Assessment of bone ingrowth around beaded coated tibial implant for total ankle replacement using mechanoregulatory algorithm.

The long-term performance of porous coated tibial implants for total ankle replacement (TAR) primarily depends on the extent of bone ingrowth at the bone-implant interface. Although attempts were made for primary fixation for immediate post-operative stability, no investigation was conducted on secondary fixation. The aim of this study is to assess bone ingrowth around the porous beaded coated tibial implant for TAR using a mechanoregulatory algorithm. A realistic macroscale finite element (FE) model of the implanted tibia was developed based on computer tomography (CT) data to assess implant-bone micromotions and coupled with microscale FE models of the implant-bone interface to predict bone ingrowth around tibial implant for TAR. The macroscale FE model was subjected to three near physiological loading conditions to evaluate the site-specific implant-bone micromotion, which were then incorporated into the corresponding microscale model to mimic the near physiological loading conditions. Results of the study demonstrated that the implant experienced tangential micromotion ranged from 0 to 71 µm with a mean of 3.871 µm. Tissue differentiation results revealed that bone ingrowth across the implant ranged from 44 to 96 %, with a mean of around 70 %. The average Young's modulus of the inter-bead tissue layer varied from 1444 to 4180 MPa around the different regions of the implant. The analysis postulates that when peak micromotion touches 30 µm around different regions of the implant, it leads to pronounced fibrous tissues on the implant surface. The highest amount of bone ingrowth was observed in the central regions, and poor bone ingrowth was seen in the anterior parts of the implant, which indicate improper osseointegration around this region. This macro-micro mechanical FE framework can be extended to improve the implant design to enhance the bone ingrowth and in future to develop porous lattice-structured implants to predict and enhance osseointegration around the implant.

Reliability assessment of new radiographic scales to evaluate radiolucency and bony in-between fin growth of partially cemented all-polyethylene glenoid components.

BACKGROUND: Current methods available for assessment of radiolucency and in-between fin (IBF) growth of a glenoid component have not undergone interobserver reliability testing for an all-polyethylene fluted central peg (FCP) glenoid. The purpose of this study was to evaluate anteroposterior radiographs of an FCP glenoid component at ≥48 months comparing commonly used scales to a new method adapted to the FCP. Our hypothesis was that the new method would result in acceptable intra- and interobserver agreement and a more accurate description of radiographic findings. METHODS: We reviewed ≥48-month follow-up radiographs of patients treated with a primary aTSA using an FCP glenoid. Eighty-three patients were included in the review. Radiographs were evaluated by 5 reviewers using novel IBF radiodensity and radiolucency assessments and the Wirth and Lazarus methods. To assess intraobserver reliability, a subset of 40 images was reviewed. Kappa statistics were calculated to determine intra- and interobserver reliability; correlations were assessed using Pearson correlation. RESULTS: Interobserver agreement (κ score) was as follows: IBF 0.71, radiolucency 0.68, Wirth 0.48, and Lazarus 0.22. Intraobserver agreement ranges were as follows: IBF radiodensity 0.36-0.67, radiolucency 0.55-0.62, Wirth 0.11-0.73, and Lazarus 0.04-0.46. Correlation analysis revealed the following: IBF to Wirth r = 0.93, radiolucency to Lazarus r = 0.92 (P value <.001 for all). CONCLUSION: This study introduces a radiographic assessment method developed specifically for an FCP glenoid component. Results show high interobserver and acceptable intraobserver reliability for the method presented in this study. The new scales provide a more accurate description of radiographic findings, helping to identify glenoid components that may be at risk for loosening.

Implant Selection Strategies for Total Joint Arthroplasty: The Effects on Cost Containment and Physician Autonomy.

BACKGROUND: With continued declines in reimbursement for total joint arthroplasty, health systems have explored implant cost containment measures to generate sustainable margins. This review evaluated how implementation of (1) implant price control programs, (2) vendor purchasing agreements, and (3) bundled payment models affected implant costs and physician autonomy in implant selection. METHODS: PubMed, EBSCOhost, and Google Scholar were searched to identify studies that evaluated the efficacy of total hip or total knee arthroplasty implant selection strategies. The review included publications between January 1, 2002, and October 17, 2022. The mean Methodological Index for Nonrandomized Studies score was 18.3 ± 1.8. RESULTS: A total of 13 studies (32,197 patients) were included. All studies implementing implant price capitation programs found decreased implant costs, ranging 2.2 to 26.1% and increased utilization of premium implants. Most studies found bundled payments models reduced total joint arthroplasty implant costs with greatest reduction being 28.9%. Additionally, while absolute single vendor agreements had higher implant costs, preferred single vendor agreements had reduced implant costs. When given price constraints, surgeons tended to select more premium implants. CONCLUSION: Alternative payment models that incorporated implant selection strategies saw reduced costs and surgeon utilization of premium implants. The study findings encourage further research on implant selection strategies, which must balance the goals of cost containment with physician autonomy and optimized patient care. LEVEL OF EVIDENCE: Level III.

Structural assessment of pre-flexion in silicone implants for arthroplasty of the first metatarsophalangeal joint.

The development of numerical models to analyze pathologies and implants related to the first metatarsophalangeal joint of the foot remains an issue for attention. The structural effects of implants pre-flexion have been discarded in several finite elements analyses due to complexities to achieve these positions. This work aims to evaluate if the pre-flexion stress state should be included or could be discarded when only flexion is applied in two different silicone commercial implants, Swanson and Tornier, during a gait cycle. Finite element models were created for silicone implants. Both models were discretized using high-order finite elements. The hyperelasticity constitutive material model of Arruda-Boyce was used, based on experimental data; its behavior was compared with linear elastic models reported and used frequently assuming small and large deformations and applying to the Swanson and Tornier implants a flexion angle of 64°, which corresponds to in vivo measurements reported after implantation. Comparison between models, regarding hyperelastic model, showed mean variations of up to 32.5% for stresses and 14.01% for bending moment in Swanson implant, while for Tornier implant mean variations of 29.73% and 632.55% was obtained for stress and bending moment respectively. The maximum stress value obtained for the hyperelastic model in the Swanson implant reached a value of 22.82% of the tensile strength of the implant material while in the Tornier implant reached a value of 25.92%, the above values were evaluated at a flexion angle of 64°. The results suggest considering in finite element analyses not only the stress state generated to achieve critical flexion position in pleflexed implants models but also the hyperelastic material behavior of silicone for implants to avoid dismissing the non-linear structural behavior of hyperelastic materials.

CT Scan Assessment and Functional Outcome of Periprosthetic Bone Grafting After Total Ankle Arthroplasty at Medium-term Follow-up.

BACKGROUND: Periprosthetic cysts can occur in up to 95% of total ankle arthroplasties (TAA) and have been correlated with implant failure. The aim of this study was to determine the clinical and radiologic outcomes, using computed tomographic (CT) scan, after periprosthetic cyst bone grafting and assess for the minimum cyst size that should be grafted. METHODS: A retrospective review was performed of all TAA procedures performed between 2007 and 2014 (n=93). A CT scan was done to assess cyst size and operative planning. Eight patients with 9 periprosthetic cysts larger than 1.75 cm3 were grafted and specimens sent for histology. The mean time to bone grafting was 7.3 (3.8-9.5) years. Functional outcome was assessed using the American Orthopaedic Foot & Ankle Society ankle score, visual analog scale, and Self-reported Foot and Ankle Score. A CT scan was performed at follow-up to assess graft incorporation and cyst size progression. The mean time to CT scan post grafting was 3.0 (0.7-4.7) years. RESULTS: There was no implant malalignment identified and no differences in the pre- and postoperative functional scores. Preoperatively cysts had a mean volume of 8.16 (2.04-14.03) cm3. The mean percentage incorporation was 89% (69%-100%). Eight of the grafted cysts were considered successful on CT, with the ninth having 69% incorporation. Five cysts were not grafted, as they were below 1.75 cm3, and remained the same size or had minimal enlargement. CONCLUSION: The satisfactory results in this small cohort suggests that prophylactic bone grafting may extend implant survival. We recommend that periprosthetic cysts greater than 1.75 cm3 be prophylactically bone grafted, and that cysts smaller than 1.75 cm3 be monitored for progression in size. LEVEL OF EVIDENCE: Level IV, Case Series.

Carcinogenic assessment of cobalt-containing alloys in medical devices or cobalt in occupational settings: A systematic review and meta-analysis of overall cancer risk from published epidemiologic studies.

In 2020, the European Commission up-classified pure cobalt metal to a Category 1B hazard, based primarily on data from rodent inhalation carcinogenicity studies of metallic cobalt. The European Commission review did not evaluate cobalt-containing alloys in medical devices, which have very different properties vs. pure cobalt metal and did not include a systematic epidemiologic review. We performed a systematic review and meta-analysis of published, peer-reviewed epidemiologic studies evaluating the association between overall cancer risk and exposure to orthopedic implants containing cobalt alloys or cobalt particulates in occupational settings. Study-specific estimates were pooled using random-effects models. Analyses included 20 papers on orthopedic implants and 10 occupational cohort papers (~1 million individuals). The meta-analysis summary estimates (95% confidence intervals) for overall cancer risk were 1.00 (0.96-1.04) overall and 0.97 (0.94-1.00) among high-quality studies. Results were also similar in analyses stratified by type of exposure/data sources (occupational cohort, implant registry or database), comparators (general or implant population), cancer incidence or mortality, follow-up duration (latency period), and study precision. In conclusion, meta-analysis found no association between exposure to orthopedic implants containing cobalt alloys or cobalt particulates in occupational settings and overall cancer risk, including an analysis of studies directly comparing metal-on-metal vs. non-metal-on-metal implants.

The importance of multisection sagittal and coronal magnetic resonance imaging evaluation in the assessment of temporomandibular joint disc position.

OBJECTIVES: The aim of this study was to evaluate diagnoses of temporomandibular (TMJ) disc displacement by comparing evaluations done on the basis of central sagittal scans only, the most often used in temporomandibular disorder (TMD) patients, with a multisection evaluation done with both sagittal and coronal scans. MATERIALS AND METHODS: Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to RDC/TMD criteria. Disc position in the intercuspal position (IP) was assessed two times using two different methods. The first method involved a TMJ disc position evaluation on the central slide in the oblique sagittal plane only. In the second method, the TMJ disc position was assessed on all oblique sagittal and coronal images. McNemar's χ2 test was used to evaluate the differences between the sensitivities of two methods. RESULTS: The first method (central oblique sagittal scans assessment) identified 148 TMJs (38.7%) with normal disc position compared with 89 TMJs (23.3%) with normal disc position found by the second method (all oblique sagittal and coronal scans assessment). The sensitivity of analysis in both planes was significantly higher than in the sagittal plane only (p < 0.001). CONCLUSIONS: The multisection analysis in the sagittal and coronal plane allows to distinguish the correct disc position from disc displacement and thus improve evaluation of TMJ internal derangement. CLINICAL RELEVANCE: The multisection sagittal and coronal images should be recommended as a standard in MRI of the TMJ disc displacement in patients with TMD to avoid false-negative diagnoses.

Learning curve assessment for total ankle replacement using the transfibular approach.

BACKGROUND: Total ankle arthroplasty is an increasingly effective option for the treatment of end-stage arthritis. One recent innovation utilizes a transfibular, lateral approach. Like any new system, there is likely a learning curve associated with its use. We analyzed a series of patients who received a total ankle arthroplasty via a transfibular approach to state if it is possible to identify and to evaluate effects of a learning curve in the use of this novel total ankle replacement system. METHODS: 76 consecutive patients meeting inclusion and exclusion criteria were retrospectively analyzed. All patients had a minimum of 24 months of follow-up. Intraoperative parameters, preoperative and postoperative subjective outcome scores, radiographic parameters, and complications were recorded and evaluated. RESULTS: There were significant learning curve effects on various surgical and postoperative parameters. Surgical time decreased with the curve stabilizing after the 16th patient. With regard to patient outcomes, a learning curve was identified for the VAS, AOFAS, and SF-12 MCS scores. The number of patients required to stabilize these curves were 21, 13, and 16, respectively. Alignment as measured by alpha and gamma angles also improved with experience, with the curves stabilizing at 18 and 15 patients, respectively. There was a larger number cases required for complication rates, with the curve stabilizing after the 39th patient. No significant learning curve was found for ankle ROM, SF-12 PCS, beta angle, tibio-talar ratio (TTR), or tibio-talar surface angle (TTS). CONCLUSIONS: This study demonstrates a significant learning curve with respect to operative time, patient outcomes, and radiographic parameters. Extrapolating this information, we urge surgeons to adequately familiarize themselves with any new implant through a training program in a high-volume center. LEVEL OF EVIDENCE: IV, case series.

Detection of α-defensin in synovial fluids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry as an innovative and cost-effective assay for improved definition of periprosthetic joint infections.

RATIONALE: Detection of α-defensins in synovial fluid is gaining more and more interest in the field of correct diagnosis of periprosthetic joint infections (PJIs). At present, they can be assessed by a quantitative enzyme-linked immunosorbent assay which is expensive and time-consuming and by a qualitative lateral flow immunoassay which is rapid but quite expensive and whose clinical sensitivity is debated. Thus, developing an alternative rapid, accurate, and low-cost assay for α-defensins is important to make α-defensins actionable as novel key clinical markers. METHODS: Synovial fluid (SF) samples were obtained from 18 patients undergoing revision of primary joint arthroplasty. Of these, eight met the 2013 Musculoskeletal Infection Society (MSIS) criteria for PJIs, the remaining were classified as aseptic failure. Microbiological analysis and Synovasure assays were carried out on all samples. Sample preparation and the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) settings were adjusted to detect human neutrophil peptide (HNP)-1, -2 and -3 and to obtain optimal results in term of sensitivity and stability. RESULTS: MALDI-TOF MS was able to detect HNPs in SF from septic patients. No signals for HNPs were detected in SF from aseptic failure. The limits of detection (LOD) were 2.5 and 1.25 µg/mL for HNP-2 and HNP-1, respectively. The turnaround time of the analysis is 20 min, and SF samples are stable at -20°C for up to 3 days. Assay sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were 100% for all parameters. On the same SF samples, the Synovasure assay showed lower sensitivity specificity, and PPV and NPV of 87.5%, 90%, 87.5% and 90%, respectively. Microbiological analysis of SF confirmed the presence of bacteria only in SF MSIS-positive patients. CONCLUSIONS: The reported MALDI-TOF MS assay was able to detect and differentiate HNPs in SF samples and showed a slightly better diagnostic accuracy than the Synovasure assay.

Musculoskeletal Infection in Orthopaedic Trauma: Assessment of the 2018 International Consensus Meeting on Musculoskeletal Infection.

Fracture-related infections (FRIs) are among the most common complications following fracture fixation, and they have a huge economic and functional impact on patients. Because consensus guidelines with respect to prevention, diagnosis, and treatment of this major complication are scarce, delegates from different countries gathered in Philadelphia in July 2018 as part of the Second International Consensus Meeting (ICM) on Musculoskeletal Infection. This paper summarizes the discussion and recommendations from that consensus meeting, using the Delphi technique, with a focus on FRIs. A standardized definition that was based on diagnostic criteria was endorsed, which will hopefully improve reporting and research on FRIs in the future. Furthermore, this paper provides a grade of evidence (strong, moderate, limited, or consensus) for strategies and practices that prevent and treat infection. The grade of evidence is based on the quality of evidence as utilized by the American Academy of Orthopaedic Surgeons. The guidelines presented herein focus not only on the appropriate use of antibiotics, but also on practices for the timing of fracture fixation, soft-tissue coverage, and bone defect and hardware management. We hope that this summary as well as the full document by the International Consensus Group are utilized by those who are charged with musculoskeletal care internationally to optimize their management strategies for the prevention and treatment of FRIs.

National Prevalence of Complications and Cost of Small Joint Arthroplasty for Hand Osteoarthritis and Post-Traumatic Arthritis.

PURPOSE: Osteoarthritis (OA) of the hand is commonly treated using implant arthroplasty. Despite the increasing prevalence of hand OA, population-based evidence regarding the complication profile and associated cost for patients undergoing proximal interphalangeal (PIP) joint and metacarpophalangeal (MCP) joint arthroplasty are lacking. Therefore, we aimed to evaluate the complication profiles and variation in cost of care for patients undergoing PIP and MCP joint arthroplasty. METHODS: We analyzed insurance claims from 2009 to 2016 using the Truven MarketScan Databases for adult patients undergoing a PIP and MCP joint arthroplasty following OA or post-traumatic arthritis diagnosis. Multivariable logistic regression was performed to investigate the association of patient-level factors and complications at 2 years after surgery. Cumulative direct cost, defined as the cost of the index surgery and 2-year postoperative episode, and patient-level characteristics were examined. RESULTS: We analyzed a total of 2,859 patients who underwent MCP joint arthroplasty (36%) or PIP joint arthroplasty (64%). On average, these procedures have a 35% complication rate. However, patients undergoing PIP joint arthroplasty were more likely to suffer a prosthetic fracture than patients undergoing MCP joint arthroplasty (3.4% vs 1.5%, respectively). Each complication resulted in an additional cost of $1,076. CONCLUSIONS: This nationwide analysis provides a population estimate of the complication profile and associated costs of MCP and PIP joint arthroplasty for hand OA and post-traumatic arthritis. Minimizing postoperative complications after MCP and PIP joint arthroplasty is one avenue to decrease health care costs. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Patient willingness to contribute to the cost of novel implants in total joint arthroplasty: the Canadian experience

Background: In Canada, health care is covered by provincial health insurance programs; patients do not directly participate in paying for their acute care expenses. The aim of this study is to assess the willingness of Canadian patients to contribute to the costs of novel total joint arthroplasty implants. Methods: We administered a questionnaire to patients attending an outpatient arthroplasty clinic in Ontario. In the questionnaire, the longevity and risk of complications of a "standard" implant were described. We asked if participants would be willing to contribute to the cost of 3 novel implants that had differing longevities and risks of complications compared with the standard implant. Results: One hundred and fifteen patients completed our questionnaire. Up to 62% of patients were willing to contribute a copayment to get an implant with greater longevity. Willingness to pay decreased to 40% for an implant with greater longevity but an increased risk of complications. Forty percent of participants were willing to pay for an implant with the same longevity as the standard implant but a decreased risk of complications. Participants with a higher income were more willing than other participants to contribute to the cost of a novel implant with greater longevity or lower complication rates. Conclusion: This study demonstrated that up to 62% of our sample of patients in Ontario were willing to share the costs of a novel total joint replacement implant. Willingness to pay was associated with the proposed benefits of the implant and certain patient characteristics. Our study shows that a high proportion of Canadian patients may be willing to copay to have access to new technologies.

Contexte: Au Canada, les soins de santé sont assurés par les régimes provinciaux d'assurance maladie; les patients ne participent pas directement au paiement des soins de santé actifs. Le but de cette étude était de vérifier si les patients canadiens sont prêts à contribuer au paiement de prothèses d'un type nouveau pour les arthroplasties totales. Méthodes: Nous avons administré un questionnaire à des patients d'une clinique externe d'arthroplastie en Ontario. Dans le questionnaire, on décrivait la durée de vie et les risques de complications associés à une prothèse « standard ¼. Nous avons demandé aux participants s'ils étaient ouverts à l'idée de contribuer au paiement de 3 prothèses d'un nouveau type, comportant une durée de vie et des risques de complications différents de ceux de la prothèse standard. Résultats: Cent quinze patients ont répondu à notre questionnaire. Jusqu'à 62 % des patients se sont dits prêts à contribuer à une forme de copaiement pour obtenir une prothèse plus durable. La volonté de payer diminuait à 40 % pour une prothèse plus durable mais comportant plus de risques de complications. Quarante pour cent des participants se sont dits prêts à payer pour une prothèse de même durée de vie que la prothèse standard, mais comportant moins de risques de complications. Les participants ayant un revenu plus élevé étaient davantage disposés à contribuer au paiement d'une prothèse d'un nouveau type plus durable et comportant moins de risques de complications comparativement aux autres participants. Conclusion: Cette étude a démontré que jusqu'à 62 % de notre échantillon de patients ontariens étaient prêts à partager les coûts d'une nouvelle prothèse pour arthroplastie totale. La volonté de payer était associée aux avantages présumés de la prothèse et à certaines caractéristiques des patients. Notre étude montre qu'une forte proportion de patients canadiens seraient prêts à s'engager dans un copaiement pour avoir accès à de nouvelles technologies.

Health economic evaluation in orthotics and prosthetics: a systematic review protocol.

BACKGROUND: Health economic evaluations are essential to support health care policy and investment decisions. To date, health economic evaluations in orthotics and prosthetics have focused on discrete components of an orthosis/prosthesis (e.g. a microprocessor controlled prosthetic knee joint) rather than the broader service provided by orthotist/prosthetists. As such, the contribution to orthotic/prosthetic policy and investment decisions is unclear. Whilst there are opportunities to conduct more informative health economic evaluations that describe the costs and benefits of the orthotic/prosthetic service, it is important that prospective research is informed by a critical review of the method design challenges and an understanding of how this research can be improved. The aim of this systematic review is to critically appraise the existing orthotic/prosthetic health economic evaluation literature and therefore determine evidence gaps, critical method design issues and the extent to which the literature informs orthotic/prosthetic policy and investment decisions. METHODS: A comprehensive range of databases-AMED, EMBASE, MEDLINE and PsychINFO, Cumulative Index of Nursing and Allied Health Literature (CINAHL), ProQuest Nursing and Allied Health, Web of Science, Cochrane Database of Systematic Reviews (CDSR) and specialty health economic databases-will be searched using National Library of Medicine Medical Subject Headings (MeSH) terms as well as the title, abstract, and keyword terms. Search terms related to the intervention (e.g. orthosis), including variants used by varying professional disciplines (e.g. brace), will be used in preference to defining the populations that use orthotic and prosthetic services (e.g. people living with rheumatoid arthritis). Search terms related to health economic evaluations will be guided by previously developed and tested search strings and align with recommendations by the Canadian Agency for Drugs and Technologies in Health. Articles meeting the inclusion criteria will be hand-searched for relevant citations, and a forward citation search using Google Scholar will also be conducted to identify early online articles not yet indexed in traditional databases. Original research published in the English language and after 1 January 2000 will be included. The Checklist for Health Economic Evaluation Reporting Standards (CHEERS) and the Consensus on Health Economic Criteria (CHEC)-Extended list will be used to appraise the methodological quality and identify sources of bias. Data extraction and appraisal will be conducted by one reviewer independently using appraisal instrument guidelines and a content specific decision aid with exemplars. A subsequent review by a second researcher will be undertaken to confirm the accuracy of the extraction and appraisal, and a final review by a third where consensus cannot be reached. The data will be extracted to a purpose-built data extraction template with decision-making guidelines to support consistency. Where possible, the findings of the review will be reported as a meta-analysis, although the heterogeneity of the literature will likely mean a narrative review that illuminates method design issues that contribute to imprecision and variation will be more appropriate. DISCUSSION: This protocol has been purposefully designed to summarise the existing evidence and appraise the methodological approaches used and the quality of the health economic evaluations in orthotics and prosthetics. What we learn from this review will be used to guide further work in this area and design more rigorous health economic evaluations into the future. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018116910.

Current Practice Patterns of Fellowship-Trained Arthroplasty Surgeons: Has the Influence of Fellowship Training Been Undervalued?

BACKGROUND: As the clinical and financial environments of total joint arthroplasty (TJA) have evolved over the last several decades so has the role of the surgeon in providing this care to patients. Our objective was to examine current practices and influential factors among fellowship-trained arthroplasty surgeons. METHODS: An electronic survey was sent to all surgeons who had completed one of the three high-volume adult reconstruction fellowships from the years 2007-2016. The survey consisted of 34 questions regarding current practice characteristics, case volumes for primary and revision total hip arthroplasty (THA) and total knee arthroplasty (TKA), use of advanced technologies, choice of surgical approach and implant design, factors influencing their choices, and their involvement in implant selection and contract negotiations. RESULTS: Questionnaires were sent to 53 surgeons; 52 were completed. Sixty percent of respondents performed at least 100 TKAs and 84% performed at least 50 THAs annually. Ninety-four percent use a single company's implant for more than 90% of primary TKA and THA. Fellowship or residency experience was the most significant influence on TKA and THA implant selection for 62% and 45% of surgeons, respectively, while contracts of their current institution were the primary influence for 17% and 12%, respectively. Fifty-five percent of surgeons used some advanced technology of which 16% said this influenced their implant choice. Eighty-six percent perform the majority of cases at centers performing at least 200 TJAs per year, and 39% participate in implant contract negotiations. CONCLUSION: Despite changes in the economic environment of TJA, this study demonstrates that experience with a specific implant during training, particularly fellowship, is the most influential factor for implant selection among fellowship-trained arthroplasty surgeons.

Comparative cost-effectiveness analysis of the subacromial spacer for irreparable and massive rotator cuff tears.

PURPOSE: There is ongoing debate regarding the optimal surgical treatment of irreparable rotator cuff tears (IRCT). This study aimed to assess within the Italian health care system the cost-effectiveness of subacromial spacer as a treatment modality for patients with IRCT. METHODS: An expected-value decision analysis was created comparing costs and outcomes of patients undergoing arthroscopic subacromial spacer implantation, rotator cuff repair (RCR), total shoulder arthroplasty, and conservative treatment for IRCTs. A broad literature search provided input data to extrapolate and inform treatment success and failure rates, costs, and health utility states for these outcomes. The primary outcome assessed was an incremental cost-effectiveness ratio (ICER) of subacromial spacer implantation versus shoulder arthroplasty, RCR, and conservative treatment. RESULTS: Subacromial spacer is favorable over both arthroscopic partial repair and shoulder arthroplasty since it costs less than both options and increases effectiveness by 0.06 and 0.10 quality-adjusted life years (QALYs), respectively. While conservative treatment is the least costly management strategy, subacromial spacer results in a gain of 0.05 QALYs for the additional cost of 522 €, resulting in an ICER of 10,440 €/QALY gain, which is below the standard willingness to pay ratio of $50,000 USD. Strategies with an ICER of less than 50,000 USD are considered to be cost-effective. CONCLUSIONS: Based on the available evidence and reasonably conservative assumptions, subacromial spacer is likely to provide a safe, effective, and cost-effective option for patients with massive IRCTs. Furthermore, this cost-effectiveness analysis may ultimately serve as a guide for development of health care system and insurer policy as well as clinical practice.

18F-Sodium Fluoride PET/CT and PET/MR Imaging of Bone and Joint Disorders.

18F-sodium fluoride (18F-NaF) PET/CT provides high sensitivity and specificity for the assessment of bone and joint diseases. It is able to accurately differentiate malignant from benign bone lesions, especially when using dynamic quantitative approaches. Its high-quality, clinical accuracy, and high feasibility for patient management and greater availability of PET/CT scanners as well as decreasing trend of the cost of radiotracer all indicate the need to consider the use of 18F-NaF PET/CT as standard bone imaging, particularly in malignant diseases of the skeleton.

Isolated Polyethylene Exchange With Increased Constraint Is Comparable to Component Revision TKA for Instability in Properly Selected Patients.

BACKGROUND: Symptomatic instability following total knee arthroplasty (TKA) is a leading cause of early failure. Most reports recommend component revision as the preferred treatment because of poor outcomes and high failure rates with isolated tibial polyethylene insert exchange (ITPIE). However, these ideas have not been tested in modern implant systems that allow insert constraint to be increased. METHODS: We retrospectively reviewed 90 consecutive patients with minimum 2-year (mean 3.7 years) follow-up who underwent revision TKA for instability at a single institution. Mean age was 62.0 years (range, 41 to 83 years), and 73% of patients were women. Forty percent of patients were treated with ITPIE when standardized preoperative and intraoperative criteria were met; 60% underwent revision of one or both components when these criteria were not met. RESULTS: Patients experienced significant improvements in Knee Society (KS) knee (48.4 to 82.6; P < .001) and function (49.0 to 81.0; P < .001) scores. There were no significant differences in improvements in KS knee scores (38.1 vs 33.1; P = .18), KS function scores (36.0 vs 34.0; P = .63), or arc of motion (5° vs 6°; P = .88) between those treated with ITPIE and component revision. Failure rates were 19.4% in the ITPIE group vs 18.5% in the component revision group (odds ratio, 1.06; P = .91). Re-revision rates were significantly lower (6.3% vs 30.8%; odds ratio, 0.15; P = .004) when polyethylene insert constraint was increased. CONCLUSION: In selected patients, ITPIE is not inferior to component revision at addressing symptomatic instability following TKA. Degree of constraint should be increased whenever possible during revision surgery for instability.