Feasibility of prehabilitation for patients awaiting total knee arthroplasty; a pilot study.

Objective: To examine the feasibility of conducting a preoperative home-based prehabilitation program for total knee arthroplasty patients at risk for delayed in-hospital recovery, and to explore the pre- and postoperative impact of this program. Design: A retrospective cohort study with matched controls, enabling subgroup analyses. Setting: Home-based. Subjects: Patients awaiting primary unilateral total knee arthroplasty between 2019 and 2020, were compared with matched historic cases from 2016 to 2017. Matching criteria were scoring ≤17 points on the De Morton Mobility Index and >12.5 s on the timed-up-and-go test. Intervention: Supervised home-based prehabilitation program versus no prehabilitation. Outcomes: Feasibility, determined by recruitment rate, adherence, and safety of the program. Preoperative impact, assessed for the intervention group by differences in mean values for aerobic capacity, muscle strength and functional mobility between the first and last sessions. Postoperative impact was defined as the time needed to achieve in-hospital independence of physical function and was measured by the differences in mean values between the intervention and control groups. Results: Recruitment rate was 71 %; adherence and drop-out rates were 88 % and 12 % respectively. No adverse events were reported. Preoperatively, the intervention group showed significant improvements in aerobic capacity on the 2-min walking test (84.29 m-98.06 m; p = 0.007) and 2-min step test (40.35 steps to 52.95 steps; p = 0.014), muscle strength on the 30 s chair stand test (7.3 stands to 10.1 stands; p = 0.002), and functional mobility as seen in the timed-up-and-go-test (19.52 s-15.85 s; p = 0.031). Postoperatively, the intervention group achieved in-hospital independence of physical function earlier (mean rank 16.11) than the control group (mean rank 24.89; p=<0.01). Conclusions: It is feasible to conduct a prehabilitation program 4-6 weeks preoperatively, for high-risk patients awaiting total knee arthroplasty. Additionally, the program appears to have a positive impact on physical fitness both pre- and postoperatively.

Patellar resurfacing in contemporary total knee arthroplasty: Frequency of complications in a matched cohort.

Introduction: Optimum patient selection and outcomes following patellar resurfacing are ongoing debates amongst the arthroplasty community. This study compared the outcomes of patients who had a total knee arthroplasty (TKA) with patellar resurfacing to those left with their native patella. Methods: A retrospective review of 1941 TKAs performed between 2016 and 2020 was conducted. 41 TKAs without patellar resurfacing and with 2-years of minimum follow-up were identified. Of these, 38 TKAs were matched on age (exact), sex (exact), and body mass index (±10) to 38 TKAs that had patellar resurfacing. The indications for patella resurfacing were subjective based upon the surgeon preference and assessment of cartilage quality. Paired t-tests and chi-square tests were used for analysis. Results: There was 1 major patellofemoral complication in both the resurfaced group (patellar fracture) and the non-resurfaced group (patellar tendon tear), requiring nonoperative management and revision surgery, respectively. However, in the non-resurfaced group there were 4 cases of subjective patellofemoral pain compared to none in the resurfaced group (p = 0.37). Additionally, 3 non-resurfaced patients required manipulation under anesthesia (MUA) compared to none in the resurfaced group (p = 0.44). Discussion: There was no difference in the frequency of major patella-specific complications between the groups. However, there was a non-statistically significant trend towards increased patellofemoral pain and MUA in the non-resurfaced group. Based on this study both methods of treatment remain viable options, but the trend towards increased pain and stiffness should continue to be closely evaluated.

A finite element analysis of patellofemoral joint biomechanics: Exploring potential causes of postoperative anterior knee pain following unicompartmental knee arthroplasty.

Purpose: Anterior knee pain is a common complication following unicompartmental knee arthroplasty (UKA). This study aimed to elucidate the mechanism of anterior knee pain after UKA by examining the biomechanical characteristics of the patellofemoral joint. Methods: This study employs the finite element analysis method. A healthy model of the right lower limb was created using CT scans of an intact right lower limb from a healthy woman. Based on this model, a preoperative pathological model was generated by removing the meniscus and part of the articular cartilage. The UKA prosthesis was then applied to this model with five different bearing thicknesses: 5 mm, 7 mm, 10 mm, 11 mm, and 13 mm. To simulate various degrees of knee joint flexion, the femur was rotated relative to the knee joint's rotational axis, producing lower limb models at flexion angles of 0°, 30°, 60°, 90°, and 120°. We applied a constant force from the center of the femoral head to the center of the ankle joint to simulate lower limb loading during squatting. The simulations were conducted using Ansys 17.0. Results: Both overstuffing and understuffing increased the peak stress on the patellar cartilage, with overstuffing having a more pronounced effect. Compared to healthy and balanced models, overstuffed and understuffed models exhibited abnormal stress distribution and stress concentration in the patellar cartilage during knee flexion. Conclusion: Overstuffing and understuffing lead to residual varus or valgus deformities after UKA, causing mechanical abnormalities in the patellofemoral joint. These abnormalities, characterized by irregular stress distribution and excessive stress, result in cartilage damage, exacerbate wear in the patellofemoral joint and consequently lead to the occurrence of anterior knee pain.

Osteoporosis in the setting of knee arthroplasty: a narrative review.

Patients undergoing knee replacement, which is mainly indicated in severe osteoarthritis, are frequently co-affected by osteoporosis and osteopenia. With a prevalence standing at around 20% in patients receiving knee arthroplasty, osteoporosis could lead to poor outcomes postoperatively. Some of these complications include periprosthetic fractures and an increased revision rate. Antiresorptive medications have been shown to be beneficial postoperatively. However, no studies have been conducted on whether they had any benefits if given preoperatively. Surgical management may also be beneficial, but this area remains full of controversy.

The applied study to improve the treatment of knee sports injuries in ultimate frisbee players based on personalized exercise prescription: a randomized controlled trial.

Objective: Ultimate frisbee can lead to severe sports injuries, especially joint injuries in the lower limbs, such as knee meniscus injuries. This study examines the impact of personalized exercise therapy on knee meniscus injuries in ultimate frisbee players in the Lingnan region of China. Methods: Seventy-six patients with confirmed meniscal injuries participated in the study, divided into an intervention group (n = 38) and a control group (n = 38). The control group received standard treatment, including drug therapy and physical therapy. The intervention group received standard treatment plus a personalized exercise regimen based on FITT-VP (frequency, intensity, time, type, volume, and progression) principles, incorporating strength training, aerobic exercise, flexibility training, neuromuscular training, and aquatic exercise. This program was monitored and adjusted over a six-month period through both online and offline methods. The primary outcomes were joint range of motion (ROM), thigh circumference atrophy index (TCAI), Lysholm Rating Scale (LRS) scores, and visual analog scores (VAS). The secondary outcome was the International Knee Documentation Committee (IKDC) score. Data were collected before the intervention, and at 1 month and 6 months after the intervention. Statistical analysis was conducted using SPSS 24.0 and GraphPad 10.0, with a significance level set at α = 0.05. Results: After 1 month, the intervention group showed significantly better results in ROM (116.67 ± 9.063), LRS score (86.316 ± 3.750), and IKDC score (80.473 ± 5.421) compared to the control group (111.784 ± 4.778, 82.579 ± 3.818, and 77.684 ± 4.430, respectively) (p < 0.05). The TCAI (3.219 ± 1.889) and VAS score (1.921 ± 0.673) in the intervention group were significantly lower than those in the control group (5.228 ± 2.131 and 2.710 ± 1.112, respectively) (p < 0.01). After 6 months, the differences in LRS and VAS scores between the groups were not significant. However, the intervention group continued to show significant improvements in ROM (134.934 ± 3.011), TCAI (1.107 ± 1.158), and IKDC score (93.315 ± 1.847) compared to the control group (125.395 ± 18.554, 4.574 ± 1.109, and 87.789 ± 4.437, respectively) (p < 0.05). Conclusion: Personalized exercise prescriptions offer significant therapeutic and rehabilitative benefits for ultimate frisbee players with knee meniscus injuries. This approach helps to reduce symptoms, alleviate pain, and improve joint function, muscle strength, and athletic performance after sports-related injuries.

Non-invasive regional parameter identification of degenerated human meniscus.

Accurate identification of local changes in the biomechanical properties of the normal and degenerative meniscus is critical to better understand knee joint osteoarthritis onset and progression. Ex-vivo material characterization is typically performed on specimens obtained from different locations, compromising the tissue's structural integrity and thus altering its mechanical behavior. Therefore, the aim of this in-silico study was to establish a non-invasive method to determine the region-specific material properties of the degenerated human meniscus. In a previous experimental magnetic resonance imaging (MRI) study, the spatial displacement of the meniscus and its root attachments in mildly degenerated (n = 12) and severely degenerated (n = 12) cadaveric knee joints was determined under controlled subject-specific axial joint loading. To simulate the experimental response of the lateral and medial menisci, individual finite element models were created utilizing a transverse isotropic hyper-poroelastic constitutive material formulation. The superficial displacements were applied to the individual models to calculate the femoral reaction force in an inverse finite element analysis. During particle swarm optimization, the four most sensitive material parameters were varied to minimize the error between the femoral reaction force and the force applied in the MRI loading experiment. Individual global and regional parameter sets were identified. In addition to in-depth model verification, prediction errors were determined to quantify the reliability of the identified parameter sets. Both compressibility of the solid meniscus matrix (+141 %, p ≤ 0.04) and hydraulic permeability (+53 %, p ≤ 0.04) were significantly increased in the menisci of severely degenerated knees compared to mildly degenerated knees, irrespective of the meniscus region. By contrast, tensile and shear properties were unaffected by progressive knee joint degeneration. Overall, the optimization procedure resulted in reliable and robust parameter sets, as evidenced by mean prediction errors of <1 %. In conclusion, the proposed approach demonstrated high potential for application in clinical practice, where it might provide a non-invasive diagnostic tool for the early detection of osteoarthritic changes within the knee joint.

Osteochondral regeneration with a tri-layered biomimetic resorbable scaffold: In vivo study in a sheep model up to 12 months of follow-up.

The treatment of osteochondral joint lesions requires the regeneration of both articular cartilage and subchondral bone tissue. Scaffold-based strategies aimed at mimicking the native osteochondral structure have been explored with mixed results. The aim of this study was to evaluate the regenerative potential of a tri-layered osteochondral cell-free scaffold in a large animal model at both 6 and 12 months of follow-up. Bilateral critical-sized osteochondral defects were created in 22 sheep. One defect was filled with the scaffold, whereas the contralateral was left empty. The repair tissue quality was evaluated at 6 and 12 months of follow-up in terms of macroscopic appearance, histology, trabecular bone formation, and inflammation grade. The mean global ICRS II score in the scaffold and control groups was 41 ± 11 vs 30 ± 6 at 6 months (p = 0.004) and 54 ± 13 vs 37 ± 11 at 12 months (p = 0.002), respectively. A higher percentage of bone was found in the treatment group compared to controls both at 6 (BV/TV 48.8 ± 8.6 % vs 37.4 ± 9.5 %, respectively; p < 0.001) and 12 months (BV/TV 51.8 ± 8.8 % vs 42.1 ± 12.6 %, respectively; p = 0.023). No significant levels of inflammation were seen. These results demonstrated the scaffold safety and potential to regenerate both cartilage and subchondral tissues in a large animal model of knee osteochondral lesions.

Demographic characteristics and clinical-radiological correlation in patients with indications for Total Knee Arthroplasty: A cross-sectional study.

OBJECTIVE: The objective of this study is to correlate clinical symptoms and functionality, using the KOOS (Knee Injury and Osteoarthritis Outcome Score) and KSS (Knee Society Score System) scores, with the radiographic changes, using the Kellgren-Lawrence classification, in patients with knee osteoarthritis and indications for Total Knee Arthroplasty (TKA). METHODS: 120 patients (189 knees) with gonarthrosis and indications for TKA were included in the study. Demographic questionnaires were applied, and clinical and functional assessment was carried out using the KOOS and KSS scores. Knee radiographs were taken and graded according to Kellgren-Lawrence. The clinical scores were compared with the radiographic classification to establish a correlation between these two measurements. Statistical analysis was performed using the τ-Kendall correlation test. RESULTS: Weak and inversely proportional correlations were found between the clinical scores and the radiographic classification. Among clinical scores evaluated, KSS showed the highest correlation with Kellgren-Lawrence classification (τ = -0.356; p < 0.001), followed by KOOS-quality of life (τ = -0.176; p = 0.004), KOOS-total score (τ = -0.166; p = 0.004), KOOS-function in daily living (τ = -0.160; p = 0.005) and KOOS-symptoms (τ = -0.159; p = 0.006). KOOS-pain (τ = -0.149; p = 0.01) and KOOS-sport and recreation function (τ = -0.142; p = 0.025) scores had the weakest correlations. CONCLUSION: There is a weak correlation between the clinical-functional scores of TKA candidates and their radiographic classification by Kellgren-Lawrence. Among clinical scores evaluated, KSS had the strongest negative correlation with the radiographic classification.

Chronic Anticoagulation in Patients Who Have Atrial Fibrillation Undergoing Outpatient Total Knee Arthroplasty: A Retrospective Matched Cohort Study.

BACKGROUND: Patients who have atrial fibrillation frequently require long-term anticoagulation with warfarin or a direct-acting oral anticoagulant (DOAC), such as apixaban or rivaroxaban, to avoid vascular complications. However, the impact of anticoagulant use on postoperative complications following total knee arthroplasty (TKA) in an outpatient setting has not been thoroughly elucidated. The purpose of this study was to examine the impact of anticoagulant use on early postoperative complications among atrial fibrillation patients undergoing outpatient TKA. METHODS: An insurance claims database was queried to identify all patients who underwent outpatient TKA between January 2010 and April 2022. There were two cohorts of patients, with associated 1:1 matched controls, who had atrial fibrillation and filled a prescription of either warfarin (N = 4,396) or DOAC (N = 5,383) for at least 30 days. The mean age was 70 years (range, 51 to 84 years) and 47.9% were women in the warfarin cohort, while the mean age was 70 years and 49.2% were women in the DOAC cohort. Postoperative 30-day medical and 90-day surgical complications were subsequently compared. RESULTS: Patients on warfarin had a higher incidence of pulmonary embolism (1.1 versus 0.2%, P < 0.001) and a lower incidence of TKA revision (0.1 versus 0.4%, P = 0.003) than matched controls. Similarly, patients on DOACs exhibited a higher incidence of pneumonia (1.4 versus 0.6%, P < 0.001) and myocardial infarction (3.2 versus 1.5%, P < 0.001) and a lower incidence of wound dehiscence (0.1 versus 0.5%, P < 0.001), joint infection (0.4 versus 0.9%, P = 0.002), and TKA revision (0.1 versus 0.4%, P = 0.002) than matched controls. CONCLUSIONS: Atrial fibrillation patients on long-term anticoagulants undergoing outpatient TKA experience higher rates of medical complications and lower rates of surgical complications than matched controls. Thus, patients on long-term anticoagulants may be considered for outpatient TKA, but should be counseled appropriately on associated medical risks.

Recent Medicare Billing Trends of Hospitals and Surgeons for Revision Hip and Knee Total Joint Arthroplasty: Is the Value of a Surgeon's Work Decreasing?

INTRODUCTION: Revision hip and knee total joint arthroplasty (TJA) is associated with higher healthcare costs and work burden than primary TJAs. However, previous studies demonstrated a decrease in the value of reimbursements for revision TJA, causing concerns for hospitals and surgeons regarding the financial sustainability of these resource-expensive procedures. This study aimed to investigate the Medicare billing trends of hospitals and surgeons for revision TJA between 2017 and 2022. METHODS: Medicare claims and payments for revision TJA were identified from the Centers for Medicare and Medicaid Services Part A and B databases. Hospital claims for revision TJA were identified through Diagnostic-Related Groups (467, 468). Surgeon claims were identified using Current Procedural Terminology codes for revision hip (27134, 27137, 27138) and knee (27486, 27487) TJA. Yearly charges, reimbursements, and markup ratios (MR = charge/reimbursement) were analyzed. All monetary values were adjusted to the 2022 U.S. dollars. RESULTS: A total of 43,125 surgeons and 152,974 hospital claims were included in this study. From 2017 to 2022, the total volume of revision TJA decreased by 19.4%. Hospital reimbursements remained relatively unchanged, with a decrease of 1.4%, while hospital charges increased by 11.8%, resulting in a 13.3% increase in the markup ratio. For surgeons, reimbursements decreased by 13.8%, and charges decreased by 11.0%, leading to a 3.3% increase in the markup ratio. The proportion of surgeon reimbursement to hospital reimbursement decreased from 8.5 to 7.5%. CONCLUSION: The comparison of the billing trends of hospitals and surgeons showed the relatively stable value of hospital reimbursement while the value of surgeon reimbursement continued to decline, implying the decreasing fiscal value of physicians' work. The study suggests the need for sustainable financial incentives for surgeons performing revision TJA and strategies to control hospital charges to alleviate financial burdens and improve patient access to revision TJA.

Gender, BMI, and Age-Related Variations in Lower Limb Alignment Parameters and CPAK Phenotypes in Chinese Patients with Knee Osteoarthritis.

OBJECTIVES: Research on the distribution of and the variation in coronal plane alignment of the knee (CPAK) in the Chinese osteoarthritis population is limited. We aimed to establish the CPAK classification based on the characteristics of lower limb alignment in the Chinese osteoarthritis population. We also investigated variations in lower limb alignment parameters and CPAK phenotypes based on gender, body mass index (BMI), and age. METHODS: A retrospective study was conducted on a total of 944 knees diagnosed with osteoarthritis in 479 patients from January 2017 to December 2023. A scatterplot was used to describe the distribution of the CPAK classification, and the differences in lower limb alignment parameters and the CPAK classification were compared across genders (male, female), ages (middle-aged/<65 years, elderly/≥65 years), and BMI categories (normal/<25 kg/m2, overweight and obese/≥25 kg/m2) using the chi-squared test or Fisher's exact test. RESULTS: The average arithmetic hip-knee-ankle angle and joint line obliquity (JLO) were -3.03° ± 5.69° and 174.45° ± 4.29°, respectively. There was a higher prevalence of constitutional varus alignment in males and the overweight or obese group, while constitutional valgus alignment was more common in females and the normal BMI group (p < 0.05). Additionally, females had a greater apex distal JLO than males (p < 0.05). There were no statistically significant differences in lower limb alignment parameters among different age groups (p > 0.05). Although there were variations in alignment parameters across different genders and BMI categories in the knee osteoarthritis population, the predominant CPAK classifications were type I (38.03%), followed by type II (20.02%) and type IV (17.06%). CONCLUSION: The most common CPAK types were I, II, and IV, and they were not influenced by gender, BMI, or age, indicating that the CPAK classification can reliably reflect constitutional alignment. A better understanding of native alignment variability can aid in providing patient-specific recommendations when considering orthopedic alignment strategies.

Revision ACL reconstruction, but not bilateral ACL reconstruction, is associated with clinically relevant inferior subjective knee function compared with primary ACL reconstruction: A comparative analysis of 6831 patients.

PURPOSE: To evaluate and compare the subjective knee function in patients undergoing revision and bilateral anterior cruciate ligament (ACL) reconstruction (ACLR) with those undergoing primary ACLR in a large cohort. METHODS: Patients without concomitant ligament injuries who underwent primary, revision or bilateral ACLR at the Capio Artro Clinic, Stockholm, Sweden, between 2005 and 2018 were identified. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2 and 5 years postoperatively from the Swedish National Knee Ligament Registry. Patients who underwent revision and bilateral ACLR were compared with those who underwent primary ACLR (control group) using Student's t test. RESULTS: A total of 6831 patients (6102 with primary ACLRs, 343 with revision ACLRs and 386 with bilateral ACLRs) were included. Preoperatively, there were significant but nonclinically relevant differences in favour of the revision ACLR group for KOOS Symptoms, Pain, Activities of Daily Living (ADL) and Sport/Rec subscale scores compared with the primary ACLR group. Postoperatively, except for the 1-year Symptoms and ADL subscales, the revision ACLR group reported significantly lower scores on all KOOS subscales than the primary ACLR group, with clinically relevant differences (>8-10 points) for the 1-, 2- and 5-year Sport/Rec and Quality of Life (QOL) subscales. The bilateral ACLR group reported significantly, but not clinically relevant, inferior scores on the 1-year Symptoms and QOL subscales and the 5-year Sport/Rec and QOL subscales compared with the primary ACLR group. CONCLUSIONS: Revision ACLR, but not bilateral ACLR, was associated with clinically relevant inferior subjective knee function compared with primary ACLR. It is important to counsel patients regarding their future subjective knee function after repeated ACLR. Compared to primary ACLR, inferior subjective results should be expected after revision ACLR, but not after bilateral ACLR. LEVEL OF EVIDENCE: Level III.

Minimally Invasive Quadricepsplasty Using the Adolphson-Cerqueira Technique: A Retrospective Study after 1-Year of Follow-up.

Aim: Knee stiffness limits activities of daily living with treatment having no gold standard technique currently. We present follow-up data 1-year after quadricepsplasty using the Adolphson-Cerqueira technique for the treatment of knee stiffness in a Brazilian population sample. Materials and methods: This retrospective study included patients who underwent a quadricepsplasty using the Adolphson-Cerqueira technique between January 2006 and March 2023 at our institution. The inclusion criteria were: (1) Knee stiffness with a range of motion <70°; (2) Patellar excursion ≥2 mm on physical examination; (3) Available knee radiography in the anteroposterior and lateral views; and (4) A follow-up at 1 year postoperatively. The Judet Classification was used to assess the outcome of the quadricepsplasty. Results: Sixty-seven patients were included. The results were 6% poor, 31.3% fair, 44.8% good, and 17.9% excellent according to the Judet Classification. A correlation was observed between age and the gain in range of motion at the 1-year postoperative follow-up, and between the gain in range of motion intraoperatively and that at the 1-year follow-up. There were five cases of complications (7.46%): one of patellar fracture, three of quadriceps tendon rupture, and one of avulsion fracture in the superior pole of the patella. Conclusion: Quadricepsplasty using the Adolphson-Cerqueira technique produced satisfactory results overall for improving knee joint stiffness and had a complication rate comparable with other currently used techniques. Clinical significance: Loss of knee range of motion remains a difficult problem without there being a clear gold standard in treatment. Many different options are described in the literature. We provide a further option with follow-up results. How to cite this article: Cerqueira FS, Silva L, Kropf LL, et al. Minimally Invasive Quadricepsplasty Using the Adolphson-Cerqueira Technique: A Retrospective Study after 1-Year of Follow-up. Strategies Trauma Limb Reconstr 2024;19(2):87-93.

Advanced therapy with mesenchymal stromal cells for knee osteoarthritis: Systematic review and meta-analysis of randomized controlled trials.

Background: Advanced cell therapies emerged as promising candidates for treatment of knee articular diseases, but robust evidence regarding their clinical applicability is still lacking. Objective: To assess the efficacy and safety of advanced mesenchymal stromal cells (MSC) therapy for knee osteoarthritis (OA) and chondral lesions. Methods: Systematic review of randomized controlled trials conducted in accordance with Cochrane Handbook and reported following PRISMA checklist. GRADE approach was used for assessing the evidence certainty. Results: 25 randomized controlled trials that enrolled 1048 participants were included. Meta-analyses data showed that, compared to viscosupplementation (VS), advanced MSC therapy resulted in a 1.91 lower pain VAS score (95 % CI -3.23 to -0.59; p < 0.00001) for the treatment of knee OA after 12 months. Compared to placebo, the difference was 0.99 lower pain VAS points (95 % CI -1.94 to -0.03; p = 0.76). According to the GRADE approach, the evidence was very uncertain for both comparisons. By excluding studies with high risk of bias, there was a similar size of effect (VAS MD -1.54, 95 % CI -2.09 to -0.98; p = 0.70) with improved (moderate) certainty of evidence, suggesting that MSC therapy probably reduces pain slightly better than VS. Regarding serious adverse events, there was no difference from advanced MSC therapy to placebo or to VS, with very uncertain evidence. Conclusion: Advanced MSC therapy resulted in lower pain compared to placebo or VS for the treatment of knee OA after 12 months, with no difference in adverse events. However, the evidence was considered uncertain. The Translational Potential of this Article: Currently, there is a lack of studies with good methodological structure aiming to evaluate the real clinical impact of advanced cell therapy for knee OA. The present study was well structured and conducted, with Risk of Bias, GRADE certainty assessment and sensitivity analysis. It explores the translational aspect of the benefits and safety of MSC compared with placebo and gold-standard therapy to give practitioners and researchers support to expand this therapy in their practice. PROSPERO registration number: CRD42020158173. Access at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=158173.

Functional Outcome in Obese Patients Undergoing Image-Based Cruciate Retaining Robotic-Assisted Total Knee Arthroplasty Using the Subvastus Approach: A Short-Term Study.

Introduction Knee osteoarthritis (OA) is a prevalent degenerative joint disease that significantly affects quality of life, especially among obese and morbidly obese individuals. Total knee arthroplasty (TKA) is an effective treatment for end-stage OA, but it presents unique challenges in obese patients. The mini-subvastus approach (SA) and robotic-assisted TKA (RA-TKA) are emerging techniques that may address these challenges. This study evaluates the clinical and radiological outcomes of cruciate-retaining (CR) RA-TKA using the mini-subvastus approach in obese and morbidly obese patients. Methods This study included 114 obese patients (215 knees) with primary OA who underwent CR RA-TKA (Maxx Meril CR knee, USA) using the Cuvis Joint® robotic system. Patients had a BMI of ≥30 kg/m² (n=101) and morbid obesity with a BMI ≥40 kg/m² (n=13). Preoperative planning involved CT scans and the J-planner for optimal implant size and positioning. Surgery was performed without tourniquets, and patients were mobilized postoperatively. Clinical outcomes were assessed using visual analog scale (VAS) scores and the American Knee Society Score (AKSS) at three and six months. Results The study included 85 females and 29 males with an average age of 61.8 years. Satisfactory knee exposure was achieved in all cases using SA, with no major complications such as wound infections, deep vein thrombosis, or component misalignment. Intraoperative challenges were managed effectively, including two cases of medial collateral ligament avulsion and one partial patellar tendon avulsion. Postoperative VAS scores showed significant pain reduction from pre-op (6.54) to post-op day 3 (1.3). AKSS improved from a pre-op average of 33.9 to 70.7 at three months and 80.9 at six months. Most patients (80%) achieved exceptional range of motion (ROM) ≥120° at six months. Discussion The mini-subvastus approach in RA-TKA offers several advantages, including reduced postoperative pain, faster recovery, and improved quadriceps strength, even in obese patients. The use of robotic assistance ensures accurate component positioning and alignment, mitigating the challenges typically associated with obese patients undergoing TKA. Conclusion The study demonstrates the feasibility and effectiveness of CR RA-TKA using the mini-subvastus approach in obese and morbidly obese patients. This technique provides adequate exposure, reduces pain, and promotes early mobilization and recovery with satisfactory clinical and radiological outcomes. The findings support the potential for wider adoption of this approach in managing knee OA in obese populations, though further studies with longer follow-up are warranted.

Native intra-articular knee microbiome is a matter of facts: a systematic review of clinical evidence.

Purpose: Growing interest surrounds the role of human gut microbiome in the development of degenerative pathologies such as osteoarthritis (OA), but microbes have recently been detected also in other sites previously considered to be sterile. Evidence emerged suggesting that even native and osteoarthritic knee joints may host several microbial species possibly involved in the osteoarthritic degeneration. This is the first systematic review critically collecting all the available evidence on the existence and composition of knee intra-articular microbiome. Methods: A systematic research on the PubMed, Cochrane and Google Scholar databases was performed. Human clinical studies investigating the presence of intra-articular microbiome in native osteoarthritic knee joints with next-generation sequencing techniques were collected. Results: A total of eight studies were included reporting data on 255 knees. All the included studies reported evidence supporting the existence of an intra-articular microbiome in native knee joints, with detection rates varying from 5.8% to 100%. Bacteria from the Proteobacteria phylum were found to be among the most identified followed by the Actinobacteria, Firmicutes, Fusobacteria, and Bacteroideta phyla. Proteobacteria phylum were also found to be more common in osteoarthritic knees when compared to healthy joints. Furthermore, several pathways correlating those microbes to knee OA progression have been suggested and summarized in this review. Conclusions: Evidence collected in this systematic review suggests that the native knee joint, previously presumed to be a sterile environment, hosts a peculiar intra-articular microbiome with a unique composition. Furthermore, its alteration may have a link with the progression of knee osteoarthritis.

Kaplan fibers of iliotibial band: a comprehensive review of current literature.

This review highlights the pivotal role of Kaplan fibers (KFs) in knee stability, particularly in the anterolateral aspect. Studies reveal their complex anatomy with varying attachments to the distal femur, demonstrating a significant impact on knee joint mechanics across different populations. Investigations into the biomechanics of KFs show their crucial role in maintaining rotational stability of the knee, especially during rotational movements. Their synergistic function with other knee structures, like the anterolateral ligament, is emphasized, underscoring their importance in knee integrity and function. MRI emerges as a key tool in detecting KFs, with varying visibility and prevalence of injuries. The review discusses the development of MRI criteria for accurate diagnosis, highlighting the need for further research to refine these criteria and understand the interplay between KF injuries, anterior cruciate ligament (ACL) ruptures, and associated knee pathologies. The review covers various lateral extra-articular tenodesis (LET) techniques used to address residual laxity and instability following ACL reconstruction. Among them, the modified Lemaire technique, which resembles the anatomical and functional characteristics of distal KFs, shows effectiveness in reducing internal rotation and residual laxity. The review emphasizes the need for further research to understand the healing dynamics of KF injuries and the efficacy of different LET techniques. It suggests that a comprehensive approach, considering both biomechanical and clinical aspects, is crucial for advancing knee joint health and rehabilitation.

A radiographic artificial intelligence tool to identify candidates suitable for partial knee arthroplasty.

INTRODUCTION: Knee osteoarthritis is a prevalent condition frequently necessitating knee replacement surgery, with demand projected to rise substantially. Partial knee arthroplasty (PKA) offers advantages over total knee arthroplasty (TKA), yet its utilisation remains low despite guidance recommending consideration alongside TKA in shared decision making. Radiographic decision aids exist but are underutilised due to clinician time constraints. MATERIALS AND METHODS: This research develops a novel radiographic artificial intelligence (AI) tool using a dataset of knee radiographs and a panel of expert orthopaedic surgeons' assessments. Six AI models were trained to identify PKA candidacy. RESULTS: 1241 labelled four-view radiograph series were included. Models achieved statistically significant accuracies above random assignment, with EfficientNet-ES demonstrating the highest performance (AUC 95%, F1 score 83% and accuracy 80%). CONCLUSIONS: The AI decision tool shows promise in identifying PKA candidates, potentially addressing underutilisation of this procedure. Its integration into clinical practice could enhance shared decision making and improve patient outcomes. Further validation and implementation studies are warranted to assess real-world utility and impact.

Identifying high-risk groups for deep vein thrombosis after primary total knee arthroplasty using preoperative Caprini scores and D-dimer levels.

BACKGROUND: Caprini score and D-dimer are well-recognized markers in deep vein thrombosis (DVT) assessment. However, their utility in guiding post-arthroplasty DVT risk is hampered by susceptibility to various post-operative factors, limiting their effectiveness as reminders. Conversely, these markers exhibit greater stability in the pre-operative setting. Despite this, research on the pre-operative predictive value of Caprini score and D-dimer for DVT following primary total knee arthroplasty (TKA) remains scarce. METHODS: In a retrospective study, we analyzed data from patients who underwent primary TKA, between August 2015 and December 2022. Upon admission, Caprini scores were assessed, and comprehensive blood panels were obtained from fasting blood samples. For all patients, lower limb vascular Doppler ultrasonography was performed pre-operatively to exclude those with pre-existing DVT, and all patients underwent DVT examination again post-operatively. RESULTS: Our study included 2,873 patients, averaging 67.98 ± 7.54years, including 676 men and 2,197 women. In this study, 303 (10.55%) patients developed postoperative DVT, and 57 (1.98%) cases presented with lower limb symptoms. DVT incidence in patients with pre-operative Caprini scores of 1-2 (6.50%), 3 (10.28%), and ≥ 4 (18.05%) showed significant differences (P < 0.05). DVT rates were 14.80% in patients with pre-operative D-dimer levels of ≥ 1 mg/L, higher than the 8.98% in those with levels of < 0.5 mg/L, and 10.61% in those with levels 0.5-1 mg/L (P < 0.05). In patients with Caprini scores of 1-2 and D-dimer levels ≤ 0.5 mg/L, the occurrence rate of postoperative DVT was only 5.84%. For patients with Caprini scores ≥ 4 and D-dimer levels ≥ 1.0 mg/L, the postoperative DVT occurrence rate soared to 24.81%, with the OR(odds ratio) was 4.744 compared to the former group. CONCLUSION: Patients with preoperative higher Caprini scores and D-dimer are more likely to develop DVT after TKA. Additionally, those with a preoperative Caprini score ≥ 4 and D-dimer level ≥ 1.0 mg/L have a significantly increased risk (24.81%) of developing DVT, identifying them as a high-risk group for DVT following TKA. These findings hold significant value for DVT risk stratification in primary TKA patients and the formulation of preoperative interventions to mitigate the risk of DVT.

Knee muscle strength, body composition, and balance performance of youth soccer players.

BACKGROUND: Muscle strength and balance abilities have been related to game performance injury prevention. This study aimed to (1)  assess knee muscle strength performance based on intra- and inter-limb asymmetries, (2)  investigate the relationships between knee muscle strength, body composition, and balance, and (3) analyze the variance in the overall stability index (OSI) explained by knee muscle strength indicators after controlling for age and body composition. METHODS: The sample included 104 young male soccer players (16.0 ± 1.6 years). Body composition, knee muscle strength, and balance ability were assessed. A paired samples t-test was used to examine differences between the preferred leg (PL) and the non-preferred leg (NPL). Pearson correlations and hierarchical multiple regression were conducted to explore the relationships between strength, body composition, and balance. RESULTS: No significant inter-limb asymmetries were detected for the knee flexors (KF) and knee extensors (KE) performance. The hamstrings-to-quadriceps ratio does not suggest the existence of intra-limb asymmetries (p = 0.06). Significant and negative correlations were found between KF (r = -0.38, p ≤ 0.01) and KE (r = -0.58, p ≤ 0.01) for the PL. Concerning the NPL, KE also revealed a significant and negative relationship with balance (r = -0.30, p ≤ 0.01). Significant and positive relationships were found between bodyweight, fat-free mass, and balance. After controlling for age and body composition, knee muscle strength could explain between 13% and 30% of the variance observed in the OSI (NPL and PL, respectively). CONCLUSIONS: The results underline knee muscle strength as an important predictor of balance. Thus, training programs targeting knee muscle strength development should be considered during the season periodization by coaches and their staff throughout the players' developmental stages.