback compounds to cause local denervation and alleviate pain.

Long-term effect of posterior nasal neurectomy for perennial allergic rhinitis.

BACKGROUND: Surgical treatment is recommended for patients with severe allergic rhinitis (AR) refractory to medical treatment. Endoscopic posterior nasal neurectomy (PNN) is primarily performed to improve rhinorrhea in severe perennial AR, however studies on its long-term prognosis are lacking. AIMS/OBJECTIVES: This study aimed to investigate the long-term prognosis of PNN. MATERIALS AND METHODS: A questionnaire survey was administered to 17 patients (12 men and 5 women) at least 1 year after PNN. Nasal symptoms and medications, as well as patient satisfaction with surgery at the time of survey, were scored. Furthermore, scores were compared between patients with postoperative periods of >5 years and <5 years. RESULTS: Nasal symptoms and medication scores significantly improved after surgery. There was no significant difference between patients with a postoperative period of >5 years and <5 years in both preoperative and postoperative nasal symptoms and medication scores. No correlation was found between patient satisfaction with surgery and postoperative period. CONCLUSIONS AND SIGNIFICANCE: PNN improved nasal symptoms and medication scores in patients with severe perennial AR. Furthermore, the study results suggest that the long-term effect of PNN for perennial AR lasts for >5 years. J. Med. Invest. 71 : 62-65, February, 2024.

Renal denervation for uncontrolled hypertension: a systematic review and meta-analysis examining multiple subgroups.

This systematic review and meta-analysis was conducted to assess the randomized controlled trial (RCT) evidence available for renal denervation (RDN) in uncontrolled arterial hypertension. Twenty-five RCTs met the eligibility criteria for the systematic review, and 16 RCTs were included in the meta-analysis. The results of the random effects meta-analysis estimated a mean difference of -8.5 mmHg [95% confidence interval (CI) -13.5 to -3.6] for office SBP, -3.6 mmHg (95% CI -5.2 to -2.0) for 24 h SBP and -3.9 mmHg (95% CI -5.6 to -2.2) for ambulatory daytime SBP in favour of RDN compared with control (medication and/or sham-only) at primary follow-up. Similarly favourable results were observed across a range of prespecified subgroup analyses, including treatment-resistant hypertension. This meta-analysis suggests that the use of RDN in uncontrolled hypertension leads to consistent reductions in blood pressure. Reductions appear to be statistically consistent in the presence or absence of medications and in populations resistant to the use of three medications.

Renal denervation in the management of hypertension.

Arterial hypertension is a global leading cause of cardiovascular, cerebrovascular, and renal disease, as well as mortality. Although pharmacotherapy is safe and effective in lowering blood pressure (BP) and cardiovascular disease risk, BP control remains poor, and the mortality rates associated with high BP have been steadily increasing. Device-based therapies have been investigated to overcome barriers to pharmacotherapy, including non-adherence and low rates of persistence to daily medications. Among these device-based therapies, catheter-based renal denervation (RDN) has been most extensively examined over the past 15 years. In this state-of-the-art article, we summarise the rationale for RDN, review the available evidence, provide recommendations for a safe procedure, and discuss the role of RDN in current guidelines and clinical practice.

Dimorphic effect of TFE3 in determining mitochondrial and lysosomal content in muscle following denervation.

BACKGROUND: Muscle atrophy is a common consequence of the loss of innervation and is accompanied by mitochondrial dysfunction. Mitophagy is the adaptive process through which damaged mitochondria are removed via the lysosomes, which are regulated in part by the transcription factor TFE3. The role of lysosomes and TFE3 are poorly understood in muscle atrophy, and the effect of biological sex is widely underreported. METHODS: Wild-type (WT) mice, along with mice lacking TFE3 (KO), a transcriptional regulator of lysosomal and autophagy-related genes, were subjected to unilateral sciatic nerve denervation for up to 7 days, while the contralateral limb was sham-operated and served as an internal control. A subset of animals was treated with colchicine to capture mitophagy flux. RESULTS: WT females exhibited elevated oxygen consumption rates during active respiratory states compared to males, however this was blunted in the absence of TFE3. Females exhibited higher mitophagy flux rates and greater lysosomal content basally compared to males that was independent of TFE3 expression. Following denervation, female mice exhibited less muscle atrophy compared to male counterparts. Intriguingly, this sex-dependent muscle sparing was lost in the absence of TFE3. Denervation resulted in 45% and 27% losses of mitochondrial content in WT and KO males respectively, however females were completely protected against this decline. Decreases in mitochondrial function were more severe in WT females compared to males following denervation, as ROS emission was 2.4-fold higher. In response to denervation, LC3-II mitophagy flux was reduced by 44% in females, likely contributing to the maintenance of mitochondrial content and elevated ROS emission, however this response was dysregulated in the absence of TFE3. While both males and females exhibited increased lysosomal content following denervation, this response was augmented in females in a TFE3-dependent manner. CONCLUSIONS: Females have higher lysosomal content and mitophagy flux basally compared to males, likely contributing to the improved mitochondrial phenotype. Denervation-induced mitochondrial adaptations were sexually dimorphic, as females preferentially preserve content at the expense of function, while males display a tendency to maintain mitochondrial function. Our data illustrate that TFE3 is vital for the sex-dependent differences in mitochondrial function, and in determining the denervation-induced atrophy phenotype.

Reduced osseointegration in disuse and denervation rat models results from impaired cellular responses to multiscale microstructured titanium surfaces.

Immobilization-induced skeletal unloading results in muscle atrophy and rapid bone loss, thereby increasing the risk of falling and the need for implant therapy in patients with extended bed rest or neuromuscular injuries. Skeletal unloading causes bone loss by altering bone growth and resorption, suggesting that implant performance might be affected. To test this, we focused on early events in implant osseointegration. We used the rat sciatic neurectomy-induced disuse model under two different settings. In Study 1, 16 Sprague Dawley rats (SD) were separated into control, sham operated+cast immobilization, and sciatic neurectomy+casting groups; titanium implants with multiscale microtextured topography and hydrophilic chemistry (modSLA) were inserted in the distal femoral metaphysis. Neurectomy surgeries and casting were performed at the same surgical setting as implant placement; rats were euthanized 4 weeks post-implantation. In Study 2, we established the unloaded condition before implantation. A total of 12 SD rats were divided into control and sciatic+femoral neurectomy groups. A total of 24 days after sciatic and femoral neurectomy surgery, rats received implants. Study 2 rats were euthanized at 4 weeks post-implantation. MicroCT and histomorphometry showed that trabecular bone and osseointegration were reduced when disuse was established before implantation. Osteoblasts isolated from Study 1 sciatic neurectomy tibial bones exhibited impaired differentiation on modSLA culture disks, revealing a possible mechanism responsible for the decreased osseointegration observed in the Study 2 rats. This study addressed the importance of considering the mechanical unloading and muscle function history before implant insertion and suggests that implant performance was reduced due to poor cellular ability to regenerate.

Lesión electromiográfica del nervio axilar en fracturas del extremo proximal del húmero. Estudio prospectivo, observacional, analizando el patrón de fractura / Electromyographic axillary nerve injury in fractures of the proximal humerus: Prospective, observational study, analysing the fracture pattern

Objetivo: Descripción y análisis de la relación entre las fracturas de húmero proximal y la lesión traumática del nervio axilar circunflejo. Material y método: Estudio prospectivo, observacional, de una serie de casos consecutivos de fracturas de extremo proximal de húmero. Se realizó valoración radiográfica, clasificando las fracturas según el sistema AO (Arbeitsgemeinshaft für Osteosynsthesefragen, Asociación de Grupo de Trabajo para el Estudio de la Fijación Interna de las Fracturas), y electromiografía (EMG) para la evaluación de la lesión del nervio axilar. Resultados: De 105 casos consecutivos de fracturas de húmero proximal, 31 pacientes cumplían los criterios de inclusión. Muestra: 86% mujeres y 14% hombres con edad media de 71,8 años (30-96 años). De los pacientes incluidos en el estudio, 58% presentó una EMG normal o leve axonotmesis, 23% presentó neuropatía del nervio axilar sin denervación muscular y 19%, lesión con denervación del nervio axilar. Los pacientes que sufrieron fracturas complejas de húmero proximal (AO11B y AO11C) tuvieron más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG, siendo esta relación estadísticamente significativa (p < 0,001). Conclusiones: Los pacientes que sufren fracturas complejas de húmero proximal (AO11B y AO11C) tienen más riesgo de presentar lesiones tipo neuropatía axilar con denervación muscular en la EMG (p < 0,001).(AU)

Objective: Description and analysis of the relation between the proximal humerus fracture patterns and the traumatic injury of the axillary nerve. Material and method: Prospective, observational study of a consecutive case series that analyzed proximal humerus fractures. Radiographic evaluation was performed, and AO (Arbeitsgemeinshaft für Osteosynsthesefragen) system was used to classify the fractures. Electromyography was used to diagnose the axillary nerve injury. Results: Thirty-one patients on 105 who had a proximal humerus fracture met inclusion criteria. Eighty-six percent of the patients included were women and 14% men. The mean age was 71.8 years (30–96 years). Of the patients included in the study, 58% had normal or mild axonotmesis EMG, 23% had axillary nerve neuropathy without muscle denervation and 19% had injury with axillary nerve denervation. Patients who suffered complex fractures of the proximal humerus (AO11B and AO11C) had a higher risk of presenting axillary neuropathy type lesions with muscle denervation in the EMG, this relationship being statistically significant (p<0.001). Conclusion: Patients who have more risk on presenting axillary nerve neuropathy with muscle denervation in electromyography are those who present complex proximal humerus fractures AO11B and AO11C (p<0.001).(AU)