Risks of major bleeding and venous thromboembolism in patients undergoing total hip or total knee arthroplasty using therapeutic dosages of DOACs.

About 1.5% of patients undergoing total hip (THA) or total knee arthroplasty (TKA) still develop postoperative venous thromboembolism (VTE), indicating that the current thromboprophylaxis strategy is not optimal. To evaluate the feasibility of therapeutic dosages of direct oral anticoagulants (DOACs) as thromboprophylaxis for high VTE risk patients, we determined the risks of major bleeding and VTE in patients who underwent THA/TKA and were treated with DOACs in therapeutic dosages for atrial fibrillation (AF). We conducted a registry-based cohort study from 2010 to 2018 in Denmark and included AF patients on therapeutic DOACs dose who underwent THA/TKA. AF patients were utilized as proxy since they have a life-long indication for therapeutic anticoagulant medication. The 49-days cumulative incidence (with death as competing risk) of major bleeding was assessed. The same was done for VTE at 49- and 90-days. 1,354 THA and TKA procedures were included. The 49-days cumulative incidence of major bleeding was 1.40% (95%Confidence Interval[CI] 0.88-2.14%). Most bleeding events occurred at the surgical site. The cumulative incidence of VTE at 49-days was 0.59% (95%CI 0.28-1.13%) and 0.74% (95%CI 0.38-1.32%) at 90-days. The incidence of major bleeding in THA/TKA patients on DOACs in therapeutic dosages was in line with previously reported incidences among THA/TKA patients on thromboprophylaxis dosages, while the incidence of VTE was relatively low. These data provide a solid basis for the design of randomized controlled trials to establish the safety and efficacy of therapeutic dosages of DOACs to prevent VTE in high-risk patients.

An Unusual Complication of Intramedullary Pin Migration during Total Knee Arthroplasty - A Case Report.

Total knee arthroplasty (TKA) is one of the most effective operations to relieve pain and improve function in the end stage of osteoarthritis (when bone on bone contact occurs). The intraoperative complications of TKA include fracture, tendon or ligament injury, and nerve or vascular complications. We herein describe an unusual complication of intramedullary pin migration within the femoral canal during TKA. A 72-year-old male patient underwent TKA with a posterior stabilization system with sacrifice of the posterior cruciate ligament. The distal femur was sectioned and balance was checked in extension. Then to make anterior, posterior, chamfer and notch cuts, the five-in-one anteroposterior (AP) cutting block was placed on the distal femur and the cuts were initiated. As there was a medial overhang of the cutting block, it was shifted laterally. While doing so, the pins had to be shifted too, and one of them was inadvertently hammered into the previously-created medullary canal opening of the femur. As usual orthopedic instruments, like the long straight artery forceps and pituitary rongeurs, failed to remove the migrated pin, an extralong laparoscopic grasper was used under fluoroscopy control to locate, grasp, and remove the migrated pin.

Modified Z-plasty of the Patellar Ligament with Reinforcement of the Quadriceps Tendon in the Treatment of Patella Baja.

Patella baja is an infrequent knee pathology, but it is limiting due to joint stiffness and localized pain in the anterior region of the knee. It may occur after trauma, prolonged immobilization or local surgical intervention. The striking pathological finding is the shortening and increase in thickness of the patellar ligament. Several surgical techniques have been described for its treatment, and there is no standardized treatment. We describe the case of a 73-year-old female patient who presented with knee stiffness, significant functional deficit, and patella baja after total knee arthroplasty. She underwent a recently described soft tissue surgical procedure, with excellent functional evolution, improving from a Lysholm Knee Score of 16 to 81 points, allowing early mobilization and return to daily life activities.

Are social determinants of health associated with an increased length of hospitalization after revision total hip and knee arthroplasty? A comparison study of social deprivation indices.

INTRODUCTION: Length of stay (LOS) has been extensively assessed as a marker for healthcare utilization, functional outcomes, and cost of care for patients undergoing arthroplasty. The notable patient-to-patient variation in LOS following revision hip and knee total joint arthroplasty (TJA) suggests a potential opportunity to reduce preventable discharge delays. Previous studies investigated the impact of social determinants of health (SDoH) on orthopaedic conditions and outcomes using deprivation indices with inconsistent findings. The aim of the study is to compare the association of three publicly available national indices of social deprivation with prolonged LOS in revision TJA patients. MATERIALS AND METHODS: 1,047 consecutive patients who underwent a revision TJA were included in this retrospective study. Patient demographics, comorbidities, and behavioral characteristics were extracted. Area deprivation index (ADI), social deprivation index (SDI), and social vulnerability index (SVI) were recorded for each patient, following which univariate and multivariate logistic regression analyses were performed to determine the relationship between deprivation measures and prolonged LOS (greater than five days postoperatively). RESULTS: 193 patients had a prolonged LOS following surgery. Categorical ADI was significantly associated with prolonged LOS following surgery (OR = 2.14; 95% CI = 1.30-3.54; p = 0.003). No association with LOS was found using SDI and SVI. When accounting for other covariates, only ASA scores (ORrange=3.43-3.45; p < 0.001) and age (ORrange=1.00-1.03; prange=0.025-0.049) were independently associated with prolonged LOS. CONCLUSION: The varying relationship observed between the length of stay and socioeconomic markers in this study indicates that the selection of a deprivation index could significantly impact the outcomes when investigating the association between socioeconomic deprivation and clinical outcomes. These results suggest that ADI is a potential metric of social determinants of health that is applicable both clinically and in future policies related to hospital stays including bundled payment plan following revision TJA.

Construction of a Risk Prediction Model for Intraoperative Hypothermia in Patients Undergoing Lower Extremity Joint Replacement.

PURPOSE: To investigate the influencing factors of intraoperative hypothermia (IOH) in patients undergoing total joint arthroplasty (TJA) of the lower extremities, establish a risk prediction model, and test the effect of application. DESIGN: A prospective, observational study was conducted. METHODS: Patients who underwent total knee arthroplasty and total hip arthroplasty from June 2020 to December 2021 were prospectively analyzed. According to the occurrence of IOH, patients were divided into the IOH group (temperature less than 36 °C) and non-IOH group (temperature ≥36 °C). We collected demographic, anesthesia, and surgical data for both groups to identify risk factors for IOH and develop a predictive model. The model's goodness of fit was assessed using the Hosmer-Lemeshow test, and its predictive efficacy was evaluated using the receiver operating characteristic curve. FINDINGS: A total of 258 patients were included in this study, with 79 patients in the IOH group and 179 patients in the non-IOH group. Logistic regression analysis showed that American Society of Anesthesiologists' grade, blood loss, and duration of surgery were independent risk factors for IOH in lower extremity TJA patients. Hosmer-Lemeshow test P = .803, area under receiver operating characteristic curve was 0.846, Youden index was 0.490, sensitivity was 65.4%, specificity was 83.6%. In the external validation cohort, the application accuracy of the model was 83.3%. CONCLUSIONS: The prediction model established in this study is suitable for the risk assessment of IOH in TJA patients with good prediction effect, which can provide a tool for clinical medical staff to identify high-risk populations preoperatively.

Neighborhood socioeconomic disadvantages associated with prolonged length of stay and non-home discharge following revision total hip and knee joint arthroplasty.

Background: Discharge disposition and length of stay (LOS) are widely recognized markers of healthcare utilization patterns of total hip and knee joint arthroplasty (TJA). These markers are commonly associated with increased postoperative complications, patient dissatisfaction, and higher costs. Area deprivation index (ADI) has been validated as a composite metric of neighborhood-level disadvantage. This study aims to determine the potential association between ADI and discharge disposition or extended LOS following revision TJA. Methods: This study conducted a retrospective analysis of a consecutive series of revision hip and knee TJA patients from a single tertiary institution. Univariate and multivariate regression analysis was used to determine the association between ADI and discharge disposition or LOS, adjusting for patient demographics and comorbidities. Results: 1047 consecutive revision TJA patients were identified across 463 different neighborhoods. 193 (18.4 %) had an extended LOS, and 334 (31.9 %) were discharged to non-home facilities. Compared with Q1 (least deprived cohort), Q2 (odds ratio [OR] = 1.63; p = 0.030) and Q4 (most deprived cohort: OR = 2.04; p = 0.002) cohorts demonstrated higher odds of non-home discharge. Patients in the highest ADI quartile (most deprived cohort) were associated with increased odds of prolonged LOS following revision TJA compared to those in the lowest ADI quartile (OR = 2.63; p < 0.001). Conclusion: This study suggests that higher levels of neighborhood-level disadvantage may be associated with higher odds of non-home discharge and prolonged LOS following revision TJA. Development of interventions based on the area deprivation index may improve discharge planning and reduce unnecessary non-home discharges in patients living in areas of socioeconomic deprivation.

Risk factors of chronic postoperative pain after total knee arthroplasty: a systematic review.

BACKGROUND: There is a lack of relevant studies to grade the evidence on the risk factors of chronic pain after total knee arthroplasty (TKA), and only quantitative methods are used for systematic evaluation. The review aimed to systematically identify risk factors of chronic postoperative pain following TKA and to evaluate the strength of the evidence underlying these correlations. METHODS: PubMed, Web of Science, Cochrane Library, Embase, and CINAHL databases were searched from initiation to September 2023. Cohort studies, case-control studies, and cross-sectional studies involving patients undergoing total knee replacement were included. A semi-quantitative approach was used to grade the strength of the evidence-based on the number of investigations, the quality of the studies, and the consistency of the associations reported by the studies. RESULTS: Thirty-two articles involving 18,792 patients were included in the final systematic review. Ten variables were found to be strongly associated with postoperative pain, including Age, body mass index (BMI), comorbidities condition, preoperative pain, chronic widespread pain, preoperative adverse health beliefs, preoperative sleep disorders, central sensitization, preoperative anxiety, and preoperative function. Sixteen factors were identified as inconclusive evidence. CONCLUSIONS: This systematic review clarifies which risk factors could be involved in future research on TKA pain management for surgeons and patients. It highlights those factors that have been controversial or weakly correlated, emphasizing the need for further high-quality studies to validate them. Most crucially, it can furnish clinicians with vital information regarding high-risk patients and their clinical attributes, thereby aiding in the development of preventive strategies to mitigate postoperative pain following TKA. TRIAL REGISTRATION: This systematic review has been registered on the PROSPERO platform (CRD42023444097).

Periarticular Infiltration Compared to Single Femoral Nerve Block in Total Knee Arthroplasty: A Prospective Randomized Study.

Objective To compare patients undergoing total knee arthroplasty (TKA) under spinal anesthesia and single femoral nerve block (FNB) with subjects undergoing TKA under spinal anesthesia and periarticular infiltration (PAI). Materials and Methods A total of 100 patients undergoing primary TKA were randomized into two groups. Group 1 included patients undergoing surgery under FNB associated with spinal anesthesia, while group 2 included patients undergoing TKA under IPA and spinal anesthesia. The assessment of these subjects in the early postoperative period included pain, active flexion, active extension, elevation of the extended limb, and morphine use. Results There was no significant difference in the types of analgesia concerning pain, the elevation of the extended limb, and morphine use. Active flexion and extension were better in the PAI group ( p = 0.04 and p = 0.02 respectively). Conclusion We conclude that the techniques are similar regarding pain control, limb elevation, and morphine use. The use of IPA provided better active flexion and extension during the hospital stay compared to single FNB in patients undergoing TKA.

Implementation of the Fast-track Protocol for Total Hip Arthroplasty in a Public Hospital in the State of São Paulo - Brazil.

Objective Evaluate the results of the implementation of the Fast Track Protocol (FTP), a medical practice based on scientific evidence, for elective total hip arthroplasty surgery, mainly comparing the National Average Hospital Admission Rate of 7.1 days. Methods 98 patients who underwent elective total hip arthroplasty surgery via the direct anterior approach, anterolateral approach and posterior approach were included in the FTP from December 2018 to March 2020, being followed up preoperatively, intraoperatively and immediately postoperatively. Results The average length of hospital stay was 2.8 days, being 2.1 days for the direct anterior approach, 3.0 days for the anterolateral access approach and 4.1 days for the posterior access approach. The average surgery time was 90 minutes, 19 (19.39%) of the patients were referred to the ICU in the postoperative period, however, none of them underwent surgery using the direct anterior approach. We had no cases of deep vein thrombosis (DVT), pulmonary embolism (PTE) or neurological injury, 19 (19.39%) patients had postoperative bleeding requiring dressing change, 4 (4.08%) needed blood transfusion, 2 (2.04%) patients had implant instability, 1 (1.02%) patient had a fracture during surgery and 1 (1.02%) patient died of cardiac complications. Conclusion FTP may be a viable alternative to reduce the length of stay and immediate postoperative complications for elective total hip arthroplasty surgery decreasing the length of stay of patients by 2 to 3 times when compared to the national average of 7.1 days.

Functional knee phenotypes appear to be more suitable for the Chinese OA population compared with CPAK classification: A study based on 3D CT reconstruction models.

PURPOSE: The aim of this study was to investigate the distribution of coronal plane alignment of the knee (CPAK) classification and functional knee phenotypes in a Chinese osteoarthritis (OA) population and to compare different lower limb alignment targets according to the distribution characteristics to find suitable total knee arthroplasty (TKA) bone cut strategies for the Chinese OA patients. METHODS: The computed tomography (CT) images were retrospectively collected and the three-dimensional (3D) models were reconstructed from 434 Chinese OA patients, including 93 males and 341 females, with a mean age of 66.4 ± 9.3 years. Femoral mechanical angle (FMA), tibial mechanical angle (TMA) and mechanical hip-knee-ankle angle (mHKA) were measured on the 3D models. Arithmetic hip-knee-ankle angle (aHKA) was calculated using FMA plus TMA, and joint line obliquity was calculated as 180 + TMA-FMA. The CPAK according to MacDessi and the functional knee phenotypes according to Hirschmann were performed. In addition, the suitable TKA bone cut strategies were explored according to the phenotypes and based on the characteristics of different alignment targets, such as mechanical alignment, anatomic alignment (AA), kinematic alignment, restricted KA (rKA) and adjusted MA (aMA). Statistical differences were determined using the independent-samples t-test or the two independent-samples Wilcoxon test, with p < 0.05 considered statistically significant. RESULTS: The Chinese OA population showed a varus alignment tendency (mHKA = 172.1° ± 7.2°), to which the TMA was a major contributor (TMA = 84.7° ± 4.4° vs. FMA = 91.3° ± 3.2°). The mHKA was on average 3.9° more varus than the aHKA. A total of 140 functional knee phenotypes were found and 45.6% were concentrated in VARFMA3°-NEUFMA0° to VARTMA3°-NEUTMA0°. More than 70% of patients had different FMA and TMA phenotypes. There were 92.9% of CPAK distributed in types I to IV, with type I accounting for 53.9%. The FMA phenotypes were less changed if the aMA and rKA were chosen, and the TMA phenotypes were less changed if the AA and rKA were chosen. CONCLUSION: Compared with the CPAK, the functional knee phenotypes were more suitable for the Chinese OA population with a wide distribution and a varus tendency, and it seemed more appropriate to choose aMA and rKA as TKA alignment targets for resection. LEVEL OF EVIDENCE: Level Ⅲ.

Comparative Functional and Isokinetic Analysis between Implants with Posterior Stabilization and Rotating Hinge Total Knee Arthroplasty.

Objective : To compare the function and muscle strength of the limb between patients undergoing knee arthroplasties using primary implants with posterior stabilization (control group) and patients with rotating hinge implants (Hinge group). Methods : Function assessment was performed using the Knee Society Score (KSS) and muscle strength using an isokinetic dynamometer using a speed of 60°/s. Results : 43 patients were analyzed, who underwent 51 surgeries, with the Hinge group comprising 25 surgeries and the control group comprising 26 primary surgeries. We did not observe significant differences between the Hinge and control groups in the values of functional KSS (p = 0.54), objective KSS (p = 0.91), peak flexor torque (p = 0.25) and peak extensor torque (p = 0.08). Patients in the Hinge group who underwent primary arthroplasties had a higher peak flexor torque (0.76 Nm/kg) than those who used the implant in revision after septic failure (0.33 Nm/kg) (p < 0.05). The constrained implant was indicated in arthroplasty revision surgeries with severe ligament instability and in cases of complex primary arthroplasties with bone destruction or severe coronal deformity in the coronal plane. Conclusion : The use of constrained implants enables joint function and muscle strength comparable to patients who underwent primary arthroplasty using conventional implants with posterior stabilization. Patients undergoing septic revision with a rotating Hinge prosthesis exhibit lower flexor muscle strength compared to those undergoing primary arthroplasty with a constrained implant.

Responsiveness of Isokinetic Dynamometry in Patients with Osteoarthritis after Knee and Hip Arthroplasty: A Prospective Repeated-Measures Cohort Study.

Functional assessments are crucial for the evaluation of rehabilitation after total knee (TKA) and hip (THA) arthroplasty. Muscle strength, a key determinant of physical function (PF), is often measured with isokinetic dynamometry (ID), which is considered the gold standard. However, studies lack evaluations of responsiveness-the ability to detect changes over time. This study aims to determine the responsiveness of ID in measuring PF in TKA and THA rehabilitation-is muscle strength a valid indicator for assessing improvement in rehabilitation processes? The pre- and post-surgery PF of 20 osteoarthritis patients (age 55-82) was assessed, using ID, performance-based and self-reported measures. Responsiveness was evaluated by comparing the observed relationship of changes in ID and PF scores with the a priori defined expected relationship of change scores. While the performance-based and self-reported measures showed significant improvements post-surgery (Cohen's d [0.42, 1.05] p < 0.05), ID showed no significant differences. Moderate correlations were found between changes in some ID parameters and selected functional tests (r ≈|0.5|, p < 0.05). Responsiveness was solely found for the peak torque of knee extension at 180°/s on the operated side. Responsiveness is an often-overlooked psychometric property of outcome measurements. The findings suggest that ID may not be fully responsive to the construct of PF after TKA and THA, raising questions about its role and usefulness in this context and the need for more appropriate assessment methods.

Inferior Outcomes for Patients Transferred Between Surgical Stages for Knee Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) in total knee arthroplasty may result in 2-stage revision surgery. There are limited data describing outcomes when the first stage is completed at an outside hospital and the patient is referred to a tertiary center. We hypothesized that patients have greater success when both surgeries occur at a single center. METHODS: There were 25 knee PJI patients who presented with an antibiotic spacer and had a minimum 2-year follow-up who were retrospectively identified at a single tertiary referral center from 2014 to 2021. A cohort matched for age, sex, body mass index, Elixhauser comorbidity measure, spacer type, infectious organism, and year of surgery was established with patients who had both stages completed at the investigating institution. Modified Delphi success criteria of no subsequent surgery or reinfection with any species were compared. RESULTS: The transferred group demonstrated a treatment success of 40% compared to 84% in the continuous group (P < .01). The transferred group was more likely to have an additional procedure between stages (44 versus 8%, P < .01), with a higher number of surgeries after primary total knee arthroplasty (4.8 versus 3.0, P < .01), between stages (1.4 versus 0.2, P < .01), and after second stage (0.8 versus 0.2, P = .03). The transferred group had longer durations between stages (20.1 versus 7.0 weeks, P < .01). CONCLUSION: Patients who have PJIs transferred between stages demonstrated higher treatment failure. Surgeons should consider transfer early with a goal of continuous management by a single institution.

Summary of the best evidence of accelerated rehabilitation nursing in perioperative period of patients undergoing hip and knee arthroplasty / 中国实用护理杂志

Objective:To search, evaluate and summarize the best evidence summary of perioperative accelerated rehabilitation nursing for patients undergoing hip and knee arthroplasty, so as to provide reference for clinical perioperative nursing.Methods:Evidence-based nursing methods were used to search for relevant databases such as BMJ Best Practice, UpToDate, PubMed, CINAHL, and CNKI, etc.. The search period was from December 2010 to December 2022. Four researchers independently evaluated the quality of the guidelines, and two researchers independently evaluated the quality of expert consensus and system evaluation. Finally, the included literature was summarized.Results:A total of 12 pieces of literature, 3 guidelines, 5 expert consensus and 4 systematic reviews were included. From 13 aspects of preoperative education, preoperative optimization, anesthesia management, perioperative blood management, perioperative pain management, perioperative fluid management, perioperative temperature protection, infection prevention, thrombus prevention, postoperative nausea and vomiting, postoperative drainage, functional exercise, and perioperative rehabilitation promotion, 35 pieces of the best evidence for hip and knee replacement patients to accelerate rehabilitation nursing in the perioperative period was summarized.Conclusions:This study summarizes the best evidence of accelerated rehabilitation nursing in the perioperative period of hip and knee arthroplasty, aiming to build and standardize the accelerated rehabilitation nursing scheme in the perioperative period of hip and knee arthroplasty, so as to provide reference for clinical perioperative nursing.

The effect of ultrasound-guided myofascial tube combined with knee joint posterior capsule space block on postoperative delirium in elderly patients undergoing total knee arthroplasty / 中国医师杂志

Objective:To evaluate the effect of ultrasound-guided adductor canal combined with knee joint posterior capsule space block on the recovery period delirium in elderly patients undergoing total knee arthroplasty (TKA).Methods:A total of 68 elderly patients who underwent unilateral TKA at the Nanjing First Hospital from December 2021 to December 2022 were selected. They were randomly divided into a control group ( n=34) and an observation group ( n=34) using a random number table method. Both groups received general anesthesia, and the observation group received ultrasound-guided myofascial tube combined with knee joint posterior capsule space block before the surgery began. The incidence of delirium within 24 hours after surgery was mainly observed in two groups of patients. The surgical time, recovery time, intraoperative blood loss, infusion volume, total use of propofol and remifentanil were recorded; The resting and motor Visual Analogue Scale (VAS) scores of the patient were recorded at 4, 8, and 24 hours postoperatively. The patient′s serum tumor necrosis factor-α (TNF-α) and melatonin levels were measured on the day before surgery, the evening after surgery, and the first day after surgery. The subjective sleep quality score was recorded on the first day after surgery; The total dosage of sufentanil for patient-controlled intravenous analgesia (PCIA) within 24 hours after surgery, the effective number of compressions (P1) and actual number of compressions (P2) of PCIA, and the number of cases of additional oxycodone analgesia were recorded; The occurrence of respiratory depression, excessive sedation, nausea, and vomiting within 24 hours after surgery was recorded; The occurrence of complications of nerve block in the observation group was recorded. Results:The incidence of delirium during the recovery period in the observation group was lower than that in the control group ( P<0.05). The dosage of propofol and remifentanil in the observation group was lower than that in the control group (all P<0.05), and the awakening time was shorter than that in the control group ( P<0.05). The VAS scores at rest and exercise at 4, 8, and 24 hours after surgery in the observation group were lower than those in the control group (all P<0.05). Compared with the day before surgery, the observation group showed an increase in melatonin levels on the night after surgery ( P<0.05) and an increase in TNF-α levels on the first day after surgery ( P<0.05); The control group had a decrease in melatonin levels on the first day after surgery ( P<0.05), and an increase in TNF-α levels on the night and day after surgery (all P<0.05). The serum melatonin levels in the observation group were higher than those in the control group on the evening and first day after surgery (all P<0.05), and TNF-α levels were lower than those in the control group (all P<0.05). The subjective sleep quality score of the observation group showed that the total dosage of PCIA sufentanil, P1, P2, and the number of cases of additional oxycodone analgesia within 24 hours after surgery were lower than those of the control group (all P<0.05). The incidence of nausea in the control group (13 cases, 38.2%) was higher than that in the observation group (3 cases, 8.8%) ( P<0.05). Conclusions:In elderly patients undergoing unilateral TKA under general anesthesia, preoperative use of ultrasound-guided adductor tube combined with knee joint posterior capsule space block can effectively reduce the occurrence of postoperative delirium.

Analysis of risk factors for periprosthetic joint infection after primary total knee arthroplasty and construction of a nomogram prediction model / 中华创伤骨科杂志

Objective:To investigate the risk factors for periprosthetic joint infection (PJI) after primary total knee arthroplasty (TKA) and construct a nomogram model for prediction of such risks.Methods:In this retrospective study, we enrolled 69 patients with PJI after primary TKA (the infection group, n=69) who had been admitted to Department of Orthopedics, Nanjing Jinling Hospital, The First School of Clinical Medicine, Southern Medical University from January 2010 to December 2019. The non-infection group included the patients of the same kind but without postoperative infection during the same period who were matched according to time of admission, age, and gender in a ratio of 1∶3 ( n=207). The data on body mass index, anesthesia method, operation time, preoperative C-reactive protein, preoperative albumin, and comorbid medical conditions were collected from both groups to screen the risk factors for postoperative development of PJI using univariate and multivariate conditional logistic regression analyses. After a nomogram of the risk factors was plotted using R software, the consistency index (C-index) was calculated. The receiver operating characteristic curve, calibration curve, and clinical decision curve were drawn. Results:Multivariate conditional logistic regression analysis showed that preoperative albumin <35 g/L ( OR=7.166, 95% CI: 3.427 to 14.983, P<0.001), operation time >90 min ( OR=3.163, 95% CI: 1.476 to 6.779, P=0.003), diabetes mellitus ( OR=3.966, 95% CI: 1.833 to 8.578, P<0.001), rheumatic diseases ( OR=3.531, 95% CI: 1.362 to 9.156, P=0.009), and chronic lung diseases ( OR=4.734, 95% CI: 1.790 to 12.521, P=0.002) were risk factors for development of PJI after primary TKA. The nomogram constructed with R software visualized the model. The C-index of the nomogram was 0.809 (95% CI: 0.751 to 0.867), indicating a good predictive capability of the model. The calibration curves of the model showed that the nomogram was in good agreement with the actual observations. The decision curves showed that the threshold probabilities of the model ranged from 0.08 to 0.75, providing a good net clinical benefit. Conclusions:Preoperative low albumin, prolonged operation time, diabetes, rheumatic diseases, and chronic lung diseases may be the risk factors for PJI after primary TKA. The nomogram prediction model based on these factors can provide a reference for clinicians to prevent PJI.

Analysis of early-period curative effect of total knee arthroplasty in the treatment of osteoarthritis combined with fixed patellar dislocation / 中华骨科杂志

Objective:To systematically investigate the short-term efficacy of total knee arthroplasty in the treatment of osteoarthritis coupled with fixed patellar dislocation.Methods:A retrospective analysis was conducted on a cohort of 11 patients diagnosed with knee osteoarthritis and fixed patellar dislocation who underwent total knee arthroplasty at Panzhihua Central Hospital from January 2018 to October 2021. The cohort comprised 4 males and 7 females, aged 63.45±4.76 years (range, 56-70 years), all of whom underwent unilateral surgery. There were 5 left and 6 right knees, with a body mass index of 23.20±2.02 kg/m 2 (range, 20.8-27.6 kg/m 2) and a disease course of 12.63±4.81 years. According to the American Society of Anesthesiologists classification, 9 cases were categorized as grade II, and 2 cases as grade III. Recovery of patellar trajectory during total knee arthroplasty, using medial synovial flap transposition to repair lateral joint capsule. Preoperative and postoperative assessments included knee joint range of motion, Knee Society score (KSS), University of California Los Angeles (UCLA) score, and visual analogue scale (VAS). Results:All 11 patients were followed up for a period of 28.64±4.01 months (range, 24-36 months). Two patients exhibited subcutaneous fat liquefaction locally after surgery, which resolved following dressing changes. All wounds achieved primary healing. Two of them developed intramuscular vein thrombosis after surgery and were cured after anticoagulant treatment. The range of motion of the knee joint increased from 63.18°±17.07° before surgery to 104.55°±16.80° at the last follow-up, with a statistically significant difference ( t=14.041, P<0.001). The KSS score increased from 38.00±6.78 points to 80.91±5.65 points, with a statistically significant difference ( t=16.472, P<0.001). The UCLA score increased from 3.18±1.17 to 6.73±1.35, with a statistically significant difference ( t=9.694, P<0.001). The VAS decreased from 6.09±0.94 points to 2.32±0.64 points, with a statistically significant difference ( t=16.600, P<0.001). At the last follow-up, imaging examinations showed no cases of patellar subluxation or dislocation, no tearing or breakage of the knee extension device, and no infection or loosening around the prosthesis. Conclusion:Utilizing medial synovial flap transposition for repairing the lateral joint capsule proves to be an effective technique for key capsule repair. Total knee arthroplasty for osteoarthritis combined with fixed patellar dislocation demonstrates satisfactory early clinical outcomes.

Treatment of polyethylene sleeve wear in rotating hinge knee joint with femoral component revision surgery / 中华骨科杂志

Objective:To investigate the clinical efficacy of femoral component revision surgery in addressing polyethylene sleeve wear in rotating hinge knee joints.Methods:A retrospective analysis was conducted on 21 patients who underwent treatment for polyethylene sleeve wear in rotating hinge knee joints at the Department of Orthopaedics, the Fourth Medical Center, PLA General Hospital, spanning from August 2008 to April 2023. There were 8 males and 13 females with a median age of 63(38, 76) years. Among them, 11 cases involved the left side, and 10 cases involved the right side. The average body mass index (BMI) was 25.0(22.5, 31.0) kg/m 2, and all cases underwent unilateral knee joint revision. The time interval from receiving the hinge knee joint prosthesis to revision was 10.5(6.0, 17.0) years, with 18 cases undergoing primary revision and 3 cases undergoing revision for the second time. Revision surgery of the femoral component sleeve was performed in all patients due to polyethylene sleeve wear. Visual analogue scale (VAS), range of motion (ROM) of the knee joint, changes in hip-knee-ankle angle (HKA), and Knee Society score (KSS) were collected and recorded to assess the surgical outcomes. Results:All patients were followed up for a median duration of 12.5(11.7, 13.4) months. Preoperatively, the VAS score was 5(3, 7) points, which significantly decreased to 0(0, 1) points at the last follow-up ( Z=5.721, P<0.001). At the last follow-up, the KSS scores decreased from 41.19±13.65 points preoperatively to 79.81±7.80 points, indicating a statistically significant difference ( t=12.560, P<0.001). HKA increased from 174.65°±5.20° preoperatively to 178.71°±2.79°, with a statistically significant difference ( t=5.533, P<0.001). Knee joint ROM increased from 69.05°±34.37° preoperatively to 110.00°±10.12°, also demonstrating a significant improvement ( t=5.960, P<0.001). Notably, patients exhibited knee joint stability with no passive flexion or extension laxity. Conclusion:Femoral component sleeve revision surgery effectively addresses polyethylene sleeve wear in rotating hinge knee joint prostheses, thereby mitigating the substantial loss of bone and soft tissue associated with overall revision procedures. The early postoperative clinical outcomes are promising and indicative of the efficacy of this surgical intervention.

The impact of constrained prostheses on the outcomes of two-stage revision for periprosthetic joint infection after total knee arthroplasty / 中华骨科杂志

Objective:To assess the clinical efficacy and infection control outcomes of two-stage revision in managing periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) utilizing either a low or high constrained prosthesis.Methods:A retrospective analysis was performed on 40 patients who underwent revision TKA in the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University from February 2019 to February 2022. According to the type of prosthesis selected in primary TKA, they were divided into low constrained prosthesis group and high constrained prosthesis group. There were 28 patients (28 knees) in the low constrained group, including 12 males and 16 females, aged 69.0(63.0, 74.0) years, with a body mass index of 25.18±0.55 kg/m 2. And there were 12 patients (12 knees) in the high-constrained group, including 5 males and 7 females, aged 66.5(65.0, 71.5) years, with a body mass index of 23.94±0.51 kg/m 2. All patients underwent two-stage revision surgery, with RHK used in 1 case and LCCK in 27 cases in the low-constrained prosthesis group. In the high-constrained prosthesis group, 3 patients were treated with RHK, 1 patient with PFC Sigma MBT, and 8 patients with LCCK. The preoperative and postoperative range of motion (ROM), Knee Society score (KSS), and postoperative infection control rate were compared between the two groups. Results:All patients were followed up. The follow-up time was 22.79±8.02 months in the low-constrained prosthesis group and 23.92±7.04 months in the high-constrained prosthesis group, with no significant difference between the two groups ( t=0.426, P=0.680). At the last follow-up, the KSS and ROM in the low-constrained prosthesis group were 77.96±9.74 and 93.48°±7.45°, respectively, significantly higher than 38.93±8.01 and 68.89°±9.44° before the operation ( P<0.05). The KSS score and ROM in the high-constrained prosthesis group were 67.83±8.31 and 80.08°±5.89° at the last follow-up, which were also significantly higher than those before operation (34.25±6.31 and 66.50°±10.48°, P<0.05). There was no significant difference in KSS and ROM between the two groups before operation ( P>0.05), but the KSS score and ROM in the low-constrained prosthesis group were significantly higher than those in the high-constrained prosthesis group at the last follow-up ( P<0.05). Bacterial culture results revealed that the primary infectious agents were coagulase-negative Staphylococcus and Staphylococcus aureus, with an overall infection control rate of 80% (32/40). The infection control rate was 89% (25/28) in the low-constrained prosthesis group and 58% (7/12) in the high-constrained prosthesis group, but the difference between the two groups was not statistically significant (χ 2=3.283, P=0.070). Conclusion:Two-stage revision effectively controls PJI, and the clinical outcomes of two-stage revision for PJI after primary TKA with a high-constrained prosthesis are inferior to those with a low-constrained prosthesis. Further exploration is needed to enhance efficacy.

The efficacy of trabecular metal Cones in reconstructing metaphyseal bone defects during revision total knee arthroplasty / 中华骨科杂志

Objective:To investigate the clinical outcomes and efficacy of trabecular metal (TM) cones for the reconstruction of metaphyseal bone defects in revision total knee arthroplasty.Methods:A retrospective analysis was conducted on 46 patients (47 knees), who underwent revision total knee arthroplasty with TM cones for metaphyseal defect reconstruction from July 2015 to August 2023. The cohort comprised 12 males and 34 females, ranging from 41 to 83 years of age, with a mean of 68.65 ± 9.09 years. Body mass index (BMI) ranged from 19.5 to 36.0 kg/m 2, averaging 27.20±4.50 kg/m 2. Bone defects were stratified according to the Anderson Orthopedic Research Institute (AORI) classification, including 64 sides (AORI T2B type 20 sides, T3 type 16 sides, F2B type 11 sides, F3 type 17 sides) which were addressed with 67 cones. Evaluations during follow-up included range of motion (ROM), visual analogue scale (VAS) for pain, and the American Knee Society Score (KSS). Long leg radiographs and knee X-rays were reassessed for femorotibial angle (FTA) and joint alignment, osseointegration of the TM cones, and any complications were documented. Results:The average follow-up duration was 46.22±26.55 months (range 16-103 months). The KSS knee score significantly improved from 29.22±19.79 preoperatively to 88.22±6.01 at the final follow-up ( F=258.118, P<0.001). Similarly, the KSS function score saw a marked increase from a preoperative average of 7.65±8.21 to 56.30±6.10 at the final follow-up ( F=354.711, P<0.001). VAS scores significantly decreased from 5.35±1.50 preoperatively to 0.28±0.50 at the final follow-up ( F=300.934, P<0.001). ROM improved from 67.72°±34.62° preoperatively to 85.33°±9.15° at the final follow-up ( F=7.798, P<0.001), and the FTA improved from 179.24°±10.30° preoperatively to 174.39°±1.69° at the final follow-up, a statistically significant enhancement ( F=9.123, P<0.001). Osseointegration was observed in 95.5% of the cases (64/67 cones). There were no instances of osteolysis or aseptic loosening observed, indicating stable prosthetic fixation. Complications were minimal, with one reported case of a femoral shaft fracture, which was successfully treated with internal fixation, resulting in satisfactory healing at 6 months. At the last follow-up (3 years after operation), the patient could walk at home with a walker and the other patients had no complications such as periprosthetic joint infection, dislocation and periprosthetic fracture. Conclusion:The application of trabecular metal cones in revision total knee arthroplasty provides an effective solution for the reconstruction of severe metaphyseal bone defects, enhancing prosthetic stability and restoring the knee joint's mechanical alignment. The trend towards successful osseointegration in the TM cones is promising, and a significant improvement in knee joint function has been observed.