Medial meniscus extrusion is a determinant factor for the gait speed among MRI-detected structural alterations of knee osteoarthritis.

Objective: Knee osteoarthritis (OA) is one of the most common causes for reduction in gait speed. Research into the mechanism of underlying knee OA pain and other symptoms such as the reduction in the gait speed is essential to development of disease-modifying treatments for knee OA. We examined the magnetic resonance imaging (MRI)-detected structural alterations in knee joints those were associated with gait speed in knee OA patients. Design: In this cross-sectional study, structural alterations in knee joints of 74 knee OA patients (51 females; mean 72.2 years old) were evaluated by MRI, and subjects' gait speed was measured. Results: The mean self-selected gait speed of the subjects was 0.73 â€‹± â€‹0.21 â€‹m/s. A simple linear regression analysis revealed that MME was only correlated with the gait speed of the subjects with knee OA, while cartilage lesion, bone marrow lesion, subchondral bone cyst, subchondral cyst, osteophytes and meniscal pathology were not. A multiple regression analysis revealed that only MME was associated with gait speed (R2 â€‹= â€‹0.484, p â€‹< â€‹0.001). The area under the receiver operating characteristic curve for determining <0.8 â€‹m/s of gait speed as evaluated by MME were 0.72 (95% confidence interval: 0.60-0.84). The relative risks at a cut-off <0.8 â€‹m/s for gait speed as evaluated by MME at 6.2 â€‹mm were 2.19 (1.28-3.46, p â€‹= â€‹0.01). Conclusions: MME was associated with and the determinant for gait speed among MRI-detected structural alterations in patients with knee OA, suggesting the importance for elucidating the etiology of MME for developing a disease-modifying treatment for knee OA.

The increase in bone mineral density by bisphosphonate with active vitamin D analog is associated with the serum calcium level within the reference interval in postmenopausal osteoporosis.

OBJECTIVES: To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD). METHODS: Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n = 93, Study 2: n = 99) were retrospectively analyzed. RESULTS: In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p < .001). A multiple regression analysis among baseline characteristics revealed that serum calcium (sCa: 8.5-10.5 mg/dL) was associated with an increased LS-BMD by treatment (r2: 0.088, p = .02). While average sCa of the patients was 9.2 mg/dL before treatment, it increased time-dependently to 9.6 mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike's information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3 mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3 mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3 mg/dL (0.8%, p = .038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed. CONCLUSION: sCa was associated with an increased LS-BMD by BPs with aVD.

Bone marrow lesion is associated with disability for activities of daily living in patients with early stage knee osteoarthritis.

Osteoarthritis of the knee (knee OA) induces pain, loss of mobility and diminished activities of daily living (ADL). Although an understanding of the pathophysiology of early stage knee OA has been developed, the structural changes associated with disability for ADL in early stage knee OA are still unclear. The aim of the present study was to examine magnetic resonance imaging (MRI)-detected changes associated with disability for ADL in patients with early stage knee OA. One hundred and thirty-two patients with early stage medial knee OA (Kellgren-Lawrence grade ≤ 2) who first visited the outpatient clinic at our university hospital were included. They were also examined by 3.0-Tesla knee MRI. The OA-associated structural changes were scored using the Whole-Organ Magnetic Resonance Imaging Score (WORMS), and clinical manifestations were evaluated by the Japanese Knee Osteoarthritis Measure (JKOM). Median quartile regression was used for the analysis. Cartilage lesion, subchondral bone attrition and osteophytes were observed in all patients. Bone marrow lesions (BMLs) and synovitis were observed in 60% and 55% of the patients, respectively. Subchondral cysts and ligament changes were observed in 6% and 17% of the patients, respectively. Pain severity of the patients was associated with medial cartilage lesions (coefficient 2.50, 95% confidence interval 0.61-4.40, p < 0.01). Disability for ADL of the patients was associated with BMLs in the medial side of the knee joint (0.82, 0.21-1.02, p = 0.04). BMLs in the medial side of the knee joint were associated with disability for ADL of patients with early stage medial knee OA.

Association of medial meniscal extrusion with medial tibial osteophyte distance detected by T2 mapping MRI in patients with early-stage knee osteoarthritis.

BACKGROUND: Medial meniscal extrusion (MME) is associated with progression of medial knee osteoarthritis (OA), but no or little information is available for relationships between MME and osteophytes, which are found in cartilage and bone parts. Because of the limitation in detectability of the cartilage part of osteophytes by radiography or conventional magnetic resonance imaging (MRI), the rate of development and size of osteophytes appear to have been underestimated. Because T2 mapping MRI may enable us to evaluate the cartilage part of osteophytes, we aimed to examine the association between MME and OA-related changes, including osteophytes, by using conventional and T2 mapping MRI. METHODS: Patients with early-stage knee OA (n = 50) were examined. MRI-detected OA-related changes, in addition to MME, were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. T2 values of the medial meniscus and osteophytes were measured on T2 mapping images. Osteophytes surgically removed from patients with end-stage knee OA were histologically analyzed and compared with findings derived by radiography and MRI. RESULTS: Medial side osteophytes were detected by T2 mapping MRI in 98% of patients with early-stage knee OA, although the detection rate was 48% by conventional MRI and 40% by radiography. Among the OA-related changes, medial tibial osteophyte distance was most closely associated with MME, as determined by multiple logistic regression analysis, in the patients with early-stage knee OA (ß = 0.711, p < 0.001). T2 values of the medial meniscus were directly correlated with MME in patients with early-stage knee OA, who showed ≥ 3 mm of MME (r = 0.58, p = 0.003). The accuracy of osteophyte evaluation by T2 mapping MRI was confirmed by histological analysis of the osteophytes removed from patients with end-stage knee OA. CONCLUSIONS: Our study demonstrates that medial tibial osteophyte evaluated by T2 mapping MRI is frequently observed in the patients with early-stage knee OA, showing close association with MME, and that MME is positively correlated with the meniscal degeneration.

Perlecan is required for the chondrogenic differentiation of synovial mesenchymal cells through regulation of Sox9 gene expression.

We previously reported that perlecan, a heparan-sulfate proteoglycan (Hspg2), expressed in the synovium at the cartilage-synovial junction, is required for osteophyte formation in knee osteoarthritis. To examine the mechanism underlying this process, we examined the role of perlecan in the proliferation and differentiation of synovial mesenchymal cells (SMCs), using a recently established mouse synovial cell culture method. Primary SMCs isolated from Hspg2-/- -Tg (Hspg2-/- ;Col2a1-Hspg2Tg/- ) mice, in which the perlecan-knockout was rescued from perinatal lethality, lack perlecan. The chondrogenic-, osteogenic-, and adipogenic-potentials were examined in the Hspg2-/- -Tg SMCs compared to the control SMCs prepared from wild-type Hspg2+/+ -Tg (Hspg2+/+ ;Col2a1-Hspg2Tg/- ) littermates. In a culture condition permitting proliferation, both control and Hspg2-/- -Tg SMCs showed similar rates of proliferation and expression of cell surface markers. However, in micromass cultures, the cartilage matrix production and Sox9 and Col2a1 mRNA levels were significantly reduced in Hspg2-/- -Tg SMCs, compared with control SMCs. The reduced level of Sox9 mRNA was restored by the supplementation with exogenous perlecan protein. There was no difference in osteogenic differentiation between the control and Hspg2-/- -Tg SMCs, as measured by the levels of Runx2 and Col1a1 mRNA. The adipogenic induction and PPARγ mRNA levels were significantly reduced in Hspg2-/- -Tg SMCs compared to control SMCs. The reduction of PPARγ mRNA levels in Hspg2-/- -Tg SMCs was restored by supplementation of perlecan. Perlecan is required for the chondrogenic and adipogenic differentiation from SMCs via its regulation of the Sox9 and PPARγ gene expression, but not for osteogenic differentiation via Runx2. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:837-846, 2017.

The MRI-detected osteophyte score is a predictor for undergoing joint replacement in patients with end-stage knee osteoarthritis.

OBJECTIVES: The aim of this prospective cohort study was to examine whether MRI-detected osteoarthritis (OA)-structural changes at baseline could predict knee OA patients who would undergo total knee arthroplasty (TKA). METHODS: In total, 128 end-stage medial-type knee OA patients were enrolled and followed up for 6 months. MRI using the whole-organ MRI scoring (WORMS) method, radiographic findings, visual analog scale (VAS) for pain and a patient-oriented outcome measure, and the Japanese Knee Osteoarthritis Measure (JKOM) were recorded at baseline. The area under the curve (AUC) was estimated to determine the discriminative value of the prediction models. RESULTS: While 74 patients (57.8%) did not undergo TKA, the remaining 54 patients (42.2%) underwent TKA during this period. The AUCs of the receiver operating characteristic (ROC) curve for the activities of daily living (ADL) score evaluated by the JKOM ADL score [0.70 (95% CI: 0.60-0.79)] and osteophyte score [0.72 (0.64-0.81)] were 0.70 or greater. The JKOM ADL score (17/40) and the osteophyte score (30/98) showed relative risks (RR) of 2.61 (1.32-5.15) and 3.01 (1.39-6.52) for undergoing TKA, respectively. CONCLUSION: The osteophyte score detected by MRI, in addition to ADL score, was found to be an important factor in determining whether the patient should undergo TKA.

Evaluation of Factor Xa-Specific Chromogenic Substrate Assays and the Determination of Pharmacokinetics of Fondaparinux.

Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 µg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study.

Case series: Revision anterior cruciate ligament reconstructions using patellar tendon autografts.

BACKGROUND: Using intra-operative findings and clinical results, including return to play (RTP) at the pre-injury level, this study investigated the causes of primary graft failure after revision anterior cruciate ligament (ACL) reconstruction with bone-patellar-tendon-bone (BPTB) autografts. METHODS: A total of 54 patients were followed for a mean of 38.2 ± 10.2 months post-surgery. Subjective and objective results were evaluated using single assessment numeric evaluation (SANE) scores, Lachman tests, KT-2000 arthrometer results, and pivot-shift tests. The change in each patient's Tegner activity scale and RTP at the pre-injury level were also evaluated. RESULTS: Inappropriate positioning of the tunnels was the most important reason (54%) for primary graft failure. After revision surgery, anterior knee stability was significantly improved (1.2 (mean) ± 1.2 (SD)mm vs 4.5(mean) ± 1.9 (SD)mm; P < 0.01). Two (4%) patients sustained revision graft ruptures while two (4%) sustained contralateral knee ACL tears. The rate of RTP at the pre-injury level was 67% (36 patients), and mean SANE scores at the time of RTP were higher than before surgery (74.8 ± 13.8 points vs 24.1 ± 16.4; P<0.001). The average time from primary graft failure to revision surgery was shorter (12.2 (mean) ± 4.0 (SD) vs 37.6 (mean) ± 8.8 (SD)months; P < 0.01) and the ratio of major cartilage injury was lower (39% vs 83%; P < 0.05) in the RTP group than that in the non-RTP group. CONCLUSIONS: The time from primary graft failure to revision surgery and the extent of the cartilage injury are major factors in RTP after revision ACL reconstructions.

Disability for daily living is a predictor for joint replacement in patients with end-stage knee osteoarthritis.

The objective indicators which reflect the past results of end-stage knee osteoarthritis (OA) patients who have already received total knee arthroplasty (TKA) could be helpful for physicians to discuss with patients who are considering TKA. The aim of this prospective cohort study was to examine whether we could predict the knee OA patients who would receive TKA in advance based on baseline data, and to set cut-off points for receiving TKA. The two-hundred and forty end-stage medial-type knee OA patients were enrolled and followed up for 6 months while performing therapeutic exercises. Radiographic findings, visual analog scale for pain and a patient-oriented outcome measure, the Japanese Knee Osteoarthritis Measure (JKOM), were recorded at baseline. Relative risks (RRs) using the area under the curve (AUC) for a receiver operating characteristic (ROC) curve were calculated to evaluate several scores for receiving TKA. While 119 patients (55.3 %) did not undergo TKA, the remaining 96 patients (44.7 %) underwent TKA during this period. The AUCs of the ROC curve for the JKOM total score [0.71 (95 % CI 0.64-0.79)] were higher than those for radiographic parameters. Among the JKOM subcategories, JKOM category III, which indicates the condition in daily life, showed the highest AUC of 0.72 (0.65-0.80). The JKOM total score (65/100) and JKOM category III score (17/40) showed RRs of 2.20 (1.33-3.63) and 1.95 (1.18-3.22) for receiving TKA, respectively. The presence of disability in daily living was found to be an important factor determining whether the patient should undergo TKA.

Reconstruction of a ruptured patellar tendon using ipsilateral semitendinosus and gracilis tendons with preserved distal insertions: two case reports.

BACKGROUND: Acute patellar tendon ruptures with poor tissue quality. Ruptures that have been neglected are difficult to repair. Several surgical techniques for the repair of the patellar tendon have been reported, however, these techniques remain difficult because of contractures, adhesions, and atrophy of the quadriceps muscle after surgery. CASE PRESENTATION: We report the cases of 2 Japanese patients (Case 1: a 16-year-old male and Case 2: a 43-year-old male) with patellar tendon ruptures who were treated by reconstruction using semitendinosus-gracilis (STG) tendons with preserved distal insertions. Retaining the original insertion of the STG appears to preserve its viability and provide the revascularization necessary to accelerate healing. Both tendons were placed in front of the patella, in a figure-of-eight fashion, providing stability to the patella. CONCLUSION: Both patients recovered near normal strength and stability of the patellar tendon as well as restoration of function after the operation.

Reference intervals of serum hyaluronic acid corresponding to the radiographic severity of knee osteoarthritis in women.

BACKGROUND: While serum levels of hyarulonic acid (sHA) is known to be useful for a burden of disease biomarker in knee OA, it is far from practical. The reference intervals must be established for biomarkers to be useful for clinical interpretation. The aim of this study was to establish the reference intervals of sHA corresponding to the radiographic severity of knee OA for elucidating whether sHA can be useful as a burden of disease marker for individual patient with knee OA. METHODS: 372 women with Kellgren & Lawrence grade (K/L) 1 through 4 painful knee OA were enrolled in this study. The patients included 54 with K/L 1, 96 with K/L 2, 97 with K/L 3, and 118 with K/L 4. Serum samples were obtained from all subjects on the day that radiographs taken. A HA binding protein based latex agglutination assay that employed an ELISA format was used to measure sHA. Age and BMI adjusted one way ANOVA was used to set the reference intervals of sHA. RESULTS: The reference intervals for sHA corresponding to the patients with K/L 4 (49.6 - 66.5 ng/ml) was established without any overlap against to those with K/L 1, 2 and 3, while those with K/L 1, 2 and 3 showed considerable overlap. CONCLUSIONS: These results indicate that sHA can be available as a burden of disease marker for the individuals with severe knee OA (K/L 4), while it is not for those with primary to moderate knee OA (K/L 1-3).

Synovial perlecan is required for osteophyte formation in knee osteoarthritis.

The osteophyte associated with osteoarthritis (OA) is a bony outgrowth formed at the margins of the affected joint through endochondral ossification-like processes. However, the mechanism of osteophyte formation and its pathogenesis are unclear. Perlecan (Hspg2), a heparan sulfate proteoglycan, is expressed in many extracellular tissues and plays critical roles in skeletal development and diseases. The aim of the present study is to identify the role of synovial perlecan in osteophyte formation using perinatal lethality rescued perlecan-knockout mice (Hspg2(-/-)-Tg) wherein perlecan expression is lacking in the synovial and other tissues, except for cartilage. We analyzed the development of osteophytes in joints of Hspg2(-/-)-Tg mice in two different animal models: the surgical OA model, in which the medial collateral ligament was transected and the medial meniscus was resected, and the TGF-ß-induced osteophyte formation model. In the surgical OA model, the osteophyte size and maturation were significantly reduced in the OA joints of Hspg2(-/-)-Tg mice compared with control mice, while OA developed on the medial side of the knee joints with no differences in the cartilage degradation score or synovitis score between control and Hspg2(-/-)-Tg mice. The reduced osteophyte formation in Hspg2(-/-)-Tg mice was associated with reduced cell proliferation and chondrogenesis. In the TGF-ß model, the osteophyte size and maturation were also significantly reduced in Hspg2(-/-)-Tg mice compared with control mice. Our findings suggest that synovial perlecan plays an important role in osteophyte development in OA, and they provide insights that may facilitate the development of OA therapy.

Isolation and characterization of multipotential mesenchymal cells from the mouse synovium.

The human synovium contains mesenchymal stem cells (MSCs), which are multipotential non-hematopoietic progenitor cells that can differentiate into a variety of mesenchymal lineages and they may therefore be a candidate cell source for tissue repair. However, the molecular mechanisms by which this can occur are still largely unknown. Mouse primary cell culture enables us to investigate the molecular mechanisms underlying various phenomena because it allows for relatively easy gene manipulation, which is indispensable for the molecular analysis. However, mouse synovial mesenchymal cells (SMCs) have not been established, although rabbit, cow, and rat SMCs are available, in addition to human MSCs. The aim of this study was to establish methods to harvest the synovium and to isolate and culture primary SMCs from mice. As the mouse SMCs were not able to be harvested and isolated using the same protocol for human, rat and rabbit SMCs, the protocol for humans was modified for SMCs from the Balb/c mouse knee joint. The mouse SMCs obtained showed superior proliferative potential, growth kinetics and colony formation compared to cells derived from muscle and bone marrow. They expressed PDGFRá and Sca-1 detected by flow cytometry, and showed an osteogenic, adipogenic and chondrogenic potential similar or superior to the cells derived from muscle and bone marrow by demonstrating in vitro osteogenesis, adipogenesis and chondrogenesis. In conclusion, we established a primary mouse synovial cell culture method. The cells derived from the mouse synovium demonstrated both the ability to proliferate and multipotentiality similar or superior to the cells derived from muscle and bone marrow.

Headless compression screw fixation of jones fractures: an outcomes study in Japanese athletes.

BACKGROUND: Internal fixation is advocated as the primary treatment for fifth metatarsal Jones fractures in athletes; however, screw insertion site discomfort and refracture can occur especially in competitive athletes. The ideal implant has not been determined. HYPOTHESIS: Headless compression screw fixation of proximal fifth metatarsal Jones fractures is an effective treatment approach especially in competitive athletes. STUDY DESIGN: Case series; Evidence level, 4. METHODS: We studied 60 athletes treated surgically with a headless compression screw for fifth metatarsal Jones fractures (mean age, 19 years). The mean follow-up time was 178 weeks. We evaluated the clinical and radiographic outcomes of headless compression screw fixation of Jones fractures. RESULTS: All athletes returned to full activity. The mean time to start running after surgery was 6.3 weeks (range, 3-12.7 weeks), and the mean time to full activity after surgery was 11.2 weeks (range, 6-25 weeks). One athlete suffered a delayed union, which healed uneventfully. One athlete suffered a nonunion and underwent reoperation for a screw exchange to an autogenous bone graft harvested from the iliac crest. No screw breakage was reported. No athlete suffered a refracture or discomfort in the screw insertion site. CONCLUSION: Headless compression screw fixation of fifth metatarsal Jones fractures provided excellent results, allowing athletes to return to full activity without both screw insertion site irritation and clinical refracture.