Adult Knee Research Articles

Cumulative effects of H+ and Pi on force and power of skeletal muscle fibres from young and older adults.

The cellular causes of the age-related loss in power output and increased fatigability are unresolved. We previously observed that the depressive effects of hydrogen (H+) (pH 6.2) and inorganic phosphate (Pi) (30mm) did not differ in muscle fibres from young and older men. However, the effects may have been saturated in the severe fatigue-mimicking condition, potentially masking age differences in the sensitivity of the cross-bridge to these metabolites. Thus, we compared the contractile mechanics of muscle fibres from the vastus lateralis of 13 young (20-32years, seven women) and 12 older adults (70-90years, six women) in conditions mimicking quiescent muscle and a range of elevated H+ (pH 6.8-6.6-6.2) and Pi (12-20-30mm). The older adult knee extensor muscles showed hallmark signs of ageing, including 19% lower thigh lean mass, 60% lower power and a greater fatigability compared to young adult muscles. Progressively increasing concentrations of H+ and Pi in the chemically-permeabilized fibre experiments caused a linear decrease in fibre force, velocity and power; however, the effects did not differ with age or sex. Fast fibre cross-sectional area was 41% smaller in older compared to young adults, which corresponded with lower absolute power. Size-specific power was greater in fibres from older compared to young adults, indicating the age-related decline in absolute power was explained by differences in fibre size. These data suggest the age-related loss in power is determined primarily by fast fibre atrophy in men and women, but the age-related increase in fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi. KEY POINTS: The causes of the age-related loss in muscle power output and the increase in fatigability during dynamic exercise remain elusive. We show that progressively increasing concentrations of hydrogen (H+) and inorganic phosphate (Pi) causes a linear decrease in muscle fibre force, velocity and power, but the depressive effects of these metabolites on cross-bridge function did not differ in fibres from older compared to young adults across a range of fatigue-mimicking conditions. We also found peak absolute power did not differ in slow fibres from young and older adults but it was ∼33% lower in older adult fast fibres, which was explained entirely by age differences in fibre size. These data suggest that fast fibre atrophy is a major factor contributing to the loss in power of older men and women, but that the age-related increase in fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi.

Shared decision making in primary malignant bone tumour surgery around the knee in children and young adults: protocol for a prospective study

BackgroundChildren and young adults needing surgery for a primary malignant bone tumour around the knee face a difficult, life-changing decision. A previous study showed that this population wants to be involved more in the decision-making process and that more involvement leads to less decisional stress and regret. Therefore, a well-designed and standardized decision-making process based on the principles of shared decision-making needs to be designed, implemented, and evaluated.MethodsWe developed a shared decision-making (SDM) model for this patient population, including an online decision aid (DA). This model has been implemented in the standard care of patients with a primary malignant bone tumour around the knee. Following implementation, we will analyse its effect on the decision-making process and the impact on patient experiences using questionnaires and interviews. Moreover, potential areas for improvement will be identified.DiscussionGiven the importance of involving patients and parents in surgical decision-making, particularly in life-changing surgery such as malignant bone tumour surgery, and given the lack of SDM models applicable for this purpose, we want to share our model with the international community, including our study protocol for evaluating and optimising the model. This study will generate valuable knowledge to facilitate the optimisation of current patient care for local treatment. The sharing of our implementation and study protocol can serve as an example for other centres interested in implementing SDM methods in an era characterized by more empowered patients and parents who desire autonomy and reliable and realistic information.

Feasibility of a Multimodal Prehabilitation Program Before Elective Knee and Hip Arthroplasty in Older Adults

ObjectivesHip osteoarthritis and knee osteoarthritis cause significant disability and pain in older adults, often leading to hip or knee replacement surgery. Prehabilitation programs have been established for these surgeries, but there are few programs for orthogeriatrics. We evaluated the feasibility of a new multimodal prehabilitation program (MPP) for older adults before hip or knee replacement due to arthrosis: the Prehabilitation for Os (PRE4OS) study. DesignWe conducted a multicenter feasibility study in the Greater Paris area. Setting and ParticipantsEligible adults were ≥75 years old awaiting hip or knee replacement with at least a 6-week delay before surgery and able to participate in the MPP follow-up. The MPP included weekly hospital sessions providing nutritional, psychological, functional, and cognitive support, along with weekly home sessions featuring physiotherapist visits. MethodsThe primary outcome was at least 80% of 1-day hospital (ODH) sessions performed by 80% of participants. Secondary outcomes included intervention achievement, quality of life, and nutritional and functional status changes. Participant's satisfaction was qualitatively assessed via structured phone interviews presurgery and at 30 days postsurgery. ResultsFrom September 2021 to September 2023, a total of 27 individuals participated in the PRE4OS study. The mean (SD) age was 83 (4.3) years, with 7 males (26%) and median baseline Activities of Daily Living score 5.5 (interquartile range 5.5–6.0). Surgeries were for insertion of hip prosthesis in 17 participants (63%) and knee prosthesis in 10 (37%). The primary outcome was achieved in 89% of participants, with comparable rates for hip and knee prostheses. In total, 60% of participants rated the MPP as “excellent” presurgery and 100% at 30 days postsurgery, expressing a willingness to recommend the protocol to a friend or family. Conclusion and ImplicationsThe MPP was feasible for individuals before hip or knee replacement and was well received. Further randomized trials are needed to assess its clinical impact.

Finite element study of stress distribution in medial UKA under varied lower limb alignment

Knee osteoarthritis (KOA) has a high incidence among the elderly, significantly impacting their quality of life and overall health. Medial unicompartmental knee arthroplasty (UKA) is an excellent choice for treating knee single-compartment lesions, and lower limb alignment has a profound impact on medial UKA. To explore the influence of different lower limb alignments on medial UKA. In this study, we selected MR and CT data of healthy adult male knee joints to establish a complete finite element analysis (FEA) model of the knee joint. After validation, we established a finite element model of medial UKA. Subsequently, we created 60 sets of FEA models with different lower limb alignments to analyze the impact of different lower limb alignments on medial UKA. A vertical load of 1000 N was applied to the FEA models with different lower limb alignments. During the process of shifting the Mikulicz line from the midpoint of the knee joint towards the medial side, the lower limb load was primarily concentrated on the medial compartment. The stress values of the lateral meniscus, tibial cartilage, and femoral cartilage gradually decreased. ROI (region of interest) 1 and ROI 2 showed the maximum principal strain changes, while ROI 3 and ROI 4 exhibited less pronounced fluctuations, with the maximum principal strain roughly proportionally increased. During the process of shifting the Mikulicz line towards the lateral side from the midpoint of the knee joint, the stress on the lateral compartment increased observably. ROI 1, ROI 2, ROI 3, and ROI 4 showed decreased maximum principal strains, approximately inversely proportional changes, but the overall reduction was relatively small. Different lower limb alignments have a profound impact on the short- and long-term joint function after UKA. When the Mikulicz line is 10 mm inside the midpoint of the knee joint or slightly outside, there is a relatively lower risk of tibial component fractures, lower stress on the lateral compartment, and lower load on the prosthesis. During medial UKA, measures such as bone resection and prosthesis selection should be taken to ensure that the Mikulicz line is in the ideal position.

The management of isolated meniscal tears in skeletally immature children. An international expert consensus.

The prevalence and appreciation of meniscal tears in children have increased in both number and complexity. There is currently a paucity of high-quality evidence that can guide surgeons in treating skeletally immature patients with meniscal injuries. The aim of this study was to develop comprehensive recommendations for the management of isolated meniscal tears in skeletally immature children. An international, two-round, modified Delphi consensus was completed. Included 'experts' were identified as having an established adult knee practice, including children and either: (1) Faculty at an international paediatric knee conference, (2) Active members of complex national paediatric multi-disciplinary groups or (3) Members of faculty on recognised national/international instructional courses aimed at teaching the management of meniscal lesions to knee surgeons. The currently available literature was reviewed, and areas of poor quality, inconclusive or absent evidence were examined and formed the focus of the study. A threshold of 70% was used to define consensus for our study based on other similar Delphi consensus studies in the literature. A total of 43 experts (Round 1) and 41 experts (Round 2) took part in the Delphi study, including surgeons from Europe, the United States of America and South America. 34 statements were identified exploring three main domains-clinical assessment, management and complex tears (bucket handle, discoid and radial). Following Round 1, consensus was reached on 17 (50%) statements; subsequently, after completion of Round 2, consensus was reached on 28 (82%) statements, leaving six (18%) with no consensus. The areas of no consensus included investigation of painless clicking, the most sensitive clinical test for meniscal pathology, treatment of small radial tears (less than 1/3 width), ability to reduce chronic bucket handle tears and timing of surgery. This is the first modified Delphi consensus that provides evidence for surgeons treating skeletally immature children with isolated meniscal tears. A valuable level of consensus was reached on the assessment and management of simple and specialist meniscal tears. These consensus statements can both inform clinical practice and be used in the development of further high-quality research studies. Level V.

Utilizing artificial intelligence for the detection of hemarthrosis in hemophilia using point-of-care ultrasonography

BackgroundRecurrent hemarthrosis and resultant hemophilic arthropathy are significant causes of morbidity in persons with hemophilia despite the marked evolution of hemophilia care. Prevention, timely diagnosis, and treatment of bleeding episodes are key. However, a physical examination or a patient’s assessment of musculoskeletal pain may not accurately identify a joint bleed. This difficulty is compounded as hemophilic arthropathy progresses. ObjectivesOur system aims to utilize artificial intelligence and ultrasonography (US; point-of-care and handheld) to enable providers, and ultimately patients, to detect joint bleeds at the bedside and at home. We aimed to develop and assess the reliability of artificial intelligence algorithms in detecting and segmenting synovial recess distension (SRD; an indicator of disease activity) on US images of adult and pediatric knee, elbow, and ankle joints. MethodsA total of 12,145 joint exams, comprising 61,501 US images from 7 international healthcare centers, were collected. The dataset included healthy participants and adult and pediatric persons with hemophilia, with and without SRD. Images were manually labeled by 2 experts and used to train binary convolutional neural network classifiers and segmentation models. Metrics to evaluate performance included accuracy, sensitivity, specificity, and area under the curve. ResultsThe algorithms exhibited high performance across all joints and all cohorts. Specifically, the knee model showed an accuracy of 97%, sensitivity of 96%, specificity of 97%, and an area under the curve of 0.97 in SRD. High Dice coefficients (80%-85%) were achieved in segmentation tasks across all joints. ConclusionThis technology could assist with the early detection and management of hemarthrosis in hemophilia.

CT Morphometric Analysis of the Medial Femoral Condyle in an Indian Population: A Comparative Study of Unicompartmental Knee Arthroplasty Implants.

Purpose The objective of this study was to evaluate the compatibility of the medial femoral condyle (MFC) dimensions in the Indian population with the standard femoral components of three commercially available unicompartmental knee arthroplasty (UKA) implants. Methods This analytical study utilized CTmorphometric data from 100 consecutive non-arthritic adult knees. MFC dimensions were measured to assess their compatibility with UKA prostheses. The proportion of knees that could be optimally replaced using three commercially available UKA femoral implant systems, Link, DePuy, and Smith & Nephew, was calculated. Results The study cohort comprised 56 males and 44 females, with a mean age of 43.28 ± 10.53 years. For the Link implant system, the 'small' size was the most compatible, fitting 43% (43) of the patients, followed by 'medium-small' (35%, n = 35) and 'medium' (16%, n = 16). For the DePuy Sigma Uni implant, the best fit was 'size 1' for 38% (38) of the patients, followed by 'size 3' (25%, n = 25), 'size 4' (13%, n = 13), 'size 2' (10%, n = 10), and 'size 5' (2%, n = 2). In the case of the Smith & Nephew system, 'size 2' was the best fit for 30% (30) of the knees, followed by 'size 3' (27%, n = 27), 'size 4' (15%, n = 15), 'size 1' (12%, n = 12), and 'size 5' (8%, n = 8). Overhang of the femoral component, due to the MFC being smaller than the smallest available femoral component size, was observed in 6% (6) of knees with Link implants, 12% (12) with DePuy implants, and 8% (8) with Smith & Nephew implants. Conclusion The findings indicate that the most suitable femoral component sizes for Indian knees were 'small' in the Link system (43%, n = 43), 'size 1' in the DePuy system (38%, n = 38), and 'size 2' in the Smith & Nephew system (30%, n = 30). The results suggest a need for implant manufacturers to consider developing customized components tailored to the Indian population to enhance fit and minimize the occurrence of femoral component overhang.

MRI analysis of the physiological patellofemoral joint morphology of adult knees.

The aim of the present study was to determine physiological reference values for the morphology of the patella and to analyse these parameters according to patella position in healthy knee joints. Healthy knee joints of 409 patients (mean age, 52.3years [± 16.8]) were analysed retrospectively on MRI images for Insall-Salvati index (ISI), sagittal patella thickness (PTS) and patella length (PLS) as well as axial patella thickness (PTA) and patella width (PWA). Differences between patellar diameters were analysed depending on ISI, side, age and gender. Mean PTS was 20.1 mm (± 2.4), PLS 44.0 mm (± 4.4), PTA 21.8 mm (± 2.4) and PWA 44.5 mm (± 4.7). Depending on the vertical patellar position (ISI), all patellar parameters (p < 0.01) showed significant differences between patients with a patella alta, norma and baja. In general, a smaller ISI showed higher measured values for the patellar parameters. There were no significant differences for the laterality. Only PTS showed a significant age difference (p = 0.031). All parameters were significantly larger in male compared to female knees (p < 0.001). Reference parameters for the patella morphology are reported. Concluding from the results, a relationship between vertical patellar position and patellar morphology seems to exist. This finding should be taken into account in diagnostics and therapy of patella disorders.

CT of Periarticular Adult Knee Fractures: Classification and Management Implications.

Periarticular knee fractures, which include fractures of the distal femur, tibial plateau, and patella, account for 5%-10% of musculoskeletal injuries encountered in trauma centers and emergency rooms. These injuries are frequently complex, with articular surface involvement. Surgical principles center on reconstruction of the articular surface as well as restoration of limb length, alignment, and rotation to reestablish functional knee biomechanics. Fixation principles are guided by fracture morphology, and thus, CT with multiplanar reformats and volume rendering is routinely used to help plan surgical intervention. Fractures involving the distal femur, tibial plateau, and patella have distinct management considerations. This comprehensive CT primer of periarticular knee fractures promotes succinct and clinically relevant reporting as well as optimized communication with orthopedic trauma surgeon colleagues by tying fracture type and key CT findings with surgical decision making. Fracture patterns are presented within commonly employed fracture classification systems, rooted in specific biomechanical principles. Fracture typing of distal femur fractures and patellar fractures is performed using Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification schemes. Tibial plateau fractures are graded using the Schatzker system, informed by a newer explicitly CT-based three-column concept. For each anatomic region, the fracture pattern helps determine the surgical access required, whether bone grafting is warranted, and the choice of hardware that achieves suitable functional outcomes while minimizing the risk of articular collapse and accelerated osteoarthritis. Emphasis is also placed on recognizing bony avulsive patterns that suggest ligament injury to help guide stress testing in the early acute period. ©RSNA, 2024 Supplemental material is available for this article.

Deep Learning-Based Joint Effusion Classification in Adult Knee Radiographs: A Multi-Center Prospective Study.

Knee effusion, a common and important indicator of joint diseases such as osteoarthritis, is typically more discernible on magnetic resonance imaging (MRI) scans compared to radiographs. However, the use of radiographs for the early detection of knee effusion remains promising due to their cost-effectiveness and accessibility. This multi-center prospective study collected a total of 1413 radiographs from four hospitals between February 2022 to March 2023, of which 1281 were analyzed after exclusions. To automatically detect knee effusion on radiographs, we utilized a state-of-the-art (SOTA) deep learning-based classification model with a novel preprocessing technique to optimize images for diagnosing knee effusion. The diagnostic performance of the proposed method was significantly higher than that of the baseline model, achieving an area under the receiver operating characteristic curve (AUC) of 0.892, accuracy of 0.803, sensitivity of 0.820, and specificity of 0.785. Moreover, the proposed method significantly outperformed two non-orthopedic physicians. Coupled with an explainable artificial intelligence method for visualization, this approach not only improved diagnostic performance but also interpretability, highlighting areas of effusion. These results demonstrate that the proposed method enables the early and accurate classification of knee effusions on radiographs, thereby reducing healthcare costs and improving patient outcomes through timely interventions.

Knee muscle strength and steadiness for individuals with anterior cruciate ligament reconstruction and knee osteoarthritis

BackgroundStrength and neuromuscular decrements following knee musculoskeletal injury may accelerate knee osteoarthritis development. This study assessed isometric knee extensor and flexor strength and steadiness between individuals with knee injury, i.e., ligament reconstruction, and knee osteoarthritis to healthy age-matched controls. MethodsFour cohorts (1: knee injury and 2: age-matched controls, and 3: radiographic knee osteoarthritis and 4: age-matched controls) were recruited. Participants performed maximal voluntary isometric knee extensor and flexor contractions. Then, strength (e.g., peak and rate of torque development) and steadiness (e.g., peak power, mean, and median frequency) were derived from each raw torque-time curve and associated power spectral density. A Kruskal-Wallis H test and Spearman's rho correlation analysis assessed cohort differences and association between knee extensor and flexor strength and steadiness. FindingsThe young adult control and knee injury cohorts exhibited greater knee extensor and flexor strength than the older, knee osteoarthritis cohort (p < 0.043). The knee injury cohort, despite being as strong as their healthy counterparts, were significantly less steady with a 92% increase in peak power frequency (p = 0.046). The osteoarthritis cohort exhibited 157% less total power compared to the knee injury and young control cohorts (p < 0.019). Knee extensor and flexor peak torque, rate of torque development, and mean torque exhibit a significant, positive relation with total power (p < 0.018). InterpretationIndividuals with knee injury and disease may exhibit weaker or less steady knee musculature, predisposing them to degenerative joint disease. Clinicians may need to restore knee extensor and flexor steadiness to facilitate better joint neuromuscular control.

Deep learning MR reconstruction in knees and ankles in children and young adults. Is it ready for clinical use?

To evaluate the diagnostic performance and image quality of accelerated Turbo Spin Echo sequences using deep-learning (DL) reconstructions compared to conventional sequences in knee and ankle MRIs of children and young adults. IRB-approved prospective study consisting of 49 MRIs from 48 subjects (10 males, mean age 16.4years, range 7-29years), with each MRI consisting of both conventional and DL sequences. Sequences were evaluated blindly to determine predictive values, sensitivity, and specificity of DL sequences using conventional sequences and knee arthroscopy (if available) as references.Physeal patency and appearance were evaluated. Qualitative parameters were compared. Presence of undesired image alterations was assessed. The prevalence of abnormal findings in the knees and ankles were 11.7% (75/640), and 11.5% (19/165), respectively. Using conventional sequences as reference, sensitivity and specificity of DL sequences in knees were 90.7% and 99.3%, and in ankles were 100.0% and 100.0%. Using arthroscopy as reference, sensitivity and specificity of DL sequences were 80.0% and 95.8%, and of conventional sequences were 80.0% and 97.9%. Agreement of physeal status was 100.0%. DL sequences were qualitatively "same-or-better" compared to conventional (p < 0.032), except for pixelation artifact for the PDFS sequence (p = 0.233). No discrete image alteration was identified in the knee DL sequences. In the ankle, we identified one DL artifact involving a tendon (0.8%, 1/125). DL sequences were faster than conventional sequences by a factor of 2 (p < 0.001). In knee and ankle MRIs, DL sequences provided similar diagnostic performance and "same-or-better" image quality than conventional sequences at half the acquisition time.

Bone Cement in Adult Hip and Knee Reconstruction: A Review of Commercially Available Options and Clinical Outcomes.

Polymethyl-methacrylate (PMMA) bone cement is used extensively in hip and knee arthroplasty. A thorough understanding of the basic chemistry underlying PMMA is important for orthopaedic surgeons because this underscores the specific way bone cement is used during surgery. Recently, clinical research has shed light on the various types of PMMA regarding the viscosity of the mixture and the effect of cement additives. These variations in composition may alter the clinical efficacy of implanted bone cement in hip and knee arthroplasty. Understanding these key differences will allow the surgeon to tailor the PMMA composition as needed to maximize outcomes of hip and knee arthroplasty. This review will summarize the preclinical feature of PMMA, evaluate current and past commercially available bone cement options, analyze preclinical results and clinical outcomes of various bone cement types, and highlight future areas of research.

Is Partial ACL Tear a Cause of Painful Swollen Knees?

Abstract Study Design: Retrospective case series. Objective: In this study, we will identify if partial ACL tear is a common hidden cause of chronic pain and swelling of the knee in adults. And we will evaluate the effectiveness of arthroscopic selective bundle reconstruction in the management of this condition. Background: The Anterior Cruciate Ligament (ACL) has two anatomical bundles, the anteromedial (AM) and the posterolateral (PL), each bundle was named according to the site of its tibial insertion.[1] Partial ACL tear is evident and symptomatic when the percentage of the torn fibers is more than 50% of ligament fibers. AM bundle is more liable to injury than PL.[2] Symptomps of partial ACL tear may be giving way and instability but persistent knee pain and swelling is often present as the main presenting symptom of the patient due to micro-instability of the knee, The primary complication of longstanding partial ACL tears is early knee degeneration.[3] Patients and Methods: 37 patients with chronic knee pain and swelling, related to activity and resistant to non-operative treatment, underwent diagnostic knee arthroscopy. In 3 cases diagnostic arthroscopy revealed osteochondral ulcers of the medial compartment of the knee managed by drilling and 4 cases showed non-specific synovitis managed by arthroscopic synovectomy. 30 of these patients, who were included in this study, were found to suffer from partial ACL tear and underwent single bundle reconstruction, 18 of them underwent selective AM bundle reconstruction while preserving PL bundle. Twelve patients underwent selective PL bundle reconstruction with AM bundle preservation. Semitendinosus tendon graft was utilized for all reconstructions. The femoral side was always fixed with an adjustable loop (Zimmer), and the tibial side with a biodegradable interference screw. Lysholm score[4] was used to assess the outcomes. Patients with severe degenerative disorders, lower limb mal-alignment and multiple ligamentous injuries of the knee were excluded from our study. Results: Marked decrease in the knee pain and swelling postoperatively. The preoperative score had a mean value of 66.17±10.39. At 2 years, the postoperative score was 96.1±6.71, indicating a highly statistically significant improvement (P value 0.001). Hypothesis: Partial ACL tears are the commonest hidden cause of pain and swelling of the knee among young adults. Conclusion: Arthroscopic selective bundle reconstruction diminishes knee pain and swelling with a very satisfactory postoperative clinical outcomes.

The meniscotibial ligament does exist: An anatomic and histological description

PurposeTo describe the anatomical and histological characteristics of the human MTL (meniscotibial ligament) that keeps the meniscus stable and are rarely discussed. Study designDescriptive laboratory study. MethodsIn total, six fresh-frozen adult cadaver knees were dissected, and the dissection protocol were designed by two experienced anatomy professors. The anatomical morphology of MTL was observed. The main anatomical specimens included meniscus, tibial plateau, MTL. The osteotome was used to excise the portion of the tibial plateau, which could obtain the complex including partial meniscus, MTL, and a tibial fragment. A histopathologic study was performed by two experienced pathologists. ResultsMacroscopically, the MTL could be divided into two parts: medial meniscotibial ligament (MMTL)and lateral meniscotibial ligament (LMTL). The MMTL is distributed continuously, whereas the LMTL is discontinuous on the tibial plateau. The average length from the tibial attachment of the LMTL to the articular surface was 19 ± 1.0mm (mean ± SD). The average length from the tibial attachment of the MMTL to the articular surface was 10 ± 1.2 mm (mean ± SD). Microscopy of the MTL showed that the MTL is a ligamentous tissue, composed of a network of oriented collagenous fibers. ConclusionsIn all knees, the MTL was inserted on the outer edge of the meniscus, attaching to the tibia below the level of articular cartilage, which was key to maintaining the rotational stability of knee and the meniscus in the physiological position on the tibial plateau. Histological analysis of this ligament demonstrated that the MTL is a veritable ligamentous structure, which is made up of collagen type I–expressing fibroblasts. Clinical relevanceThis article contributes to the understanding of the anatomical and histological characteristics of the MTL. It is beneficial to promote the development of relevant surgical techniques for the MTL lesion.

Effect of Medial Patellofemoral Complex Reconstruction Technique on Patellofemoral Contact Pressure, Contact Area, and Kinematics.

Medial patellofemoral ligament (MPFL) reconstruction is considered by many to be the gold standard to treat lateral patellar instability; however, some investigators have reported good clinical results after isolated medial quadriceps tendon-femoral ligament (MQTFL) reconstruction or a combined MPFL/MQTFL reconstruction. A handful of studies have preliminarily investigated the biomechanical consequences of these various medial patellar stabilizing procedures. Despite this, no existing study has included multiple medial patellofemoral complex (MPFC) reconstructions and assessment of lateral patellar translation at distinct flexion angles. Combined MPFL/MQTFL reconstruction would restore patellofemoral contact areas, forces, and kinematics closest to the native state compared with isolated reconstruction of the MPFL or MQTFL alone. Controlled laboratory study. Ten adult cadaveric knee specimens were prepared and analyzed under 5 different conditions: (1) intact state, (2) transected MPFC, (3) isolated MPFL reconstruction, (4) isolated MQTFL reconstruction, and (5) combined MPFL/MQTFL reconstruction. Patellar tilt, lateral patellar translation, patellofemoral contact forces, and patellofemoral contact areas were measured in each condition from 0° to 80° through simulated knee flexion using a custom servohydraulic load frame with pressure sensor technology and a motion capture system for kinematic data acquisition. The isolated MPFL, isolated MQTFL, and combined MPFL/MQTFL reconstruction conditions produced significantly less lateral patellar tilt compared with the transected MPFC state (P < .05). No statistically significant differences were found when each reconstruction technique was compared with the intact state in patellar tilt, lateral patellar translation, contact forces, and contact areas. All 3 reconstruction techniques (isolated MPFL reconstruction, isolated MQTFL reconstruction, and combined MPFL/MQTFL reconstruction) restored native knee kinematics, contact forces, and contact areas without overconstraint. Isolated MPFL reconstruction, isolated MQTFL reconstruction, and combined MPFL/MQTFL reconstruction all restore patellofemoral stability comparable with the intact MPFC state without the overconstraint that could be concerning for increasing risk of patellofemoral arthritis.

Bilateral simultaneous total knee arthroplasty with and without patellar resurfacing. A prospective single surgeon series with a minimum follow-up of 7 years

BackgroundTotal knee arthroplasty (TKA) is the most effective treatment for end-stage adult knee osteoarthritis, but it has been reported that patient satisfaction may vary. A malfunction of the patellofemoral joint may produce anterior knee pain (AKP) for several reasons. While some surgeons systematically resurface the patella despite the risk of potential complications such as fracture, loosening, or wear of the patella, others prefer to preserve it to reduce AKP and revision rates. This study aimed to evaluate whether patellar resurfacing had better clinical and functional outcomes, complications, and revision rates in patients undergoing simultaneous bilateral total knee arthroplasty.MethodsWe conducted a prospective cohort study, including patients who underwent bilateral simultaneous TKA in which the patella was replaced in one knee and preserved in the other, with a minimum follow-up of 7 years. We assessed clinical and functional outcomes with the Knee Society Score (KSS) and Visual Analogue Scale (VAS); complications and revision rates were also registered.ResultsThe final series consisted of 43 patients with 86 knee arthroplasties. After a mean of 7.6 years of follow-up, no significant differences were found regarding KSS (clinical: 82.8 ± 7.4 versus 83.2 ± 3.4, p = 0.92; functional 89.1 ± 8.2: versus 90.4 ± 6.8; p = 0.99), VAS (2.0 ± 0.9 versus 1.8 ± 1.0; p = 0.84), complications (10.5% versus 8.1%; p = 0.57), or revision rates (2.3% versus 2.3%; p = 0.99) when comparing patellar resurfacing versus retention.ConclusionIn the context of total knee arthroplasty, patellar replacement did not demonstrate statistically significant differences concerning patellar retention in clinical nor functional outcomes, AKP, complications, or revision rates after a minimum of 7 years of follow-up.

Aspirin as Venous Thromboembolism Prophylaxis in Arthroplasty Patients: An Analysis of Clinical Practice Guidelines Recommendations

BackgroundVenous thromboembolism (VTE) is a recognized postoperative complication of hip or knee arthroplasty and incurs major morbidity and mortality. While anticoagulants are the mainstay of chemoprophylaxis, aspirin has recently emerged as a popular prophylactic agent. However, there is a lack of high-quality evidence comparing aspirin to anticoagulants as a method of VTE prophylaxis, and current guidelines are conflicting regarding using aspirin as first-line chemoprophylaxis. We aimed to investigate guideline characteristics that are associated with the recommendation for or against aspirin as a first-line agent. MethodsMEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and PubMed databases were searched from 1966 to January 2024 to identify clinical practice guidelines for VTE prophylaxis in adult hip or knee arthroplasty inpatients of average risk. The characteristics of the guideline were collected by 2 independent reviewers. Logistic regression was used to test the association between the recommendation for or against aspirin and guideline characteristics. ResultsThere were 26 guidelines published from February 2003 to September 2023 and included in this study. There were 5 guidelines that recommended aspirin and 11 guidelines that recommended against aspirin as first-line therapy. With a more recent year of publication, aspirin was more likely to be recommended (odds ratio 1.72, 95% confidence interval: 1.05 to 2.84) and less likely to be recommended against (odds ratio 0.61, 95% confidence interval: 0.41 to 0.90). No other variables, including the level of evidence used, the composition of the guideline working group, or the objective of the guideline, were associated with the recommendation for or against aspirin. ConclusionsGuidelines were inconsistent in their recommendations regarding aspirin as first-line therapy as VTE prophylaxis in arthroplasty patients. Adequately powered randomized controlled trials using modern practices, such as early postoperative mobilization, are needed to better inform clinical practice guidelines.

Thickness and width of the menisci of adult knee joint: a descriptive cross-sectional observational study in cadavers.

The goal was to determine the thickness and width of the knee joint meniscus at their different regions. The objective was to compare the dimensions at these regions and over the right- and left-sided specimens. The present study included 50 adult cadaveric knee joints, and 100 menisci (50 medial menisci and 50 lateral menisci) were studied. The meniscus was distributed into anterior, middle and posterior parts. Thickness and width at the mid-point of these three parts were determined by using the Vernier caliper. The breadth of the medial meniscus was 8.38 ± 1.64 mm, 7.68 ± 1.92 mm and 13.93 ± 2.69 mm at the anterior, middle and posterior one-third regions. Same measurements for the lateral menisci at these regions were 9.84 ± 1.78 mm, 8.82 ± 2.01 mm and 10.18 ± 2.23 mm, respectively. The thickness of the medial meniscus was 4.49 ± 0.78 mm, 4.07 ± 0.81 mm and 4.79 ± 0.93 mm at these regions. The lateral meniscus thickness was 3.82 ± 0.69 mm, 4.43 ± 0.98 mm and 4.36 ± 0.8 mm, respectively. It is believed that this data is enlightening to the arthroscopic surgeon during the meniscus transplantation either by using synthetic material or allograft as the proper sizing of the meniscus is important to prevent complications due to inaccurate sizing.

The Impact of the Comprehensive Unit-Based Safety Program on the Perioperative Efficiency and Patient Safety of Adult Hip and Knee Arthroplasty Procedures: Retrospective Comparative Study

BackgroundThe complexity of health care delivery systems presents a unique challenge for the perioperative space. In the area of arthroplasty procedures, the shift of complex patients into ambulatory surgery centers and reimbursement that is no longer commensurate with the inflated costs of performing these procedures have created difficulties for hospitals and physicians alike. Thus, there is a critical need to optimize perioperative workflows while maintaining high-quality care provision. MethodsOur institution implemented the Comprehensive Unit-based Safety Program (CUSP) to improve the quality and efficiency of total knee and hip arthroplasties (TKAs and THAs). This initiative involved extensive collaboration with clinical and administrative teams, as well as 5 intervention-driven workgroups. First-case on-time start rates and duration of first-case delays, case length, anesthesia preparation, in-room patient preparation, operation, patient exit, and room turnover after CUSP implementation were analyzed using independent samples median testing, Mann-Whitney U testing, and a percentage-point difference calculation. ResultsAfter CUSP arthroplasty implementation, first-case on-time start rates increased from 43 to 81%. Statistically significant decreases were observed in median times for first-case delays, case length, in-room patient preparation, operation, patient exit, and room turnover for TKAs and THAs, but not anesthesia preparation. ConclusionsThe implementation of CUSP arthroplasty for TKAs and THAs resulted in significant improvements in nearly all efficiency metrics, as well as preventions of patient safety missteps. These results exemplify the versatility of CUSP as a quality improvement method that can maintain patient safety and perioperative efficiency in the arthroplasty service of a large-scale medical center. Level of EvidenceIII.