Joint replacement and human immunodeficiency virus

The incidence of human immunodeficiency virus(HIV)-infected cases that need total joint replacement(TJR)is generally rising.On the other hand,modern management of HIV-infected cases has enabled them to achieve longevity while increasing the need for arthroplasty procedures due to the augmented degenerative joint disease and fragility fractures,and the risk of osteonecrosis.Although initial investigations on joint replacement in HIV-infected cases showed a high risk of complications,the recent ones reported acceptable outcomes.It is a matter of debate whether HIV-infected cases are at advanced risk for adverse TJR consequences;however,the weak immune profile has been associated with an increased probability of complications.Likewise,surgeons and physicians should be aware of the complication rate after TJR in HIV-infected cases and include an honest discussion of the probable unwelcoming complication with their patients contemplating TJR.Therefore,a fundamental review and understanding of the interaction of HIV and arthroplasty are critical.

Role of pulsed electromagnetic fields after joint replacements

Although the rate of patients reporting satisfaction is generally high after joint replacement surgery, up to 23% after total hip replacement and 34% after total knee arthroplasty of treated subjects report discomfort or pain 1 year after surgery. Moreover, chronic or subacute inflammation is reported in some cases even a long time after surgery. Another open and debated issue in prosthetic surgery is implant survivorship, especially when related to good prosthesis bone ingrowth. Pulsed Electro Magnetic Fields(PEMFs) treatment, although initially recommended after total joint replacement to promote bone ingrowth and to reduce inflammation and pain, is not currently part of usual clinical practice. The purpose of this review was to analyze existing literature on PEMFs effects in joint replacement surgery and to report results of clinical studies and current indications. We selected all currently available prospective studies or RCT on the use of PEMFs in total joint replacement with the purpose of investigating effects of PEMFs on recovery, pain relief and patients’ satisfaction following hip, knee or shoulder arthroplasty. All the studies analyzed reported no adverse effects, and good patient compliance to the treatment. The available literature shows that early control of joint inflammation process in the first days after surgery through the use of PEMFs should be considered an effective completion of the surgical procedure to improve the patient’s functional recovery.

Early diagnosis and treatment of pulmonary embolism after total joint replacement: report of five cases

Objective To study the early diagnosis and treatment of pulmonary embolism (PE) after total joint replacement (TJR). Methods From April 1987 to December 2001, we performed 1 336 total knee replacements (TKR) in 926 patients and 1 745 total hip replacements (RHRs) in 1 566 patients. In this group there were 5 PE patients after operation. Two patients died (all after TKR), and 3 patients salvaged successfully (2 after TKR, 1 after THR). Results The total incidence of PE after TJR was 0. 2% (5/2 492), the incidence of PE after TKR was 0. 4% (4/926), and the incidence of PE after THR was 0.06% (1/1 556). In the patients who suffered PE, 2 died. The incidence of PE before 2000 was 0%. Conclusion Death after total joint replacement is due to pulmonary embolism ( PE), especially massive PE. The incidence of PE after TKR is higher than that after THR. Pulmonary angiography is the gold standard for the diagnosis of PE. With more understanding on PE and more popularity of joint replacement, the diagnosis of PE

Meta-analysis of new intervention measures for preventing side effects of artificial joint replacement

BACKGROUND Intertrochanteric fracture of the femur occurs mostly among older people,and seriously affects daily life and quality of life.At present,physical intervention,drug treatment,routine intervention and rehabilitation training are widely used for prevention of side effects,but it is still inconclusive which intervention has the best effect.AIM To compare the effects of new intervention measures for preventing side effects of artificial joint replacement.METHODS We searched the Chinese and English literatures for comparative studies on the prevention of side effects of new interventions for artificial joint replacement from July 2013 to June 2023 in China HowNet,PubMed,Wanfang,Weipu and other databases.Study quality was evaluated by improved Jadad scoring standard,and the effects of different interventions on preventing different complications were analyzed by meta-analysis of evidence-based medicine with Review Manager 5.0 software.RESULTS Ten articles,including 869 cases,were finally included.The preventive effects of different interventions on the side effects of artificial joint replacement were studied,and valid data were extracted.There were two articles on the preventive effects of drug intervention,four on comparison of the preventive effects of combined and single interventions,and three on the preventive effects of physical intervention,rehabilitation training and routine intervention.Meta-analysis showed that the preventive effect of rivaroxaban was significantly better than low molecular weight heparin calcium[mean difference(MD)=-0.16,95%CI:-0.28 to-0.04,P<0.05].The effect of combined intervention was significantly better than that of single intervention(MD=-0.08,95%CI:-0.16 to-0.01,P<0.001).Physical intervention was significantly better than routine intervention and rehabilitation training(MD=0.26,95%CI:0.16–0.36,P<0.001).CONCLUSION Rivaroxaban combined with rehabilitation training is preferred for preventing deep vein thrombosis after artificial joint replacement.In the prevention of pulmonary embolism,rivaroxaban drug intervention is given priority.The effect of combined intervention is better than that of single intervention.

Running-in friction of hip joint replacements can be significantly reduced:The effect of surface-textured acetabular cup

Hip joint replacements represent the most effective way of treatment for patients suffering from joint diseases.Despite the rapid improvement of implant materials over the last few decades,limited longevity associated with wear-related complications persists as the main drawback.Therefore,improved tribological perfor-mance is required in order to extend the service life of replacements.The effect of surface texturing of ultra-high molecular weight polyethylene(UHMWPE)acetabular cup was investigated in the present study.Unique tilling method was utilized for manufacturing the dimples with controlled diameter and depths on the contact surface of the cup.The experiments with four commercial femoral components and two model lubricants were realized.The main attention was paid to a coefficient of friction considering the differences between the original and the dimpled cups.Results showed remarkable lowering of friction,in general.Focusing on the simulated human synovial fluid,friction was reduced by 40%(alumina ceramic),38.8%(zirconia toughened ceramic),25.5%(metal),and 9.9%(oxinium).In addition,the dimples helped to keep the friction stable without fluctuations.To conclude,the paper brings a new insight into frictional behaviour of the hip replacements during running-in phase which is essential for overall implant lifespan.It is believed that proper surface texturing may rapidly improve the life quality of millions of patients and may lead to considerable financial savings.

Knowledge and attitudes of orthopedic surgeons regarding prosthesis joint infection

BACKGROUND Periprosthetic joint infection(PJI)is a critical complication after joint arthroplasty and is accompanied by increasing rates of morbidity and mortality.Several studies have aimed at preventing PJI.AIM To research the knowledge level and attitudes of orthopedic surgeons,who play a key role in both preventing and managing PJI.METHODS We conducted a web-based survey to evaluate orthopedic surgeons'knowledge level and attitudes regarding PJI.The Likert scale survey utilized consisted of 30 questions which were prepared based on the"Proceedings of the International Consensus on Periprosthetic Joint Infection".RESULTS A total of 264 surgeons participated in the survey.Their average age was 44.8,and 173 participants(65.5%)had more than 10 years of experience.No statistically significant relationship was found between the PJI knowledge of the surgeons and their years of experience.However,participants who worked in training and research hospitals demonstrated higher levels of knowledge than the ones in the state hospitals.It was also noticed that surgeons'knowledge concerning the duration of antibiotic therapy and urinary infections was not consistent with their attitudes.CONCLUSION Even though orthopedic surgeons have adequate knowledge about preventing and managing PJI,their attitudes might contradict their knowledge.Future studies are required to examine the causes and solutions of the contradictions between orthopedic surgeons'knowledge and attitudes.

Rural implementation of the perioperative surgical home:A case-control study

BACKGROUND Perioperative surgical home(PSH)is a novel patient-centric surgical system developed by American Society of Anesthesiologist to improve outcomes and patient satisfaction.PSH has proven success in large urban health centers by reducing surgery cancellation,operating room time,length of stay(LOS),and readmission rates.Yet,only limited studies have assessed the impact of PSH on surgical outcomes in rural areas.AIM To evaluate the newly implemented PSH system at a community hospital by comparing the surgical outcomes using a longitudinal case-control study.METHODS The research study was conducted at an 83-bed,licensed level-III trauma rural community hospital.A total of 3096 TJR procedures were collected retrospectively between January 2016 and December 2021 and were categorized as PSH and non-PSH cohorts(n=2305).To evaluate the importance of PSH in the rural surgical system,a case-control study was performed to compare TJR surgical outcomes(LOS,discharge disposition,and 90-d readmission)of the PSH cohort against two control cohorts[Control-1 PSH(C1-PSH)(n=1413)and Control-2 PSH(C2-PSH)(n=892)].Statistical tests including Chi-square test or Fischer’s exact test were performed for categorical variables and Mann-Whitney test or Student’s t-test were performed for continuous variables.The general linear models(Poisson regression and binomial logistic regression)were performed to fit adjusted models.RESULTS The LOS was significantly shorter in PSH cohort compared to two control cohorts(median PSH=34 h,C1-PSH=53 h,C2-PSH=35 h)(P value<0.05).Similarly,the PSH cohort had lower percentages of discharges to other facilities(PSH=3.5%,C1-PSH=15.5%,C2-PSH=6.7%)(P value<0.05).There was no statistical difference observed in 90-d readmission between control and PSH cohorts.However,the PSH implementation reduced the 90-d readmission percentage(PSH=4.7%,C1-PSH=6.1%,C2-PSH=3.6%)lower than the national average 30-d readmission percentage which is 5.5%.The PSH system was effectively established at the rural community hospital with the help of team-based coordinated multi-disciplinary clinicians or physician comanagement.The elements of PSH including preoperative assessment,patient education and optimization,and longitudinal digital engagement were vital for improving the TJR surgical outcomes at the community hospital.CONCLUSION Implementation of the PSH system in a rural community hospital reduced LOS,increased directto-home discharge,and reduced 90-d readmission percentages.

Distal femur complex fractures in elderly patients treated with megaprosthesis:Results in a case series of 11 patients

BACKGROUND Surgical treatment of complex fractures of the distal femur in the elderly is controversial.Osteoporosis and pre-existent osteoarthritis are common comorbidities in the elderly which add to the need for early walking and rapid restoration of function and also pose significant obstacles to achievement of satisfactory results with standard fixation techniques.Recently,several authors have suggested that primary arthroplasty could be a viable alternative option to standard fixation techniques in selected patients with complex distal femur fractures.AIM To present our experience with 11 cases of distal femur fractures treated with knee arthroplasty and large femoral resection in a population of patients over the age of 85.METHODS Data from 11 consecutive patients(10 females,1 male)presenting with acute intra-articular supracondylar or intercondylar distal femur fractures and with pre-existent primary osteoarthritis who were treated with primary knee arthroplasty were recorded.We collected standard demographic data,comorbidities and patient reported outcomes including Visual Analogical Scale(VAS),Oxford Knee Score(OKS)and Barthel’s Index.Post-operative joint range of motion(ROM)and standard radiographic data were also collected.RESULTS At a mean follow-up of 23.2 mo,all of the implants were well-positioned and osteointegrated.Furthermore,all the patients were alive and walking either independently or with walking aids.There was a marked improvement in pain(VAS 4.5 postop vs 1.9 at the last follow-up),OKS score(29.5 postop vs 36.81 at the last follow-up),ROM(96.2°postop vs 102°at the last follow-up)and restoration of pre-injury ambulatory status(average Barthel Index 77.3).The radiographic evaluations showed good restoration of the articular geometry.No deaths and no complications were recorded.CONCLUSION In conclusion,we believe that knee megaprosthesis in the case of complex fractures of the distal femur is a valid surgical choice.This is particularly true in elderly patients with severe osteoporosis and pre-existing osteoarthritis.It is important to note that this surgery should be performed by surgeons with proven experience in prosthetic hip and knee surgery and that a scrupulous selection of the cases is completed.

Tribological Performance of Bioimplants: A Comprehensive Review

Total joint replacements(TJR) have been a huge success for orthopaedic surgery in the past century and are gaining increasing importance today due to the aging population. However, the short longevity of artificial joints is one of the major problems in bioimplant industry and needs to be rectified since an increasing number of young people, with more active lifestyles, must receive TJR. Wear mechanisms are discussed in this paper to describe the root causes of the failures and to give some general ideas to increase the lifespan of artificial joints. The suitable material combination is of great importance for the wear resistance of bioimplants, and bioceramics will exert a crucial effect in their future progress. Other materials, such as metal alloys and polymers, are also discussed in this paper. Surface finish is another factor affecting the tribological performance of bioimplants. In recent years, surface texture technology has fascinated many researchers, and a good design of texture pattern requires a comprehensive understanding of wear mechanisms, material properties, and dynamic fluid theory. This review also covers a summary of in vitro wear tests, including simulators, lubricant, and testing parameters.

DEXA overestimates bone mineral density in adults with knee replacements

We examined bone mineral density(BMD)measurements made by dual-energy-xray-absorptiometry(DEXA)taken from 100 patients(♂46/♀54,66±6yr)who previously underwent single total-knee arthroplasty(TKA)to determine if automated software-based artifact detection(ASAD)adequately removes implant artifact from the DXA image before analysis and if potential inaccuracies could be overcome through manual artifact correction(MAC).We also sought to determine if software-based inaccuracies would result in fracture risk misclassification(Low-BMD/Osteopenia=Young-Adult T-Score<−1).Select Results:When using ASAD,limbs with implants had higher BMD(+12.0±1.7%,p<0.001)compared to control limbs resulting in a 2.5±0.2%overestimation of total-body BMD(single implant).Consequently,the prevalence of osteopenia in 95%of patients who would have been observed to have low leg BMD(18/19 patients)and 80%of those found to have low total-body BMD(4/5 patients)would have gone un-diagnosed.This overestimation was eliminated when using MAC.These results reveal a potential issue with ASAD for total-body DEXA scans in TKA patients and highlight the importance of careful review and MAC in those with joint replacements before making diagnostic decisions.