Proteomic analysis of synovial fluid identifies periostin as a biomarker for anterior cruciate ligament injury.

OBJECTIVE: Emerging evidence suggests that injury to the anterior cruciate ligament (ACL) typically initiates biological changes that contribute to the development of osteoarthritis (OA). The molecular biomarkers or mediators of these biological events remain unknown. The goal of this exploratory study was to identify novel synovial fluid biomarkers associated with early biological changes following ACL injury distinct from findings in end-stage OA. METHODS: Synovial fluid was aspirated from patients with acute (≤30 days) and subacute (31-90 days) ACL tears and from patients with advanced OA and probed via tandem mass spectrometry for biomarkers to distinguish OA from ACL injury. Periostin (POSTN) was identified as a potential candidate. Further analyses of POSTN were performed in synovial fluid, OA cartilage, torn ACL remnants, and cultured cells and media by Western blot, PCR, immunostaining and ELISA. RESULTS: Synovial fluid analysis revealed that POSTN exhibited higher expression in subacute ACL injury than OA. POSTN expression was relatively low in cartilage/chondrocytes suggesting it is also produced by other intra-articular tissues. Conversely, high and time-dependent expression of POSTN in ACL tear remnants and isolated cells was consistent with the synovial fluid results. CONCLUSIONS: Elevated POSTN may provide a synovial fluid biomarker of subacute ACL injury setting separate from OA. Increased expression of POSTN in ACL suggests that the injured ACL may play a pivotal role in POSTN production, which is sensitive to time from injury. Previous studies have shown potential catabolic effects of POSTN, raising the possibility that POSTN contributes to the initiation of joint degeneration and may offer a window of opportunity to intervene in the early stages of post-traumatic OA.

Distinct degenerative phenotype of articular cartilage from knees with meniscus tear compared to knees with osteoarthritis.

OBJECTIVE: To compare the transcriptome of articular cartilage from knees with meniscus tears to knees with end-stage osteoarthritis (OA). DESIGN: Articular cartilage was collected from the non-weight bearing medial intercondylar notch of knees undergoing arthroscopic partial meniscectomy (APM; N = 10, 49.7 ± 10.8 years, 50% females) for isolated medial meniscus tears and knees undergoing total knee arthroplasty (TKA; N = 10, 66.0 ± 7.6 years, 70% females) due to end-stage OA. Ribonucleic acid (RNA) preparation was subjected to SurePrint G3 human 8 × 60K RNA microarrays to probe differentially expressed transcripts followed by computational exploration of underlying biological processes. Real-time polymerase chain reaction amplification was performed on selected transcripts to validate microarray data. RESULTS: We observed that 81 transcripts were significantly differentially expressed (45 elevated, 36 repressed) between APM and TKA samples (≥ 2 fold) at a false discovery rate of ≤ 0.05. Among these, CFD, CSN1S1, TSPAN11, CSF1R and CD14 were elevated in the TKA group, while CHI3L2, HILPDA, COL3A1, COL27A1 and FGF2 were highly expressed in APM group. A few long intergenic non-coding RNAs (lincRNAs), small nuclear RNAs (snoRNAs) and antisense RNAs were also differentially expressed between the two groups. Transcripts up-regulated in TKA cartilage were enriched for protein localization and activation, chemical stimulus, immune response, and toll-like receptor signaling pathway. Transcripts up-regulated in APM cartilage were enriched for mesenchymal cell apoptosis, epithelial morphogenesis, canonical glycolysis, extracellular matrix organization, cartilage development, and glucose catabolic process. CONCLUSIONS: This study suggests that APM and TKA cartilage express distinct sets of OA transcripts. The gene profile in cartilage from TKA knees represents an end-stage OA whereas in APM knees it is clearly earlier in the degenerative process.

Molecular influence of anterior cruciate ligament tear remnants on chondrocytes: a biologic connection between injury and osteoarthritis.

OBJECTIVE: Anterior cruciate ligament (ACL) injury initiates a cascade of events often leading to osteoarthritis (OA). ACL reconstruction does not alter the course of OA, suggesting that heightened OA risk is likely due to factors in addition to the joint instability. We showed that torn ACL remnants express periostin (POSTN) in the acute phase of injury. Considering that ACL injury predisposes to OA and that POSTN is associated with cartilage metabolism, we hypothesize that ACL injury affects chondrocytes via POSTN. DESIGN: Cartilage was obtained from osteoarthritic patients and ACL remnants were collected from patients undergoing ACL reconstruction. Crosstalk between ACL remnants and chondrocytes was studied in a transwell co-culture system. Expression of POSTN and other anabolic and catabolic genes was assessed via real-time polymerase chain reaction (PCR). Immunostaining for periostin was performed in human and mouse cartilage. The impact of exogenous periostin and siRNA-mediated ablation of periostin on matrix metabolism and cell migration was examined. Furthermore, the effect of anabolic (transforming growth factor beta 1 [TGF-ß1]) and catabolic (interleukin 1 beta [IL-1ß]) factors on POSTN expression was investigated. RESULTS: ACL remnants induced expression of POSTN, MMP13 and ADAMTS4. Periostin levels were significantly higher in osteoarthritic compared to normal cartilage. Exogenous periostin induced MMP13 expression and cell migration, and repressed COL1A1 expression while POSTN knockdown inhibited expression of both anabolic and catabolic genes and impeded cell migration. TGF-ß1 and IL-1ß treatment did not alter POSTN expression but influenced chondrocyte metabolism as determined by quantification of anabolic and catabolic genes via real-time PCR. CONCLUSIONS: ACL remnants can exert paracrine effects on cartilage, altering cellular homeostasis. Over time, this metabolic imbalance could contribute to OA development.

Transcriptome comparison of meniscus from patients with and without osteoarthritis.

OBJECTIVE: To assess the impact of osteoarthritis (OA) on the meniscus by comparing transcripts and biological processes in the meniscus between patients with and without OA. DESIGN: RNA microarrays were used to identify transcripts differentially expressed (DE) in meniscus obtained from 12 OA and 12 non-OA patients. The non-OA specimens were obtained at the time of arthroscopic partial meniscectomy. Real-time PCR was performed on selected transcripts. Biological processes and gene-networking was examined computationally. Transcriptome signatures were mapped with 37 OA-related transcripts to evaluate how meniscus gene expression relates to that of OA cartilage. RESULTS: We identified 168 transcripts significantly DE between OA (75 elevated, 93 repressed) and non-OA samples (≥1.5-fold). Among these, CSN1S1, COL10A1, WIF1, and SPARCL1 were the most prominent transcripts elevated in OA meniscus, POSTN and VEGFA were most highly repressed in OA meniscus. Transcripts elevated in OA meniscus represented response to external stimuli, cell migration and cell localization while those repressed in OA meniscus represented histone deacetylase activity (related to epigenetics) and skeletal development. Numerous long non-coding RNAs (lncRNAs) were DE between the two groups. When segregated by OA-related transcripts, two distinct clustering patterns appeared: OA meniscus appeared to be more inflammatory while non-OA meniscus exhibited a "repair" phenotype. CONCLUSIONS: Numerous transcripts with potential relevance to the pathogenesis of OA are DE in OA and non-OA meniscus. These data suggest an involvement of epigenetically regulated histone deacetylation in meniscus tears as well as expression of lncRNAs. Patient clustering based on transcripts related to OA in articular cartilage confirmed distinct phenotypes between injured (non-OA) and OA meniscus.

The role for arthroscopic partial meniscectomy in knees with degenerative changes: a systematic review.

AIMS: Patients with osteoarthritis of the knee commonly have degenerative meniscal tears. Arthroscopic meniscectomy is frequently performed, although the benefits are debatable. Recent studies have concluded that there is no role for arthroscopic washout in osteoarthritis of the knee. Our aim was to perform a systematic review to assess the evidence for the efficacy of arthroscopic meniscectomy in patients with meniscal tears and degenerative changes in the knee. PATIENTS AND METHODS: A literature search was performed, using the PubMed/MEDLINE database, for relevant articles published between 1975 and 2015. A total of six studies, including five randomised controlled trials and one cross-sectional study of a prospective cohort, met the inclusion criteria. Relevant information including study design, operations, the characteristics of the patients, outcomes, adverse events and further operations were extracted. RESULTS: The degree of osteoarthritis in the patients who were included and the rate of cross over from one form of treatment to another varied in the studies. Two randomised controlled trials showed a benefit of arthroscopic surgery in patients with limited degenerative joint disease, compared with conservative treatment. One cross-sectional study showed that patients with less severe degenerative changes had better outcomes. CONCLUSION: Patients with symptomatic meniscal tears and degenerative changes in the knee can benefit from arthroscopic meniscectomy, particularly if the osteoarthritis is mild. A trial of conservative management may be effective and should be considered, especially in patients with moderate osteoarthritis. Cite this article: Bone Joint J 2016;98-B:934-8.

Relationship of age and body mass index to the expression of obesity and osteoarthritis-related genes in human meniscus.

OBJECTIVE: Aging and obesity contribute to the initiation and progression of osteoarthritis with little information on their relation to gene expression in joint tissues, particularly the meniscus. Here, we test the hypothesis that patient age and body mass index (BMI) correlate with the expression of osteoarthritis- and obesity-related gene signatures in the meniscus. DESIGN: Meniscus was obtained from patients (N=68) undergoing arthroscopic partial meniscectomy. The mRNA expression of 24 osteoarthritis-related and 4 obesity-related genes in meniscus was assessed by quantitative real-time PCR. The relationship between gene expression and patient age and BMI was analyzed using Spearman's rank-order correlation. Hierarchical cluster dendrogram and heat map were generated to study inter-gene associations. RESULTS: Age was negatively correlated (P<0.05) with the expression of MMP-1 (r=-0.447), NFκB2 (r=-0.361), NFκBIA (r=-0.312), IκBA (r=-0.308), IL-8 (r=-0.305), ADAMTS-4 (r=-0.294), APLN (apelin) (r=-0.250) and IL-6 (r=-0.244). Similarly, BMI was negatively correlated with the expression of APLN (r=-0.328), ACAN (r=-0.268) and MMP-1 (r=-0.261). After adjusting for the correlation between age and BMI (r=0.310; P=0.008), the only independent effect of BMI on gene expression was for APLN (r=-0.272). However, age had an independent effect on the expression on ADAMTS-4 (r=-0.253), MMP-1 (r=-0.399), IL-8 (r=-0.327), COL1A1 (r=-0.287), NFκBIA (r=-0.278), NFκB2 (r=-0.312) and IκBA (r=-0.299). The gene correlation analysis identified four clusters of potentially relevant genes: transcription factors, matrix-degrading enzymes, cytokines and chemokines, and obesity genes. CONCLUSION: Age and BMI were negatively correlated with several osteoarthritis- and obesity-related genes. Although the bulk of these changes appeared to be driven by age, expression of APLN was related to BMI. Inter-gene correlation analysis implicated a common role for strongly correlated genes. Although age-related variations in gene expression appear to be more relevant than obesity-related differences for the role of the meniscus in osteoarthritis development, further investigation into the role of APLN in meniscus and joint health is warranted.

Scientific Evidence Base for Cartilage Injury and Repair in the Athlete.

Soccer players and athletes in high-impact sports are frequently affected by knee injuries. Injuries to the anterior cruciate ligament and menisci are frequently observed in soccer players and may increase the risk of developing an articular cartilage lesion. In high-level athletes, the overall prevalence of knee articular cartilage lesions has been reported to be 36% to 38%. The treatment for athletic patients with articular cartilage lesions is often challenging because of the high demands placed on the repair tissue by impact sports. Cartilage defects in athletes can be treated with microfracture, osteochondral grafting, and autologous chondrocyte implantation. There is increasing scientific evidence for cartilage repair in athletes, with more extensive information available for microfracture and autologous chondrocyte implantation than for osteochondral grafting. The reported rates and times to return to sport at the preinjury level are variable in recreational players, with the best results seen in younger and high-level athletes. Better return to sport is consistently observed for all repair techniques with early cartilage repair. Besides minimizing sensorimotor deficits and addressing accompanying pathologies, the quality of the repair tissue may be a significant factor for the return to sport.

Failures, re-operations, and complications after autologous chondrocyte implantation--a systematic review.

OBJECTIVE: To determine and compare failure, re-operation, and complication rates of all generations and techniques of autologous chondrocyte implantation (ACI). METHODS: A systematic review of multiple medical databases was performed according to PRISMA guidelines. Levels I-IV evidence were included. Generations of ACI and complications after ACI were explicitly defined. All subject and defect demographic data were analyzed. Modified Coleman Methodology Scores (MCMSs) were calculated for all studies. RESULTS: 82 studies were identified for inclusion (5276 subjects were analyzed; 6080 defects). Ninety percent of the studies in this review were rated poor according to the MCMS. There were 305 failures overall (5.8% subjects; mean time to failure 22 months). Failure rate was highest with periosteal ACI (PACI). Failure rates after PACI, collagen-membrane cover ACI (CACI), second generation, and all-arthroscopic, second-generation ACI were 7.7%, 1.5%, 3.3%, and 0.83%, respectively. The failure rate of arthrotomy-based ACI was 6.1% vs 0.83% for all-arthroscopic ACI. Overall rate of re-operation was 33%. Re-operation rate after PACI, CACI, and second-generation ACI was 36%, 40%, and 18%, respectively. However, upon exclusion of planned second-look arthroscopy, re-operation rate was highest after PACI. Unplanned re-operation rates after PACI, CACI, second-generation, and all-arthroscopic second-generation ACI were 27%, 5%, 5%, and 1.4%, respectively. Low numbers of patients undergoing third-generation ACI precluded comparative analysis of this group. CONCLUSIONS: Failure rate after all ACI generations is low (1.5-7.7%). Failure rate is highest with PACI, and lower with CACI and second-generation techniques. One out of three ACI patients underwent a re-operation. Unplanned re-operations are seen most often following PACI. Hypertrophy and delamination is most commonly seen after PACI. Arthrofibrosis is most commonly seen after arthrotomy-based ACI. Use of a collagen-membrane cover, second-generation techniques, and all-arthroscopic, second-generation approaches have reduced the failure, complication, and re-operation rate after ACI.

The core and hip in soccer athletes compared by gender.

Gender differences in hip and core strength and range of motion may contribute to the gender based variance in injury risk. This study was designed to test the primary hypothesis that hip and core strength, flexibility and lower extremity dynamic alignment differ in male and female soccer athletes. Ninety-eight collegiate soccer players (54 male, 44 female) participated in this study. Athletes were evaluated for hip range of motion, and hip and abdominal strength. Both male and female soccer players demonstrated limited hip rotation, with less hip internal rotation in males (p<0.0001), and poor abdominal core control, although the males are stronger (p=0.02). Overall hip ROM is shifted towards internal rotation in females compared to males. Female soccer players also have a significant side-to-side disparity in hip abductor strength (p<0.0001), not present in males. The shift in hip ROM towards internal rotation combined with the hip abductor imbalance may be associated with a position of ACL risk with internally rotated hips and valgus knees in female soccer players. Limitations in hip and core strength and range of motion may play a role in the disparity between the male and female rate of ACL injury.

Impact of first-line vs second-line antibiotics for the treatment of acute uncomplicated sinusitis.

CONTEXT: Studies suggest little benefit in relief of acute sinusitis symptoms from the use of newer and more expensive (second-line) antibiotics instead of older and less expensive (first-line) antibiotics. However, researchers have failed to include development of complications and cost of care in their analyses. OBJECTIVE: To compare the effectiveness and cost of first-line with second-line antibiotics for the treatment of acute uncomplicated sinusitis in adults. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study using a pharmaceutical database containing demographic, clinical (International Classification of Diseases, Ninth Revision), treatment, and charge information for 29 102 adults with a diagnosis of acute sinusitis receiving initial antibiotic treatment between July 1, 1996, and June 30, 1997. MAIN OUTCOME MEASURES: Absence of additional claim for an antibiotic in the 28 days after the initial antibiotic, presence of a claim for a second antibiotic, serious complications of sinusitis, and direct charges and use for the acute sinusitis treatment. RESULTS: There were 17 different antibiotics prescribed in this study. The majority (59.5%) of patients received 1 of the first-line antibiotics. The overall success rate was 90.4% (95% confidence interval [CI], 90.0%-90.8%). The success rate for the 17 329 patients who received a first-line antibiotic was 90.1% and for the 11 773 patients who received a second-line antibiotic was 90.8%, a difference of 0.7% (95% CI, 0.01%-1.40%; P<.05). There were 2 cases of periorbital cellulitis, one in each treatment group. The average total direct charge for patients receiving a first-line antibiotic was $68.98 and a second-line antibiotic was $135.17, a difference of $66.19 (95% CI, $64.95-$67.43; P<.001). This difference was due entirely to the difference in charge of antibiotics and not other charges, such as professional fees, laboratory tests, or emergency department visits. CONCLUSIONS: Patients treated with a first-line antibiotic for acute uncomplicated sinusitis did not have clinically significant differences in outcomes vs those treated with a second-line antibiotic. However, cost of care was significantly higher for patients treated with a second-line antibiotic.