Joint Replacement Research Articles

Physical and Cognitive Function Trends in Post-acute Care after Total Joint Arthroplasty in Medicare Beneficiaries: 2013-2018

ObjectivesPhysical and cognitive conditions of patients discharged to skilled nursing facilities (SNFs), inpatient rehabilitation facilities (IRFs), and home with home health agencies (HHAs) following total joint arthroplasty (TJA) have not been evaluated. The purpose of this study is to examine the physical and cognitive function trends of Medicare beneficiaries discharged to SNFs, HHAs, and IRFs following TJA from 2013 to 2018. DesignObservational study using Medicare enrollment, claims, and assessment data from 2013–2018. Setting and Participants1,278,939 Medicare beneficiaries discharged to SNFs, HHAs, or IRFs for post-acute care following TJA from 2013 to 2018. MethodsMedicare data were used to examine the association between the endpoints of interest [discharge destination (SNF, HHA, or IRF) and the physical (measured using activities of daily living) and cognitive (measured using a range of setting-specific metrics) status of patients in each setting] and the year of TJA (2013–2018) by estimating multivariable models that controlled for patient- and hospital-level covariates. ResultsMultivariable analysis of 1,278,939 TJAs revealed that SNF discharge decreased [44.15% (2013)–21.57% (2018), P < .001], HHA increased (46.72%–72.47%, P < .001), and IRF decreased (9.13%–5.69%, P < .001). For SNF, the mean physical function scores [14.61 (2013)–14.23 (2018), P < .001] and cognitive impairment (13.25%–12.33%, P = .01) decreased, indicating less dependence. Physical function scores (3.09–3.94, P < .001) and cognitive impairment (13.95%–16.52%, P < .001) increased for HHA patients, indicating greater dependence. For IRF, motor functional independence measure decreased (38.81–37.78, P < .001) and cognitive dependence increased (39.08%–46.36%, P < .001), indicating greater dependence. Conclusions and ImplicationsFrom 2013 to 2018, patients were increasingly discharged to HHA. Although SNF patients were less dependent over time, HHA and IRF patients were physically and cognitively more dependent. Each setting is likely to benefit from policy and fiscal supports that help them manage changes in the volume and clinical intensity of patients requiring their services.

Influence of obesity on developing osteoarthritis and the recovery after knee joint replacement – a review

Obesity is a chronic disease accompanied by inflammation. It is becoming more and more prevalent all around the world and so are its consequences. Osteoarthritis (OA) is a degenerative disease of the joints. The range of its risk factors is broad, but the most common is obesity. OA can be treated in a surgical and non-surgical way. The surgical method - knee replacement is the most effective way of treating OA, but unfortunately it does not solve the problem. Obesity takes a part not only in development of OA, but is also involved in developing postoperative complications and impairing the recovery in general. The influence of obesity is determined not only by the weight and increased mechanical forces affecting the organism, but also on a molecular level by the hormonal activity of the substances produced by white adipose tissue. Condition of the patient should be optimised before the surgery in order to minimize the risk of complications and increase the chances for fast and effective recovery. Obese patients after the surgery need proper nutrition and care focused on their needs, which often is a challenge to the healthcare providers. After the surgery those patients cannot be sent back to the condition that made them sick. Reduction of weight is suggested to prevent the development of postoperative complications and OA. Prehabilitation seems to improve the immediate postoperative results. Starting regular training a few weeks after the surgery seems to positively affect the process of recovery.

Current Use of Patient-Reported Outcome Measures Ignores Functional Demand.

Patient-reported outcome measures (PROMs) are used in orthopaedic surgery to measure aspects of musculoskeletal function that are important to patients, such as disability and pain. However, current assessments of function using PROMs do not necessarily consider a patient's functional demands in detail. A patient's functional demands could serve as a confounder to their perception of their functional ability. Hence, functional demands may need to be adjusted for when PROMs are used to measure musculoskeletal function. We conducted a cross-sectional study in which new orthopaedic patients completed a questionnaire regarding demographics, function [Patient-Reported Outcomes Measurement Information System], functional demand (Tegner Activity Level Scale), pain self-efficacy, and symptoms of depression. 169 eligible patients with diverse orthopaedic conditions were enrolled in the study from an orthopaedic clinic, and 19 were excluded for incomplete questionnaires. The mean Patient-Reported Outcomes Measurement Information System score was 36.5 ± 9.1, and the mean Tegner score was 2.6 ± 2.0. In the multivariable regression model, patient-reported function was significantly associated with functional demand (β = 0.17, P < 0.001). Significant associations were observed for pain self-efficacy (β = 0.15, P < 0.001), acuity (β = -0.10, P = 0.004), and age 80 years or older (β = -0.16, P = 0.004). No notable association was observed with depression or age 65 to 79 years. Higher patient-reported physical function is associated with higher levels of functional demand when controlling for psychosocial factors, acuity, and age. Because of its confounding effect on measuring physical function, functional demand should be assessed and included in models using PROMs before and after surgery. For example, payment models using improvements in PROMs, such as the short form of the Hip dysfunction and Osteoarthritis Outcome Score and the Knee injury and Osteoarthritis Outcome Score after joint arthroplasty, should include functional demand in the model when assessing quality of care. Level II.

Does the Addition of Low-Dose Antibiotics Compromise the Mechanical Properties of Polymethylmethacrylate (PMMA)?

The increasing numbers of total joint replacements and related implant-associated infections demand solutions, which can provide a high-dose local delivery of antibiotics. Antibiotic-loaded bone cement (ALBC) is an accepted treatment method for infected joint arthroplasties. The mechanical properties of low-dose gentamicin-loaded bone cement (BC) in medium- and high-viscosity versions were compared to unloaded BC using a vacuum mixing system. As an additional control group, manual mixed unloaded BC was used. In a uniaxial compression test, ultimate compressive strength, compressive yield strength, and compression modulus of elasticity, as well as ultimate and yield strain, were determined according to ISO 5833-2022 guidelines. All groups exceeded the minimum compressive strength (70 MPa) specified in the ISO 5833 guidelines. Both ALBC groups showed a similar ultimate compressive and yield strength to the unloaded BC. The results showed that vacuum mixing increased the compression strength of BC. ALBC showed similar compressive strength to their non-antibiotic counterparts when vacuum mixing was performed. Added low-dose gentamicin acted as a plasticizer on bone cement. From a biomechanical point of view, the usage of gentamicin-based ALBC formulations is viable.

Proximal interphalangeal joint arthroplasty: current trends and evidence-based practice.

Arthroplasty of the proximal interphalangeal joint (PIPJ) has evolved since its inception over 60 years ago. This review examines the indications for surgery, highlights the differences in current arthroplasty designs, variances in surgical techniques, clinical controversies, current implant outcomes data and salvage options for the failed implant. Overall, PIPJ implant arthroplasty is a good and reliable option for symptomatic PIPJ degenerative, post-traumatic or inflammatory arthritis given the proper clinical setting. If current techniques for implantation and rehabilitation are followed, predictable pain relief and satisfactory function can be anticipated. The purpose of this review article is to examine the current evidence-based indications for PIPJ arthroplasty and examine the reported, implant-specific outcomes of this procedure. Various techniques and rehabilitation strategies will also be outlined.

Long-term results of 292 CarpoFit®-joint replacements for trapeziometacarpal osteoarthritis: a prospective cohort study with a 10-year follow-up.

We report a prospective consecutive series of CarpoFit® (Implantcast, Buxtehude, Germany) trapeziometacarpal prostheses used between 2006 and 2014 for 292 patients with stage I-III trapeziometacarpal arthritis who remained symptomatic after conservative treatment. Patients were assessed at 3 months, 6 months and 1 year postoperatively for thumb movement, pinch strength and by validated patient-derived outcome scores and radiographs. Follow-up at 5 and 10 years was by outcome scores alone. Complications and revisions were recorded. Of the patients, 91% were either satisfied or very satisfied with their treatment at 10 years. Pain relief and functional outcomes were significantly improved within 3 months. Results were sustained during the entire observation period. The implant survival was 95% after 10 years. Prosthetic arthroplasty is a reliable treatment option for trapeziometacarpal osteoarthritis and the CarpoFit® prosthesis has excellent long-term results for patient satisfaction, functional scores and implant survivorship.Level of evidence: III.

Development, Calibration and Validation of Time Series Analysis and Artificial Neural Network Joint Model for Urban Noise Prediction

Noise in large urban areas, which is mainly generated by road traffic and by the human activities carried out nearby and inside the area under study, is a relevant problem. The continuous exposure to high noise levels, in fact, can lead to several problems, largely documented in the scientific literature. The analysis and forecasting of the noise level in a given area are, then, fundamental for control and prevention, especially when field measurements present peculiar trends and slopes, which can be modeled with a Time Series Analysis approach. In this paper, a hybrid model is presented for the analysis and the forecasting of noise time series in urban areas: this technique is based on the application of a deterministic decomposition model followed in cascade by a predictor of the forecasting errors based on an artificial neural network. Two variants of the hybrid model have been implemented and presented. The time series used to calibrate and validate the model is composed of sound pressure level measurements detected on a busy road near the commercial port of an Italian city. The proposed hybrid model has been calibrated on a part of the entire time series and validated on the remaining part. Residuals and error analysis, together with a detailed statistical description of the simulated noise levels and error metrics describe in detail the method’s performances and its limitations.

Temporomandibular joint alloplastic replacement failure

Temporomandibular joint disorders are common, with alloplastic temporomandibular joint replacement (TMJR) being one method of addressing chronic pain and movement limitations that cannot otherwise be managed. Despite this, TMJR has known complications that can lead to failure. We present our experience of managing these cases and review the current evidence on the management and outcomes of alloplastic TMJR failures. Until 2015 our unit regularly used Dundee full metal prostheses, and encountered multiple issues such as infection, heterotopic bone formation, and progression of osteoarthritis beneath the condylar element. We also present our experience with other standard TMJR implants. One common cause of failure we observed is improper placement of a prosthesis due to poor technique, for instance, placement of the fossa implant too close to the ear canal can cause unresolved postoperative pain. There is no consensus on the management of TMJR, but non-surgical measures are preferred initially and surgical intervention is reserved for later stages. Recently our unit has managed numerous failure cases, employing a multidisciplinary approach combined with thorough preoperative planning and postoperative care, which has proven effective in reducing complications and improving outcomes. Based on our experience, we do not recommend the use of Dundee full metal prostheses for TMJR. Appropriate training in the placement of contemporary implants remains crucial. Suboptimal alignment of the implant in some cases does not need surgical intervention, but surgical management is justifiable in cases of persistent symptoms and functional limitations. When placing stock implants or designing a custom-made implant for an adult, we recommend that the posterior edge of the fossa component is at least 3 mm away from the bone of the ear canal.

Research progress of highly wear‐resistant and oxidation‐resistant polymer acetabular cup prosthesis

AbstractThe polymer‐based acetabular cup prosthesis, a vital component of hip replacement surgery, significantly contributes to the recovery of patients afflicted with osteoarthritic conditions. Nevertheless, the current clinical usage of polymer acetabular cup prostheses commonly encounters the challenge of balancing wear resistance and oxidation resistance, significantly impacting both their lifespan and patients′ quality of life. Consequently, researchers have persistently enhanced the attributes of polymer acetabular cup prosthetic materials. These enhancements, including irradiation and filler modifications, are intended to concurrently bolster both the wear and oxidation resistance of the prosthesis materials. This comprehensive approach aims to address wear‐associated clinical complications like osteolysis and oxidative brittleness, ultimately extending their in vivo service life. For this reason, this paper retrospectively discusses the progress of research on the modification of polymer acetabular cup prosthesis materials for high wear and oxidation resistance and explores potential design methods for optimising artificial acetabular cup materials, with a view to providing new ideas for extending the service life of artificial joint implants.

Facile Preparation of Irradiated Poly(vinyl alcohol)/Cellulose Nanofiber Hydrogels with Ultrahigh Mechanical Properties for Artificial Joint Cartilage.

In this study, Poly(vinyl alcohol)/cellulose nanofiber (PVA/CNF) hydrogels have been successfully prepared using γ-ray irradiation, annealing, and rehydration processes. In addition, the effects of CNF content and annealing methods on the hydrogel properties, including gel fraction, micromorphology, crystallinity, swelling behavior, and tensile and friction properties, are investigated. Consequently, the results show that at an absorbed dose of 30 kGy, the increase in CNF content increases the gel fraction, tensile strength, and elongation at break of irradiated PVA/CNF hydrogels, but decreases the water absorption. In addition, the cross-linking density of the PVA/CNF hydrogels is significantly increased at an annealing temperature of 80 °C, which leads to the transition of the cross-sectional micromorphology from porous networks to smooth planes. For the PVA/CNF hydrogel with a CNF content of 0.6%, the crystallinity increases from 19.9% to 25.8% after tensile annealing of 30% compared to the original composite hydrogel. The tensile strength is substantially increased from 65.5 kPa to 21.2 MPa, and the modulus of elasticity reaches 4.2 MPa. Furthermore, it shows an extremely low coefficient of friction (0.075), which suggests that it has the potential to be applied as a material for artificial joint cartilage.

Cartilage Integrity: A Review of Mechanical and Frictional Properties and Repair Approaches in Osteoarthritis.

Osteoarthritis (OA) is one of the most common causes of disability around the globe, especially in aging populations. The main symptoms of OA are pain and loss of motion and function of the affected joint. Hyaline cartilage has limited ability for regeneration due to its avascularity, lack of nerve endings, and very slow metabolism. Total joint replacement (TJR) has to date been used as the treatment of end-stage disease. Various joint-sparing alternatives, including conservative and surgical treatment, have been proposed in the literature; however, no treatment to date has been fully successful in restoring hyaline cartilage. The mechanical and frictional properties of the cartilage are of paramount importance in terms of cartilage resistance to continuous loading. OA causes numerous changes in the macro- and microstructure of cartilage, affecting its mechanical properties. Increased friction and reduced load-bearing capability of the cartilage accelerate further degradation of tissue by exerting increased loads on the healthy surrounding tissues. Cartilage repair techniques aim to restore function and reduce pain in the affected joint. Numerous studies have investigated the biological aspects of OA progression and cartilage repair techniques. However, the mechanical properties of cartilage repair techniques are of vital importance and must be addressed too. This review, therefore, addresses the mechanical and frictional properties of articular cartilage and its changes during OA, and it summarizes the mechanical outcomes of cartilage repair techniques.

Cardiometabolic disease risk in relation to objectively measured physical activity, sedentary behaviour in South African adults with knee and hip osteoarthritis

Purpose This study aimed to investigate the relationship between cardiometabolic disease risk and time spent in device-measured activity behaviours in a cohort of people with advanced osteoarthritis (OA) awaiting joint replacement surgery. Materials and methods Cardiometabolic risk biomarkers were assessed in people with OA (n = 96; hip n = 38, knee n = 58; mean (SD) age = 64.3 (9.8) years; 71% female). Physical activity (PA) and sedentary behaviour (SB) were measured by accelerometer over seven days (24 h/day). Results There were similar patterns of PA and SB between the hip and knee OA participants except for total number of steps (hip = 3365 (2926) vs knee 4344 (2836) steps/day; p = 0.018) and total stepping time (hip = 50.8 (38.2) vs knee = 67.2 (38.5) min/day; p = 0.005). Each additional cardiometabolic risk factor accumulated was associated with a 26.3 min/day increase in sedentary behaviour (p = 0.032; 95% CI: 2.3, 50.2), a 26.3 min/day decrease in upright time (p = 0.032; −50.2, –2.3) and a 23.6 min/day decrease in standing time (p = 0.032; −45.1, –2.1). Conclusions In people with hip or knee OA, increased cardiometabolic disease risk was associated with more sitting and less upright and standing time. Findings support targeting reductions in sedentary behaviour for improvements in cardiometabolic health in people with osteoarthritis. IMPLICATIONS FOR REHABILITATION Knee and hip osteoarthritis is a condition which is associated with an increased risk of cardiometabolic disease but also due to the low levels of physical activity and high levels of sedentary behaviour. Offsetting sedentary behaviour with light physical activity offers a feasible interventional target to reduce the risk of cardiometabolic disease in people with hip and knee osteoarthritis.

What Is the Incidence of and Outcomes After Debridement, Antibiotics, and Implant Retention (DAIR) for the Treatment of Periprosthetic Joint Infections in the AJRR Population?

Debridement, antibiotics, and implant retention (DAIR) is used to manage acute periprosthetic joint infections (PJIs) after total joint arthroplasty (TJA). Given the uncertain success of single or multiple DAIR attempts and possible long-term deleterious effects this treatment can create when trying to treat persistent infection, it is important to understand the frequency with which surgeons in the United States are attempting multiple debridements for PJI and whether those procedures are achieving the desired goal. In the context of the American Joint Replacement Registry (AJRR), we asked: (1) What proportion of patients who undergo DAIR have only one DAIR, and what percentage of those patients have more than one? (2) Of the patients who undergo one or more DAIR procedures, what is the proportion who progress to additional surgical procedures? (3) What is the cumulative incidence of medical or surgical endpoints related to infection on the affected leg (other than additional DAIR procedures)? DAIR procedures to treat PJI, defined by ICD-9/10 and CPT (Current Procedural Technology) codes, reported to the AJRR from 2012 to 2020 were merged with Centers for Medicare and Medicaid Services (CMS) data from 2012 to 2020 to determine the incidence of patients aged 65 and older who underwent additional PJI-related procedures on the same joint. Linking to CMS ensures no loss to follow-up or patient migration to a non-AJRR site. As of 2021, the AJRR captures roughly 35% of all arthroplasty procedures performed in the United States. Of the total 2.2 million procedures in the AJRR, only 0.2% of the procedures were eligible based on our inclusion criteria. Additionally, 61% of the total population is Medicare eligible, and thus, these patients are linked to CMS. Of the 5029 DAIR attempts after a TKA, 46% (2318) were performed in female patients. Similarly, there were a total of 798 DAIR attempts after a THA, and 50% (398) were performed in female patients. For the purposes of decreasing confounding factors, bilateral THAs and TKAs were excluded from the study population. When querying for eligible procedures from 2012 to 2020, the patient population was limited to those 65 years and older, and a subsequent reoperation for infection had to be reported after a primary TJA. This limited the patient population as most infections reported to AJRR resulted in a revision, and we were searching for DAIRs. Although 5827 TJAs were identified as a primary TJA with a subsequent infectious event, more than 65% (3788) of that population did not have a reported event. The following conditions were queried as secondary outcomes after the first DAIR: sepsis, cellulitis, postoperative infection, endocarditis, amputation, knee fusion, resection, drainage, arthrotomy, and debridement. To answer our first and second study questions, we used frequency testing from the available AJRR data. Because of competing risks and issues with incomplete data, we used the cumulative incidence function to evaluate the outcomes specific to study question 3. Of the patients who underwent DAIR, 93% (5406 of 5827) had one DAIR and 8% (421 of 5827) had more than one. Among the DAIR population, at least 35% of TKAs and 38% of THAs were identified as having experienced an additional PJI-related event (an additional surgical procedure on the same joint, sustained an infectious endpoint in the linked CMS-AJRR dataset, or they had died). The cumulative incidence of developing a further medical or surgical condition related to the joint that had the initial DAIR were as follows: 48% (95% CI 42% to 54%) at 8 years after a DAIR following a TKA and 42% (95% CI 37% to 46%) at 4 years after a DAIR following a THA. The timepoints for TKA and THA are different because there are more longitudinal procedure data available for TKAs regarding DAIR procedures than for THAs. In this study, we used data from the AJRR to assess the incidences of single and multiple DAIR attempts and additional surgical- and infection-related sequalae. Continued investigation is required to determine the fate of infected joints that undergo DAIR with regard to ultimate patient outcome. Future cross-sectional studies using large datasets are necessary to assess functional outcomes and determine the risk of persistent infection after DAIR more precisely. Level III, therapeutic study.

OBESITY AND TOTAL HIP ARTHROPLASTY SURGERY

Obesity is a known risk factor for developing osteoarthritis and is also associated with an increased risk of developing complications post total hip replacement (THR). This study investigated the association between obesity and the risk of undergoing THR in Australia.From July 2017 to June 2018 a National Health Survey was conducted by the Australian Bureau of Statistics to collect height and weight data on a representative sample of patients across urban and rural areas across the country. This study examined a cohort of patients undergoing primary THR utilising data from the Australian Orthopaedic Association National Joint Replacement Registry from the same time period. Obesity classes were determined according to WHO criteria.Body mass index (BMI) for patients undergoing THR were obtained and the distribution of THR patients by BMI category was compared to the general population, in age and sex sub-groups.Generalised linear models assuming a binomial distribution and a log link were used to generate relative risks. Data from underweight categories, and age categories 34 years and younger, were excluded from further analyses because of small numbers.Data from the health survey showed there were 35.6% of persons overweight and 31.3% obese. During the same period, 32,495 primary THR were performed for osteoarthritis in Australia on patients who had a BMI recorded. Of these patients 37.1% were overweight and 41.7% were obese. Compared to the general population, there was a higher incidence of Class I, II, and III obesity in patients undergoing THR in both sexes aged 35 to 74 years. Class III obese females and males aged 55–64 years were 2.9 and 1.7 times more likely to undergo HR, respectively (p&lt;0.001). Class III obese females and males underwent THR on average 5.7 and 7.0 years younger than their normal weight counterparts, respectively.Obese Australians are at increased risk of undergoing THR, and at a younger age. A national approach to address the prevalence of obesity, and possible prevention strategies, is needed.

The Impact of Physiotherapy on a patient with Ankylosing Spondylitis Following Bilateral Total Hip Replacement: A Case Study

Ankylosing spondylitis (AS) is a chronic, progressive inflammatory disorder primarily affecting the axial skeleton, with a prevalence of approximately 0.25% in India, predominantly in males. This case study explores the physiotherapeutic management of a 35-year-old male patient underwent bilateral Total Hip Replacement and presented with primary complaint of progressive stiffness in the back and neck region along with pain in his right hip joint. Outcome measures included Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Visual Analog Scale (VAS), and Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR) with significant improvements observed over 12 weeks: BASFI improved from 7 to 2, BASDAI from 8.1 to 3.8, VAS pain from 8 to 3, and HOOS, JR score from 40 to 60. The results demonstrate that AS-specific exercises combined with a home-based exercise protocol can significantly enhance pain management, functional capacity, disease activity and hip disability in AS patients.

LONG-TERM RESULTS OF THE BIRMINGHAM HIP RESURFACING IMPLANT IN THE UNITED STATES: AN UPDATED ANALYSIS OF A SINGLE INSTITUTION'S EXPERIENCE

We previously reported the five to ten-year results of the Birmingham Hip Resurfacing (BHR) implant. The purpose of this study was to evaluate the survivorship, radiographic results, and clinical outcomes of the BHR at long-term follow-up.We retrospectively reviewed 250 patients from the original cohort of 324 BHRs performed from 2006 to 2013 who met contemporary BHR indications. Of these, 4 patients died and 4 withdrew. From the 242 patients, 224 patients (93%) were available for analysis. Modified Harris hip score (mHHS) and University of California, Los Angeles (UCLA) scores were collected and compared to a matched total hip arthroplasty (THA) cohort. Mean follow-up was 14 years.Survivorship free of aseptic revision was 97.4% and survivorship free of any revision was 96.0% at 15 years. Revisions included 3 periprosthetic joint infections, 2 for elevated metal ions and symptomatic pseudotumor, 2 for aseptic femoral loosening, and 1 for unexplained pain. The mean mHHS was 93 in BHR patients at final follow-up, similar to the THA cohort (p=0.44). The UCLA score was significantly higher for BHR patients (p=0.02), however there were equal proportions of patients who remained highly active (UCLA 9 or 10) in both groups, 60.5% and 52.2% (p=0.45) for BHR and THA respectively. Metal ion levels at long term follow-up were low (mean serum cobalt 1.8±1.5 ppb and mean serum chromium 2.2±2.0 ppb).BHR demonstrated excellent survivorship in males less than 60 years of age at time of surgery. Clinical outcomes and activity levels were similar to THA patients. Failures related to the metal-on-metal bearing were rare and metal levels were low at long-term follow-up.Level of evidence: IIIKeywords: survivorship; hip arthroplasty; activity; metal-on-metalSurface Replacement Arthroplasty demonstrates low revision rates and similar activity level compared to total hip arthroplasty at long-term follow-up.

SSP: self-supervised pertaining technique for classification of shoulder implants in x-ray medical images: a broad experimental study

Multiple pathologic conditions can lead to a diseased and symptomatic glenohumeral joint for which total shoulder arthroplasty (TSA) replacement may be indicated. The long-term survival of implants is limited. With the increasing incidence of joint replacement surgery, it can be anticipated that joint replacement revision surgery will become more common. It can be challenging at times to retrieve the manufacturer of the in situ implant. Therefore, certain systems facilitated by AI techniques such as deep learning (DL) can help correctly identify the implanted prosthesis. Correct identification of implants in revision surgery can help reduce perioperative complications and complications. DL was used in this study to categorise different implants based on X-ray images into four classes (as a first case study of the small dataset): Cofield, Depuy, Tornier, and Zimmer. Imbalanced and small public datasets for shoulder implants can lead to poor performance of DL model training. Most of the methods in the literature have adopted the idea of transfer learning (TL) from ImageNet models. This type of TL has been proven ineffective due to some concerns regarding the contrast between features learnt from natural images (ImageNet: colour images) and shoulder implants in X-ray images (greyscale images). To address that, a new TL approach (self-supervised pertaining (SSP)) is proposed to resolve the issue of small datasets. The SSP approach is based on training the DL models (ImageNet models) on a large number of unlabelled greyscale medical images in the domain to update the features. The models are then trained on a small labelled data set of X-ray images of shoulder implants. The SSP shows excellent results in five ImageNet models, including MobilNetV2, DarkNet19, Xception, InceptionResNetV2, and EfficientNet with precision of 96.69%, 95.45%, 98.76%, 98.35%, and 96.6%, respectively. Furthermore, it has been shown that different domains of TL (such as ImageNet) do not significantly affect the performance of shoulder implants in X-ray images. A lightweight model trained from scratch achieves 96.6% accuracy, which is similar to using standard ImageNet models. The features extracted by the DL models are used to train several ML classifiers that show outstanding performance by obtaining an accuracy of 99.20% with Xception+SVM. Finally, extended experimentation has been carried out to elucidate our approach’s real effectiveness in dealing with different medical imaging scenarios. Specifically, five different datasets are trained and tested with and without the proposed SSP, including the shoulder X-ray with an accuracy of 99.47% and CT brain stroke with an accuracy of 98.60%.

Blood metal concentrations and cardiac structure and function in total joint arthroplasty patients.

There is concern regarding potential long-term cardiotoxicity with systemic distribution of metals in total joint arthroplasty (TJA) patients. To determine the association of commonly used implant metals with echocardiographic measures in TJA patients. The study comprised 110 TJA patients who had a recent history of high chromium, cobalt or titanium concentrations. Patients underwent two-dimensional, three-dimensional, Doppler and speckle-strain transthoracic echocardiography and a blood draw to measure metal concentrations. Age and sex-adjusted linear and logistic regression models were used to examine the association of metal concentrations (exposure) with echocardiographic measures (outcome). Higher cobalt concentrations were associated with increased left ventricular end-diastolic volume (estimate 5.09; 95%CI: 0.02-10.17) as well as left atrial and right ventricular dilation, particularly in men but no changes in cardiac function. Higher titanium concentrations were associated with a reduction in left ventricle global longitudinal strain (estimate 0.38; 95%CI: 0.70 to 0.06) and cardiac index (estimate 0.08; 95%CI, -0.15 to -0.01). Elevated cobalt and titanium concentrations may be associated with structural and functional cardiac changes in some patients. Longitudinal studies are warranted to better understand the systemic effects of metals in TJA patients.

Differences in the relationship between pain and anxiety in total knee and hip arthroplasty: a longitudinal cross-lagged analysis mediated by depression and pain catastrophizing.

Acute postsurgical pain (APSP) is an important risk factor for pain chronification, with reports of being more intense after total knee arthroplasty (TKA) than after total hip arthroplasty (THA). Psychological variables have been associated with differences in postsurgical pain experience. This study aimed to analyse the longitudinal reciprocal association between pain and anxiety levels in patients undergoing TKA or THA, to investigate the moderator role of the type of surgery and to explore psychological mediators in the anxiety - pain association. Patients undergoing TKA (n = 120) or THA (n = 109) were evaluated before surgery and in the acute postsurgical period (48h postsurgery). Presurgical assessment comprised sociodemographic, pain-related and psychological variables (anxiety, depression, pain catastrophizing, self-efficacy, optimism and satisfaction with life). Postsurgical assessment focused on pain frequency, pain intensity and anxiety. Longitudinal associations were explored using cross-lagged panel models that included the indirect effect paths through possible mediators (pain catastrophizing and depression). Multigroup analyses compared TKA and THA. In the global sample, higher APSP was predicted by higher presurgical pain and worse presurgical anxiety. Multigroup analyses revealed that worse APSP was predicted by higher presurgical anxiety in patients undergoing TKA and by higher presurgical pain in patients undergoing THA. Furthermore, there was a positive significant indirect effect of pain catastrophizing, but not depressive symptoms, in the relationship between presurgical anxiety and APSP in THA. Anxiety and APSP are differently interrelated in TKA and THA. Psychological characteristics could be managed before surgery to favour better APSP control and potentially prevent pain chronification after total joint arthroplasty.

Periprosthetic Ulna Fractures Following Aptis Distal Radioulnar Joint Arthroplasty: A Series of Four Cases

Periprosthetic Ulna Fractures Following Aptis Distal Radioulnar Joint Arthroplasty: A Series of Four Cases