Synovial Fluid Fatty Acid Profiles Are Differently Altered by Inflammatory Joint Pathologies in the Shoulder and Knee Joints

Simple Summary Anomalies of fatty acid metabolism characterize osteoarthritis and rheumatoid arthritis in the knee joint. No previous study has investigated the synovial fluid fatty acid manifestations in these aging-related inflammatory diseases in the shoulder. The present experiment compared the fatty acid alterations between the shoulder and knee joints in trauma controls and in patients with end-stage osteoarthritis or end-stage rheumatoid arthritis. The fatty acid signatures in the synovial fluid of trauma controls were mostly uniform in both anatomical locations. Shoulders with rheumatoid arthritis were characterized by elevated percentages of arachidonic acid and docosahexaenoic acid and with reduced proportions of oleic acid. The fatty acid profiles of knees with osteoarthritis or rheumatoid arthritis were relatively uniform and displayed lower proportions of linoleic acid, docosahexaenoic acid and total n-6 polyunsaturated fatty acids. The results indicate location- and disease-dependent differences in the synovial fluid fatty acid composition. These alterations may affect joint lubrication, synovial inflammation and pannus formation as well as cartilage and bone degradation and contribute to the pathogeneses of inflammatory joint diseases. Anomalies of fatty acid (FA) metabolism characterize osteoarthritis (OA) and rheumatoid arthritis (RA) in the knee joint. No previous study has investigated the synovial fluid (SF) FA manifestations in these aging-related inflammatory diseases in the shoulder. The present experiment compared the FA alterations between the shoulder and knee joints in patients with end-stage OA or end-stage RA. SF samples were collected during glenohumeral or knee joint surgery from trauma controls and from OA and RA patients (n = 42). The FA composition of SF total lipids was analyzed by gas chromatography with flame ionization and mass spectrometric detection and compared across cohorts. The FA signatures of trauma controls were mostly uniform in both anatomical locations. RA shoulders were characterized by elevated percentages of 20:4n-6 and 22:6n-3 and with reduced proportions of 18:1n-9. The FA profiles of OA and RA knees were relatively uniform and displayed lower proportions of 18:2n-6, 22:6n-3 and total n-6 polyunsaturated FAs (PUFAs). The results indicate location- and disease-dependent differences in the SF FA composition. These alterations in FA profiles and their potential implications for the production of PUFA-derived lipid mediators may affect joint lubrication, synovial inflammation and pannus formation as well as cartilage and bone degradation and contribute to the pathogeneses of inflammatory joint diseases.Peer reviewe

Operative versus conservative treatment of small, nontraumatic supraspinatus tears in patients older than 55 years: over 5-year follow-up of a randomized controlled trial

BackgroundNontraumatic rotator cuff tear is a common shoulder problem that can be treated either conservatively or operatively. In the previous publications of the 1- and 2-year results of this trial, we found no significant between-group clinical differences. The aim of this study was to investigate the differences in mid-term clinical and radiologic outcomes in patients older than 55 years.Materials and methodsOne hundred eighty shoulders with symptomatic, nontraumatic supraspinatus tears were randomly assigned to 1 of the 3 cumulatively designed treatment groups: physiotherapy (group 1); acromioplasty and physiotherapy (group 2); and rotator cuff repair, acromioplasty, and physiotherapy (group 3). The change in the Constant score was the primary outcome measure. The secondary outcome measures were the change in the visual analog scale score for pain and patient satisfaction. Radiologic analysis included evaluation of glenohumeral osteoarthritis (OA) and rotator cuff tear arthropathy (CTA).ResultsA total of 150 shoulders (mean age, 71 years) were available for analysis after a mean follow-up period of 6.2 years. The mean sagittal tear size of the supraspinatus tendon tear at baseline was 10 mm in all groups (P = .33). During follow-up, 8 shoulders in group 1 and 2 shoulders in group 2 crossed over to rotator cuff repair. The mean baseline Constant score was 57.1, 58.2, and 58.7 in groups 1, 2, and 3, respectively (P = .85). There were no significant differences (P = .84) in the mean change in the Constant score: 18.5 in group 1, 17.9 in group 2, and 20.0 in group 3. There were no statistically significant differences in the change in the visual analog scale pain score (P = .74) and patient satisfaction (P = .83). At follow-up, there were no statistically significant differences in the mean progression of glenohumeral OA (P = .538) or CTA (P = .485) among the groups. However, the mean progression of glenohumeral OA from baseline to follow-up was statistically significant in the trial population (P = .0045).ConclusionsOn the basis of this study, operative treatment is no better than conservative treatment regarding small, nontraumatic, single-tendon supraspinatus tears in patients older than 55 years. Operative treatment does not protect against degeneration of the glenohumeral joint or CTA. Conservative treatment is a reasonable option for the primary initial treatment of these tears.Level of evidenceLevel IIRandomized Controlled TrialTreatment StudyKeywordsRotator cuff tearconservative treatmentrotator cuff repairConstant scoreVAS pain scorepatient satisfactionradiographic analysisrandomized controlled trial </div

Distinct fatty acid signatures in infrapatellar fat pad and synovial fluid of patients with osteoarthritis versus rheumatoid arthritis

Background: Infrapatellar fat pad (IFP) has recently emerged as a potential source of inflammation in knee arthropathies. It has been proposed to be one source of adipocytokines, fatty acids (FA), and FA-derived lipid mediators that could contribute to the pathophysiological processes in the knee joint. Alterations in synovial fluid (SF) lipid composition have been linked to both osteoarthritis (OA) and rheumatoid arthritis (RA). The aim of the present study was to compare the FA signatures in the IFP and SF of RA and OA patients. Methods: Pairs of IFP and SF samples were collected from the same knees of RA (n=10) and OA patients (n=10) undergoing total joint replacement surgery. Control SF samples (n=6) were harvested during diagnostic or therapeutic arthroscopic knee surgery unrelated to RA or OA. The FA composition in the total lipids of IFP and SF was determined by gas chromatography with flame ionization and mass spectrometric detection. Results: Arthropathies resulted in a significant reduction in the SF proportions of n-6 polyunsaturated FA (PUFA), more pronouncedly in OA than in RA. OA was also characterized with reduced percentages of 22:6n-3 and lower product/precursor ratios of n-3 PUFA. The proportions of total monounsaturated FA increased in both RA and OA SF. Regarding IFP, RA patients had lower proportions of 20:4n-6, total n-6 PUFA, and 22:6n-3, as well as lower product/precursor ratios of n-3 PUFA compared to OA patients. The average chain length of SF FA decreased in both diagnoses and the double bond index in OA. Conclusions: The observed complex alterations in the FA signatures could have both contributed to but also limited the inflammatory processes and cartilage destruction in the RA and OA knees.Peer reviewe

Trends of shoulder instability surgery in Finland: a nationwide register study

Objective Rate of shoulder instability surgery (SIS) has increased in different specific populations. We analysed nationwide trend of SIS in adults in Finland between 1997 and 2014. Design A retrospective register study. Setting National Hospital Discharge Register of Finland. Participants A total of 22 550 adult patients with SIS in Finland (1997-2014). Primary and secondary outcome measures Analysis included appropriate diagnosis (International Classification of Diseases 10) and procedure coding combinations applicable for SIS. The primary outcome variable was the incidence of SIS per 100 000 person-years, and the secondary outcomes were the study year, sex, age groups (18-29, 30-49 and over 50 years of age) and the type of hospital (public or private). Results The overall nationwide rate of SIS in adults increased 177% between 1997 and 2014 in Finland. The rate was the lowest (13/100 000 person-years) in 1997, and the peak rate (40/100 000 person-years) was noted in 2007. The increase in rate was rapid between 1997 and 2007, after which the rate became stable. During the study period, the highest increases were noted in the young adults age group (270%), and especially in the middle-aged group who were operated on in private hospitals (930%). Conclusions The rate of SIS increased almost threefold in Finland from 1997 to 2014. The increase was most significant in young and middle-aged adults (18-50 years), in men, and in private hospitals

Increasing incidence of rotator cuff repairs—A nationwide registry study in Finland

Background Rotator cuff repair incidence rates have reportedly increased in the United States and England. Here we analyzed nationwide data relating to rotator cuff repairs recorded in the Finnish National Hospital Discharge Register (NHDR). Methods The NHDR was reviewed to identify adult patients who underwent rotator cuff repair between 1998 and 2011. Incidence rates per 10 5 person-years were calculated using the annual adult population size. Results During the 14-year time period, 50,646 rotator cuff repairs were performed on subjects aged 18 years or older. The incidence of rotator cuff repair showed an almost linear increase of 204 %, from 44 per 10 5 person-years in 1998 to 131 per 10 5 person-years in 2011. The most common concomitant procedure was acromioplasty, which was performed in approximately 40 % of rotator cuff repairs in 2011. Other common concomitant procedures included tenodesis (7 %) and tenotomy (6 %) of the long head of the biceps tendon, and resection of the acromioclavicular joint (3 %). Conclusions This nationwide analysis revealed a remarkable increase in the incidence of rotator cuff repair from 1998 to 2011 in Finland. This progress can be questioned, since there are not convincing data of the superiority of the operative treatment over non-operative management in all rotator cuff tears.BioMed Central open acces

Rappeumaperäisen kierukkarepeämän artroskooppinen osaresektio - lumekirurgiakontrolloidun tutkimuksen 5-vuotistulokset

English abstrac

Arthroscopic Bankart versus open Latarjet as a primary operative treatment for traumatic anteroinferior instability in young males : a randomised controlled trial with 2-year follow-up

Objectives To compare the success rates of arthroscopic Bankart and open Latarjet procedure in the treatment of traumatic shoulder instability in young males. Design Multicentre randomised controlled trial. Setting Orthopaedic departments in eight public hospitals in Finland. Participants 122 young males, mean age 21 years (range 16-25 years) with traumatic shoulder anteroinferior instability were randomised. Interventions Arthroscopic Bankart (group B) or open Latarjet (group L) procedure. Main outcome measures The primary outcome measure was the reported recurrence of instability, that is, dislocation at 2-year follow-up. The secondary outcome measures included clinical apprehension, sports activity level, the Western Ontario Shoulder Instability Index, the pain Visual Analogue Scale, the Oxford Shoulder Instability Score, the Constant Score and the Subjective Shoulder Value scores and the progression of osteoarthritic changes in plain films and MRI. Results 91 patients were available for analyses at 2-year follow-up (drop-out rate 25%). There were 10 (21%) patients with redislocations in group B and 1 (2%) in group L, p=0.006. One (9%) patient in group B and five (56%) patients in group L returned to their previous top level of competitive sports (p=0.004) at follow-up. There was no statistically significant between group differences in any of the other secondary outcome measures. Conclusions Arthroscopic Bankart operation carries a significant risk for short-term postoperative redislocations compared with open Latarjet operation, in the treatment of traumatic anteroinferior instability in young males. Patients should be counselled accordingly before deciding the surgical treatment.Peer reviewe

Arthroscopic partial meniscectomy for a degenerative meniscus tear : a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial

Objectives To assess the long-term effects of arthroscopic partial meniscectomy (APM) on the development of radiographic knee osteoarthritis, and on knee symptoms and function, at 5 years follow-up. Design Multicentre, randomised, participant- and outcome assessor-blinded, placebo-surgery controlled trial. Setting Orthopaedic departments in five public hospitals in Finland. Participants 146 adults, mean age 52 years (range 35-65 years), with knee symptoms consistent with degenerative medial meniscus tear verified by MRI scan and arthroscopically, and no clinical signs of knee osteoarthritis were randomised. Interventions APM or placebo surgery (diagnostic knee arthroscopy). Main outcome measures We used two indices of radiographic knee osteoarthritis (increase in Kellgren and Lawrence grade >= 1, and increase in Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing and osteophyte sum score, respectively), and three validated patient-relevant measures of knee symptoms and function ( Western Ontario Meniscal Evaluation Tool (WOMET), Lysholm, and knee pain after exercise using a numerical rating scale). Results There was a consistent, slightly greater risk for progression of radiographic knee osteoarthritis in the APM group as compared with the placebo surgery group (adjusted absolute risk difference in increase in Kellgren-Lawrence grade >= 1 of 13%, 95% CI -2% to 28%; adjusted absolute mean difference in OARSI sum score 0.7, 95% CI 0.1 to 1.3). There were no relevant between-group differences in the three patient-reported outcomes: adjusted absolute mean differences (APM vs placebo surgery), -1.7 (95% CI -7.7 to 4.3) in WOMET, -2.1 (95% CI -6.8 to 2.6) in Lysholm knee score, and -0.04 (95% CI -0.81 to 0.72) in knee pain after exercise, respectively. The corresponding adjusted absolute risk difference in the presence of mechanical symptoms was 18% (95% CI 5% to 31%); there were more symptoms reported in the APM group. All other secondary outcomes comparisons were similar. Conclusions APM was associated with a slightly increased risk of developing radiographic knee osteoarthritis and no concomitant benefit in patient-relevant outcomes, at 5 years after surgery.Peer reviewe

Near-Infrared Spectroscopy Enables Arthroscopic Histologic Grading of Human Knee Articular Cartilage

Purpose: To develop the means to estimate cartilage histologic grades and proteoglycan content in ex vivo arthroscopy using near-infrared spectroscopy (NIRS). Methods: In this experimental study, arthroscopic NIR spectral measurements were performed on both knees of 9 human cadavers, followed by osteochondral block extraction and in vitro measurements: reacquisition of spectra and reference measurements (proteoglycan content, and three histologic scores). A hybrid model, combining principal component analysis and linear mixed-effects model (PCA-LME), was trained for each reference to investigate its relationship with in vitro NIR spectra. The performance of the PCA-LME model was validated with ex vivo spectra before and after the exclusion of outlying spectra. Model performance was evaluated based on Spearman rank correlation (ρ) and root-mean-square error (RMSE). Results: The PCA-LME models performed well (independent test: average ρ = 0.668, RMSE = 0.892, P < .001) in the prediction of the reference measurements based on in vitro data. The performance on ex vivo arthroscopic data was poorer but improved substantially after outlier exclusion (independent test: average ρ = 0.462 to 0.614, RMSE = 1.078 to 0.950, P = .019 to .008). Conclusions: NIRS is capable of nondestructive evaluation of cartilage integrity (i.e., histologic scores and proteoglycan content) under similar conditions as in clinical arthroscopy. Clinical Relevance: There are clear clinical benefits to the accurate assessment of cartilage lesions in arthroscopy. Visual grading is the current standard of care. However, optical techniques, such as NIRS, may provide a more objective assessment of cartilage damage.publishedVersionPeer reviewe