Addressing metallosis in knee arthroplasty:From diagnostic challenges to innovative treatments

In this editorial,we comment on the article by Toro et al published in the recent issue of World Journal of Orthopedics.This editorial review provides a comprehensive exploration of the landscape surrounding knee arthroplasty metallosis,focusing on key aspects ranging from the mechanisms influencing susceptibility to clinical implications and advanced treatment strategies.We elucidate the complex interplay of implant design,patient-specific variables,and wear-related processes contributing to metallosis.Furthermore,we seek to shed light on diagnostic challenges,the necessity of a multidisciplinary approach,and the imperative for vigilant implant surveillance.Uni-on-uni revision,as a targeted treatment modality,is discussed,highlighting its potential to address metallosis in unicompartmental knee arthroplasty(UKA).There is a need for heightened awareness among clinicians regarding the subtle presentations of metallosis,coupled with the limitations of traditional imaging techniques.Addressing metallosis requires a collaborative,multidisciplinary approach to effectively navigate the complexities associated with this complication.Furthermore,the review emphasizes the evolving paradigm of personalized care,with uni-on-uni revision emerging as a promising surgical solution.In conclusion,the editorial outlines the dynamic nature of knee arthroplasty metallosis and its multifaceted impact on clinical practice.It calls for ongoing collaboration,education,and integration of innovative solutions to enhance diagnostic accuracy,proactive management,and overall patient outcomes in the realm of UKA.

Role of infrapatellar fat pad in pathological process of knee osteoarthritis: Future applications in treatment

It has been found that obese people have a higher proportion in suffering from osteoarthritis (OA),not only in the weight-bearing joints like knee and hip joints,even in non-weight-bearing joints such as hand joints.One of the reasons is because the large amount of adipose tissue secretes some factors,which can promote the occurrence of arthritis.As an important structure of the knee joint,the infrapatellar fat pad (IPFP) is actually a piece of adipose tissue.The aim of this review is to offer a comprehensive view of the anatomy and physiological characteristics of IPFP and its relationship with the pathological process of OA,indicating the important function of IPFP in OA.At the same time,with the development of adipose derived stem cells in the treatment of OA,owing to its special advantages,the IPFP is becoming a kind of important,minimally invasive fat stem cell source,providing a new approach for the treatment of OA.We hope that this review will offer an overview of all published data regarding the IPFP and will indicate novel directions for future research.

Effects of Bushen Huoxue Decoction on Nitric Oxide (NO) in Serum,Articular Cartilage and Synovium in Rabbits of Knee Osteoarthritis

Forty-eight New Zealand rabbits were divided into normal group (n=18), control group (n=18) and Chinese herbs treatment group (n=12) randomly. The rabbits in the normal group received sham-operation, and the OA model was established by Hulth's method. All the rabbits in the treatment group were given Bushen Huoxue Decoction (补肾活血汤) from the 6th week after the operation. At 6th, 8th and 12th week after the operation, the NO concentrations of the serum, joint cartilage and synovium were examined. Results: Indicated that the NO concentrations of the serum,joint cartilage and synovium in the control group were all significantly higher than those in the normal group, with the joint cartilage more obvious (P<0.05). In the Chinese herbs treatment group the NO concentrations in all the parts obviously decreased as compared with the control group (P<0.05). It is suggested that Bushen Huoxue Decoction decrease the levels of NO in the serum, synovium and joint cartilage in the OA rabbit.

Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve

Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, hut cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhe-sion stage. Moreover, seeded cells were distributed throughout the material.

Enriched environment upregulates growth-associated protein 43 expression in the hippocampus and enhances cognitive abilities in prenatally stressed rat offspring

In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we investigated the effects of enriched environment on cognitive abilities in prenatally stressed rat offspring, as well as the underlying mechanisms. Reverse transcription-PCR and western blot assay results revealed that growth-associated protein 43 mRNA and protein levels were upregulated on postnatal day 15 in the prenatal restraint stress group. Growth-associated protein 43 expression was significantly lower in the prenatal restraint stress group compared with the negative control and prenatal restraint stress plus enriched environment groups on postnatal days 30 and 50. Morris water maze test demonstrated that cognitive abilities were noticeably increased in rats from the prenatal restraint stress plus enriched environment group on postnatal day 50. These results indicate that enriched environment can improve the spatial learning and memory ability of prenatally stressed offspring by upregulating growth-associated protein 43 expression.

Cortical bone trajectory screws in the treatment of lumbar degenerative disc disease in patients with osteoporosis

Lumbar degenerative disc disease(DDD)in the elderly population remains a global health problem,especially in patients with osteoporosis.Osteoporosis in the elderly can cause failure of internal fixation.Cortical bone trajectory(CBT)is an effective,safe and minimally invasive technique for the treatment of lumbar DDD in patients with osteoporosis.In this review,we analyzed the anatomy,biomechanics,and advantages of the CBT technique in lumbar DDD and revision surgery.Additionally,the clinical trials and case reports,indications,advancements and limitations of this technique were further discussed and reviewed.Finally,we concluded that the CBT technique can be a practical,effective and safe alternative to traditional pedicle screw fixation,especially in DDD patients with osteoporosis.

Season of the year influences infection rates following total hip arthroplasty

AIM To research the influence of season of the year on periprosthetic joint infections.METHODS We conducted a retrospective review of the entire Medicare files from 2005 to 2014. Seasons were classified as spring, summer, fall or winter. Regional variations were accounted for by dividing patients into four geographic regions as per the United States Census Bureau(Northeast, Midwest, West and South). Acute postoperative infection and deep periprosthetic infections within 90 d after surgery were tracked. RESULTS In all regions, winter had the highest incidence of periprosthetic infections(mean 0.98%, SD 0.1%) and was significantly higher than other seasons in the Midwest, South and West(P < 0.05 for all) but not the Northeast(P = 0.358). Acute postoperative infection rates were more frequent in the summer and were significantly affected by season of the year in the West.CONCLUSION Season of the year is a risk factor for periprosthetic joint infection following total hip arthroplasty(THA). Understanding the influence of season on outcomes following THA is essential when risk-stratifying patients to optimize outcomes and reduce episode of care costs.

In vitro effects of sodium hyaluronate on the proliferation and the apoptosis in chondrocytes from patients with Kashin-Beck disease and osteoarthritis

Objective：To identify the in vitro effects of sodium hyaluronate（HA） on the proliferation and the apoptosis of chondrocytes from patients with Kashin-Beck disease（KBD） and osteoarthritis（OA）. Methods：Samples of articular cartilages from KBD and OA patients, as well as healthy volunteers（6 subjects in each of the 3 groups） were dissected, digested with collagenase and the cells cultured in monolayers. Chondrocytes from each sample were assigned to an untreated group and two HA-treated groups： H0（no HA）, H100（HA, 0.1 g/L） and H500（HA, 0.5 g/L）. The first passage chondrocytes were used to observe proliferation using the MTT assay, and apoptosis by flow cytometry through Annexin V/PI staining. Results：HA promoted proliferation of chondrocytes in all the three groups, and.in KBD and OA groups, for cells cultured for 4 and 6 days, H500 significantly promoted the cell proliferation. The apoptotic rates of both KBD and OA group chondrocytes were in the order H500 〈 HA100 〈 H0. Conclusion：Sodium hyaluronate administration has a dosedependent in vitro effect to promote proliferation and inhibit apoptosis of chondrocytes from patients with KBD and OA.

Hybrid External Fixation for Open Severe Comminuted Fractures of the Distal Femur

Background: The treatment of distal femoral open comminuted fractures is a major problem for orthopedic surgeon. The basic and important aim in treatment of these fractures is to assemble the condylar fragments and then fix the condyles to the femoral shaft by minimum handling of the bone and soft tissues. Objectives: To evaluate the treatment of distal femoral open comminuted fractures (type C2 and C3) with hybrid external fixator. Methods: Thirty-four patients with distal femur open comminuted fracture (type C2 and C3) were treated by hybrid external fixator between January 2005 and December 2008. All of the fractures were opened with extension to joint surface. 30 patients were male and 4 were female. Their average age was 30.5 years (17 to 72 years). Average follow up period was 36 months. 12 patients had isolated fracture and 22 patients had multiple fractures. The bony and functional results were evaluated by the association for the study and application of the method of Ilizarov (ASAMI) protocol and knee society score. Results: 29 out of 34 fractures (85%) had union without bone grafts. Average time of union was 6.1 months (4 - 19 ms). The average knee range of motion was 87.5 degrees (30 - 115 degrees). The bony results were excellent in 24 patients (70.5%), good in 6 (17.7%), fair in 2 (5.9%), and poor in 2 (5.9%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%) according to ASAMI protocol. According to the knee society score the functional results were excellent in 9 (26.44%) patients, good in 13 (38.26%), fair in 7 (20.6%), and poor in 5 (14.7%). Conclusion: Hybrid external fixator is an effective method for treatment of distal femoral open comminuted fractures (type C2 and C3) and may be considered as an alternative surgical methods in the management of these fractures.

Effects of Early Weightbearing on Microfracture Treatment of Osteochondral Lesions of Talus with Subchondral Bone Defects

When subchondral bone defects are present in osteochondral lesions of the talus(OCLT),it is inconclusive whether to allow early weightbearing after microfracture treatment because of the lack of effective support of the newly-formed fibrocartilage.After performing arthroscopic debridement and microfracture treatment on OCLT patients with subchondral bone defects,we allowed patients to have an early postoperative weightbearing exercise to observe their clinical outcome.Forty-two OCLT patients with subchondral bone defects were analyzed.Patients were randomly divided into two groups with 21 patients in each group.After arthroscopic debridement and microfracture treatment,group A was allowed to have early partial weightbearing while weightbearing was delayed in group B.Visual analogue scale(VAS)was used to evaluate joint pain before and after surgery.American Orthopaedic Foot and Ankle Society(AOFAS)anklc-hindfoot score was used to evaluate joint function.Tegner activity scale was used to assess patient's exercise level.The AOFAS ankle-hindfoot score in group A increased from 54.4 to 87.6,and that in group B increased from 54.9 to 87.3.The VAS score in group A decreased from 6.5 to 2.2,and that in group B decreased from 6.4 to 2.3.The Tegner activity scale increased from 2.6 to 4.4 in group A,and that in group B increased from 2.6 to 3.9.There was significant difference in the Tegner activity scale between group A and group B(P<0.05).It was suggested that when performing microfracture treatmenf on OCLT patients with subchondral bone defects,early postoperative weightbearing may achieve similar clinical outcomes as delayed weightbearing,and patients may be better able to return to sports.

Sacral chondroblastoma — a rare location, a rare pathology: A case report and review of literature

BACKGROUND Chondroblastoma(CB)is an intermediate tumor of cartilage origin.CB involving the sacrum is a very rare pathology.CASE SUMMARY A 17-year-old male with sacral CB was diagnosed as CB during the first surgery,and 18 mo later,the tumor recurred and a second surgery was performed with the same pathology result of CB.CONCLUSION We recommend complete removal of the tumor in a timely manner,provided that surgical conditions are met.At the same time,other diseases should be carefully differentiated in terms of imaging or pathological features so as to avoid erroneous diagnostic conclusions.

A Case Report of Oseoid Osteoma in the Ulnar Cortex of the Distarl Radius Extending into the Distal Radioulnal Joint<br>—COX-2 Produced Prostaglandin E2 Possible Case of the Symptoms<br>

An 18-year-old girl presented with an osteoid osteoma in the ulnar side of the cortex of the distal radius extending into the distal radioulnar joint. The osteoid osteoma was removed from the distal radius at surgery. The patient’s symptoms were dramatically improved the day after surgery. A high concentration of prostaglandin E2 (PGE2) was seen in the joint and surrounding soft tissues, and cyclooxygenase-2 (COX-2) receptors were stained in the joint capsule and synovium inside the joint. This case report is the first to describe the concentration of PGE2 and stained COX-2 receptors in an osteoid osteoma in the ulnar cortex of the distal radius extending into the distal radioulnar joint.

Luteolin affects the EMT transformation and cell biological behavior of osteosarcoma U2OS cells via the PI3K/AKT/NF-κB signaling pathway

Objective:To investigate the effect of luteolin on the Epithelial-mesenchymal transition(EMT)of osteosarcoma cell line U2OS and its molecular mechanism by regulating phosphoinositide 3-kinase/protein kinase B/nuclear factor-kappa B(PI3K/AKT/NF-κB)signaling pathway.Methods:U2OS cells were treated in different concentrations(10,20 and 40μmol/L)of luteolin.MTT was used to detect the effect of luteolin on the proliferation of osteosarcoma U2OS cells.Transwell chamber assay was used to detect the influence of luteolin on migration of U2OS cells.qPCR was used to detect the influence of luteolin on the mRNA expression of Bax,Bcl-2 and Caspase-2 in U2OS cells.Western blot was used to observe the change of p-PI3K,p-AKT,p-IKK and NF-κB proteins.Immunofluorescence was used to detect the influence of luteolin on the protein expression of E-cadherin and vimentim.Results:Luteolin inhibited significantly the proliferation of U2OS cells(P<0.05)in a time-concentration-dependent manner.Luteolin inhibited significantly the migration of U2OS cells(P<0.05).After treatment with luteolin,the mRNA expression of Bax and Caspase-2 was increased significantly(P<0.05),but Bcl-2 was reduced significantly(P<0.05)in U2OS cells.The protein expression of p-PI3K,p-AKT,p-IKK,NF-κB,E-cadherin and vimentin was decreased significantly(P<0.05).Conclusions:Luteolin inhibits the proliferation,migration and EMT transformation of osteosarcoma U2OS cells,which may be related to the inhibition of PI3K/AKT/NF-κB signaling pathway.

Enhancing Orthopedic Knowledge Assessments:The Performance of Specialized Generative Language Model Optimization

Objective This study aimed to evaluate and compare the effectiveness of knowledge base-optimized and unoptimized large language models(LLMs)in the field of orthopedics to explore optimization strategies for the application of LLMs in specific fields.Methods This research constructed a specialized knowledge base using clinical guidelines from the American Academy of Orthopaedic Surgeons(AAOS)and authoritative orthopedic publications.A total of 30 orthopedic-related questions covering aspects such as anatomical knowledge,disease diagnosis,fracture classification,treatment options,and surgical techniques were input into both the knowledge base-optimized and unoptimized versions of the GPT-4,ChatGLM,and Spark LLM,with their generated responses recorded.The overall quality,accuracy,and comprehensiveness of these responses were evaluated by 3 experienced orthopedic surgeons.Results Compared with their unoptimized LLMs,the optimized version of GPT-4 showed improvements of 15.3%in overall quality,12.5%in accuracy,and 12.8%in comprehensiveness;ChatGLM showed improvements of 24.8%,16.1%,and 19.6%,respectively;and Spark LLM showed improvements of 6.5%,14.5%,and 24.7%,respectively.Conclusion The optimization of knowledge bases significantly enhances the quality,accuracy,and comprehensiveness of the responses provided by the 3 models in the orthopedic field.Therefore,knowledge base optimization is an effective method for improving the performance of LLMs in specific fields.

Exogenous platelet-derived growth factor improves neurovascular unit recovery after spinal cord injury

The blood-spinal cord barrier plays a vital role in recovery after spinal cord injury.The neurovascular unit concept emphasizes the relationship between nerves and vessels in the brain,while the effect of the blood-spinal cord barrier on the neurovascular unit is rarely reported in spinal cord injury studies.Mouse models of spinal cord injury were established by heavy object impact and then immediately injected with plateletderived growth factor(80μg/kg)at the injury site.Our results showed that after platelet-derived growth factor administration,spinal cord injury,neuronal apoptosis,and blood-spinal cord barrier permeability were reduced,excessive astrocyte proliferation and the autophagyrelated apoptosis signaling pathway were inhibited,collagen synthesis was increased,and mouse locomotor function was improved.In vitro,human umbilical vein endothelial cells were established by exposure to 200μM H2O2.At 2 hours prior to injury,in vitro cell models were treated with 5 ng/mL platelet-derived growth factor.Our results showed that expression of blood-spinal cord barrier-related proteins,including Occludin,Claudin 5,andβ-catenin,was significantly decreased and autophagy was significantly reduced.Additionally,the protective effects of platelet-derived growth factor could be reversed by intraperitoneal injection of 80 mg/kg chloroquine,an autophagy inhibitor,for 3 successive days prior to spinal cord injury.Our findings suggest that platelet-derived growth factor can promote endothelial cell repair by regulating autophagy,improve the function of the blood-spinal cord barrier,and promote the recovery of locomotor function post-spinal cord injury.Approval for animal experiments was obtained from the Animal Ethics Committee,Wenzhou Medical University,China(approval No.wydw2018-0043)in July 2018.

Association between Physical Activity and Telomere Length in a North Chinese Population： A China Suboptimal Health Cohort Study

Several studies have demonstrated an association between physical activity and telomere length; however, the association remains inconsistent. A cross-sectional study consisting of 588 participants （375 females, median age of 33.8 years） was carried out to investigate the association between telomere length and physical activity in a general population from North China. The results show that relative telomere length is not significantly different in participants in the northern Chinese population with different levels of physical activity, either in the model only adjusted for age （F = 2.127, P = 0.120） or in the model adjusted for demographics and lifestyle （F = 1.227, P = 0.294）. The gender-stratified analysis also produced insignificant results. Our study confirmed a non-significant association between physical activity and telomere length in the northern Chinese population, which adds to the inconsistent association between physical activity and telomere length across different ethnic populations.

Association between the SUMO4 M55V Polymorphism and Susceptibility to Type 2 Diabetes Mellitus:A Meta-analysis

Objective The aim of this study is to determine whether the SUMO4 M55V polymorphism is associated with susceptibility to type 2 diabetes mellitus （T2DM）. Methods A meta-analysis was performed to detect the potential association of the SUMO4 M55V polymorphism and susceptibility to T2DM under dominant, recessive, co-dominant （homogeneous and heterogeneous）, and additive models. Results A total of eight articles including 10 case-control studies, with a total of 2932 cases and 2679 controls, were included in this meta-analysis. The significant association between the SUMO4 M55V polymorphism and susceptibility to T2DM was observed in the dominant model （GG ＋ GA versus AA： OR = 1.21, 95% CI = 1.05-1.40, P = 0.009）, recessive model （GG versus GA ＋ AA： OR = 1.29, 95% CI = 1.07-1.356, P = 0.010）, homozygous model （GG versus AA： OR = 1.41, 95% CI = 1.06-1.56, P = 0.001）, and additive model （G versus A： OR = 1.18, 95% CI = 1.08-1.29, P = 0.001）, and marginally significant in the heterozygous model （GA versus AA： OR = 1.16, 95% CI = 0.98-1.36, P = 0.080）. In subgroup analyses, significant associations were observed in the Chinese population under four genetic models excluding the heterozygous model, whereas no statistically significant associations were observed in the Japanese population under each of the five genetic models. Conclusion The meta-analysis demonstrated that the G allele of the SUMO4 M55V polymorphism could be a susceptible risk locus to T2DM, mainly in the Chinese population, while the association in other ethnic population needs to be further validated in studies with relatively large samples.

Comparison of clinical outcomes among total knee arthroplasties using posterior-stabilized,cruciate-retaining,bi-cruciate substituting,bi-cruciate retaining designs:a systematic review and network meta-analysis

Background:Despite the advent of innovative knee prosthesis design,a consistent first-option knee implant design in total knee arthroplasty(TKA)remained unsettled.This study aimed to compare the clinical effects among posterior-stabilized(PS),cruciate-retaining(CR),bi-cruciate substituting(BCS),and bi-cruciate retaining designs for primary TKA.Methods:Electronic databases were systematically searched to identify eligible randomized controlled trials(RCTs)and cohort studies from inception up to July 30,2021.The primary outcomes were the range of knee motion(ROM),and the secondary outcomes were the patient-reported outcome measures(PROMs)and complication and revision rates.Confidence in evidence was assessed using Confidence in Network Meta-Analysis.The Bayesian network meta-analysis was performed for synthesis.Results:A total of 15 RCTs and 18 cohort studies involving 3520 knees were included.The heterogeneity and inconsistency were acceptable.There was a significant difference in ROM at the early follow-up when PS was compared with CR(mean difference[MD]=3.17,95%confidence interval[CI]0.07,7.18)and BCS was compared with CR(MD=9.69,95%CI 2.18,17.51).But at the long-term follow-up,there was no significant difference in ROM in any one knee implant compared with the others.No significant increase was found in the PROMs and complication and revision rates at the final follow-up time.Conclusions:At early follow-up after TKA,PS and BCS knee implants significantly outperform the CR knee implant in ROM.But in the long run,the available evidence suggests different knee prostheses could make no difference in clinical outcomes after TKA with extended follow-up.

Millimeter waves in medical applications:status and prospects

Millimeter waves are electromagnetic waves with wavelengths of 1–10 mm,which have characteristics of high frequency and short wavelength.They have gradually and widely been used in engineering and medical fields.We have identified studies related to millimeter waves in the biomedical field and summarized the biological effects of millimeter waves and their current status in medical applications.Finally,the shortcomings of existing studies and future developments were analyzed and discussed,with the aim of providing a reference for further research and development of millimeter waves in the medical field.

Footprint Mismatch of Cervical Disc Prostheses with Chinese Cervical Anatomic Dimensions

Background：The footprint of most prostheses is designed according to Caucasian data.Total disc replacement （TDR） has been performed widely for cervical degenerative diseases in China.It is essential to analyze the match sizes of prostheses footprints and Chinese cervical anatomic dimensions in our study.Methods：The anatomic dimensions of the C4-C7 segments of 138 patients （age range 16-77 years） in a Chinese population were measured by computed tomography scans.We compared the footprints of the most commonly used cervical disc prostheses （Bryan：Medtronic,Minneapolis,MN,USA; Prestige LP：Medtronic,Fridley,Minnesota,USA; Discover：DePuy,Raynham,MA,USA; Prodisc-C：Synthes,West Chester,PA,USA） in China with Chinese cervical anatomic dimensions and assessed the match of their size.Results：The mismatch of available dimensions of prostheses and anatomic data of cervical endplates ranged from 17.03% （C4/C5,Prestige LP,Prodisc-C） to 57.61% （C6/C7,Discover） in the anterior-posterior （AP） diameter,and 35.51% （C4/C5,Prodisc-C,Prestige LP） to 94.93% （C6/C7,Bryan） in the center mediolateral （CML） diameter.About 21.01% of endplates were larger than the largest prostheses in the AP diameter and 57.25% in the CML diameter.All available footprints of prostheses expect the Bryan with an unfixed height,can accommodate the disc height （DH）,however,36.23% of the middle DH was less than the smallest height of the prostheses.The average disc sagittal angles （DSAs） of C4-C7 junctions were 5.04＆#176;,5.15＆#176;,and 4.13＆#176; respectively.Only the Discover brand had a built-in 7＆#176; lordotic angle,roughly matching with the DSA.Conclusions：There is a large discrepancy between footprints of prostheses and Chinese cervical anatomic data.In recent years,possible complications of TDR related with mismatch sizes are increasing,such as subsidence,displacement,and heterotopic ossification.Manufacturers of prostheses should introduce or produce additional footprints of prostheses for Chinese TDR.