Development of a Machine-Learning Model for Anterior Knee Pain After Total Knee Arthroplasty With Patellar Preservation Using Radiological Variables.

BACKGROUND: Anterior knee pain (AKP) following total knee arthroplasty (TKA) with patellar preservation is a common complication that significantly affects patients' quality of life. This study aimed to develop a machine-learning model to predict the likelihood of developing AKP after TKA using radiological variables. METHODS: A cohort of 131 anterior stabilized TKA cases (105 patients) without patellar resurfacing was included. Patients underwent a follow-up evaluation with a minimum 1-year follow-up. The primary outcome was AKP, and radiological measurements were used as predictor variables. There were 2 observers who made the radiological measurement, which included lower limb dysmetria, joint space, and coronal, sagittal, and axial alignment. Machine-learning models were applied to predict AKP. The best-performing model was selected based on accuracy, precision, sensitivity, specificity, and Kappa statistics. Python 3.11 with Pandas and PyCaret libraries were used for analysis. RESULTS: A total of 35 TKA had AKP (26.7%). Patient-reported outcomes were significantly better in the patients who did not have AKP. The Gradient Boosting Classifier performed best for both observers, achieving an area under the curve of 0.9261 and 0.9164, respectively. The mechanical tibial slope was the most important variable for predicting AKP. The Shapley test indicated that high/low mechanical tibial slope, a shorter operated leg, a valgus coronal alignment, and excessive patellar tilt increased AKP risk. CONCLUSIONS: The results suggest that global alignment, including sagittal, coronal, and axial alignment, is relevant in predicting AKP after TKA. These findings provide valuable insights for optimizing TKA outcomes and reducing the incidence of AKP.

A Cross-Sectional, Retrospective, and Comparative Study between Delirium and Non-Delirium Psychiatric Disorders in a Psychogeriatric Inpatient Population Referred to Consultation-Liaison Psychiatry Unit.

Background and objectives: Delirium is the most prevalent psychiatric disorder in inpatient older people. Its presence is associated with higher rates of institutionalization, functional disability and mortality. This study aims to evaluate delirium in a hospitalized psychogeriatric population, focusing on which factors predict the appearance of delirium, the impact it generates and the diagnostic concordance between non-psychiatric physicians and psychiatrists. Material and methods: This is an observational, cross-sectional, retrospective, and comparative study. We obtained data from a sample of 1017 patients (≥65 years) admitted to general hospital and referred from different services to the consultation-liaison psychiatry (CLP) unit. Logistic regression was performed using delirium as the dependent variable. To estimate the concordance of the diagnoses, the Kappa coefficient was used. To assess the impact of delirium, an ordinal regression, Wilcoxon median test and Fisher's test were performed. Results: Delirium is associated with a higher number of visits, OR 3.04 (95% CI 2.38-3.88), longer length of stay and mortality, OR 2.07 (95% CI, 1.05 to 4.10). The model to predict delirium shows that being >75 years old has an OR of 2.1 (95% CI, 1.59-2.79), physical disability has an OR of 1.66 (95% CI, 1.25-2.20), history of delirium has an OR of 10.56 (95% CI, 5.26-21.18) and no use of benzodiazepines has an OR of 4.24 (95% CI, 2.92-6.14). The concordance between the referring physician's psychiatric diagnosis and the psychiatrist CLP unit showed a kappa of 0.30. When analysing depression and delirium, the concordance showed Kappa = 0.46. Conclusions: Delirium is a highly prevalent psychiatric disorder, but it is still underdiagnosed, with low diagnostic concordance between non-psychiatric doctors and psychiatrists from CLP units. There are multiple risk factors associated with the appearance of delirium, which must be managed to reduce its appearance.

Knee haemophilic arthropathy care in Chile: Midterm outcomes and complications after total knee arthroplasty.

INTRODUCTION: Total knee arthroplasty (TKA) can improve knee function in the general population, but challenges arise for TKA use in haemophilic patients (HPs). AIM: This study aimed to evaluate the midterm clinical experience of a single medical centre in TKA in HPs. METHODS: We performed a case series of consecutive TKAs from 2007 to 2013 in HPs. All patients received coagulation factor supplementation according to the institutional protocol. Surgery was performed without a tourniquet by a standard midline medial parapatellar approach. We compared the range of motion (ROM) and flexion contracture before surgery and 1-year postoperative using paired Wilcoxon-non-parametric test (P < .05 was considered significant). The need for revision surgery was considered TKA survival failure. RESULTS: Forty-one HP/60 TKAs were reviewed (19 cases were bilateral). Preoperative median ROM and flexion contracture was 75° (range, 0°-95°) and 20° (range, 5°-80°), respectively. The postoperative median ROM increased to 83° (range, 45°-110°), and median flexion contracture decrease to 0° (range, 0°-40°) a statistically significant difference (P < .01). Postoperative median clinical Knee Society Score (KSS) and functional KSS were 88 (range, 59-97) and 100 (range, 30-100), respectively. Six patients required revision (6.66%) due to infection. TKA survival at 5 years was 92% (range, 82%-96%). CONCLUSION: This study supports that TKA improves function and ROM in haemophilic knee arthropathy. The protocol of coagulation factors used in this cohort is valid as no related complications were reported. A higher incidence of complications, especially infections, must be expected compared with a TKA in non-HPs.

Effect of sevoflurane and propofol on tourniquet-induced endothelial damage: a pilot randomized controlled trial for knee-ligament surgery.

BACKGROUND: The glycocalyx layer is a key structure in the endothelium. Tourniquet-induced ischemic periods are used during orthopedic surgery, and the reactive oxygen species generated after ischemia-reperfusion may mediate the shedding of the glycocalyx. Here, we describe the effects of tourniquet-induced ischemia-reperfusion and compare the effects of sevoflurane and propofol on the release of endothelial biomarkers after ischemia-reperfusion in knee-ligament surgery. METHODS: This pilot, single-center, blinded, randomized, controlled trial included 16 healthy patients. After spinal anesthesia, hypnosis was achieved with sevoflurane or propofol according to randomization. During the perioperative period, five venous blood samples were collected for quantification of syndecan-1, heparan sulfate, and thrombomodulin from blood serum by using ELISA assays kits. Sample size calculation was performed to detect a 25% change in the mean concentration of syndecan-1 with an alpha of 0.05 and power of 80%. RESULTS: For our primary outcome, a two-way ANOVA with post-hoc Bonferroni correction analysis showed no differences in syndecan-1 concentrations between the sevoflurane and propofol groups at any time point. In the sevoflurane group, we noted an increase in syndecan-1 concentrations 90 min after tourniquet release in the sevoflurane group from 34.6 ± 24.4 ng/mL to 47.9 ± 29.8 ng/mL (Wilcoxon test, p < 0.01) that was not observed in patients randomized to the propofol group. The two-way ANOVA showed no intergroup differences in heparan sulfate and thrombomodulin levels. CONCLUSIONS: Superficial endothelial damage without alterations in the cell layer integrity was observed after tourniquet knee-ligament surgery. There was no elevation in serum endothelial biomarkers in the propofol group patients. Sevoflurane did not show the protective effect observed in in vitro and in vivo studies. TRIAL REGISTRATION: The trial was registered in www.clinicaltrials.gov (ref: NCT03772054, Registered 11 December 2018).

Tibiotalocalcaneal arthrodesis with distal tibial allograft for massive bone deficits in the ankle.

BACKGROUND: The purpose of this study was to assess the outcomes of distal tibial structural allograft to obtain a stable TTC fusion. METHODS: Retrospectively, ten patients were carried out with a minimum one year follow-up. The median age was 72 (33-81). The median BMI was 28 (24-33). Indications for TTC arthrodesis included failed total ankle arthroplasty (n=7 patients), prior nonunion (n=2 patients), and a trauma injury. RESULTS: Union rate was 80%. The median initial height of the distal tibial allograft was 19mm (14-24mm). In seven cases the allograft did not lose height. The AOFAS score median was 69 (31-84). SF-12 median physical component was 39 (30-53), and 59 (23-62) for mental component. The VAS median was 2 (0-8). CONCLUSIONS: TTC using distal tibial allograft shows a lower rate of collapse than other structural grafts and provides a fusion rate higher or in accordance with the literature. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Searching for the Best Treatment for Ramp Lesions: A Systematic Review and Network Meta-Analysis.

Ramp lesions are a common occurrence in patients with anterior cruciate ligament (ACL) tears. These lesions can be difficult to diagnose due to their concealed nature, and their treatment is crucial due to the stabilizing function of the medial meniscocapsular region. The optimal treatment option for ramp lesions varies depending on the size and stability of the lesion. The purpose of this study was to evaluate the best treatment option for ramp lesions based on the stability of the lesion, including no treatment, biological treatment, and arthroscopic repair. We hypothesize that stable lesions have a favorable prognosis with techniques that do not require the use of meniscal sutures. In contrast, unstable lesions require appropriate fixation, either through an anterior or posteromedial portal. This study is a systematic review and meta-analysis with a level of evidence IV. The study used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for a systematic review of clinical studies reporting outcomes of ramp lesion treatment. The PubMed/MEDLINE database was searched using Mesh and non-Mesh terms related to ramp lesions, medial meniscus ramp lesions, and meniscocapsular injuries. The inclusion criteria encompassed clinical studies in English or Spanish that reported the treatment of ramp meniscal lesions, with a follow-up of at least six months and inclusion of functional results, clinical stability tests, radiological evaluation, or arthroscopic second look. The analysis included 13 studies with 1614 patients. Five studies distinguished between stable and unstable ramp lesions using different criteria (displacement or size) for assessment. Of the stable lesions, 90 cases received no treatment, 64 cases were treated biologically (debridement, edge-curettage, or trephination), and 728 lesions were repaired. There were 221 repaired unstable lesions. All different methods of repair were registered. In stable lesions, three studies were included in a network meta-analysis. The best-estimated treatment for stable lesions was biological (SUCRA 0.9), followed by repair (SUCRA 0.6), and no treatment (SUCRA 0). In unstable lesions, seven studies using International Knee Documentation Committee Subjective Knee Form (IKDC) and 10 studies using Lysholm for functional outcomes showed significant improvement from preoperative to postoperative scores after repair, with no differences between repairing methods. We recommend simplifying the classification of ramp lesions as stable or unstable to determine treatment. Biological treatment is preferred for stable lesions rather than leaving them in situ. Unstable lesions, on the other hand, require repair, which has been associated with excellent functional outcomes and healing rates.

Access to knee arthroplasty among National Health Fund beneficiaries in Chile between 2004 and 2021. / Radiografía al acceso en artroplastia de rodilla entre los beneficiarios del Fondo Nacional de Salud entre 2004 y 2021.

Introduction: Knee osteoarthritis affects the quality of life, with knee arthroplasty being a cost-effective treatment for the severe stage of this disease. Access to knee arthroplasty is a health indicator of the Organisation for Economic Co-operation and Development. The objectives of this study are to determine the incidence of knee arthroplasty between 2004 and 2021 in beneficiaries of the National Health Fund in Chile, the proportion of patients who underwent surgery in the private system, and to estimate the patient's out-of-pocket expenditure for surgery. Methods: Cross-sectional study. We used the Department of Statistics and Health Information database. Patients discharged from a Chilean health center who underwent knee arthroplasty surgery between 2004 and 2021 were investigated. We analyzed the proportion of patients by their National Health Fund category and whether their surgery was performed in public or private network facilities. Results: Of the 31 526 knee arthroplasty procedures, 21 248 (67.38%) were performed on National Health Fund patients and 16 238 in public institutions (51.49%). Patients from the National Health Fund showed a systematic increase in knee arthroplasty volume until 2019 but decreased in 2020 and 2021 by 68% and 51%. Of the total number of patients in the public system operated on for knee arthroplasty, 856 (9%) belonged to group A1, 12 806 (60%) to group B, 2044 (10%) to group C, and 4421 (21%) to group D. The expenditure incurred by these patients was estimated to vary between 24.4% and 27.2%. The historical proportions of access to this surgery in private institutions are 7% in group A, 13% in group B, 24% in group C, and 52% in group D. Conclusion: Fifty percent of knee arthroplasty surgeries are performed in public institutions, and two-thirds are performed on patients of the National Health Fund. Forty-six percent of the C and D groups were operated in the private system. The pandemic has increased the access gap, leading to a substantial increase in the proportion of patients from the National Health Fund of the B, C, and D groups who have migrated to the private system to access this surgery.

Introducción: La artrosis de rodilla es una patología que afecta la calidad de vida, siendo la artroplastía de rodilla un tratamiento costo-efectivo para la etapa severa de esta enfermedad. El acceso a artroplastia de rodilla es un indicador de salud de la Organización de Cooperación y Desarrollo Económico. Los objetivos de este estudio son determinar la incidencia de artroplastia de rodilla entre 2004 y 2021 en los beneficiarios del Fondo Nacional de Salud en Chile, la proporción que se operaron en el sistema privado y estimar el gasto del bolsillo del paciente para operarse. Método: Estudio transversal. Se utilizó la base de datos del Departamento de Estadística e Información de Salud. Se pesquisaron pacientes que egresaron de un centro de salud chileno que fueron intervenidos por artroplastia rodilla entre 2004 y 2021. Se analizó la proporción de pacientes por tramo del Fondo Nacional de Salud y si se realizó su cirugía en establecimiento de la red pública o privada. Resultados: De las 31 526 intervenciones de artroplastia de rodilla, 21 248 (67,38%) fueron realizadas en pacientes del Fondo Nacional de Salud y 16 238 en instituciones públicas (51,49%). Los pacientes de dicho fondo presentan un alza sistemática en el volumen de artroplastías de rodilla hasta 2019, pero disminuyeron en 2020 y 2021 un 68% y un 51%. Del total de pacientes del sistema público operados de artroplastia de rodilla, 856 (9%) pertenecían al tramo A1, al tramo B 12 806 (60%), al tramo C 2044 (10%) y al tramo D 4421 (21%). Se estimó que el gasto incurrido por estos pacientes varía entre el 24,4 y 27,2%. Las proporciones históricas de acceso en instituciones privadas a esta cirugía son en el tramo A 7%, tramo B 13%, tramo C 24% y tramo D 52%. Conclusión: El 50% de las cirugías de artroplastía de rodilla se realizan en instituciones públicas y dos tercios se realizan en pacientes del Fondo Nacional de Salud. El 46% de los tramos C y D se operaron en el sistema privado. La pandemia ha aumentado la brecha de acceso, lo que ha provocado un alza significativa en la proporción de pacientes del Fondo Nacional de Salud de los tramos B, C y D que han migrado al sistema privado para acceder a esta cirugía.

Estimación de la eficiencia del uso de pabellones electivos en el sistema de salud público chileno entre 2018 y 2021. / Efficiency estimation on the use of elective surgical theaters in the Chilean public health system from 2018 to 2021.

Objective: The efficient use of wards intended for elective surgeries is essential to resolve cases on the surgical waiting list. This study aims to estimate the efficiency of ward use in the Chilean public health system between 2018 and 2021. Methods: The design was an ecological study. Section A.21 of the database constructed by the monthly statistical summaries that each public health network facility reported to the Ministry of Health between 2018 and 2021 was analyzed. Data from subsections A, E and F were extracted: ward staffing, total elective surgeries by specialty, number and causes of suspension of elective surgeries. Then, the surgical performance during working hours and the percentage of hourly occupancy for a working day was estimated. Additionally, an analysis was made by region with data from 2021. Results: The percentage of elective wards in use ranged from 81.1% to 94.1%, while those enabled for those staffing ranged from 70.5% to 90.4% during 2018 and 2021. The total number of surgeries was highest in 2019 (n = 416 339), but for 2018, 2020, and 2021 it ranged from 259 000 to 297 000. Suspensions varied between 10.8% (2019) and 6.9% (2021), with the leading cause being patient-related. When analyzing the number of cases canceled monthly by facility, we saw that the leading cause was trade union-related. The maximum throughput of a ward intended for elective surgery was reached in 2019 and was 2.5 surgeries; in 2018, 2020 and 2021, the throughput borders on two surgeries per ward enabled for elective surgery. The percentage of ward time occupied during working hours by contract day varies between 80.7% (2018) and 56.8% (2020). Conclusions: All the parameters found and estimated in this study show that there is an inefficient utilization of operating rooms in Chilean public healthcare facilities.

Objetivo: El uso eficiente de pabellones destinados a cirugías electivas es fundamental para resolver patologías en lista de espera quirúrgica. El objetivo general de este estudio es estimar la eficiencia del uso de pabellones en el sistema de salud público de Chile entre los años 2018 y 2021. Métodos: El diseño fue un estudio ecológico. Se analizó la Sección A.21 de la base de datos construida por los resúmenes estadísticos mensuales que cada establecimiento de la red de salud pública reportó al Ministerio de Salud de Chile entre 2018 y 2021. Se extrajeron los datos de la subsección A, E y F: dotación de pabellones, total de cirugías electivas por especialidad, número y causas de suspensión de cirugías electivas. Luego se estimó el rendimiento quirúrgico en horario hábil y el porcentaje de ocupación horaria respecto de una jornada laboral. Adicionalmente, se hizo un análisis por región con datos de 2021. Resultados: El porcentaje de pabellones electivos respecto de los en dotación varió entre 81,1 y 94,1%; mientras que los habilitados respecto de los en dotación varió entre 70,5 y 90,4% durante 2018 y 2021. El número total de cirugías fue más alto en 2019 (n = 416 339), pero en 2018, 2020 y 2021 variaron entre 259 y 297 mil cirugías. Las suspensiones varían entre 10,8 (2019) y 6,9%w(2021), siendo la principal causa de suspensión atribuida al "paciente". Al analizar la cantidad de pacientes suspendidos mensualmente por institución, se observa que la principal causa es "gremial". El rendimiento máximo de un pabellón destinado a cirugía electiva se alcanzó en 2019 y fue de 2,5 cirugías; mientras que en 2018, 2020 y 2021 el rendimiento bordea las dos cirugías por pabellón habilitado para cirugía electiva. El porcentaje de tiempo de pabellón ocupado en horario hábil respecto a una jornada de contrato varía entre 80,7 (2018) y 56,8% (2020). Conclusiones: Todos los parámetros encontrados y estimados en este estudio muestran que el uso de pabellones en el sistema público de Chile es ineficiente.

Polyethylene Luxation in an Oxinium Fixed-bearing Unicompartmental Knee Replacement Leading to Metallosis: A Case Reports for an Early and a Late Presentation.

Introduction: Polyethylene (PE) subluxation is a rare complication after fixed-bearing unicompartmental knee replacement. We present two cases of PE luxation with a rapid onset of metallosis in a unicompartmental knee replacement made of Oxinium, one early presentation 3 months after surgery and the other case 6 years after. Case Report: Case 1: A 84-year-old male underwent a fixed-bearing medial unicompartmental knee replacement in his left knee. Standard surgery was carried out with robotic assistance. Three months after surgery, he felt acute pain in the anterior portion of his knee. Radiographs showed that the PE was luxated anteriorly and a radiopaque "cloud" that blurs the vision of the implants suggesting metallosis. In the revision surgery, abundant blackish liquid and metallic-like debris were deposited in the synovial tissue and capsule around the knee. The tibial and femoral components presented extensive wear areas, suggesting extensive metal-to-metal contact. Both components were removed, and a posterior stabilized total knee prosthesis was placed. Case 2: A 50-year-old male patient underwent a fixed-bearing medial unicompartmental knee replacement. After 6 years, he complained of insidious pain in the posteromedial side of his knee. During the physical examination, significant joint effusion, a loss of extension, and a limited flexion were observed, with flexion reaching only up to 80°. The patient did not report systemic symptoms associated with metallosis, and no signs of systemic involvement were found. Radiographs show similar findings than in case 1, but the radiopaque "cloud" was limited to the knee. In the revision surgery, both components were removed. The tibial and femur components had extensive wear, especially in the posterior-central portion. A posterior stabilized total knee prosthesis was used. Conclusion: Emphasis on careful engagement between the PE and the tibial component is a must, checking that no tissue or cement gets in the way of the anchoring system. Furthermore, prosthesis designs must look for models with a more friendly, engaging system to prevent early presentation. The radiographs assessing the height of the PE - especially in the posterior area - must be carried out. In the case of metallosis and PE luxation, we suggest performing a revision surgery with total knee arthroplasty; however, there is little evidence for a strong recommendation.

Increase in Postoperative Body Mass Index in Patients After Total Knee Arthroplasty.

Objectives The aim of this is to investigate the changes in body mass index (BMI) following knee arthroplasty and to evaluate their impact on patient-reported outcomes and functional evaluations. Methods This observational study included 90 patients who underwent total knee arthroplasty (TKA) and were followed up for a median period of 2.6 years. BMI measurements were recorded before and after surgery, and patient-reported outcomes and functional evaluations were assessed using standardized scales and tests. Results Following TKA, BMI increased statistically significantly (Wilcoxon signed-rank test, p < 0.000). In addition, half of the patients experienced an increase in BMI, with 32% moving up in their BMI category. However, there were no clinically significant differences in patient-reported outcomes or functional evaluations between the group that gained BMI and the group that maintained or lost BMI. Conclusion This study reveals that patients tend to have increased BMI following TKA. However, these BMI changes do not significantly impact patient-reported outcomes or functional evaluations. It underscores the importance of patient education regarding healthy lifestyle habits, including diet and physical activity, to address postoperative weight gain effectively.

Gonyautoxins 2/3 Local Periarticular Injection for Pain Management after Total Knee Arthroplasty: A Double-Blind, Randomized Study.

The purpose of this study was to compare the efficacy of periarticular infiltration of gonyautoxin 2/3 (GTX 2/3) and a mixture of levobupivacaine, ketorolac, and epinephrine for pain management after total knee arthroplasty (TKA). Forty-eight patients were randomly allocated to receive periarticular infiltration of 40 µg GTX 2/3 (n = 24) diluted in 30 mL of sodium chloride 0.9% (study group) or a combination of 300 mg of levobupivacaine, 1 mg of epinephrine, and 60 mg ketorolac (n = 24) diluted in 150 mL of sodium chloride 0.9% (control group). Intraoperative anesthetic and surgical techniques were identical for both groups. Postoperatively, all patients received patient-controlled analgesia (morphine bolus of 1 mg; lockout interval of 8 minutes), acetaminophen, and ketoprofen for 72 hours. A blinded investigator recorded morphine consumption, which was the primary outcome. Also, the range of motion (ROM) and static and dynamic pain were assessed at 6, 12, 36, and 60 hours after surgery. The incidence of adverse events, time to readiness for discharge, and length of hospital stay were also recorded. The median of total cumulative morphine consumption was 16 mg (range, 0-62 mg) in the GTX 2/3 group and 9 mg (range, 0-54 mg) in control group, which did not reach statistical difference (median test, p = 0.40). Furthermore, static and dynamic pain scores were similar at all time intervals. GTX 2/3 was inferior in range of motion at 6 and 12 hours; nevertheless, we noted no difference after 36 hours. No differences between groups were found in terms of complications, side effects, or length of hospital stay. No significant differences were found between groups in terms of breakthrough morphine requirement. However, local anesthetic use resulted in an increased ROM in the first 12 hours. This prospective randomized clinical trial shows that GTX 2/3 is a safe and efficient drug for pain control after TKA; nevertheless, more studies using GTX 2/3 with larger populations are needed to confirm the safety profile and efficiency. This is level 1 therapeutic study, randomized, double-blind clinical trial.

Latin American formal consensus on the appropriate indications of extra-articular lateral procedures in primary anterior cruciate ligament reconstruction.

OBJECTIVES: To create a practice guideline for the appropriate indications of an extra-articular procedure in primary anterior cruciate ligament reconstruction (ACLR). METHODS: The formal consensus method described by the Haute Autorité de Santé was used. The Latin American Society of Arthroscopy, Articular Replacement, and Sports Injuries (SLARD) recruited three groups of experts on ACLR. Initially, the steering group, consisting of eight surgeons, performed a systematic review of the literature and elaborated on 192 scenarios for primary ACLR. The rating group, composed of 23 surgeons, rated each scenario in two rounds, with an in-between in-person meeting for discussion. Median scores and agreement levels were estimated to classify each scenario as inappropriate, uncertain or appropriate for adding anterolateral reconstruction. Finally, the lecture group, consisting of 10 surgeons, revised each stage of the method, results and interpretation. RESULTS: Of the scenarios, 11.97% were rated as appropriate for adding an extra-articular lateral procedure, 7.81% as inappropriate and 80.21% as uncertain. The key recommendations for the addition of extra-articular lateral techniques were as follows: it is appropriate when the patient is under 25 years of age, has high-grade physical examination findings, practises a pivoting sport and has hyperlaxity; meanwhile, it is inappropriate when the patient has low-grade physical examination findings, has normal laxity and does not practise a pivoting sport. CONCLUSIONS: The appropriate indications of extra-articular lateral procedures in primary ACLR were determined on the basis of the best available evidence and expert opinion following a formal consensus method. LEVEL OF EVIDENCE: V.

Anterior knee pain and sit-up tests predicts patients' satisfaction and improvement in quality of life after anterior stabilized total knee replacement without patellar resurfacing.

PURPOSE: The purpose of this study was to assess patient satisfaction and identify risk factors for dissatisfaction after anterior stabilised conventional total knee arthroplasty (TKA) without patellar resurfacing, using the Goodman score. METHODS: We conducted a cross-sectional study using data from our institutional database from 1 January 2018 to 1 March 2021. Patients who underwent TKA with the Vanguard® Cruciate Retaining Anterior Stabilized Knee System (Zimmer Biomet, Warsaw, Indiana, USA) without patellar replacement were included. Patients with other bearing surfaces (posterior stabilised or medial congruent) or diagnosed with infection or instability were excluded. Patients' reported outcomes, body mass index (BMI), passive range of motion, the timed up-and-go test, sit-up test, and algometry were assessed. Patients were also asked if they had anterior knee pain. Satisfaction was assessed using the Goodman scale, and logistic multivariate regression was used to identify variables associated with dissatisfaction and perceived improvement in quality of life. RESULTS: A total of 131 TKA patients were included in the study. The median satisfaction score was 100 (interquartile range [IQR], 87.5 to 100), with the 75-point threshold at the 90th percentile according to Section A of Goodman. Section B of Goodman showed that 113 TKA patients (86.26%) reported "great improvement" or "more than I ever dreamed." Multivariate logistic regression revealed that anterior knee pain (OR 5.16, 95% CI 1.24 to 21.39), the sit-up test (OR 0.63, 95% CI 0.49 to 0.81), and BMI (OR 0.84, 95% CI 0.70 to 0.99) were significantly associated with patient dissatisfaction and a worse perceived improvement in quality of life. The receiver operating characteristics curve for the models had areas under the curve of 0.83 (95% CI 0.69 to 0.97) and 0.82 (95% CI 0.70 to 0.94), respectively. CONCLUSION: Anterior stabilised TKA without patellar resurfacing can achieve 90% satisfaction and 86% improvement in quality of life. To improve these results, it is essential to prevent and treat anterior knee pain and enhance quadriceps strength. LEVEL OF EVIDENCE: Level III (retrospective cohort study).

Concordance in Radiological Parameters of Different Knee Views After Total Knee Arthroplasty.

Background Total knee arthroplasty (TKA) is a cost-effective treatment for the end-stage of knee osteoarthritis. Despite the improvements in this surgery, a significant percentage of patients still report dissatisfaction after knee arthroplasty. Radiological results have been used to predict clinical outcomes and satisfaction after knee replacement. This study aims to evaluate the concordance of a set of radiographic views to assess alignment on total knee arthroplasty. Methods A concordance study was designed with 105 patients (130 TKA) that underwent conventional total knee arthroplasty cruciate-retaining design recruited for the study and scheduled for their annual radiograph control. Measurements were performed on the following radiograph after total knee replacement: full-length standing anteroposterior and lateral radiograph, anteroposterior standing, lateral and axial knee view, and the knee "seated view". A musculoskeletal radiologist and a knee surgeon were recruited to perform the radiological measurement and then estimate the interobserver agreement.  Results There was an excellent correlation between Limb Length (LL), Hip-knee-ankle angle (HKA), Sagittal mechanical tibial component alignment (smTA), extension lateral and medial joint space (eLJS and eMJS), 90º flexion lateral and medial joint space (fLJS and fMJS) and Sagittal anatomic lateral view tibial component alignment (saLTA); the good correlation between Mechanical lateral femoral component alignment (mLFA), Sagittal anatomic tibial component alignment (saTA), Sagittal anatomic lateral view femoral component alignment 2 (saLFA2), Patella Height (PH); and moderate to poor correlation for the rest of measurements. Conclusion Excellent and good concordance can be achieved for radiographic measurements in different knee views to assess results after TKA. These findings must encourage future studies to address functional and survival outcomes using all knee views and not just one plane.

Similar Patient Satisfaction and Quality of Life Improvement Achieved with TKA and THA According to the Goodman Scale: A Comparative Study.

Background: Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are effective treatments for severe knee and hip osteoarthritis. Historically, TKA has been associated with lower satisfaction than THA, but recent advances in knee surgery have led to lower dissatisfaction rates. This study aimed to compare the satisfaction and self-reported improvement in the quality of life of two cohorts of patients who underwent TKA and THA, respectively. Methods: This observational study compared two previously published cohorts of patients who underwent THA and TKA in a single university center. The Goodman scale was used to assess satisfaction and self-perception of improved quality of life after TKA and THA at a minimum one-year follow-up. Propensity score matching was used to balance age, gender, and follow-up between groups. Significance was set at 0.05. Results: The study included a total of 105 THAs and 131 TKAs. Both groups had high levels of satisfaction with pain relief, ability to do house/yard work, and overall satisfaction, with above 90% satisfaction rates. Regarding improvement in quality of life, both groups had 86% of patients reporting improvement as "much better." After propensity score matching, no significant difference was found between THA and TKA for any of the comparisons made using the Goodman scale. Conclusions: The study showed that both TKA and THA resulted in high levels of satisfaction and improvement in quality of life. There was no significant difference in satisfaction rates between TKA and THA, contrary to the historical trend of lower satisfaction rates for TKA.

Impact of COVID-19 outbreak in knee arthroplasty in Chile: a cross-sectional, national registry-based analysis. / Impacto de la pandemia por COVID-19 en la incidencia de artroplastías de rodilla en Chile: estudio transversal basado en registro nacional.

Introduction: The need for beds and health personnel to treat coronavirus (COVID- 19) patients has led to the suspension of many elective sur-geries in Chile, including knee arthroplasties. This study aims to determine the incidence of knee arthroplasty in 2020, reflecting the effect of the COVID- 19 pandemic, and estimate the cost and time it would take to recover the waiting list prior to March 2020. Methods: A cross- sectional study was designed. We analyzed databases from The Department of Statistics and Health Information databases from Chile for 2019 and 2020, identifying patients with surgical discharges associated with knee arthroplasty codes. We estimated the time it would take to recover the surgeries unperformed in 2020 by simulating a monthly workload increase from the 2019 baseline. The costs of knee arthroplasty paid by the National Health Fund to institutions were estimated by diagnosis-related groups. Results: We found that the incidence rate of knee arthroplasty in 2020 decreased by 64% compared with 2019. The impact was higher in the public system (68%) and the National Health Found (63%). A simulated increase in knee arthroplasty productivity by 30% would allow recovering the postponed knee arthroplasty surgeries in 27 months, at a monthly cost to the public system of 318 million Chilean pesos (378 thousand US dollars). Conclusions: The incidence rate of knee arthroplasty during 2020 decreased by 64%, revealing the extensive waiting line for people with knee osteoarthritis. An increase between 20- 40% in productivity compared with 2019 would allow recovering the unperformed surgeries in 20 to 41 months, at a monthly cost to the public network between 210 and 425 million Chilean pesos (250 to 506 thousand US dollars).

Introducción: Debido a la respuesta de los servicios de salud a la pandemia por COVID- 19, se han suspendido cirugías electivas como la artroplastía de rodilla. El objetivo de este estudio es determinar la incidencia de artroplastías de rodilla en 2020 reflejando el efecto de la pandemia, y estimar el tiempo y el costo para recuperar la situación de lista de espera previa a marzo de 2020. Métodos: Estudio transversal. Se analizaron las bases de datos del Departamento de Estadística e Información en Salud de Chile de 2019 y 2020, identificando pacientes asociados a códigos de artroplastía de rodilla. Se calculó el número mensual de artroplastias realizadas durante 2019 para estimar el tiempo que tomará recuperar las cirugías no realizadas en 2020. El costo asociado a artroplastía de rodilla se hizo según el método de pago utilizado por el Fondo Nacional de Salud estimado por grupos relacionados por diagnóstico. Resultados: En 2020 la tasa de incidencia de artroplastía de rodilla por 100 000 habitantes disminuyó 64% comparado con 2019. El impacto fue mayor en el sistema público (68%) y en beneficiarios del Fondo Nacional de Salud (63%). Un aumento en la productividad en 30% respecto a 2019 haría que en 27 meses se recuperen las cirugías no realizadas en 2020, significando un costo adicional mensual en el sistema público de 318 262 530 pesos chilenos (equivalentes a 378 mil dólares americanos, USD). Conclusiones: Hubo una importante disminución de la tasa de artroplastías de rodilla en 2020, estimándose una caída del 64% en la incidencia por 100 000 habitantes. Esto muestra un incremento importante de personas que esperan la resolución a la artrosis de rodilla. Un aumento entre 20 y 40% respecto de 2019 permitiría recuperar las cirugías no realizadas en un plazo entre 20 y 41 meses, a un costo mensual en el sistema público que varía entre 210 y 425 millones pesos chilenos (de 250 a 506 mil dólares americanos, USD).

The role of anterior supra-acetabular external fixator as definitive treatment for anterior ring fixation in unstable pelvic fractures.

PURPOSE: Management of anterior ring injuries is still a matter of discussion, and there are only few studies reporting anterior external fixator as definitive treatment for unstable pelvic injuries. This study aimed to describe the clinical and radiological outcomes of a consecutive series of mechanically unstable pelvic injuries that were treated with definitive anterior supra-acetabular external fixator for the anterior ring, and to identify risk factors for failure. METHODS: We included a consecutive series of patients with unstable pelvic ring fractures who underwent anterior supra-acetabular external fixation for definitive treatment, between January 2012 and January 2020. All demographics, associated injuries and procedures, injury mechanism, and complications were analysed. Pelvic fracture was classified based on Orthopaedic Trauma Association/Tile AO (OTA/AO) and Young-Burgess classifications. Complications associated with the external fixator were revised. All patients were functionally evaluated at final follow-up and asked to report their clinical outcomes using the Majeed score. RESULTS: A total of 47 patients were included, of which 25 were females. The median age was 44 years (interquartile range 23-59). Median follow-up duration was 14 months (interquartile range 6-31). The most frequent aetiology was motor vehicle accident (35), followed by fall from height (8). All fractures required posterior pelvic ring fixation. The median time during which patients had external fixation in situ was 11 weeks (interquartile range 9-13). All patients achieved healing of pelvic fracture at median time of 10 weeks (interquartile range 8-12). At final follow-up, the median displacement of the anterior pelvis was 6 mm (interquartile range 0-11). Superficial infection was the most common complication (n = 7). No washout procedures were needed. No major complication was reported. No patient required reoperation for anterior ring fracture. The median Majeed score was 88 points (range 60-95; interquartile range 80-90) at final follow-up. CONCLUSION: Our findings suggest that the use of supra-acetabular external fixator is safe and effective for definitive treatment of the anterior ring in unstable pelvic fractures. It is a method with high proportion of excellent results, regardless of the type of fracture. The rate of complications is low, and it does not compromise functional results.

Construct Validity of a Virtual Reality Simulator for Surgical Training in Knee Arthroscopy.

Objective Surgical techniques are learned gradually throughout an orthopedic residency. Training on real patients carries drawbacks such as limited access and elevated risk. Alternatively, surgical simulation allows residents to practice in a safe environment with greater access to standardized surgical tasks. Virtual reality simulators display images inside an artificial joint, often providing real-time haptic feedback to allow for realistic interaction. The objective of this study was to evaluate the construct validity of a virtual reality simulator for knee arthroscopy by analyzing the capacity of system parameters to distinguish between expert and novice surgeons. Design This comparative cross-sectional study contrasts the automated performance reports for novice and expert orthopedic surgeons after executing surgical tasks on the ARTHRO Mentor virtual reality simulator. Setting Surgical simulation center at the University of Chile Clinical Hospital, Santiago, Chile. Participants The novice group consisted of 20 second-year orthopedic and traumatology residents at the University of Chile School of Medicine. The expert group consisted of 10 experienced arthroscopic surgeons. All participants carried out standardized tasks in the knee arthroscopy virtual reality simulator. The median performance scores of the two groups were compared, and multivariate logistic regression was performed to assess the capacity of the system to discriminate between the two groups. Results Median performance on the vast majority of surgical tasks was superior for the expert group. The expert group had performance values equal to or higher than the novice group on 43 of the 44 variables recorded for the basic tasks and 74 of the 75 advanced task variables. The multivariate logistic regression analysis discriminated expert from novice users with 100% accuracy. Conclusion The virtual reality simulator for knee arthroscopy showed good construct validity, with performance metrics accurately discriminating between expert and novice users.

Scissor Position of the Orthopedic Table for the Resolution of Intertrochanteric and Subtrochanteric Hip Fractures.

During the surgical resolution of intertrochanteric and subtrochanteric hip fractures on an orthopedic table, a fluoroscope needs to be used in orthogonal planes. This requires that the contralateral leg does not obstruct the radioscopic view, so patients are often placed in a hemilithotomy position. This position, also called the Lloyd-Davis position, involves hip flexion, hip abduction, hip external rotation, and knee flexion. However, rare complications, such as acute leg posterior compartment syndrome, have been described. In addition, patients with severe osteoarthritis and joint stiffness or a history of total hip arthroplasty may have difficulty achieving this position, and the well leg may be at risk of injury in a hemilithotomy position. A previously described position called the "scissor position" is, in our opinion, a safer and more efficient technique for placing the well leg on the orthopedic table, using only a pillow and a self-adhesive compression bandage. This simple position allows a lateral fluoroscopic view of the injured femur without overlapping or interference from the other limb.