Arthroscopic cartilage regeneration facilitating procedure can modify the clinical course of knee osteoarthritis.

BACKGROUND: The effectiveness of arthroscopic treatment for knee osteoarthritis (OA) has been controversial. This study compares the clinical outcomes of the arthroscopic cartilage regeneration facilitating procedure (ACRFP) and conservative treatment. METHODS: During the year of 2016, 524 patients (882 knees) who were older than 40 years of age and diagnosed with different stages of knee OA were scheduled for ACRFP under the protocol of knee health promotion option (KHPO) for knee OA. Of those, 259 patients (413 knees) eventually received ACRFP (the ACRFP group), and 265 patients (469 knees) didn't receive ACRFP but received conservative treatment (the non-ACRFP group). A telephone questionnaire was used to evaluate the subjective satisfaction and the incidence of receiving arthroplasty for these patients. RESULTS: After the mean follow-up period of 61.6 months (SD 4.5), there were 220 patients (374 knees, 90.6%) in the ACRFP group and 246 patients (431 knees, 90.0%) in the non-ACRFP group completed the outcome study. The satisfactory rate was statistically higher for the ACRFP group (90.64%) than for the non-ACRFP group (70.3%) and the difference in subjective satisfaction was more obvious in patients with more advanced knee OA. As for the incidence of patients having subsequently received arthroplasty, it was higher (13.46%) in the non-ACRFP group than in the ACRFP group (4.28%). CONCLUSION: Compared with conservative treatment, ACRFP could satisfy more patients with knee OA and modify their natural course by decreasing the incidence of subsequent arthroplasty.

Proximal tibia osteotomy with absorbable spacer combined with fibular osteotomy versus high tibial osteotomy for medial compartmental knee osteoarthritis.

PURPOSE: The study aimed to compare the perioperative complications, short-term clinical outcomes, patient-reported outcomes, and radiographic parameters of tibiofibular proximal osteotomy combined with absorbable spacer insertion (TPOASI) and open-wedge high tibial osteotomy (OWHTO) in a two year postoperative time period. METHODS: A total of 160 patients with Kellgren-Lawrence classification grade 3 medial compartmental knee OA were randomized to receive either TPOASI (n = 82) or OWHTO (n = 78). The primary and secondary outcomes were measured preoperatively, postoperatively, and at each follow-up examination. The primary outcomes were the between-group change in the Western Ontario and McMaster Universities Global score (WOMAC). Secondary measures included visual analog scale (VAS), radiographic parameters, American Knee Society Score (KSS), operation time, blood loss, length of incision, hospital stay, and relevant complications. Postoperative radiographic parameters, including the femorotibial angle (FTA), varus angle (VA), and joint line convergence angle (JLCA), were measured to evaluate the correction of varus deformity. RESULTS: No significant differences were found in the baseline data between the two groups. Both methods improved functional status and pain postoperatively. For primary outcomes of both groups, statistical difference was observed in WOMAC scores at the 6-month follow-up (P < 0.001). For secondary outcomes, no statistical difference was observed between the groups during the 2-year follow-up (P > 0.05). For TPOASI vs. OWHTO, the mean hospital stay (6.6 ± 1.3 days vs. 7.8 ± 2.1 days) was shorter (P < 0.001), and both blood loss (70.56 ± 35.58 vs. 174.00 ± 66.33 mL) and complication rate (3.7% vs. 12.8%) were significantly lower (P < 0.005 for both). CONCLUSIONS: Both approaches showed satisfactory functional outcomes and alleviated pain. However, TPOASI is a simple, feasible method with few complications, and it could be widely used.

Arthroscopic cartilage regeneration facilitating procedure: A decompressing arthroplasty for knee osteoarthritis.

The effectiveness of arthroscopic treatment for knee osteoarthritis (OA) has always been a subject of debate. This study presents an innovative concept for the arthroscopic management of knee OA and investigates its clinical outcomes. An arthroscopic cartilage regeneration facilitating procedure (ACRFP) was performed on 693 knees of 411 patients with knee OA, with a mean age of 60 years (34-90 years), to eliminate the medial abrasion phenomenon (MAP) and decompress the patellofemoral joints. The Knee Society Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to determine the subjective outcome. Roentgenographic changes in all cases and magnetic resonance imaging (MRI) variations in 20 randomly selected cases were evaluated for objective outcomes. We evaluated 634 knees in 369 patients (93.7%) with more than 3 years of follow-up (mean, 40 months; SD, 9) and found that the overall subjective satisfaction rate was 91.1%. Scores for KSS and all KOOS subscales improved statistically. Reversal of cartilage degeneration was observed in 80.1% of the entire series (radiographic outcome study) and 72.2% of the 18 randomly selected cases (1-year MRI outcome study). We found significant association between gender and OA severity, with regards to the subjective outcomes. Age, body mass index, pre-operative hyaluronic acid injection, OA severity, and type and severity of the medial plica were found to be important predictors of radiographic outcomes. An analysis of failed cases reaffirmed the need for early ACRFP and skilled post-operative care. ACRFP is an effective treatment for knee OA. It can benefit most patients and modify their degeneration processes if performed in time. However, further investigations are needed to confirm our concept of treatment.

Medial abrasion syndrome: a neglected cause of persistent pain after knee arthroplasty.

INTRODUCTION: Persistent post-operative pain (PPOP) has detracted from some otherwise successful knee arthroplasties. This study investigated medial abrasion syndrome (MAS) as a cause of PPOP after knee arthroplasty. The surgical techniques and outcomes of incorporating this concept into the management of both primary arthroplasty cases and patients suffering from unknown causes of PPOP after arthroplasties were presented. MATERIALS AND METHODS: In a 1-year period, the author performed unicompartmental or total knee arthroplasty (the UKA or TKA group) that also eliminated medial abrasion phenomenon (MAP) on 196 knees of 150 patients at advanced stages of knee osteoarthritis (OA). During the same year, 16 knees of 16 patients with unknown causes of PPOP after knee arthroplasties were referred to the author for the arthroscopic medial release procedure (the AMR group) after being diagnosed as MAS. Subjective satisfaction, Knee Society Score (KSS), and Knee injury and Osteoarthritis Outcome Score (KOOS) evaluations were used for outcome study. RESULTS: All 166 patients were followed for more than 3 years (mean 3.7 years, 3.1-4.2) for the outcome study. All knees receiving arthroplasty showed medial plicae with MAP at the time of surgery. Only 2 of them suffered from PPOP: one was a neglected tibial plateau fracture with residual varus deformity after UKA, and the other was a late infection after TKA and received revision. The satisfactory rate was 98.8% in the UKA group, 99.1% in the TKA group, and 100% in the AMR group. The Knee Society Scores and all subscales of KOOS were statistically improved in all groups. CONCLUSIONS: MAS is a cause of pain in patients who have received knee arthroplasties, and MAP should be eliminated to ensure a successful knee arthroplasty. PPOP after knee arthroplasty can be caused by MAS, which can be managed by AMR.

Why arthroscopic partial meniscectomy?

"Arthroscopic Partial Meniscectomy versus Sham Surgery for a Degenerative Meniscal Tear" published in the New England Journal of Medicine on December 26, 2013 draws the conclusion that arthroscopic partial medial meniscectomy provides no significant benefit over sham surgery in patients with a degenerative meniscal tear and no knee osteoarthritis. This result argues against the current practice of performing arthroscopic partial meniscectomy (APM) in patients with a degenerative meniscal tear. Since the number of APM performed has been increasing, the information provided by this study should lead to a change in clinical care of patients with a degenerative meniscus tear.

Role of medial abrasion phenomenon in the pathogenesis of knee osteoarthritis.

Osteoarthritis of the knee affects a large population worldwide and is associated with an extremely high economic burden largely attributable to the effects of disability, comorbid disease, and the expense of treatment. Since the initiating events that result in the cartilage degradation are poorly understood, there has been very limited success in demonstrating disease modification in clinical trials of potential therapies. Medial plica related medial abrasion phenomenon has recently been identified to have close relationship with medial compartment osteoarthritis. We hypothesized that this abrasion phenomenon will elicit lifelong interplay between pathologic medial plica and the facing medial femoral condyle and might play a role in the pathogenesis of knee osteoarthritis by both physical and chemical effects. After evaluating current evidence, we designed a study to prove that the concentrations of total protein, cartilage degrading related cytokines (tumor necrosis factor-α and interleukin-1ß) and enzyme (matrix metalloproteinase-3) are higher in the medial compartment of the knee having the phenomenon of medial abrasion. The accumulating data and findings about medial abrasion phenomenon might be important for the understanding of the pathogenesis or progression of this common disease. We hope that our hypothesis will stimulate further studies verifying if medial abrasion phenomenon plays more roles in the pathogenesis of knee osteoarthritis. Further clinical observations for its appropriate treatment based on this hypothesis are also mandatory for the benefits of patients.

Patients with knee osteoarthritis undergoing total knee arthroplasty have a lower risk of subsequent severe cardiovascular events: propensity score and instrumental variable analysis.

OBJECTIVE: This population-based study investigated the subsequent cardiovascular risk of patients with knee osteoarthritis underwent total knee arthroplasty in Taiwan. MATERIALS AND METHODS: This was a population-based follow-up study of 22931 patients diagnosed with knee osteoarthritis between 2008 and 2011. Each patient was followed for 3 years or until death. Treatment was dichotomized into conservative treatment and TKA. The association between TKA and cardiovascular disease (CVD) events was analyzed using propensity score analysis and instrumental variable analysis and two-stage least-squares regression model. RESULTS: Patients with knee osteoarthritis who underwent TKA had a lower 3-year cumulative risk of stroke and acute myocardial infarction (AMI). After adjusting for measured risk and confounding factors, propensity score showed a 0.56 fold (adjusted OR = 0.56; 95% CI, 0.51-0.61; p<0.001) risk for CVD in those with TKA. Use of instrumental variable analysis for adjusting measured and unmeasured factors and two-stage least squares regression model revealed that the average treatment effect of TKA was statistically associated with a decreased 7% risk of CVD events (95% CI, 0.2%-13.6%). CONCLUSION: Our study revealed that patients with knee osteoarthritis who underwent TKA had a lower risk of suffering from a future severe cardiovascular event. This benefit may be attributed to an improvement in physical activity, reduction of psychosocial stress, and/or a decreased use of NSAIDs as a result of having undergone TKA.

Medial abrasion syndrome: a neglected cause of knee pain in middle and old age.

Knee pain is a prevailing health problem of middle and old age. Medial plica-related medial abrasion syndrome (MAS), although a well-known cause of knee pain in younger individuals, has rarely been investigated in older individuals. This prospective study was conducted to investigate the prevalence and clinical manifestations of this syndrome as a cause of knee pain in middle and old age. The outcomes of arthroscopic treatment for this syndrome were also evaluated.A total of 232 knees of 169 patients >40 years of age (41-82, median: 63 years old) suffering from chronic knee pain were analyzed. The clinical diagnosis, predisposing factors, presenting symptoms, and physical signs were investigated. The sensitivity and specificity of each parameter of the clinical presentation for the diagnosis of MAS were evaluated after confirmation by arthroscopy. For patients with MAS, the roentgenographic and arthroscopic manifestations were investigated, and arthroscopic medial release (AMR) was performed. The outcomes were evaluated by the changes in the pain domain of the Knee Society scoring system and by patient satisfaction. The prevalence of medial plica was 95%, and osteoarthritis (OA) was the most common clinical diagnosis. Symptoms of pain and crepitus in motion and local tenderness during physical examination were the most sensitive parameters for the diagnosis. A history of a single knee injury combined with local tenderness and a palpable band found during physical examination were the most specific parameters for the diagnosis. The majority of patients suffering from this syndrome were successfully treated using AMR, yielding a satisfaction rate of 85.5% after a minimum of 3 years.MAS is a common cause of knee pain in middle and old age and can be effectively treated by AMR. Its concomitance with OA warrants further investigation.

CHADS 2 Scores in the Prediction of Major Adverse Cardiovascular Events in Patients with Cushing's Syndrome.

Vascular events are one of the major causes of death in case of Cushing's syndrome (CS). However, due to the relative low frequency of CS, it is hard to perform a risk assessment for these events. As represented congestive heart failure (C), hypertension (H), age (A), diabetes (D), and stroke (S), the CHADS2 score is now accepted to classify the risk of major adverse cardiovascular events (MACEs) in patients with atrial fibrillation. In this study, participants were enrolled from the National Health Research Institute Database (NHIRD) of Taiwan, and we reviewed 551 patients with their sequential clinically diagnosed CS data between 2002 and 2009 in relation to MACEs risk using CHADS2 score. Good correlation could be identified between the CS and CHADS2 score (AUC = 0.795). Our results show that patients with CS show significantly higher risk of vascular events and the CHADS2 score could be applied for MACEs evaluation. Adequate lifestyle modifications and aggressive cardiovascular risks treatment are suggested for CS patients with higher CHADS2 score.

Matrix metalloproteases and tissue inhibitors of metalloproteinases in medial plica and pannus-like tissue contribute to knee osteoarthritis progression.

Osteoarthritis (OA) is characterized by degradation of the cartilage matrix, leading to pathologic changes in the joints. However, the pathogenic effects of synovial tissue inflammation on OA knees are not clear. To investigate whether the inflammation caused by the medial plica is involved in the pathogenesis of osteoarthritis, we examined the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α in the medial plica and pannus-like tissue in the knees of patients with medial compartment OA who underwent either arthroscopic medial release (stage II; 15 knee joints from 15 patients) or total knee replacement (stage IV; 18 knee joints from 18 patients). MMP-2, MMP-3, MMP-9, IL-1ß, and TNF-α mRNA and protein levels measured, respectively, by quantitative real-time PCR and Quantibody human MMP arrays, were highly expressed in extracts of medial plica and pannus-like tissue from stage IV knee joints. Immunohistochemical staining also demonstrated high expression of MMP-2, MMP-3, and MMP-9 in plica and pannus-like tissue of stage IV OA knees and not in normal cartilage. Some TIMP/MMP ratios decreased significantly in both medial plica and pannus-like tissue as disease progressed from stage II to stage IV. Furthermore, the migration of cells from the pannus-like tissue was enhanced by IL-1ß, while plica cell migration was enhanced by TNF-α. The results suggest that medial plica and pannus-like tissue may be involved in the process of cartilage degradation in medial compartment OA of the knee.

Experience-based virtual training system for knee arthroscopic inspection.

BACKGROUND: Arthroscopic surgical training is inherently difficult due to limited visibility, reduced motion freedom and non-intuitive hand-eye coordination. Traditional training methods as well as virtual reality approach lack the direct guidance of an experienced physician. METHODS: This paper presents an experience-based arthroscopic training simulator that integrates motion tracking with a haptic device to record and reproduce the complex trajectory of an arthroscopic inspection procedure. Optimal arthroscopic operations depend on much practice because the knee joint space is narrow and the anatomic structures are complex. The trajectory of the arthroscope from the experienced surgeon can be captured during the clinical treatment. Then a haptic device is used to guide the trainees in the virtual environment to follow the trajectory. RESULTS: In this paper, an experiment for the eight subjects' performance of arthroscopic inspection on the same simulator was done with and without the force guidance. The experiment reveals that most subjects' performances are better after they repeated the same inspection five times. Furthermore, most subjects' performances with the force guidance are better than those without the force guidance. In the experiment, the average error with the force guidance is 33.01% lower than that without the force guidance. The operation time with the force guidance is 14.95% less than that without the force guidance. CONCLUSIONS: We develop a novel virtual knee arthroscopic training system with virtual and haptic guidance. Compared to traditional VR training system that only has a single play-script based on a virtual model, the proposed system can track and reproduce real-life arthroscopic procedures and create a useful training database. From our experiment, the force guidance can efficiently shorten the learning curve of novice trainees. Through such system, novice trainees can efficiently develop required surgical skills by the virtual and haptic guidance from an experienced surgeon.

Quantification of tumor necrosis factor-α and matrix metalloproteinases-3 in synovial fluid by a fiber-optic particle plasmon resonance sensor.

The availability of techniques for sensitive detection of early stage osteoarthritis is critical for improving patient health. This study illustrates the feasibility of a fiber-optic particle plasmon resonance (FOPPR) sensor with gold nanoparticles on the unclad region of optical fiber probes for analysis of osteoarthritis biomarkers, tumor necrosis factor-α (TNF-α) and matrix metalloproteinases-3 (MMP-3). Results show that the sensor can achieve a refractive index resolution of 5.18 × 10⁻7 RIU and limits of detection for TNF-α and MMP-3 as low as 8.22 pg ml⁻¹ (0.48 pM) and 34.3 pg ml⁻¹ (1.56 pM), respectively. Additionally, the FOPPR sensor shows a good correlation in determining TNF-α and MMP-3 in synovial fluid with the clinically accepted enzyme-linked immunosorbent assay (ELISA) method. Finally, given the FOPPR sensor's nature of being low-cost, label-free, highly sensitive, real-time, simple-to-operate, the FOPPR sensor could offer potential to monitor biomarkers of various diseases, and provide an ideal technical tool for point-of-care diagnostics.

Forced-convective vitrification with liquid cryogens.

Cell cryopreservation by vitrification generally requires using vitrification solutions with high concentrations of cryoprotectants (CPAs), which are toxic and induce osmotic stresses associated with the addition and removal of CPAs. To increase the cooling rate and reduce the CPA concentration required for vitrification, this study proposed an innovative approach, named forced-convective vitrification with liquid cryogens, in which liquid oxygen at a temperature below its boiling point (LOX(bbp)) was used as the cryogen to reduce the generation of insulating bubbles of gaseous oxygen and the sample was subjected to a constant velocity to remove insulation bubbles from the sample. Results show that changing the cryogen from liquid nitrogen at its boiling temperature (LN(abp)) to LOX(bbp), increasing the sample velocity and reducing the test solution volume increased the cooling rate and thereby decreased the CPA concentration required for vitrification. Using the same velocity (1.2 m/s), the cooling rate achieved with LOX(bbp) was 2.3-fold greater than that achieved with LN(abp). With LOX(bbp), the increase in the sample velocity from 0.2 to 1.2 m/s enhanced the cooling rate by 1.9 times. With LOX(bbp), a velocity of 1.2m/s and a test solution volume of 1.73 µl, the CPA concentration required for vitrification decreased to 25%. These results indicate that the new approach described here can reduce the CPA concentration required for vitrification, and thus decreases the toxicity and osmotic stresses associated with adding and removing the CPA.

Cryopreserved chondrocytes in porous biomaterials with surface elastin and poly-L-lysine for cartilage regeneration.

The ability of cryopreserved chondrocytes to revitalize and propagate is a key biotechnology in cartilage regeneration. This study shows the formation of neocartilage from cryopreserved chondrocytes in scaffolds grafted with elastin and poly-L-lysine. Cryopreserved chondrocytes in elastin- and poly-L-lysine-grafted constructs were cultured in a dynamic bioreactor and assessed by biochemical assay and staining. Elastin demonstrated a better efficacy for recruiting cryopreserved chondrocytes onto the pore surface of constructs than poly-L-lysine. However, surface elastin and poly-L-lysine did not significantly enhance the biocompatibility to cryopreserved chondrocytes. Chondrocytes multiplied from cryopreserved chondrocytes in elastin-grafted constructs is faster than that in poly-L-lysine-grafted constructs. In addition, elastin could stimulate cryopreserved chondrocytes to synthesize more glycosaminoglycans and collagen than poly-L-lysine. Porous biomaterials with surface elastin and poly-L-lysine can maintain active chondrocytic proliferation and extracellular matrix secretion from chondrocytes with appropriate cryopreservation.

Arthroscopic cartilage regeneration facilitating procedure for osteoarthritic knee.

BACKGROUND: The effectiveness of arthroscopic treatment for osteoarthritic knee is a controversy. This study presents the technique of a novel concept of arthroscopic procedure and investigates its clinical outcome. METHOD: An arthroscopic procedure targeted on elimination of focal abrasion phenomenon and regaining soft tissue balance around patello-femoral joint was applied to treat osteoarthritis knees. Five hundred and seventy-one knees of 367 patients with osteoarthritis received this procedure. There were 70 (19%) male and 297 (81%) female and the mean age was 60 years (SD 10). The Knee Society score (KSS) and the knee injury and osteoarthritis outcome score (KOOS) were used for subjective outcome study. The roentgenographic changes of femoral-tibial angle and joint space width were evaluated for objective outcomes. The mean follow-up period was 38 months (SD 3). RESULTS: There were 505 knees in 326 patients available with more than 3 years follow-up and the mean follow-up period was 38 months (SD 3). The subjective satisfactory rate for the whole series was 85.5%. For 134 knees with comprehensive follow-up evaluation, the KSS and all subscales of the KOOS improved statistically. The femoral-tibial angle improved from 1.57 degrees (SD 3.92) to 1.93 degrees (SD 4.12) (mean difference: 0.35, SD 0.17). The joint space width increased from 2.02 millimeters (SD 1.24) to 2.17 millimeters (SD 1.17) (mean difference: 0.13, SD 0.05). The degeneration process of the medial compartment was found being reversed in 82.1% of these knees by radiographic evaluation. CONCLUSIONS: Based on these observations arthroscopic cartilage regeneration facilitating procedure is an effective treatment for osteoarthritis of the knee joint and can be expected to satisfy the majority of patients and reverse the degenerative process of their knees.

Application of albumin-grafted scaffolds to promote neocartilage formation.

This study investigates the capacity of albumin-grafted biomaterials as tissue engineering scaffolds to regenerate cartilaginous components. Porcine knee chondrocytes were seeded and cultivated in porous ternary matrix consisting of polyethylene oxide, chitin, and chitosan with surface albumin. The results revealed that the quantity of albumin did not affect the viability of porcine knee chondrocytes in the constructs. However, a high grafting concentration of albumin favored the adhesion of porcine knee chondrocytes on the scaffolding pore surface. After cultivation over 4 weeks, an increase in the concentration of albumin enhanced the quantities of porcine knee chondrocytes, glycosaminoglycans, and collagen in the constructs. The histological staining of porcine knee chondrocytes showed an active chondrocytic growth in the albumin-grafted constructs. In addition, the safranin-O staining indicated that the surface albumin could stabilize the secretion of glycosaminoglycans. Moreover, the immunochemical staining against type II collagen exhibited a regular production of collagen by phenotypic porcine knee chondrocytes in the constructs. Albumin-grafted polyethylene oxide/chitin/chitosan scaffolds can be a promising biomimetic substrate in neocartilage formation.

Integration of fiber optic-particle plasmon resonance biosensor with microfluidic chip.

This article reports the integration of the fiber optic-particle plasmon resonance (FO-PPR) biosensor with a microfluidic chip to reduce response time and improve detection limit. The microfluidic chip made of poly(methyl methacrylate) had a flow-channel of dimensions 4.0 cm × 900 µm × 900 µm. A partially unclad optical fiber with gold or silver nanoparticles on the core surface was placed within the flow-channel, where the volume of the flow space was about 14 µL. Results using sucrose solutions of various refractive indexes show that the refractive index resolution improves by 2.4-fold in the microfluidic system. The microfluidic chip is capable of delivering a precise amount of biological samples to the detection area without sample dilution. Several receptor/analyte pairs were chosen to examine the biosensing capability of the integrated platform: biotin/streptavidin, biotin/anti-biotin, DNP/anti-DNP, OVA/anti-OVA, and anti-MMP-3/MMP-3. Results show that the response time to achieve equilibrium can be shortened from several thousand seconds in a conventional liquid cell to several hundred seconds in a microfluidic flow-cell. In addition, the detection limit also improves by about one order of magnitude. Furthermore, the normalization by using the relative change of transmission response as the sensor output alleviate the demand on precise optical alignment, resulting in reasonably good chip-to-chip measurement reproducibility.

Matrix metalloprotease-3 expression in the medial plica and pannus-like tissue in knees from patients with medial compartment osteoarthritis.

AIMS: The severity of cartilage degeneration is positively correlated with the severity of the pathologic change of medial plica. However, knowledge of the pathogenic mechanisms and the impact of plica on cartilage destruction is limited. The aim of the present study was therefore to investigate matrix metalloprotease-3 (MMP-3) expression in the plica isolated from patients with medial compartment osteoarthritis of the knee. METHODS AND RESULTS: Immunohistochemistry showed that MMP-3 was highly expressed in pannus-like tissue and the plica. Western blotting of culture supernatants showed that interleukin-1ß (IL-1ß) treatment induced MMP-3 release by cells isolated from pannus tissue or the plica. Furthermore, reverse transcriptase polymerase chain reaction and real-time polymerase chain reaction analysis showed that MMP-3 mRNA levels were increased after IL-1ß treatment of the cultured cells. MMP-3 and IL-1ß mRNAs were expressed in the plica and pannus-like tissue, with MMP-3 mRNA being expressed at significantly higher levels in the plica than in normal synovial membrane and highly expressed in the plica at different stages in osteoarthritis (OA) patients. CONCLUSION: Pannus-like tissue and the plica express IL-1ß and MMP-3. Moreover, MMP-3 mRNA and protein expression in the plica may contribute to the pathogenesis of OA.

Fiber-optic particle plasmon resonance sensor for detection of interleukin-1ß in synovial fluids.

A facile and label-free biosensing method has been developed for determining an osteoarthritis concerned cytokine, interleukin-1ß (IL-1ß), in synovial fluids. The biosensing technique, fiber-optic particle plasmon resonance (FOPPR), is based on gold nanoparticles-modified optical fiber where the gold nanoparticle surface has been modified by a mixed self-assembled monolayer for further conjugation of anti-IL-1ß antibody and minimization of nonspecific adsorption. Upon binding of IL-1ß to anti-IL-1ß on the gold nanoparticle surface, the absorbance of the gold nanoparticle layer on the optical fiber changes and the signal change is enhanced through multiple total internal reflections along the optical fiber. Results show that the detection of IL-1ß in synovial fluid by this sensor agrees quantitatively with the clinically accepted enzyme-linked immunosorbent assay (ELISA) method but a much shorter analysis time is required (<10 min). The sensor response versus log concentration of IL-1ß was linear (r=0.9947) over the concentration range of 0.050-10 ng/mL and a limit of detection (LOD) of 21 pg/mL (1.2 pM) was achieved. Such a LOD for IL-1ß (17 kDa) represents a major advancement in the field of real-time monitoring of low molecular weight proteins in complex biological fluids.

Medial plica in patients with knee osteoarthritis: a histomorphological study.

UNLABELLED: The gross appearance and histological features of the medial plicae removed from 48 consecutive patients who had received total knee replacement for severe medial compartment osteoarthritis of their knees were investigated prospectively. The prevalence of the medial plica was 100%. A small branch of skeletal muscle originating from articularis genu inserting into the proximal synovial stroma of the medial plica was found in all knees. The synovial fold of the distal part of the medial plica was disclosed to have a close relationship with the gracilis tendon sheath. Histologically, the majority of advanced pathologic presentation was found at the middle and distal portion of the medial plica that might abrade on the articular cartilage of the medial femoral condyle. Noticeable cartilaginous lesion was found on the facing medial femoral condyle in all knees. The histomorphological findings of the medial plica imply the close interplay between this structure and the medial femoral condyle that might play a role in the pathogenesis of medial compartment osteoarthritis of the knee. CLINICAL RELEVANCE: The findings of this study support the beneficial effect of some surgical procedure that would remove the pathologic medial plica for the treatment of medial compartment OA knee.