Patellar Cartilage Research Articles

3D printed porous sulfonated polyetheretherketone scaffold for cartilage repair: Potential and limitation.

ObjectiveThe treatment of cartilage lesions has always been a difficult problem. Although cartilage tissue engineering provides alternative treatment options for cartilage lesions, biodegradable tissue engineering scaffolds have limitations.MethodsIn this study, we constructed a porous PEEK scaffold via 3D printing, surface-engineered with concentrated sulfuric acid for 15 s (SPK-15), 30 s (SPK-30), and 60 s (SPK-60). We systematically evaluated the physical and chemical characteristics and biofunctionalities of the scaffolds, and then evaluated the macrophage polarization modulating ability and anti-inflammatory effects of the sulfonated PEEK, and observed the cartilage-protective effect of SPK using a co-culture study. We further evaluated the repair effect of PEEK and SPK by implanting the prosthetic scaffold into a cartilage defect in a rabbit model.ResultsCompared to the PEEK, SPK-15 and SPK-60 scaffolds, SPK-30 has a good micro/nanostructure, appropriate biomechanical properties (compressive modulus, 43 ± 5 MPa; Shaw hardness, 20.6 ± 1.3 HD; close to native cartilage, 30 ± 8 MPa, 17.8 ± 0.8 HD), and superior biofunctionalities. Compared to PEEK, sulfonated PEEK can favor macrophage polarization to the M2 phenotype, which increases anti-inflammatory cytokine secretion. Furthermore, SPK can also prevent macrophage-induced cartilage degeneration. The in-vivo animal experiment demonstrates that SPK can favor new tissue ingrowth and integration, prevent peri-scaffold cartilage degeneration and patellar cartilage degeneration, inhibit inflammatory cytokine secretion, and promote cartilage function restoration.ConclusionThe present study confirmed that the 3D printed porous sulfonated PEEK scaffold could promote cartilage functional repair, and suggests a new promising strategy for treating cartilage defects with a functional prosthesis that spontaneously inhibits nearby cartilage degeneration.Translational potential of this articleIn the present study, we propose a new cartilage repair strategy based on a porous, non-biodegradable polyetheretherketone (PEEK) scaffold, which may bring up a new treatment route for elderly patients with cartilage lesions in the future.

Novel Framework for Measuring Whole Knee Osteoarthritis Progression Using Magnetic Resonance Imaging.

We developed and validated a set of composite scores that combine quantitative magnetic resonance imaging (MRI)-based measurements of hyaline cartilage damage, bone marrow lesions (BMLs), and effusion-synovitis into composite scores. We selected 300 participants (n=100 for development cohort; n=200 for validation cohort) from the Osteoarthritis Initiative with complete clinical, radiographic, and MRI data at baseline and 24 months. We used semiautomated programs to quantify tibiofemoral and patellar cartilage damage, BML volume, and whole-knee effusion-synovitis volume. The candidate composite scores were formed by summing changes from baseline to 24 months based on prespecified methods. We evaluated the candidate composite scores for 1) the ability to differentiate groups with and without knee osteoarthritis progression (17 radiographic and patient-reported definitions), 2) sensitivity to change (standardized response means), and 3) relative performance relating to legacy outcome measures of knee osteoarthritis progression. Three of 13 developed composite scores qualified for testing in the validation cohort (ranked by sensitivity to change): whole-knee cumulative cartilage damage, unweighted total knee score, and BML plus effusion-synovitis volume. Change in cumulative cartilage damage associated with radiographic progression (Kellgren/Lawrence grade: odds ratio [OR] 1.84; joint space width progression: OR 2.11). Changes in the unweighted total knee score (OR 1.97) and BML plus effusion-synovitis score (OR 1.92) associated with Western Ontario and McMaster Universities Osteoarthritis Index knee pain progression. Two composite scores emerged, reflecting discrete domains of knee osteoarthritis progression. First, cumulative damage, which is measured by a whole-knee cartilage damage score, reflects the damage accrued over time. Second, dynamic disease activity, which is measured by a BML plus effusion-synovitis score, relates to changes in a patient's state of disease and symptoms.

Arthroscopic Patellar Osteochondral Transplantation

The undersurface location of the patellar articular cartilage presents unique challenges to osteochondral defect treatment. Current osteochondral grafting techniques and instrumentation require arthrotomy and patellar eversion to access the defect with the necessary perpendicular trajectory. We describe an all-arthroscopic patellar osteochondral grafting technique, with transpatellar retrograde reaming for recipient socket creation and graft fixation, to treat focal patellar cartilage defects.

Association between osteoarthritis-related serum biochemical markers over 11 years and knee MRI-based imaging biomarkers in middle-aged adults

To describe the associations between osteoarthritis (OA)-related biochemical markers (COMP, MMP-3, HA) and MRI-based imaging biomarkers in middle-aged adults over 10-13 years. Blood serum samples collected during the Childhood Determinants of Adult Health (CDAH)-1 study (year:2004-06; n=156) and 10-13 year follow-up at CDAH-3 (n=167) were analysed for COMP, MMP-3, and HA using non-isotopic ELISA. Knee MRI scans obtained during the CDAH-knee study (year:2008-10; n=313) were assessed for cartilage volume and thickness, subchondral bone area, cartilage defects, and BML. In a multivariable linear regression model describing the association of baseline biochemical markers with MRI-markers (assessed after 4-years), we found a significant negative association of standardised COMP with medial femorotibial compartment cartilage thickness (β:-0.070; 95%CI:-0.138,-0.001), and standardised MMP-3 with patellar cartilage volume (β:-141.548; 95%CI:-254.917,-28.179) and total bone area (β:-0.729; 95%CI:-1.340,-0.118). In multivariable Tobit regression model, there was a significant association of MRI-markers with biochemical markers (assessed after 6-9 years); a significant negative association of patellar cartilage volume (β:-0.001; 95%CI:-0.002,-0.00004), and total bone area (β:-0.158; 95%CI-0.307,-0.010) with MMP-3, and total cartilage volume (β:-0.001; 95%CI:-0.001,-0.0001) and total bone area (β:-0.373; 95%CI:-0.636,-0.111) with COMP. No significant associations were observed between MRI-based imaging biomarkers and HA. COMP and MMP-3 levels were negatively associated with knee cartilage thickness and volume assessed 4-years later, respectively. Knee cartilage volume and bone area were negatively associated with COMP and MMP-3 levels assessed 6-9 years later. These results suggest that OA-related biochemical markers and MRI-markers are interrelated in early OA.

Obesity impacts the mechanical response and biochemical composition of patellofemoral cartilage: An in vivo, MRI-based investigation

Obesity is a primary risk factor for osteoarthritis. While previous work has addressed relationships between in vivo cartilage mechanics, composition, and obesity in the tibiofemoral joint, there is limited information on these relationships in the patellofemoral joint. The purpose of this study was to compare the patellofemoral cartilage mechanical response to walking in participants with normal and obese body mass indices (BMIs). Additionally, patellar cartilage T1rho relaxation times were measured before exercise to characterize the biochemical composition of the tissue. Fifteen participants (eight with normal BMI and seven with obese BMI) underwent baseline magnetic resonance imaging (MRI) of their right knee. They then walked on a treadmill for 20 min at a speed normalized to their leg length before a second MRI scan. Subsequently, three-dimensional models of the bones and articular surfaces of the patellofemoral joint were created via manual segmentation of the pre- and post-exercise MR images to compute cartilage thickness and strain. Strain was defined as the change in patellofemoral cartilage thickness normalized to the baseline thickness. Results showed that participants with an obese BMI exhibited significantly increased patellofemoral cartilage strain compared to those with a normal BMI (5.4 ± 4% vs. 1.7 ± 3%, respectively; p = 0.003). Furthermore, patellar cartilage T1rho values were significantly higher in participants with obese versus normal BMIs (95 ms vs. 83 ms, respectively; p = 0.049), indicative of decreased proteoglycan content in those with an obese BMI. In summary, the altered patellofemoral cartilage strain and composition observed in those with an obese BMI may be indicative of cartilage degeneration.

T1ρ magnetic resonance imaging for quantitative assessment of patella cartilage in healthy subjects and athletes

Knee osteoarthritis (OA) is one of major reasons to causes pain and limit mobility for aging people. Early diagnosis of articular cartilage degeneration is of utmost importance for the prevention of OA. Thus, it is necessary to develop a novel magnetic resonance imaging technique to detect the early articular cartilage degeneration. Methods. T1ρ and T2-weighted images of the knees were obtained for 50 asymptomatic young subjects (23 men and 27 women; average age, 23.9 ± 1.8 years) and 17 Chinese National Men's hockey players (average age, 20.7 ± 1.1 years), using a 3.0-T MRI scanner. Quantitative T1ρ relaxation maps of the bilateral patella cartilage were generated by post-processing, and each map was divided into 15 regions of interest (ROIs). T1ρ values of each ROI were measured and compared between asymptomatic subjects and athletes. Results. T1ρ values of left patellar cartilage in athletes were significantly higher than those in healthy subjects (P < 0.05). T1ρ values of right patellar cartilage in athletes were also higher than healthy controls (P < 0.05). T1ρ values of patellar cartilage in both athletes and healthy subjects uncovered no apparent difference between the left knees and right knees (P > 0.05). Conclusion. T1ρ MRI could potentially represent a useful tool for the measurement of early articular cartilage degeneration in clinical practice.

Hip-Knee Joint Coordination Patterns are Associated With Patellofemoral Joint Cartilage Composition in Patients With Anterior Cruciate Ligament Reconstruction.

Joint coordination variability during walking that is associated with patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction are not well understood. The purpose of this study was to assess between-limb differences in joint coordination variability and to determine the relationship of coordination variability with postoperative patellofemoral joint cartilage composition. Thirty-five patients underwent bilateral gait analysis and a magnetic resonance exam of the reconstructed knee joint at 6months post anterior cruciate ligament reconstruction. Vector coding was used to assess coordination variability during the early (1%-33%), mid (34%-66%), and late (67%-100%) stance phase. The T1ρ/T2 mapping was used to evaluate the glycosaminoglycan-collagen matrix of the patellar and femoral trochlear cartilage. Compared with the uninjured limb, the reconstructed limb exhibited higher hip sagittal/knee sagittal plane coordination variability during midstance as well as higher knee sagittal/ankle sagittal plane coordination variability during both mid and late stance. The hip sagittal/knee sagittal plane coordination variability during midstance predicted 14.6% of the variance in patellar cartilage T1ρ values within the reconstructed limb. In addition, sex of participants was able to predict 32.4% and 13.7% of the variance in femoral trochlea T1ρ and T2 values, respectively. The study results demonstrate that a multijoint mechanism may be associated with early patellofemoral joint cartilage degeneration at 6months after anterior cruciate ligament reconstruction.

Influence of Articular Geometry and Tibial Tubercle Location on Patellofemoral Kinematics and Contact Mechanics.

Trochlear groove geometry and the location of the tibial tubercle, where the patellar tendon inserts, have both been associated with patellofemoral instability and can be modified surgically. Although their effects on patellofemoral biomechanics have been investigated individually, the interaction between the two is unclear. The authors' aim was to use statistical shape modeling and musculoskeletal simulation to examine the effect of patellofemoral geometry on the relationship between tibial tubercle location and patellofemoral function. A statistical shape model was used to generate new knee geometries with trochlear grooves ranging from shallow to deep. A Monte Carlo approach was used to create 750 knee models by randomly selecting a geometry and randomly translating the tibial tubercle medially/laterally and anteriorly. Each knee model was incorporated into a musculoskeletal model, and an overground walking trial was simulated. Knees with shallow trochlear geometry were more sensitive to tubercle medialization with greater changes in lateral patella position (-3.0mm/cm medialization shallow vs -0.6mm/cm deep) and cartilage contact pressure (-0.51MPa/cm medialization shallow vs 0.04MPa/cm deep). However, knees with deep trochlear geometry experienced greater increases in medial cartilage contact pressure with medialization. This modeling framework has the potential to aid in surgical decision making.

Quadriceps muscle strength at 2years following anterior cruciate ligament reconstruction is associated with tibiofemoral joint cartilage volume.

Quadriceps strength deficits following anterior cruciate ligament reconstruction (ACLR) are linked to altered lower extremity biomechanics, tibiofemoral joint (TFJ) space narrowing and cartilage composition changes. It is unknown, however, if quadriceps strength is associated with cartilage volume in the early years following ACLR prior to the onset of posttraumatic osteoarthritis (OA) development. The purpose of this cross-sectional study was to examine the relationship between quadriceps muscle strength (peak and across the functional range of knee flexion) and cartilage volume at ~ 2years following ACLR and determine the influence of concomitant meniscal pathology. The involved limb of 51 ACLR participants (31 isolated ACLR; 20 combined meniscal pathology) aged 18-40years were tested at 2.4 ± 0.4years post-surgery. Isokinetic knee extension torque generated in 10° intervals between 60° and 10° knee flexion (i.e. 60°-50°, 50°-40°, 40°-30°, 30°-20°, 20°-10°) together with peak extension torque were measured. Tibial and patellar cartilage volumes were measured using magnetic resonance imaging (MRI). The relationships between peak and angle-specific knee extension torque and MRI-derived cartilage volumes were evaluated using multiple linear regression. In ACLR participants with and without meniscal pathology, higher knee extension torques at 60°-50° and 50°-40° knee flexion were negatively associated with medial tibial cartilage volume (p < 0.05). No significant associations were identified between peak concentric or angle-specific knee extension torques and patellar cartilage volume. Higher quadriceps strength at knee flexion angles of 60°-40° was associated with lower cartilage volume on the medial tibia ~ 2years following ACLR with and without concomitant meniscal injury. Regaining quadriceps strength across important functional ranges of knee flexion after ACLR may reduce the likelihood of developing early TFJ cartilage degenerative changes. III.

Clinical validation of the use of prototype software for automatic cartilage segmentation to quantify knee cartilage in volunteers

BackgroundThe cartilage segmentation algorithms make it possible to accurately evaluate the morphology and degeneration of cartilage. There are some factors (location of cartilage subregions, hydrarthrosis and cartilage degeneration) that may influence the accuracy of segmentation. It is valuable to evaluate and compare the accuracy and clinical value of volume and mean T2* values generated directly from automatic knee cartilage segmentation with those from manually corrected results using prototype software.MethodThirty-two volunteers were recruited, all of whom underwent right knee magnetic resonance imaging examinations. Morphological images were obtained using a three-dimensional (3D) high-resolution Double-Echo in Steady-State (DESS) sequence, and biochemical images were obtained using a two-dimensional T2* mapping sequence. Cartilage score criteria ranged from 0 to 2 and were obtained using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). The femoral, patellar, and tibial cartilages were automatically segmented and divided into subregions using the post-processing prototype software. Afterwards, all the subregions were carefully checked and manual corrections were done where needed. The dice coefficient correlations for each subregion by the automatic segmentation were calculated.ResultsCartilage volume after applying the manual correction was significantly lower than automatic segmentation (P < 0.05). The percentages of the cartilage volume change for each subregion after manual correction were all smaller than 5%. In all the subregions, the mean T2* relaxation time within manual corrected subregions was significantly lower than in regions after automatic segmentation (P < 0.05). The average time for the automatic segmentation of the whole knee was around 6 min, while the average time for manual correction of the whole knee was around 27 min.ConclusionsAutomatic segmentation of cartilage volume has a high dice coefficient correlation and it can provide accurate quantitative information about cartilage efficiently without individual bias.Advances in knowledge: Magnetic resonance imaging is the most promising method to detect structural changes in cartilage tissue. Unfortunately, due to the structure and morphology of the cartilages obtaining accurate segmentations can be problematic. There are some factors (location of cartilage subregions, hydrarthrosis and cartilage degeneration) that may influence segmentation accuracy. We therefore assessed the factors that influence segmentations error.

Deconstruction of Knee Cartilage Injury in Athletes Using MR Images Based on Artificial Intelligence Segmentation Algorithm.

The knee joint is the second largest joint in the human body, with a wide range of functional activities and strong support for the human body. Moreover, the cartilage of the knee joint is hyaline cartilage, which is relatively brittle, so it is most vulnerable to trauma. In clinical work, the damage of articular cartilage is a disease with a high rate of orthopedic visits. In this paper, all the experimental group cases included in the observation were patients with acute articular cartilage injury or OA diagnosed by knee arthroscopy. All experimental groups and control groups did not have any strenuous exercise one day before MRI (magnetic resonance imaging), and they sat for 30 minutes before the examination. Conventional scanning sagittal FSE-T1WI, FSE-T2WI, FS-FSE-T1WI, FS-FSE-T2WI, FS-PDWI, and coronal FS-PDWI sequence. In the normal control group, after the T2 color map was generated in the workstation, the articular cartilage was divided on the midsagittal plane, and the patellar cartilage and tibial plateau were roughly divided into upper, middle, lower and anterior, middle, and posterior thirds. In order to ensure the maximum comparability of the results, an artificial intelligence segmentation algorithm is used to divide the region of interest equally, and the central part of each partition is selected as much as possible for measurement. The T2 values of the three partitions of each cartilage were measured one by one and averaged. For the comparison results of T2 value of cartilage in the same part: according to patellar cartilage, femoral cartilage, and tibial cartilage, the P values are 0.973, 0.150, and 0.525, respectively. Therefore, early detection and early treatment of articular cartilage injury are of great significance to the performance of athletes' competition level and the extension of sports life.

Patellar MACI With Tibial Tubercle Osteotomy

Background: Chondral pathology is frequently encountered during knee arthroscopies with a prevalence rate of 63% to 66%. Prior studies have demonstrated that unaddressed or excised fragments result in poor knee function and arthritis. As a result, chondral-related procedures have increased in popularity, and now more than 200,000 procedures are performed annually. Indications: We present a case of an active 32-year-old woman, prior collegiate basketball player, with persistent left knee pain noted to have a full-thickness patellar articular cartilage defect and maltracking. Technique: A patellar autologous matrix-induced chondrocyte is implanted with a concomitant tibial tubercle osteotomy (TTO) and lateral retinacular lengthening. Results: At 9 weeks, the patient had no knee pain with full range of motion symmetric to the contralateral side while slowly progressing with quadriceps strengthening. Discussion/Conclusion: Successful outcomes addressing large patellar chondral defects and maltracking can be achieved with matrix autologous chondrocyte implantation and concomitant TTO with lateral retinacular lengthening.

A morphologic and morphometric study of articular facets of Patella

Background: The patella plays a major role in flexion and extension of the knee. The patella morphology can be a predisposing factor in patella instability. The congruency between the patella and femur affects the kinematics of the patellofemoral joint, contact mechanics of the patellar cartilage, and strain in the underlying bone, whereby higher stresses and strains potentially contribute to cartilage wear and anterior knee pain. Aim and Objective: The present study was conducted to assess the morphology of facets of patella. Materials and Methods: The present study was conducted to assess the morphology of facets of patella. Ninety-six patella of unknown sex from bone store of Department of Anatomy were included in the study. The patellar morphology and morphometry were investigated. Statistical analysis was performed using the SPSS (v 12.01) software package (SPSS Inc., Chicago, Illinois). Statistical significance was set at P &lt; 0.05. Results: In the present study; 96 patella of unknown sex from bone store of Department of Anatomy were included in the study. The mean size of the right lateral facet was 23.34 mm and left lateral facet patella was 23.06. P value was non-significant. The shape of lateral facet was concave in 93.9% in the left patella and 100% in the right patella. The shape of lateral facet was flat in 6.1% in the left patella and 0% in the right patella. The mean size of the right medial facet was 17.68 mm and left medial facet patella was 17.39 mm. P value was nonsignificant. The shape of medial facet was concave in 2% in the left patella and 10.6% in the right patella. The shape of medial facet was convex in 69.4% in the left patella and 61.7% in the right patella. The shape of medial facet was flat in 28.6% in the left patella and 27.6% in the right patella. P value was non-significant. Conclusion: The present study concluded that the mean size of the right lateral facet was more left lateral facet patella. The shape of lateral facet was concave in 93.9% in the left patella and 100% in the right patella. The shape of lateral facet was flat in 6.1% in the left patella and 0% in the right patella. The mean size of right medial facet was more than left medial facet patella. The shape of medial facet was concave in 2% in the left patella and 10.6% in the right patella. The shape of medial facet was convex in 69.4% in the left patella and 61.7% in the right patella. The shape of medial facet was flat in 28.6% in the left patella and 27.6% in the right patella.

MORPHOLOGICAL ANALYSIS OF 3D MR IMAGES OF PF JOINTS IN ASYMPTOMATIC SUBJECTS

Understanding the pathogenesis of patellofemoral osteoarthritis (PFOA) will be enhanced by elucidating the onset and progression in asymptomatic PFOA. Demonstrating of the cartilage defect of 3D MR images, obtained from a cohort population, in order from the smallest to the largest, can mimic the morphological progression process of PFOA. The purpose of this study was to clarify the frequency, classification, and morphological progression process of PFOA by observing MRI 3D images in a cohort population of subjects without a history of visiting hospitals for knee disease. The subjects were 561 at 30–79 years old who were registered in the Kanagawa Knee Study. The main exclusion criteria were those who have a past history of consecutive visits to the hospital for more than 3 months for knee symptoms. We obtained 3D MR images of the PF joints using 3D image analysis system volume analyzer (SYNAPSE 3D, Fujifilm Corporation, Tokyo). The cartilage defects were classified as medial and lateral type. MR images of the PF joints were displayed with cartilage area ratios of the patella and presented in order of highest to lowest, separated into the medial and lateral type. Of the 561 subjects, cartilage defects were detected on 3D images of the patella in 37 subjects (6.6%). Medial lesion was detected in 26 subjects (4.6%) and lateral lesion in 11 subjects (2.0%), showing that medial lesion was significantly more frequent (p=0.01). For the medial type, the patellar cartilage defect was located in the center of the medial facet, expanded to the surrounding area, and further distally and medially. 3D MR images of the patellofemoral joint showed the cartilage defect of the patella expanded along with the medial ridge of the femoral trochlea. For the lateral type, the patellar cartilage defect was located in the center of the lateral facet, expanded to the surrounding area, and further distally and laterally. 3D MR images of the patellofemoral joint showed the cartilage defect of the patella expanded along with the lateral ridge of the femoral trochlea (Fig. 1). According to 3D MR images, the frequency of the patella cartilage defect was 6.6% in 561 asymptomatic subjects. Patellar cartilage defects occurred more frequently on the medial facet than on the lateral facet. The patellar cartilage defect occurred at the center of each facet and expanded along with each side of the ridge of the femoral trochlea. Fujifilm Corporation and Japan Society for the Promotion of Science Grant JP22K09349 I Sekiya received a research grant from Fujifilm Corporation including lending of the analysis software used in this study. Kimiko Takanashi is to be thanked for technical assistance. CORRESPONDENCE ADDRESS: sekiya.arm@tmd.ac.jp

Comparison of Clinical Outcomes after Total Knee Arthroplasty with and without Patellar Resurfacing in the Same Patients.

BackgroundPatellar resurfacing is performed in total knee arthroplasty (TKA) to improve pain in the anterior compartment of the knee joint and to restore proper coordination and movement of the patellofemoral joint. The purpose of this study was to analyze differences in clinical outcomes according to patellar resurfacing in patients who underwent bilateral TKA.MethodsForty-three patients who underwent bilateral primary TKA with patellar resurfacing on one side only were included. Patellar resurfacing was performed selectively according to the status of the patella cartilage surface. Knee Society score (knee and function), Feller score, Kujala score, and Samsung Medical Center (SMC) score (pain and function) were evaluated.ResultsThere were no significant differences in Knee Society pain and function scores, Feller score, Kujala score, and SMC pain and function scores according to patellar resurfacing. On the comparison of SMC scores, there was no difference except for two questions.ConclusionsIt is advisable not to perform resurfacing on normal patellae. However, in order to apply this result to damaged patellae, comparative studies between resurfaced patellae and damaged patellae are needed.

Quantification of Sodium Relaxation Times and Concentrations as Surrogates of Proteoglycan Content of Patellar CARTILAGE at 3T MRI.

Sodium MRI has the potential to depict cartilage health accurately, but synovial fluid can influence the estimation of sodium parameters of cartilage. Therefore, this study aimed to reduce the impact of synovial fluid to render the quantitative compositional analyses of cartilage tissue technically more robust. Two dedicated protocols were applied for determining sodium and relaxation times. For each protocol, data were acquired from 10 healthy volunteers and one patient with patellar cartilage damage. Data recorded with multiple repetition times for measurement and multi-echo data acquired with an additional inversion recovery pulse for measurement were analysed using biexponential models to differentiate longitudinal relaxation components of cartilage () and synovial fluid (), and short () from long () transversal relaxation components. Sodium relaxation times and concentration estimates in patellar cartilage were successfully determined: = 14.5 ± 0.7 ms; = 37.9 ± 2.9 ms; c(-protocol) = 200 ± 48 mmol/L; = 0.4 ± 0.1 ms; = 12.6 ± 0.7 ms; c(-protocol) = 215 ± 44 mmol/L for healthy volunteers. In conclusion, a robust determination of sodium relaxation times is possible at a clinical field strength of 3T to quantify sodium concentrations, which might be a valuable tool to determine cartilage health.

No patella resurfacing total knee arthroplasty leads to reduction in the thickness of patellar cartilage to less than half within 5\u2009years: a quantitative longitudinal evaluation using MRI

PurposePatellar resurfacing in total knee arthroplasty (TKA) remains controversial as recent meta-analyses have not shown its clear superiority; however, most authors recommend it because it is associated with less frequent anterior knee pain and need for reoperation. We aimed to clarify the changes in patellar cartilage thickness in no patellar resurfacing TKA using a ceramic femoral component on magnetic resonance imaging (MRI).MethodsBetween 2009 and 2014, 40 consecutive patients (59 knees) were included in this study. All patients underwent TKA using zirconia ceramic femoral implants without patellar resurfacing. Indications for no patellar resurfacing TKA were absence of anterior knee pain, patellar compression pain, and osteoarthritic changes in the patellofemoral joint on plain radiography. The mean postoperative follow-up duration was 81.5 months (range, 25–131 months). Clinical and radiological evaluations were performed preoperatively and 5 years after TKA. Patellar cartilage thickness was evaluated preoperatively and every year for 5 years after TKA using MRI T2-weighted imaging. The patellar cartilage was divided into three regions of interest: medial, central, and lateral. To standardise the variation in patellar thickness among patients, the percent cartilage thickness was calculated.ResultsThe implant’s position was appropriate in all cases. Compared to preoperative scores, 5 years postoperatively, the Japanese Orthopedic Association score and Oxford knee score significantly improved from 52.1 to 84.7; mean tilting angle and congruence angle did not change significantly; mean lateral shift ratio significantly increased from 7.1% to 14.6%; cartilage thickness significantly decreased (P < 0.05); and the percentage cartilage thickness of the central, medial, and lateral cartilage zones gradually thinned to less than half. Four patients underwent conversion to patellar resurfacing due to anterior knee pain, without loosening the femoral and tibial implants.ConclusionThe patellar cartilage thickness decreased to less than half its preoperative level within 5 years after no patellar resurfacing TKA; this would led to clinical problems and conversion to patellar resurfacing.Level of evidenceLevel III.

Patellar cartilage increase following ACL reconstruction with and without meniscal pathology: a two-year prospective MRI morphological study

BackgroundAnterior cruciate ligament reconstruction (ACLR) together with concomitant meniscal injury are risk factors for the development of tibiofemoral (TF) osteoarthritis (OA), but the potential effect on the patellofemoral (PF) joint is unclear. The aim of this study was to: (i) investigate change in patellar cartilage morphology in individuals 2.5 to 4.5 years after ACLR with or without concomitant meniscal pathology and in healthy controls, and (ii) examine the association between baseline patellar cartilage defects and patellar cartilage volume change.MethodsThirty two isolated ACLR participants, 25 ACLR participants with combined meniscal pathology and nine healthy controls underwent knee magnetic resonance imaging (MRI) with 2-year intervals (baseline = 2.5 years post-ACLR). Patellar cartilage volume and cartilage defects were assessed from MRI using validated methods.ResultsBoth ACLR groups showed patellar cartilage volume increased over 2 years (p < 0.05), and isolated ACLR group had greater annual percentage cartilage volume increase compared with controls (mean difference 3.6, 95% confidence interval (CI) 1.0, 6.3%, p = 0.008) and combined ACLR group (mean difference 2.2, 95% CI 0.2, 4.2%, p = 0.028). Patellar cartilage defects regressed in the isolated ACLR group over 2 years (p = 0.02; Z = − 2.33; r = 0.3). Baseline patellar cartilage defect score was positively associated with annual percentage cartilage volume increase (Regression coefficient B = 0.014; 95% CI 0.001, 0.027; p = 0.03) in the pooled ACLR participants.ConclusionsHypertrophic response was evident in the patellar cartilage of ACLR participants with and without meniscal pathology. Surprisingly, the increase in patellar cartilage volume was more pronounced in those with isolated ACLR. Although cartilage defects stabilised in the majority of ACLR participants, the severity of patellar cartilage defects at baseline influenced the magnitude of the cartilage hypertrophic response over the subsequent ~ 2 years.

Modified particle swarm optimization based magnetic resonance imaging analysis for identification of risk factors tissue damage incidence

AbstractThis study was to analyse the risk factors of unstable patella and the incidence of tissue damage (TD) with magnetic resonance imaging (MRI) image under the modified particle swarm optimization (MPSO). In this study, 45 patients with patella instability who visited hospital from 1 November 2018 to 28 September 2020 were selected as the experimental group (group E), and 45 volunteers with healthy knee joints were recruited as the control group (group C). MRI images under MPSO were to evaluate the four groups of related indicators (trochlear groove angle, trochlear groove depth, trochlear surface ratios, and Insall‐Salvati index) of unstable patella in the two groups and count the incidence of TD caused by unstable patella. Comparison of four indicators revealed that there was an obvious difference in the data of the two groups. The abnormal rate of patients with unstable patella in the group E was much higher than that of the group C, and the difference was statistical (p &lt; 0.05). The incidences of trochlea dysplasia and high patella accounted for 88.9% and 57.8% in group E and accounted for 4.4% and 3.2% in the group C, respectively, showing statistically obvious differences (p &lt; 0.05). The incidence of patella cartilage TD, thigh cartilage TD, lateral meniscus TD, medial meniscus TD, patella medial retinaculum TD, patella lateral retinaculum TD, patellar ligament damage, and joint effusions were 14.5%, 11.45%, 50.38%, 49.62%, 10.69%, 16.03%, 9.16%, and 79.39%, respectively in the patients with unstable patella in the group E. In short, trochlear dysplasia and high patella were risk factors for unstable patella, and unstable patella was one of the risk factors for multiple TDs of the knee joint. This study provided a new research basis for the early treatment of unstable patella.

Particulated Juvenile Articular Cartilage and Matrix-Induced Autologous Chondrocyte Implantation Are Cost-Effective for Patellar Chondral Lesions

To compare the cost-effectiveness of nonoperative management, particulated juvenile allograft cartilage (PJAC), and matrix-induced autologous chondrocyte implantation (MACI) in the management of patellar chondral lesions. A Markov model was used to evaluate the cost-effectiveness of three strategies for symptomatic patellar chondral lesions: 1) nonoperative management, 2) PJAC, and 3) MACI. Model inputs (transition probabilities, utilities, and costs) were derived from literature review and an institutional cohort of 67 patients treated with PJAC for patellar chondral defects (mean age 26 years, mean lesion size 2.7 cm2). Societal and payer perspectives over a 15-year time horizon were evaluated. The principal outcome measure was the incremental cost-effectiveness ratio (ICER) using a $100,000/quality-adjusted life year (QALY) willingness-to-pay threshold. Sensitivity analyses were performed to assess the robustness of the model and the relative effects of variable estimates on base case conclusions. From a societal perspective, nonoperative management, PJAC, and MACI cost $4,140, $52,683, and $83,073 and were associated with 5.28, 7.22, and 6.92 QALYs gained, respectively. PJAC and MACI were cost-effective relative to nonoperative management (ICERs $25,010/QALY and $48,344/QALY, respectively). PJAC dominated MACI in the base case analysis by being cheaper and more effective, but this was sensitive to the estimated effectiveness of both strategies. PJAC remained cost-effective if PJAC and MACI were considered equally effective. In the management of symptomatic patellar cartilage defects, PJAC and MACI were both cost-effective compared to nonoperative management. Because of the need for one surgery instead of two, and less costly graft material, PJAC was cheaper than MACI. Consequently, when PJAC and MACI were considered equally effective, PJAC was more cost-effective than MACI. Sensitivity analyses accounting for the lack of robust long-term data for PJAC or MACI demonstrated that the cost-effectiveness of PJAC versus MACI depended heavily on the relative probabilities of yielding similar clinical results. III, economic and decision analysis.