Preoperative prediction model for risk of readmission after total joint replacement surgery: a random forest approach leveraging NLP and unfairness mitigation for improved patient care and cost-effectiveness.

BACKGROUND: The Center for Medicare and Medicaid Services (CMS) imposes payment penalties for readmissions following total joint replacement surgeries. This study focuses on total hip, knee, and shoulder arthroplasty procedures as they account for most joint replacement surgeries. Apart from being a burden to healthcare systems, readmissions are also troublesome for patients. There are several studies which only utilized structured data from Electronic Health Records (EHR) without considering any gender and payor bias adjustments. METHODS: For this study, dataset of 38,581 total knee, hip, and shoulder replacement surgeries performed from 2015 to 2021 at Novant Health was gathered. This data was used to train a random forest machine learning model to predict the combined endpoint of emergency department (ED) visit or unplanned readmissions within 30 days of discharge or discharge to Skilled Nursing Facility (SNF) following the surgery. 98 features of laboratory results, diagnoses, vitals, medications, and utilization history were extracted. A natural language processing (NLP) model finetuned from Clinical BERT was used to generate an NLP risk score feature for each patient based on their clinical notes. To address societal biases, a feature bias analysis was performed in conjunction with propensity score matching. A threshold optimization algorithm from the Fairlearn toolkit was used to mitigate gender and payor biases to promote fairness in predictions. RESULTS: The model achieved an Area Under the Receiver Operating characteristic Curve (AUROC) of 0.738 (95% confidence interval, 0.724 to 0.754) and an Area Under the Precision-Recall Curve (AUPRC) of 0.406 (95% confidence interval, 0.384 to 0.433). Considering an outcome prevalence of 16%, these metrics indicate the model's ability to accurately discriminate between readmission and non-readmission cases within the context of total arthroplasty surgeries while adjusting patient scores in the model to mitigate bias based on patient gender and payor. CONCLUSION: This work culminated in a model that identifies the most predictive and protective features associated with the combined endpoint. This model serves as a tool to empower healthcare providers to proactively intervene based on these influential factors without introducing bias towards protected patient classes, effectively mitigating the risk of negative outcomes and ultimately improving quality of care regardless of socioeconomic factors.

A Digital Health Intervention Platform (Active and Independent Management System) to Enhance the Rehabilitation Experience for Orthopedic Joint Replacement Patients: Usability Evaluation Study.

BACKGROUND: Optimal rehabilitation programs for orthopedic joint replacement patients ensure faster return to function, earlier discharge from hospital, and improved patient satisfaction. Digital health interventions show promise as a supporting tool for re-enablement. OBJECTIVE: The main goal of this mixed methods study was to examine the usability of the AIMS platform from the perspectives of both patients and clinicians. The aim of this study was to evaluate a re-enablement platform that we have developed that uses a holistic systems approach to address the de-enablement that occurs in hospitalized inpatients, with the older adult population most at risk. The Active and Independent Management System (AIMS) platform is anticipated to deliver improved patient participation in recovery and self-management through education and the ability to track rehabilitation progression in hospital and after patient discharge. METHODS: Two well-known instruments were used to measure usability: the System Usability Scale (SUS) with 10 items and, for finer granularity, the User Experience Questionnaire (UEQ) with 26 items. In all, 26 physiotherapists and health care professionals evaluated the AIMS clinical portal; and 44 patients in hospital for total knee replacement, total hip replacement, or dynamic hip screw implant evaluated the AIMS app. RESULTS: For the AIMS clinical portal, the mean SUS score obtained was 82.88 (SD 13.07, median 86.25), which would be considered good/excellent according to a validated adjective rating scale. For the UEQ, the means of the normalized scores (range -3 to +3) were as follows: attractiveness=2.683 (SD 0.100), perspicuity=2.775 (SD 0.150), efficiency=2.775 (SD 0.130), dependability=2.300 (SD 0.080), stimulation=1.950 (SD 0.120), and novelty=1.625 (SD 0.090). All dimensions were thus classed as excellent against the benchmarks, confirming the results from the SUS questionnaire. For the AIMS app, the mean SUS score obtained was 74.41 (SD 10.26), with a median of 77.50, which would be considered good according to the aforementioned adjective rating scale. For the UEQ, the means of the normalized scores were as follows: attractiveness=2.733 (SD 0.070), perspicuity=2.900 (SD 0.060), efficiency=2.800 (SD 0.090), dependability=2.425 (SD 0.060), stimulation=2.200 (SD 0.010), and novelty=1.450 (0.260). All dimensions were thus classed as excellent against the benchmarks (with the exception of novelty, which was classed as good), providing slightly better results than the SUS questionnaire. CONCLUSIONS: The study has shown that both the AIMS clinical portal and the AIMS app have good to excellent usability scores, and the platform provides a solid foundation for the next phase of research, which will involve evaluating the effectiveness of the platform in improving patient outcomes after total knee replacement, total hip replacement, or dynamic hip screw.

Safety Considerations for Outpatient Arthroplasty.

Since 2018, the number of total joint arthroplasties (TJAs) performed on an outpatient basis has dramatically increased. Both surgeon and anesthesiologist should be aware of the implications for the safety of outpatient TJAs and potential patient risk factors that could alter this safety profile. Although smaller studies suggest that the risk of negative outcomes is equivalent when comparing outpatient and inpatient arthroplasty, larger database analyses suggest that, even when matched for comorbidities, patients undergoing outpatient arthroplasty may be at increased risk of surgical or medical complications. Appropriate patient selection is critical for the success of any outpatient arthroplasty program. Potential exclusion criteria for outpatient TJA may include age greater than 75 years, bleeding disorder, history of deep vein thrombosis, uncontrolled diabetes mellitus, and hypoalbuminemia, among others. Patient optimization before surgery is also warranted. The potential risks of same-day versus next-day discharge have yet to be elicited in a large-scale manner.

Predicting Pulmonary Embolism in Total Joint Arthroplasty Patients A Pilot Study.

Postoperative venous thromboembolism (VTE) is a common and costly complication following total joint arthroplasty (TJA). Development of a refined thrombophilic screening panel will better equip clinicians to identify patients at high-est risk for developing VTEs. In this pilot study, 62 high-risk TJA recipients who had developed pulmonary emboli (PE) within 90-days of surgery were eligible to participate. Of these patients, 14 were enrolled and subsequently adminis-tered a pre-determined panel of 18 hematologic tests with the aim of identifying markers that are consistently elevated or deficient in patients developing PE. A separate cohort of seven high-risk TJA recipients who did not report a symp-tomatic VTE within 90-days of surgery were then enrolled and Factor VIII and lipoprotein(a) levels were assessed. The most common aberrance was noted in 10 patients (71.4%) who had elevated levels of Factor VIII followed by five patients (35.7%) who had elevated levels of lipoprotein(a). Factor VIII was significantly prevalent (p < 0.001) while lipoprotein(a) failed to achieve statistical significance (p = 0.0708). Of the patients who were within normal limits of Factor VIII, three-fourths were "high-normal" with Fac-tor VIII levels within 5% of the upper limit of normal. This study demonstrates the potential utility of this hematologic panel as part of a perioperative screening protocol aimed at identifying patients at risk for developing VTEs. However, future larger scale studies assessing the capabilities and limitations of our findings are warranted.

Metabolic Dysregulation and Its Role in Postoperative Pain among Knee Osteoarthritis Patients.

Knee osteoarthritis (KOA) is characterized by low-grade inflammation, loss of articular cartilage, subchondral bone remodeling, synovitis, osteophyte formation, and pain. Strong, continuous pain may indicate the need for joint replacement in patients with end-stage OA, although postoperative pain (POP) of at least a two-month duration persists in 10-40% of patients with OA. STUDY PURPOSE: The inflammation observed in joint tissues is linked to pain caused by the production of proinflammatory cytokines. Since the biosynthesis of cytokines requires energy, their production is supported by extensive metabolic conversions of carbohydrates and fatty acids, which could lead to a disruption in cellular homeostasis. Therefore, this study aimed to investigate the association between POP development and disturbances in energy metabolic conversions, focusing on carbohydrate and fatty acid metabolism. METHODS: Peripheral blood samples were collected from 26 healthy subjects and 50 patients with end-stage OA before joint replacement surgery. All implants were validated by orthopedic surgeons, and patients with OA demonstrated no inherent abnormalities to cause pain from other reasons than OA disease, such as malalignment, aseptic loosening, or excessive bleeding. Pain levels were assessed before surgery using the visual analogue scale (VAS) and neuropathic pain questionnaires, DN4 and PainDETECT. Functional activity was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Three and six months after surgery, pain indices according to a VAS of 30 mm or higher were considered. Total RNA isolated from whole blood was analyzed using quantitative real-time RT-PCR (qRT-PCR) for the expression of genes related to carbohydrate and fatty acid metabolism. Protein levels of the examined genes were measured using an ELISA in the peripheral blood mononuclear cells (PBMCs). We used qRT-PCR because it is the most sensitive and reliable method for gene expression analysis, while an ELISA was used to confirm our qRT-PCR results. KEY FINDINGS: Among the study cohort, 17 patients who reported POP demonstrated significantly higher (p < 0.05) expressions of the genes PKM2, LDH, SDH, UCP2, CPT1A, and ACLY compared to pain-free patients with KOA. Receiver-operating characteristic (ROC) curve analyses confirmed the association between these gene expressions and pain development post-arthroplasty. A principle component analysis identified the prognostic values of ACLY, CPT1A, AMPK, SDHB, Caspase 3, and IL-1ß gene expressions for POP development in the examined subjects. CONCLUSION: These findings suggest that the disturbances in energy metabolism, as observed in the PBMCs of patients with end-stage KOA before arthroplasty, may contribute to POP development. An understanding of these metabolic processes could provide insights into the pathogenesis of KOA. Additionally, our findings can be used in a clinical setting to predict POP development in end-stage patients with KOA before arthroplasty.

Patients' perspective of fast-track total joint arthroplasty: a systematic review.

The introduction of fast-track protocols decreased length of hospital stay and improved rehabilitation and outcomes in total joint arthroplasty. Despite improved clinical results published in many papers, the patient perspective of these protocols is less investigated. Purpose of this study was to explore the patient perspective of fast-track protocols in arthroplasty. A systematic search for articles of patient experiences in total hip, knee, and shoulder arthroplasty was conducted using EMBASE, MEDLINE, Cochrane, and Web-of-Science for articles published from inception to February 14, 2023. In total 12 studies were included involving 672 patients. Most patients were satisfied with short length of hospital stay and preferred rehabilitation at home with relatives for support. Various experiences were reported regarding pain and postoperative out of hospital physical therapy. Frequently, feelings of insecurity were reported because of lack of personalized information. Based on current qualitative literature, patients are satisfied with short length of hospital stay in fast-track total joint arthroplasty. Improvements in personalized information and physical therapy protocols is needed.

Mid- and long-term clinical results of the Elektra and Moovis prosthesis for trapeziometacarpal joint replacement.

BACKGROUND: Total joint arthroplasty as a surgical treatment option for trapeziometacarpal joint arthritis is recently revived. The aim of this study is to report on mid- and long-term results of the Elektra (single-mobility) and Moovis (dual-mobility) prosthesis for treatment of primary thumb carpometacarpal joint arthritis. METHODS: In this retrospective, monocentric, descriptive cohort study, 31 prostheses were evaluated that were implanted by a single surgeon in 26 patients between 2009 and 2019. Indication for surgery was trapeziometacarpal joint osteoarthritis (Eaton/Littler Stage II and III). Clinical and radiological follow-up was performed at a minimum of 24 months. The postoperative assessment included range of motion, pain, strength as well as functional scores (DASH, MHQ). Implant survival and complications were the primary endpoints. RESULTS: 10 Elektra and 21 Moovis prostheses were implanted between 2009 and 2019 with a mean follow-up of 74.2 months in the Elektra and 41.4 months in the Moovis group. The average patients' age at surgery was 64 years. Postoperative pain levels (VAS 0-10) were below 2 at rest and under stress in both groups. Grip/pinch strength and range of motion showed results comparable to the contralateral hand. Opposition was excellent with an average Kapandji index of 9.6 in both groups. Elektra achieved slightly better functional scores in the DASH and MHQ score. Satisfaction was high in both groups, and 96% of the patients would recommend the procedure. Metacarpophalangeal hyperextension > 15° was seen in 3 patients per group preoperatively and was corrected to < 5° post-surgery. 3 Elektra prostheses were revised due to cup loosening and dislocation for cup and/or neck replacement or secondary trapeziectomy. 1 Moovis prosthesis was revised with an exchange of the neck to a larger size due to restricted movement. After the mean follow-up of 7.9 years in Elektra and 3.5 years in MOOVIS, cumulative survival was 68.6% vs. 95.2%, respectively. CONCLUSIONS: In this mid- to long-term retrospective analysis, total joint arthroplasty in primary trapeziometacarpal joint arthritis results in low pain levels, excellent mobility and clinical function. Patient satisfaction is overall high. While revision due to cup loosening occurred more often in patients with single-mobility implants, no cases of dislocation or loosening of components were observed in the dual-mobility group. TRIAL REGISTRATION: The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of the Medical Faculty of Heidelberg University, reference number S-150/2020.

Aspirin or enoxaparin for VTE prophylaxis after primary partial, total or revision hip or knee arthroplasty: A secondary analysis from the CRISTAL cluster randomized trial.

BACKGROUND: This study compares aspirin to enoxaparin for symptomatic VTE prophylaxis within 90 days of any type of hip or knee arthroplasty performed for any diagnosis, in patients enrolled in the CRISTAL trial. MATERIALS AND METHODS: CRISTAL was a cluster-randomised crossover, registry-nested non-inferiority trial across 31 hospitals in Australia. The primary publication was restricted to patients undergoing primary total hip or knee arthroplasty for a diagnosis of osteoarthritis. This report includes all enrolled patients undergoing hip or knee arthroplasty procedures (partial or total, primary or revision) performed for any indication. Hospitals were randomized to administer patients aspirin (100mg daily) or enoxaparin (40mg daily), for 35 days after hip arthroplasty and 14 days after knee arthroplasty. Crossover occurred after the patient enrolment target had been met for the first group. The primary outcome was symptomatic VTE within 90 days. Analyses were performed by randomization group. RESULTS: Between April 20, 2019 and December 18, 2020, 12384 patients were enrolled (7238 aspirin group and 5146 enoxaparin). Of these, 6901 (95.3%) given aspirin and 4827 (93.8%) given enoxaparin (total 11728, 94.7%) were included in the final analyses. Within 90 days, symptomatic VTE occurred in 226 (3.27%) aspirin patients and 85 (1.76%) enoxaparin patients, significant for the superiority of enoxaparin (estimated treatment difference 1.85%, 95% CI 0.59% to 3.10%, p = 0.004). Joint-related reoperation within 90 days was lower in the enoxaparin group (109/4827 (2.26%) vs 171/6896 (2.47%) with aspirin, estimated difference 0.77%; 95% CI 0.06% to 1.47%, p = 0.03). There were no significant differences in the other secondary outcomes. CONCLUSION: In patients undergoing hip or knee arthroplasty (of any type, performed for any indication) enrolled in the CRISTAL trial, aspirin compared to enoxaparin resulted in a significantly higher rate of symptomatic VTE and joint-related reoperation within 90 days. These findings extend the applicability of the CRISTAL trial results. TRIAL REGISTRATION: Anzctr.org.au, identifier: ACTRN12618001879257.

Enhanced Recovery After Surgery Orthopaedics Program in a Community-Based Health Care System.

Enhanced Recovery After Surgery programs are common among healthcare systems and various surgical disciplines. Although evidence supporting the physiological rationale of multiple nutrition, physical activity, and pain control strategies before, during, and after surgical procedures is accumulating, implementing such strategies may pose a substantial challenge. The purpose of this quality improvement initiative was to outline the development, workflow, and implementation of an Enhanced Recovery After Surgery program for same-day total joint replacement procedures in a rural healthcare setting. This was not just an academic exercise. Our leadership had a strong desire to support our patients by identifying ways to hasten their recovery so that they can return to their preferred activities.

Compliant Intramedullary Stems for Joint Reconstruction.

The longevity of current joint replacements is limited by aseptic loosening, which is the primary cause of non-infectious failure for hip, knee, and ankle arthroplasty. Aseptic loosening is typically caused either by osteolysis from particulate wear, or by high shear stresses at the bone-implant interface from over-constraint. Our objective was to demonstrate feasibility of a compliant intramedullary stem that eliminates over-constraint without generating particulate wear. The compliant stem is built around a compliant mechanism that permits rotation about a single axis. We first established several models to understand the relationship between mechanism geometry and implant performance under a given angular displacement and compressive load. We then used a neural network to identify a design space of geometries that would support an expected 100-year fatigue life inside the body. We additively manufactured one representative mechanism for each of three anatomic locations, and evaluated these prototypes on a KR-210 robot. The neural network predicts maximum stress and torsional stiffness with 2.69% and 4.08% error respectively, relative to finite element analysis data. We identified feasible design spaces for all three of the anatomic locations. Simulated peak stresses for the three stem prototypes were below the fatigue limit. Benchtop performance of all three prototypes was within design specifications. Our results demonstrate the feasibility of designing patient- and joint-specific compliant stems that address the root causes of aseptic loosening. Guided by these results, we expect the use of compliant intramedullary stems in joint reconstruction technology to increase implant lifetime.

Acetabular Fractures in older patients Intervention Trial (AceFIT): a feasibility triple-arm randomized controlled study.

Aims: To assess the feasibility of a randomized controlled trial (RCT) that compares three treatments for acetabular fractures in older patients: surgical fixation, surgical fixation and hip arthroplasty (fix-and-replace), and non-surgical treatment. Methods: Patients were recruited from seven UK NHS centres and randomized to a three-arm pilot trial if aged older than 60 years and had a displaced acetabular fracture. Feasibility outcomes included patients' willingness to participate, clinicians' capability to recruit, and dropout rates. The primary clinical outcome measure was the EuroQol five-dimension questionnaire (EQ-5D) at six months. Secondary outcomes were Oxford Hip Score, Disability Rating Index, blood loss, and radiological and mobility assessments. Results: Between December 2017 and December 2019, 60 patients were recruited (median age 77.4 years, range 63.3 to 88.5) (39/21 M/F ratio). At final nine-month follow-up, 4/60 (7%) had withdrawn, 4/60 (7%) had died, and one had been lost to follow-up; a 98% response rate (50/51) was achieved for the EQ-5D questionnaire. Four deaths were recorded during the three-year trial period: three in the non-surgical treatment group and one in the fix-and-replace group. Conclusion: This study has shown a full-scale RCT to be feasible, but will need international recruitment. The Acetabular Fractures in older patients Intervention Trial (AceFIT) has informed the design of a multinational RCT sample size of 1,474 or 1,974 patients for a minimal clinically important difference of 0.06 on EQ-5D, with a power of 0.8 or 0.9, and loss to follow-up of 20%. This observed patient cohort comprises a medically complex group requiring multidisciplinary care; surgeon, anaesthetist, and ortho-geriatrician input is needed to optimize recovery and rehabilitation.

How Would We Know Whether Joint Replacements Are Successful if We Do Not Ask Patients?

Joint replacements are among the most effective and most frequently performed surgeries in Canada. Patient-reported outcome measures (PROMs) are measurement instruments completed by patients about aspects of their health status, including pain and function. PROMs data from three provinces show that approximately nine in 10 patients report higher PROM scores after joint replacement surgery. These data can help identify factors that lead to better care and opportunities to further understand what contributes to a patient's perception of surgical success. Expanding the collection of PROMs to more patients and more provinces is needed to help healthcare planners and clinicians understand these important outcomes.

Titanium-Doped Diamond-like Carbon Layers as a Promising Coating for Joint Replacements Supporting Osteogenic Differentiation of Mesenchymal Stem Cells.

Diamond-like carbon (DLC) layers are known for their high corrosion and wear resistance, low friction, and high biocompatibility. However, it is often necessary to dope DLC layers with additional chemical elements to strengthen their adhesion to the substrate. Ti-DLC layers (doped with 0.4, 2.1, 3.7, 6.6, and 12.8 at.% of Ti) were prepared by dual pulsed laser deposition, and pure DLC, glass, and polystyrene (PS) were used as controls. In vitro cell-material interactions were investigated with an emphasis on cell adhesion, proliferation, and osteogenic differentiation. We observed slightly increasing roughness and contact angle and decreasing surface free energy on Ti-DLC layers with increasing Ti content. Three-week biological experiments were performed using adipose tissue-derived stem cells (ADSCs) and bone marrow mesenchymal stem cells (bmMSCs) in vitro. The cell proliferation activity was similar or slightly higher on the Ti-doped materials than on glass and PS. Osteogenic cell differentiation on all materials was proved by collagen and osteocalcin production, ALP activity, and Ca deposition. The bmMSCs exhibited greater initial proliferation potential and an earlier onset of osteogenic differentiation than the ADSCs. The ADSCs showed a slightly higher formation of focal adhesions, higher metabolic activity, and Ca deposition with increasing Ti content.

Irradiation Behavior of Analgesic and Nonsteroidal Anti-Inflammatory Drug-Loaded UHMWPE for Joint Replacement.

Local delivery of pain medication can be a beneficial strategy to address pain management after joint replacement, as it can decrease systemic opioid usage, leading to less side and long-term effects. In this study, we used ultrahigh molecular weight polyethylene (UHMWPE), commonly employed as a bearing material for joint implants, to deliver a wide set of analgesics and the nonsteroidal anti-inflammatory drug tolfenamic acid. We blended the drugs with UHMWPE and processed the blend by compression molding and sterilization by low-dose gamma irradiation. We studied the chemical stability of the eluted drugs, drug elution, tensile properties, and wear resistance of the polymer blends before and after sterilization. The incorporation of bupivacaine hydrochloride and tolfenamic acid in UHMWPE resulted in either single- or dual-drug loaded materials that can be sterilized by gamma irradiation. These compositions were found to be promising for the development of clinically relevant drug-eluting implants for joint replacement.

Insulin resistance and osteocalcin associate with the incidence and severity of postoperative delirium in elderly patients undergoing joint replacement.

AIM: While insulin sensitivity plays an important role in maintaining glucose metabolic homeostasis and cognitive function, its impact on postoperative delirium (POD) remains unclear. This study aimed to investigate the association between POD and indicators of insulin sensitivity, including insulin resistance and osteocalcin. METHODS: A total of 120 elderly patients undergoing joint replacement were recruited and divided into delirium and non-delirium groups. Plasma and cerebrospinal fluid (CSF) samples were collected for the analysis of biomarkers, including insulin, uncarboxylated osteocalcin (ucOC), total osteocalcin (tOC), and glucose. Insulin resistance was assessed through the homeostatic model assessment of insulin resistance (HOMA-IR). MAIN RESULTS: Out of the total, 28 patients (23.3%) experienced POD within 5 days after surgery. Patients with delirium exhibited higher levels of preoperative HOMA-IR and ucOC in CSF and plasma, and of tOC in CSF (P = 0.028, P < 0.001, P = 0.005, P = 0.019). After adjusting for variables, including age, Mini-Mental State Examination score, surgical site and preoperative fracture, only preoperative ucOC in CSF and HOMA-IR were significantly linked to the incidence of delirium (OR = 5.940, P = 0.008; OR = 1.208, P = 0.046, respectively), both of which also correlated with the severity of delirium (P = 0.007, P < 0.001). Receiver operating curve analysis indicated that preoperative HOMA-IR and ucOC in CSF might partly predict POD (area under the curve [AUC] = 0.697, 95% confidence interval [CI] = 0.501-0.775, AUC = 0.745, 95% CI = 0.659-0.860). CONCLUSIONS: We observed that preoperative elevated HOMA-IR and ucOC in CSF were associated with the incidence and severity of POD. While these preliminary results need confirmation, they suggest a potential involvement of insulin resistance and osteocalcin in the pathological mechanism of POD. Geriatr Gerontol Int 2024; 24: 421-429.

Current thinking in open temporomandibular joint surgery. Is this still indicated in the management of articular temporomandibular joint disorder?

Management of temporomandibular disorders (TMD) follows a stepwise approach of conservative management, minimally invasive surgery (arthrocentesis and arthroscopy), open surgery and alloplastic replacement. The majority of patients treated in primary care and managed initially in secondary care have myofascial pain and can be managed conservatively with rest, topical NSAIDs, muscle massage, and a bite orthosis. Those who fail to improve and have articular related pain with limitation of function should initially undergo arthroscopic investigation and arthrocentesis, which is effective at resolving symptoms in 80% of patients. Arthroscopy provides the best diagnostic aid should there be a failure to improve and should enable the surgeon to appropriately plan open surgery. Historically, surgical intervention was based on a 'one size fits all' philosophy with the surgeon carrying out a procedure which they are used to doing regardless of the pathology. Prior to arthroscopy this carried an '80% chance of getting 80% better' regardless of approach. Prior arthroscopy reduced success rates to 50%-60% and a better success rate is needed. Basing surgical intervention on the pathology encountered is a sensible approach to joint management, with the surgeon performing surgery on the articular surfaces or disc as indicated. Having used this approach over the last 15 years the author has achieved success rates of 80% in the longer term and this philosophy, rationale, and technique will be discussed along with analysis of more recent publications in the field.

Cardiac function may be compromised in patients with elevated blood cobalt levels secondary to metal-on-metal hip implants.

Aims: Elevated blood cobalt levels secondary to metal-on-metal (MoM) hip arthroplasties are a suggested risk factor for developing cardiovascular complications including cardiomyopathy. Clinical studies assessing patients with MoM hips using left ventricular ejection fraction (LVEF) have found conflicting evidence of cobalt-induced cardiomyopathy. Global longitudinal strain (GLS) is an echocardiography measurement known to be more sensitive than LVEF when diagnosing early cardiomyopathies. The extent of cardiovascular injury, as measured by GLS, in patients with elevated blood cobalt levels has not previously been examined. Methods: A total of 16 patients with documented blood cobalt ion levels above 13 µg/l (13 ppb, 221 nmol/l) were identified from a regional arthroplasty database. They were matched with eight patients awaiting hip arthroplasty. All patients underwent echocardiography, including GLS, investigating potential signs of cardiomyopathy. Results: Patients with MoM hip arthroplasties had a mean blood cobalt level of 29 µg/l (495 nmol/l) compared to 0.01 µg/l (0.2 nmol/l) in the control group. GLS readings were available for seven of the MoM cohort, and were significantly lower when compared with controls (-15.5% vs -18% (MoM vs control); p = 0.025)). Pearson correlation demonstrated that GLS significantly correlated with blood cobalt level (r = 0.8521; p < 0.001). However, there were no differences or correlations for other echocardiography measurements, including LVEF (64.3% vs 63.7% (MoM vs control); p = 0.845). Conclusion: This study supports the hypothesis that patients with elevated blood cobalt levels above 13 µg/l in the presence of a MoM hip implant may have impaired cardiac function compared to a control group of patients awaiting hip arthroplasty. It is the first study to use the more sensitive parameter of GLS to assess for any cardiac contractile dysfunction in patients with a MoM hip implant and a normal LVEF. Larger studies should be performed to determine the potential of GLS as a predictor of cardiac complications in patients with MoM arthroplasties.

Complications of prosthesis versus trapeziectomy in trapeziometacarpal joint arthritis: A systematic review.

OBJECTIVE: Thumb osteoarthritis is a frequent pathology, mainly affecting the elderly. The surgical treatment initially described and having proved its worth is total trapeziectomy. Since the advent of trapeziometacarpal prostheses, several studies showed the non-inferiority of this technique on clinical criteria, with superiority in bone sparing, although neither technique demonstrated overall superiority. We therefore examined the specific complications of each surgical technique by analyzing their nature and prevalence through a review of the literature to compare them on these new parameters. METHODS: Seventy-four of the 320 articles reviewed were included, 38 of which concerned trapeziectomy, and 36 concerned prostheses, for a total of 4,865 patients. They were original studies, involving adults undergoing trapeziometacarpal arthroplasty or trapeziectomy, published after 2015, reporting at least one well-described complication. RESULTS: 6.13% of trapeziectomies presented severe complications (in particular thumb collapse and metacarpophalangeal hyperextension), 3.31% moderate complications and 1.90% minor complications, leading to a 2.0% revision rate. 23.88% of prostheses had severe complications (loosening, dislocation and wear), 5.06% moderate complications and 1.36% minor complications, leading to a 12.8% revision rate. In addition, we analyzed more recent prosthesis designs separately, and found lower prevalence of severe complications (16.56%) and revision surgery (4.3%). CONCLUSION: Revision surgery for trapeziometacarpal prostheses is usually only a standard trapeziectomy with the same follow-up as first-line trapeziectomy, whereas revision surgery for trapeziectomies is much more complex and the results are uncertain. For this reason, we would reserve total trapeziectomy for revision surgeries and patients with low functional demand for whom a second surgery is not desirable. Further studies could confirm this attitude, especially focusing on the latest generation of dual mobility implants.