Aspiration and injection therapies for joints

Therapeutic Controlled Release Strategies for Human Osteoarthritis

Osteoarthritis is a progressive, irreversible debilitating whole joint disease that affects millions of people worldwide. Despite the availability of various options (non-pharmacological and pharmacological treatments and therapy, orthobiologics, and surgical interventions), none of them can definitively cure osteoarthritis in patients. Strategies based on the controlled release of therapeutic compounds via biocompatible materials may provide powerful tools to enhance the spatiotemporal delivery, expression, and activities of the candidate agents as a means to durably manage the pathological progression of osteoarthritis in the affected joints upon convenient intra-articular (injectable) delivery while reducing their clearance, dissemination, or side effects. The goal of this review is to describe the current knowledge and advancements of controlled release to treat osteoarthritis, from basic principles to applications in vivo using therapeutic recombinant molecules and drugs and more innovatively gene sequences, providing a degree of confidence to manage the disease in patients in a close future.

Recent advances in polymeric microparticle-based drug delivery systems for knee osteoarthritis treatment

Due to the poor bioavailability and high joint clearance of drugs, sustained delivery of therapeutic agents has proven difficult in the treatment of osteoarthritis (OA). Intra-articular (IA) drug delivery strategy is an attractive option for enhancing OA patients' prognosis, for which various polymer materials have been used as drug carriers due to their attractive delivery properties, to slow or even reverse the progress of OA by prolonging the duration of therapeutic agent residence in the joint. This article focuses on the recent developments in natural and synthetic polymer-based microsphere drug delivery systems for treating knee osteoarthritis. It evaluates the translational potential of some novel formulations for clinical application.

Knee Osteoarthritis Therapy: Recent Advances in Intra-Articular Drug Delivery Systems

Drug delivery for osteoarthritis (OA) treatment is a continuous challenge because of their poor bioavailability and rapid clearance in joints. Intra-articular (IA) drug delivery is a common strategy and its therapeutic effects depend mainly on the efficacy of the drug-delivery system used for OA therapy. Different types of IA drug-delivery systems, such as microspheres, nanoparticles, and hydrogels, have been rapidly developed over the past decade to improve their therapeutic effects. With the continuous advancement in OA mechanism research, new drugs targeting specific cell/signaling pathways in OA are rapidly evolving and effective drug delivery is critical for treating OA. In this review, recent advances in various IA drug-delivery systems for OA treatment, OA targeted strategies, and related signaling pathways in OA treatment are summarized and analyzed based on current publications.

Acoustic Emissions as a Non-invasive Biomarker of the Structural Health of the Knee

The longitudinal assessment of joint health is a long-standing issue in the management of musculoskeletal injuries. The acoustic emissions (AEs) produced by joint articulation could serve as a biomarker for joint health assessment, but their use has been limited by a lack of mechanistic understanding of their creation. In this paper, we investigate that mechanism using an injury model in human lower-limb cadavers, and relate AEs to joint kinematics. Using our custom joint sound recording system, we recorded the AEs from nine cadaver legs in four stages: at baseline, after a sham surgery, after a meniscus tear, and post-meniscectomy. We compare the resulting AEs using their b-values. We then compare joint anatomy/kinematics to the AEs using the X-ray reconstruction of moving morphology (XROMM) technique. After the meniscus tear the number and amplitude of the AE peaks greatly increased from baseline and sham (b-value = 1.33 ± 0.15; p < 0.05). The XROMM analysis showed a close correlation between the minimal inter-joint distances (0.251 ± 0.082 cm during extension, 0.265 ± .003 during flexion, at 145°) and a large increase in the AEs. This work provides key insight into the nature of joint AEs, and details a novel technique and analysis for recording and interpreting these biosignals.

Intra-articular targeting of nanomaterials for the treatment of osteoarthritis

Osteoarthritis is a prevalent and debilitating disease that involves pathological contributions from numerous joint tissues and cells. The joint is a challenging arena for drug delivery, since the joint has poor bioavailability for systemically administered drugs and experiences rapid clearance of therapeutics after intra-articular injection. Moreover, each tissue within the joint presents unique barriers to drug localization. In this review, the various applications of nanotechnology to overcome these drug delivery limitations are investigated. Nanomaterials have reliably shown improvements to retention profiles of drugs within the joint space relative to injected free drugs. Additionally, nanomaterials have been modified through active and passive targeting strategies to facilitate interactions with and localization within specific joint tissues such as cartilage and synovium. Last, the limitations of drawing cross-study comparisons, the implications of synovial fluid, and the potential importance of multi-modal therapeutic strategies are discussed. As emerging, cell-specific disease modifying osteoarthritis drugs continue to be developed, the need for targeted nanomaterial delivery will likely become critical for effective clinical translation of therapeutics for osteoarthritis. STATEMENT OF SIGNIFICANCE: Improving drug delivery to the joint is a pressing clinical need. Over 27 million Americans live with osteoarthritis, and this figure is continuously expanding. Numerous drugs have been investigated but have failed in clinical trials, likely related to poor bioavailability to target cells. This article comprehensively reviews the advances in nano-scale delivery vehicles designed to overcome the delivery barriers in the joint. This is the first review to analyze active and passive targeting strategies systematically for different target sites while also delineating between tissue homing and whole joint retention. By bringing together the lessons learned across numerous nano-scale platforms, researchers may be able to hone future nanomaterial designs, allowing emerging therapeutics to perform with clinically relevant efficacy and disease modifying potential.

Corticosteroids and Hyaluronic Acid Injections

Osteoarthritis is a common condition that affects many individuals resulting in pain, reduced mobility, and decreased function. Corticosteroids have been a mainstay of osteoarthritis treatment. Studies have shown that they provide short-term pain improvement and can be used for osteoarthritis flares. Hyaluronic acid injections have extensively been studied in knee osteoarthritis but to a lesser degree in other joints. Despite some debate between societies, a large number of recent studies have shown hyaluronic acid to be a viable treatment option showing longer-term improvement in both pain and function.

Treatment of knee osteoarthritis: platelet-derived growth factors vs. hyaluronic acid. A randomized controlled trial

OBJECTIVE

Aim of this trial was to compare efficacy of activated platelet-rich plasma against hyaluronic acid as intra-articular injections to people with osteoarthritis of the knee.

DESIGN

Phase-2 randomized controlled trial, with blind patients and outcome assessors.

SETTING

Outpatient rehabilitation service; years 2011-2013.

SUBJECTS

Patients with knee osteoarthritis grades 2-3 at magnetic resonance imaging (MRI) were included after consent and randomized. Target sample size was 25 patients per group.

INTERVENTIONS

Patients received three activated platelet-rich plasma (intervention group) or hyaluronic acid (controls) intra-articular injections at 4-week intervals.

MAIN MEASURES

Main outcome measure was proportion of patients with >1 grade improvement at six months from last injection, as assessed by a radiologist blind to study group. Patients were evaluated over time clinically and with functional scales (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm, Tegner, American Knee Society Score (AKSS), Lequesne, visual analogue scale (VAS) for pain).

RESULTS

Overall, 30 patients were randomized to intervention and 28 to control group. For primary outcome, 28 patients (29 knees) in the intervention and 22 (25 knees) in the control group were available. Patients with at least 1 grade improvement at repeat MRI were 14 (48.3%) in the intervention and 2 (8%) in the control group ( P < 0.003). Improvement in symptoms and functional scales was consistently higher in the intervention group. No side-effects were observed in either group.

CONCLUSION

Activated platelet-rich plasma reduces articular damage as evident at MRI, as soon as six months after treatment; it reduces pain and improves patient's function and overall quality of life.

Precise control of drug loading and release of an NSAID–polymer conjugate for long term osteoarthritis intra-articular drug delivery

The synthesis of biocompatible polymer diclofenac conjugates (PDCs) that have a high drug loading and high degree of control over diclofenac (DCF) release is described.

Steroids, lidocain and ioxaglic acid modify the viscosity of hyaluronic acid: in vitro study and clinical implications

Background

Viscosupplementaion by intra-articular injection of hyaluronic acid (HA) is a therapeutic modality for treating osteoarthritis of the knee, of the hip and less frequently of other joints. During viscosupplementation, it is usual to inject other drugs, without knowing whether this association may have a deleterious effect thereon. The rheological properties of a viscosupplement are highly dependent on the product [molecular weight × concentration] of HA. Therefore, any reduction of its viscoelastic properties is related either to a decrease of its concentration or/and of its molecular weight. The presence of other molecules can create favorable or unfavorable molecular interactions with HA. The objective of the study was to investigate the effect of products, that are commonly associated with HA (corticosteroids, lidocain, iodinated contrast media), on the rheological behavior of HA, then to try drawing practical conclusions.

Methods

The rheological behavior of both a linear and a cross-linked HA, was studied before and after mixing with different volumes (ratio 1:0.5–1:4) of the following compounds: phosphate buffered saline (PBS, as a control), cortivazol, triamcinolone hexacetonide, lidocain chlorhydrate and meglumine ioxaglate. The flow curve of the different samples was obtained using a measuring method based on a constant shear rate.

Results

Whatever the dilution and the added molecule were, viscosity of the cross-linked viscosupplement remained much higher than that of the linear one. Addition of PBS at a ratio 1:1 caused a dramatic decrease (up to 97.5 %) of HA viscosity. Cortivazol and lidocain had a similar effect than PBS on linear HA. Both were much deleterious on cross-linked HA viscosity. Among corticosteroids, triamcinolone decreased much less HA viscosity than cortivazol. The effect of meglumine ioxaglate was dose-dependent. Up to a ratio 1:1 viscosity of the linear HA remained above the dilution effect. On the cross-linked HA, the deleterious effect of the contrast agent was evident as soon as a ratio 1:1 and became very marked at 1:2.

Conclusion

HA viscosity varies widely in presence of other molecules. These changes are due to both dilution and molecular interactions. This study suggests that addition of other molecules with HA can lead to a major decrease of its viscosity. However, provided to respect a maximum ratio of 1:1, the contrast medium and triamcinolone seem to have no major deleterious effect on the viscosity level, especially on crosslinked HA. The study also suggests a deleterious effect of lidocain on the cross-linked HA. These in vitro data suggest that drugs associations must be avoided when they are not essential. However, clinical trials are needed to determine whether these rheological changes may have a significant impact on the clinical outcome.

AMSSM Scientific Statement Concerning Viscosupplementation Injections for Knee Osteoarthritis: Importance for Individual Patient Outcomes

OBJECTIVE

Osteoarthritis (OA) is a disabling disease that produces severe morbidity reducing physical activity. Our position statement on treatment of knee OA with viscosupplementation injection [hyaluronic acid (HA)] versus steroid [intra-articular corticosteroid (IAS)] and placebo [intra-articular placebo (IAP)] is based on the evaluation of treatment effect by examining the number of subjects within a treatment arm that met the Outcome Measures in Rheumatoid Arthritis Clinical Trials-Osteoarthritis Research Society International (OMERACT-OARSI) criteria, which is different and more relevant than methods used in other reviews which examined if the average change across the treatment groups was clinically different.

DATA SOURCES

We performed a systematic literature search for all relevant articles from 1960 to August 2014 in the MEDLINE, EMBASE, and Cochrane CENTRAL. We performed a network meta-analysis (NMA) of the relevant literature to determine if there is a benefit from HA as compared with IAS and IAP.

MAIN RESULTS

Eleven articles met the inclusion criteria from the search strategy. On NMA, those subjects receiving HA were 15% and 11% more likely to respond to treatment by the OMERACT-OARSI criteria than those receiving IAS or IAP, respectively (P < 0.05 for both).

CONCLUSIONS

In light of the aforementioned results of our NMA, the American Medical Society for Sport Medicine recommends the use of HA for the appropriate patients with knee OA.

Sonographically guided posteromedial approach for intra-articular knee injections: a safe, accurate, and efficient method

Osteoarthritis of the knee can be a debilitating and extremely painful condition. In patients who desire to postpone knee arthroplasty or in those who are not surgical candidates, percutaneous knee injection therapies have the potential to reduce pain and swelling, maintain joint mobility, and minimize disability. Published studies cite poor accuracy of intra-articular knee joint injections without imaging guidance. We present a sonographically guided posteromedial approach to intra-articular knee joint injections with 100% accuracy and no complications in a consecutive series of 67 patients undergoing subsequent computed tomographic or magnetic resonance arthrography. Although many other standard approaches are available, a posteromedial intra-articular technique is particularly useful in patients with a large body habitus and theoretically allows for simultaneous aspiration of Baker cysts with a single sterile preparation and without changing the patient's position. The posteromedial technique described in this paper is not compared or deemed superior to other standard approaches but, rather, is presented as a potentially safe and efficient alternative.

Where and how to inject the knee--a systematic review

Objectives

The knee can be injected at different anatomic sites with or without image-guidance. We undertook a systematic review to determine the accuracy of intra-articular knee injection (IAKI) and whether this varied by site, use of image-guidance, and experience of injectors, and whether accuracy of injection, site, or use of image-guidance influenced outcomes following IAKIs.

Methods

Medline, Embase, AMED, CINAHL, Web of Knowledge, Cochrane Central Registers for Controlled Trials up to Dec 2012 were searched for studies that evaluated either accuracy of IAKIs or outcomes related to accuracy, knee injection sites, or use of image-guidance. Within-study and between-study analyses were performed.

Results

Data from 23 publications were included. Within-study analyses suggested IAKIs at the superomedial patellar, medial midpatellar (MMP), superolateral patellar (SLP) and lateral suprapatellar bursae sites were more accurate when using image-guidance than when blinded (ranges of pooled risk difference 0.09–0.19). Pooling data across studies suggested blinded IAKIs at the SLP site were most accurate (87%) while MMP (64%) and anterolateral joint line (ALJL) sites were (70%) least accurate. Overall about one in five blinded IAKIs were inaccurate. There was some evidence that experience of the injector was linked with improved accuracy for blinded though not image-guided injections. Based on a small number of studies, short but not longer-term outcomes for ultrasound-guided were found to be superior to blinded IAKIs.

Conclusions

Image-guided IAKIs are modestly more accurate than blinded IAKIs especially at the MMP and ALJL sites. Blinded injections at SLP site had good accuracy especially if performed by experienced injectors. Further studies are required to address the question whether accurate localization is linked with an improved response.

Ultrasound-guided procedures around the wrist and hand: how to do

Ultrasound has emerged as a low-cost, radiation-free and effective imaging technique to detect joint abnormalities and to guide percutaneous procedures. Being superficial, wrist and hand tendons and joints represent a good target to perform such procedures using ultrasound guidance. This kind of approach allows for a clear and real-time visualization of the needles during their whole path. In this setting, the knowledge of technical aspects and tips is essential to act in the most accurate way on target tissues that can be as small as a few millimetres. The aim of this review is to summarize the local treatments of inflammatory and degenerative disease described in literature (such as treatment of De Quervain's tenosynovitis, trigger finger, trapezio-metacarpal joint osteoarthritis, etc.), emphasizing precautions and tricks based on day-by-day experience that may help to improve the outcome of percutaneous ultrasound-guided procedures around the wrist and hand.

Crystal suspensions of poorly soluble peptides for intra-articular application: a novel approach for biorelevant assessment of their in vitro release

Crystal suspensions of 3 poorly soluble peptides (MSC1, 2 and 3), intended for intra-articular administration were prepared and in vitro release was tested by a modified USP IV apparatus, combined with a dialysis system. Half-lives of release profiles were ∼5 days for MSC1 and ∼0.5 days for MSC2 and MSC3, showing the potential to achieve sustained exposure from crystal suspensions after intra-articular administration. The in vitro release setup discriminated between (i) different formulations, (ii) different concentrations of API and (iii) different APIs. In addition it was shown that this method allows the modification of release conditions in order to gain more biorelevance for in vitro release testing in the field of intra-articular application: the influence of synovial fluid components hyaluronic acid and albumin was demonstrated, showing prolonged half-lives for suspensions containing 2.5% bovine serum albumin (5 days) and accelerated release rates for suspensions containing 1% sodium hyaluronate (2.5 days) in comparison to a suspension in phosphate buffered saline (4 days). Furthermore, it was demonstrated that release rates of a suspension containing an artificial synovial fluid were in accordance with suspensions containing bovine synovial fluid (t1/2∼4 days).

Management strategies for osteoarthritis, ankylosing spondylitis, and gouty arthritis

Rheumatic diseases are among the most frequent causes of pain and disability. Effective management of rheumatic diseases including osteoarthritis (OA), ankylosing spondylitis (AS), and gouty arthritis requires an understanding of the underlying disease mechanisms.Symptoms of OA result from both mechanical factors and elements of inflammation. Current management strategies target both of these factors and generally consist of nonpharmacologic and pharmacologic interventions, including use of nonspecific nonsteroidal antiinflammatory drugs (NSAIDs) and cyclooxygenase-2-specific inhibitors (coxibs), which have analgesic and antiinflammatory properties. Other approaches include intraarticular hyaluronate and the use of alternative therapies under investigation such as acupuncture or glucosamine.Disease mechanisms in AS involve enthesitis, an inflammation at the site of insertion of ligaments, tendons, or joint capsules to bone. Posture and exercise are important nonpharmacologic strategies that may be made easier with the use of NSAIDs or coxibs. Recently developed therapies, including tumor necrosis factor inhibitors, target the underlying disease mechanisms and have demonstrated dramatic symptomatic effects. Disease-modifying effects still need to be established.In gout, hyperuricemia leads to crystal-induced inflammation in some patients. Etoricoxib, one of the newer coxibs, has shown promise in treating acute gout, with efficacy similar to indomethacin, the current standard NSAID often used in these patients. Oral or intraarticular steroids can also be considered. For chronic care uricosurics can be beneficial if renal function is normal and excretion is not excessive, but allopurinol is used most often. Nonpharmacologic modalities, such as rest and cold applications, are useful for acute episodes, and lifestyle modification in the form of diet can also play a role in chronic disease management.

Distribution of effusion in knee arthritis as measured by high-resolution ultrasound

Information about the distribution of effusion within the arthritic knee joint should be considered in selecting an anatomical approach for arthrocentesis. We recorded ultrasound measurements of fluid distribution in the knees of patients attending our clinic for knee injections under ultrasound guidance. In a cross-sectional observational study, we used high-resolution ultrasound (US) to record measurements of maximum fluid depth in the medial, midline and lateral regions of the suprapatellar pouch (SPP) in 46 patients with arthritis attending for routine US-guided injection of the knee. Mean fluid depth [in millimetres, (SD)] was significantly greater in the lateral SPP [9.2 (5.1)] than in the medial [6.5 (4.6)] or the midline [5.9 (3.7)] regions with the knee in relaxed full extension (p < 0.001 for comparison of lateral SPP with both midline and medial SPP). Small effusions were more commonly detected in the lateral SPP than elsewhere. In patients with painful knee arthritis, fluid distributes maximally to the lateral SPP in the extended knee. This has implications regarding the anatomical approach to arthrocentesis that clinicians should choose to perform and teach.

Lidocaine cytotoxicity to the bovine articular chondrocytes in vitro: changes in cell viability and proteoglycan metabolism

PURPOSE

A lot of studies on the effect of intra-articular injections are clinical, but many questions on the effect of lidocaine to articular chondrocytes remain unanswered. This study was performed to determine the effects of varying concentrations and exposure times of lidocaine on the viability and proteoglycan metabolism of chondrocytes in vitro.

METHOD

Cartilage was obtained from metatarsal joints of adult bovines. Chondrocytes in alginate beads were cultured in medium containing 6% fetal calf serum at 370 mOsmol at cell densities of 4 million cells/ml. They were then cultured for 24 h under 21% oxygen with 0.125, 0.25, 0.5, and 1% lidocaine and without lidocaine as control. The cell viability profile across intact beads was determined by manual counting using fluorescent probes and transmission electron microscopy.

RESULT

Lactate production was measured enzymatically as a marker of energy metabolism. Glycosaminoglycan (GAG) accumulation was measured using a modified dimethylmethylene blue assay. Cell viability decreased in a time- and dose-dependent manner in the concentration range of 0.125-1.0% lidocaine under the confocal microscope. Under the electron microscope, apoptosis increased as the concentration of lidocaine increased. GAG accumulation/tissue volume decreases as the concentration of lidocaine increased. However, GAG produced per million cells and the rate of lactate production per live cell were significantly higher for cells cultured at 0.5 and 1% lidocaine than the control group. Bovine chondrocytes cultured in alginate beads under high oxygen pressure are negatively influenced by increasing concentrations of lidocaine.

CONCLUSION

Cell viability and proteoglycan production (GAG accumulation/tissue volume) decreased as the concentration of lidocaine increased. These data suggest caution in prolonged exposure of cartilage to high concentration lidocaine. Repeated joint injection of lidocaine potentially worsens osteoarthrosis by accelerating cartilage degradation.

Efficacy of ultrasonography-guided shoulder MR arthrography using a posterior approach

AIM

Shoulder MR arthrography has an important role in the assessment of rotator cuff lesions, labral tears, glenohumeral ligaments, rotator interval lesions, and postoperative shoulder status. Injection in direct MR arthrography can be performed with palpation, fluoroscopy, ultrasonography (US), or MRI. Recently, the posterior approach is the preferred method due to the presence of fewer stabilizers, absence of important articular structures and less extravasation, has been advocated. Our aim was to assess the efficacy of US-guided MR arthrography via a posterior approach on the glenohumeral joint.

MATERIALS AND METHODS

Thirty MR arthrographies were performed on 29 patients. Ultrasonography (Xario, Toshiba) examinations were conducted by a wide-band 5-12 Mhz linear array transducer set to muscle-skeleton. Diluted contrast medium (1 ml gadolinium chelate and 100 ml saline, approximately 15 ml) was delivered into the glenohumeral joint space from between the humeral head and posterior labrum with a 20-gauge spinal needle. MRI examination was conducted by a 1.5 T scanner. Fat-saturated T1-weighted spin echo was applied on coronal, axial, and sagittal planes within the first 30 min after contrast material injection.

RESULTS

One (3.3%) arthrography was not successful due to technical reasons associated with obesity. Contrast extravasation around the infraspinatus and teres minör muscles was depicted in twelve examinations. One (3.3%) patient developed vasovagal collapse.

CONCLUSION

Ultrasonography-guided posterior approach is an easy, reliable, fast, and comfortable method in experienced hands. It may be an alternative for fluoroscopy-guided shoulder MR arthrography.

Are joint and soft tissue injections painful? Results of a national French cross-sectional study of procedural pain in rheumatological practice

BACKGROUND

Joint, spinal and soft tissue injections are commonly performed by rheumatologists in their daily practice. Contrary to other procedures, e.g. performed in pediatric care, little is known about the frequency, the intensity and the management of procedural pain observed in osteo-articular injections in daily practice.

METHODS

This observational, prospective, national study was carried out among a French national representative database of primary rheumatologists to evaluate the prevalence and intensity of pain caused by intra-and peri-articular injections, synovial fluid aspirations, soft tissue injections, and spinal injections. For each physician, data were collected over 1 month, for up to 40 consecutive patients (>18-years-old) for whom a synovial fluid aspiration, an intra or peri-articular injection or a spinal injection were carried out during consultations. Statistical analysis was carried out in order to compare patients who had suffered from pain whilst undergoing the procedure to those who had not. Explanatory analyses were conducted by stepwise logistic regression with the characteristics of the patients to explain the existence of pain.

RESULTS

Data were analysed for 8446 patients (64% female, mean age 62 +/- 14 years) recruited by 240 physicians. The predominant sites injected were the knee (45.5%) and spine (19.1%). Over 80% of patients experienced procedural pain which was most common in the small joints (42%) and spine (32%) Pain was severe in 5.3% of patients, moderate in 26.6%, mild in 49.8%, and absent in 18.3%. Pain was significantly more intense in patients with severe pain linked to their underlying pathology and for procedures performed in small joints.Preventative or post-procedure analgesia was rarely given, only to 5.7% and 36.3% of patients, respectively. Preventative analgesia was more frequently prescribed in patients with more severe procedural pain.

CONCLUSION

Most patients undergoing intra-or peri-articular injections, synovial fluid aspirations and spine injections suffer from procedural pain. Most patients experience usually mild procedural pain and procedural pain management is uncommonly provided by physicians. Specific research and guidelines for the management of procedural pain related to rheumatologic care should be established to improve the quality of care provided by physicians.

Pilot investigation of hyaluronate injections for first metacarpal-carpal (MC-C) osteoarthritis

Hyaluronate intraarticular injections are widely used for treatment of pain associated with osteoarthritis of the knee, but there is no published literature on its use in osteoarthritis of the hand. We describe an open-label, baseline-controlled pilot study in which 5 weekly injections of 10 mg sodium hyaluronate (molecular weight 500-730 kDa) in 1 mL was used to treat 16 patients with osteoarthritic first metacarpal-carpal (MC-C) joints. The injections were performed easily and were well tolerated. Mean pain score at 5 months after the last injection, on a 10-point visual analog scale, decreased from 4.74 to 2.56 at rest. Pain on use decreased from 5.91 to 4.33. Pinch strength and a short questionnaire on hand function did not significantly change. The results of this small pilot study suggest that intraarticular injections into the first MC-C joint are easily administered, well tolerated, and could be an effective treatment option for patients with osteoarthritis of this joint. Further investigation using larger, blind controlled clinical studies are warranted.

Intra-articular injections

Intra-articular injections are one method that physicians may use to treat joint pain. This method offers direct access to the source of pain for the troubled patient. Substances ranging from steroids to hyaluronic acid have been injected successfully into the various joints of the body in an attempt to provide relief for chronic joint pain. Anesthesiologists and orthopedic surgeons have begun to use intra-articular injections of local anesthetics for postoperative analgesia. The history, agents, and methods of intra-articular injections are reviewed.

Viscosupplementation with hyaluronans for osteoarthritis of the knee: clinical efficacy and economic implications

Treatment with intra-articular viscosupplementation with hyaluronan (hyaluronic acid) and its derivatives is an important component of the management of osteoarthritis (OA) of the knee. Several intra-articular hyaluronan formulations are now available that vary in their physical properties, duration of effect and treatment schedules. Although aspects regarding their mechanism of action are not completely understood, numerous clinical trials, systematic reviews and meta-analyses have confirmed the efficacy of intra-articular hyaluronan therapies for relieving OA-related pain and improving joint function. Data indicate that intra-articular hyaluronan preparations provide OA pain relief that is comparable to or greater than that observed with conventional treatment, NSAID medications, intra-articular corticosteroids, arthroscopic lavage, physical therapy and exercise. Other studies indicate that multiple courses of hyaluronan are effective. Intra-articular hyaluronan formulations are well tolerated and are associated with a low incidence of adverse effects, usually localised to the injected joint. Local adverse events associated with intra-articular hyaluronan products are typically mild to moderate in severity, benign and transient, although their aetiology is unknown. The cost effectiveness of intra-articular hyaluronan has been demonstrated, but only in a limited number of studies. Cost savings with intra-articular hyaluronan can also be realised with reduction of NSAID medication use and the possibility of delaying total knee replacement, which can reduce the need for costly revision procedures. Because different intra-articular hyaluronan formulations require different numbers of injections and office visits, are associated with variable treatment costs, and provide varying degrees of efficacy, not all intra-articular hyaluronan formulations may be equally cost effective over time.

Variations in corticosteroid/anesthetic injections for painful shoulder conditions: comparisons among orthopaedic surgeons, rheumatologists, and physical medicine and primary-care physicians

Background

Variations in corticosteroid/anesthetic doses for injecting shoulder conditions were examined among orthopaedic surgeons, rheumatologists, and primary-care sports medicine (PCSMs) and physical medicine and rehabilitation (PMRs) physicians to provide data needed for documenting inter-group differences for establishing uniform injection guidelines.

Methods

264 surveys, sent to these physicians in our tri-state area of the western United States, addressed corticosteroid/anesthetic doses and types used for subacromial impingement, degenerative glenohumeral and acromioclavicular arthritis, biceps tendinitis, and peri-scapular trigger points. They were asked about preferences regarding: 1) fluorinated vs. non-fluorinated corticosteroids, 2) acetate vs. phosphate types, 3) patient age, and 4) adjustments for special considerations including young athletes and diabetics.

Results

169 (64% response rate, RR) surveys were returned: 105/163 orthopaedic surgeons (64%RR), 44/77 PCSMs/PMRs (57%RR), 20/24 rheumatologists (83%RR). Although corticosteroid doses do not differ significantly between specialties (p > 0.3), anesthetic volumes show broad variations, with surgeons using larger volumes. Although 29% of PCSMs/PMRs, 44% rheumatologists, and 41% surgeons exceed "recommended" doses for the acromioclavicular joint, >98% were within recommendations for the subacromial bursa and glenohumeral joint. Depo-Medrol^® (methylprednisolone acetate) and Kenalog^® (triamcinolone acetonide) are most commonly used. More rheumatologists (80%) were aware that there are acetate and phosphate types of corticosteroids as compared to PCSMs/PMRs (76%) and orthopaedists (60%). However, relatively fewer rheumatologists (25%) than PCSMs/PMRs (32%) or orthopaedists (32%) knew that phosphate types are more soluble. Fluorinated corticosteroids, which can be deleterious to soft tissues, were used with these frequencies for the biceps sheath: 17% rheumatologists, 8% PCSMs/PMRs, 37% orthopaedists. Nearly 85% use the same non-fluorinated corticosteroid for all injections; <10% make adjustments for diabetic patients.

Conclusion

Variations between specialists in anesthetic doses suggest that surgeons (who use significantly larger volumes) emphasize determining the percentage of pain attributable to the injected region. Alternatively, this might reflect a more profound knowledge that non-surgeons specialists have of the potentially adverse cardiovascular effects of these agents. Variations between these specialists in corticosteroid/anesthetic doses and/or types, and their use in some special situations (e.g., diabetics), bespeak the need for additional investigations aimed at establishing uniform injection guidelines, and for identifying knowledge deficiencies that warrant advanced education.

Intra-articular injections

Intra-articular injections are one method that physicians may use to treat joint pain. This method offers direct access to the source of pain for the troubled patient. Substances ranging from steroids to hyaluronic acid have been injected successfully into the various joints of the body in an attempt to provide relief for chronic joint pain. Anesthesiologists and orthopedic surgeons have begun to use intra-articular injections of local anesthetics for postoperative analgesia. This history, agents, and methods of intra-articular injections are reviewed.

Hyaluronic acid based materials for intestine tissue engineering: a morphological and biochemical study of cell-material interaction

A wide number of gastro-intestinal disorders are associated with structural alterations of this district leading to an impaired gastrointestinal function. The study of cell material interactions represents one of the major issues for the development of tissue engineering purposes. Benzyl esters of hyaluronic acid are promising materials because they exhibit good tissue compatibility and are available in various configurations. In this work they have been studied for the possible application of intestinal cell growth and functioning. The preliminary investigation on the morphologic and biochemistry data obtained by monitoring the growth and differentiation of intestinal epithelial cells on two hyaluronic acid benzyl esters is reported. Two types of materials structures were studied: a three dimensional matrix and a macroporous flat sheet membrane. Caco-2 cell line was used: these cells undergo spontaneous enterocytic differentiation after several days in culture. The differentiation status of these cells grown on different materials was used as a parameter of biocompatibility and cell functioning. The status of cell growth and differentiation was monitored by studying cell morphology using scanning electron microscopy. The results obtained were confirmed by biochemical determinations. Although both the configurations of the two polymers exhibited good compatibility with respect to intestinal cells, only the flat sheet membrane proved to induce cell differentiation, leading us to the conclusion that it is a promising substrate for the proposed application.

An integrated analysis of five double-blind, randomized controlled trials evaluating the safety and efficacy of a hyaluronan product for intra-articular injection in osteoarthritis of the knee

OBJECTIVE

Five double-blind, randomized, saline-controlled trials (RCTs) were included in the United States marketing application for an intra-articular hyaluronan (IA-HA) product for the treatment of osteoarthritis (OA) of the knee. We report an integrated analysis of the primary Case Report Form (CRF) data from these trials.

METHOD

Trials were similar in design, patient population and outcome measures - all included the Lequèsne Algofunctional Index (LI), a validated composite index of pain and function, evaluating treatment over 3 months. Individual patient data were pooled; a repeated measures analysis of covariance was performed in the intent-to-treat (ITT) population. Analyses utilized both fixed and random effects models. Safety data from the five RCTs were summarized.

RESULTS

A total of 1155 patients with radiologically confirmed knee OA were enrolled: 619 received three or five IA-HA injections; 536 received "placebo" saline injections. In the active and control groups, mean ages were 61.8 and 61.4 years; 62.4% and 58.8% were women; baseline total Lequèsne scores 11.03 and 11.30, respectively. Integrated analysis of the pooled data set found a statistically significant reduction (P < 0.001) in total Lequèsne score with hyaluronan (HA) (-2.68) vs placebo (-2.00); estimated difference -0.68 (95% CI: -0.56 to -0.79), effect size 0.20. Additional modeling approaches confirmed robustness of the analyses.

CONCLUSIONS

This integrated analysis demonstrates that multiple design factors influence the results of RCTs assessing efficacy of intra-articular (IA) therapies, and that integrated analyses based on primary data differ from meta-analyses using transformed data.

Viscosupplementation for the treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is the most prevalent chronic joint disorder worldwide and is associated with significant pain and disability.

OBJECTIVES

To assess the effects of viscosupplementation in the treatment of OA of the knee. The products were hyaluronan and hylan derivatives (Adant, Arthrum H, Artz (Artzal, Supartz), BioHy (Arthrease, Euflexxa, Nuflexxa), Durolane, Fermathron, Go-On, Hyalgan, Hylan G-F 20 (Synvisc Hylan G-F 20), Hyruan, NRD-101 (Suvenyl), Orthovisc, Ostenil, Replasyn, SLM-10, Suplasyn, Synject and Zeel compositum).

SEARCH STRATEGY

MEDLINE (up to January (week 1) 2006 for update), EMBASE, PREMEDLINE, Current Contents up to July 2003, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Specialised journals and reference lists of identified randomised controlled trials (RCTs) and pertinent review articles up to December 2005 were handsearched.

SELECTION CRITERIA

RCTs of viscosupplementation for the treatment of people with a diagnosis of OA of the knee were eligible. Single and double-blinded studies, placebo-based and comparative studies were eligible. At least one of the four OMERACT III core set outcome measures had to be reported (Bellamy 1997).

DATA COLLECTION AND ANALYSIS

Each trial was assessed independently by two reviewers for its methodological quality using a validated tool. All data were extracted by one reviewer and verified by a second reviewer . Continuous outcome measures were analysed as weighted mean differences (WMD) with 95% confidence intervals (CI). However, where different scales were used to measure the same outcome, standardized mean differences (SMD) were used. Dichotomous outcomes were analyzed by relative risk (RR).

MAIN RESULTS

Seventy-six trials with a median quality score of 3 (range 1 to 5) were identified. Follow-up periods varied between day of last injection and eighteen months. Forty trials included comparisons of hyaluronan/hylan and placebo (saline or arthrocentesis), ten trials included comparisons of intra-articular (IA) corticosteroids, six trials included comparisons of nonsteroidal anti-inflammatory drugs (NSAIDs), three trials included comparisons of physical therapy, two trials included comparisons of exercise, two trials included comparisons of arthroscopy, two trials included comparisons of conventional treatment, and fifteen trials included comparisons of other hyaluronans/hylan. The pooled analyses of the effects of viscosupplements against 'placebo' controls generally supported the efficacy of this class of intervention. In these same analyses, differential efficacy effects were observed for different products on different variables and at different timepoints. Of note is the 5 to 13 week post injection period which showed a percent improvement from baseline of 28 to 54% for pain and 9 to 32% for function. In general, comparable efficacy was noted against NSAIDs and longer-term benefits were noted in comparisons against IA corticosteroids. In general, few adverse events were reported in the hyaluronan/hylan trials included in these analyses.

AUTHORS' CONCLUSIONS

Based on the aforementioned analyses, viscosupplementation is an effective treatment for OA of the knee with beneficial effects: on pain, function and patient global assessment; and at different post injection periods but especially at the 5 to 13 week post injection period. It is of note that the magnitude of the clinical effect, as expressed by the WMD and standardised mean difference (SMD) from the RevMan 4.2 output, is different for different products, comparisons, timepoints, variables and trial designs. However, there are few randomised head-to-head comparisons of different viscosupplements and readers should be cautious, therefore, in drawing conclusions regarding the relative value of different products. The clinical effect for some products, against placebo, on some variables at some timepoints is in the moderate to large effect-size range. Readers should refer to relevant tables to review specific detail given the heterogeneity in effects across the product class and some discrepancies observed between the RevMan 4.2 analyses and the original publications. Overall, the analyses performed are positive for the HA class and particularly positive for some products with respect to certain variables and timepoints, such as pain on weight bearing at 5 to 13 weeks postinjection. In general, sample-size restrictions preclude any definitive comment on the safety of the HA class of products; however, within the constraints of the trial designs employed no major safety issues were detected. In some analyses viscosupplements were comparable in efficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events. In other analyses HA products had more prolonged effects than IA corticosteroids. Overall, the aforementioned analyses support the use of the HA class of products in the treatment of knee OA.

Intraarticular corticosteroid for treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is a common joint disorder. In the knee, injections of corticosteroids into the joint (intraarticular (IA)) may relieve inflammation, and reduce pain and disability.

OBJECTIVES

To evaluate the efficacy and safety of IA corticosteroids in treatment of OA of the knee.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2003), MEDLINE (to January (week 1) 2006 for update), EMBASE, PREMEDLINE (all to July 2003), and Current Contents (Sept 2000). Specialised journals, trial reference lists and review articles were handsearched.

SELECTION CRITERIA

Randomised controlled trials of IA corticosteroids for patients with OA of the knee: single/double blind, placebo-based/comparative studies, reporting at least one core OMERACT III outcome measure.

DATA COLLECTION AND ANALYSIS

Methodological quality of trials was assessed, and data were extracted in duplicate. Fixed effect and random effects models, giving weighted mean differences (WMD), were used for continuous variables. Dichotomous outcomes were analysed by relative risk (RR).

MAIN RESULTS

Twenty-eight trials (1973 participants) comparing IA corticosteroid against placebo, against IA hyaluronan/hylan (HA products), against joint lavage, and against other IA corticosteroids, were included.IA corticosteroid was more effective than IA placebo for pain reduction (WMD -21.91; 95% confidence interval (CI) -29.93 to -13.89) and patient global assessment (the RR was 1.44 (95% CI 1.13 to 1.82)) at one week post injection with an NNT of 3 to 4 for both, based on n=185 for pain on 100 mm visual analogue scale (VAS) and n=158 for patient global assessment. Data on function were sparse at one week post injection and neither statistically significant nor clinically important differences were detected. There was evidence of pain reduction between two weeks (the RR was 1.81 (95% CI 1.09 to 3.00)) to three weeks (the RR was 3.11 (95% CI 1.61 to 6.01), but a lack of evidence for efficacy in functional improvement. At four to 24 weeks post injection, there was lack of evidence of effect on pain and function (small studies showed benefits which did not reach statistical or clinical importance, i.e. less than 20% risk difference). For patient global, there were three studies which consistently showed lack of effect longer than one week post injection. However, all were fairly small sample sizes (less than 50 patients per group). This was supported by another study which did not find statistically significant differences, at any time point, on a continuous measure of patient global assessment (100 mm VAS).In comparisons of corticosteroids and HA products, no statistically significant differences were in general detected at one to four weeks post injection. Between five and 13 weeks post injection, HA products were more effective than corticosteroids for one or more of the following variables: WOMAC OA Index, Lequesne Index, pain, range of motion (flexion), and number of responders. One study showed a difference in function between 14 to 26 weeks, but no differences in efficacy were detected at 45 to 52 weeks. In general, the onset of effect was similar with IA corticosteroids, but was less durable than with HA products. Comparisons of IA corticosteroids showed triamcinolone hexacetonide was superior to betamethasone for number of patients reporting pain reduction up to four weeks post injection (the RR was 2.00 (95% CI 1.10 to 3.63). Comparisons between IA corticosteroid and joint lavage showed no differences in any of the efficacy or safety outcome measures.

AUTHORS' CONCLUSIONS

The short-term benefit of IA corticosteroids in treatment of knee OA is well established, and few side effects have been reported. Longer term benefits have not been confirmed based on the RevMan analysis. The response to HA products appears more durable. In this review, some discrepancies were observed between the RevMan 4.2 analysis and the original publication. These are likely the result of using secondary rather than primary data and the statistical methods available in RevMan 4.2. Future trials should have standardised outcome measures and assessment times, run longer, investigate different patient subgroups, and clinical predictors of response (those associated with inflammation and structural damage).

Current trends in crystal identification

PURPOSE OF REVIEW

This review is an attempt to keep current in the sparse literature addressing the still underutilized area of crystal identification.

RECENT FINDINGS

The emphasis has been on the subtleties of the microscopic identification of common crystals and other less common potentially confusing crystals. Imaging is noted to provide increasing help, but microscopic crystal identification remains the gold standard.

SUMMARY

Quality control is still a concern as is the infrequency of attempted arthrocentesis for crystal identification.

A double-blind randomized controlled trial comparing alternate forms of high molecular weight hyaluronan for the treatment of osteoarthritis of the knee

OBJECTIVE

To compare the safety and effectiveness of a high molecular weight hyaluronan produced by biological fermentation (Bio-HA) with those of avian-derived hyaluronan that uses cross-linking to achieve high molecular weight (CL-HA).

DESIGN

This was a prospective, multicenter, randomized, double-blind trial evaluating patients with confirmed osteoarthritis of the knee. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC Index) pain subscale was the primary effectiveness measure (visual analog scale). Both products were administered via three weekly injections, with follow-up evaluations at weeks 3, 6 and 12. Acetaminophen was permitted as rescue medication and quantitated by pill counts.

RESULTS

Analyses were performed on the intent-to-treat population, defined as all patients receiving at least one injection. Of the 321 patients randomized to treatment, 314 patients (98%) completed the final study assessment. Improvement in the average WOMAC Index pain score was 29.8mm (-61.6%) for Bio-HA and 28.8mm (-54.9%) for CL-HA, meeting the prospective criteria for non-inferiority. For the secondary outcome measures, statistically significant differences favored Bio-HA for the number of patients requiring acetaminophen (P=0.013) and patient global satisfaction evaluations (P=0.03). Local reactions differed between the products in that 15 effusions were reported in 13 CL-HA patients (8.1%) after injection, compared to one effusion (0.6%) after Bio-HA injection (P=0.0015).

CONCLUSION

The effectiveness of Bio-HA was not inferior to that of CL-HA. The significantly higher incidence of post-injection effusion in the CL-HA group provides a safety advantage for Bio-HA. These data suggest that Bio-HA has an improved benefit-risk profile compared with CL-HA.

Newer Therapeutic Approaches: Gout

Newer approaches to the treatment of gout have included modifications and further attention to aspects of current therapies, and development of interesting new therapies. Colchicine prophylaxis appears to be needed longer than previously recognized after introduction of a urate-lowering agent. Diet has received attention, though most dietary effects are small. New agents under investigation include pegylated formulations of uricase and a new potent xanthine oxidase inhibitor, febuxostat. Some cardiovascular drugs have been shown to be uricosuric.

Injectable corticosteroids in treatment of arthritis of the knee

Injection of corticosteroid preparations for the local treatment of musculoskeletal disorders affecting the knee, such as osteoarthritis and rheumatoid arthritis, has been used widely since the 1950s. This local therapy minimizes systemic toxicity and can result in rapid improvement in symptoms, most often as an adjunctive therapy for acute or severe symptom flares. The evidence assessing safety and efficacy is reviewed and analyzed. Intra-articular knee injection technique is described and is a procedure that is easy to learn and can be performed quickly in an office or hospital setting.

Corticosteroid injections for painful shoulders

The painful shoulder is a common clinical entity with a broad array of possible causes. A caregiver for an affected patient needs to determine the aetiology for the pain, often relying primarily on the history and physical examination and supplemented with laboratory testing and imaging when needed. However, initial treatment decisions are often made before ordering these tests in situations not involving trauma. Most conditions affecting the shoulder are treated with conservative measures such as rest, physical therapy and analgesics. When such measures fail, local corticosteroid injections can be a valuable tool to help achieve symptom relief for a wide range of the most common conditions affecting the shoulder joint. This review aims to help the clinician distinguish among the commonly encountered causes of shoulder pain and guide therapy when the use of local corticosteroid injections is considered.

Intraarticular corticosteroid for treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is a common joint disorder. In the knee, injections of corticosteroids into the joint (intra-articular (IA)) may relieve inflammation, and reduce pain and disability.

OBJECTIVES

To evaluate the efficacy and safety of IA corticosteroids in treatment of OA of the knee.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2003), MEDLINE, EMBASE, PREMEDLINE (all to July 2003), and Current Contents (Sept 2000). Specialised journals, trial reference lists and review articles were handsearched.

SELECTION CRITERIA

Randomised controlled trials of IA corticosteroids for patients with OA of the knee: single/double blind, placebo-based/comparative studies, reporting at least one core OMERACT III outcome measure.

DATA COLLECTION AND ANALYSIS

Methodological quality of trials was assessed, and data were extracted in duplicate. Fixed effect and random effects models, giving weighted mean differences (WMD), were used for continuous variables. Dichotomous outcomes were analysed by relative risk (RR).

MAIN RESULTS

Twenty-six trials (1721 participants) comparing IA corticosteroid against placebo, against IA hyaluronan/hylan (HA products), against joint lavage, and against other IA corticosteroids, were included.IA corticosteroid was more effective than IA placebo for pain reduction (WMD -17.79; 95% confidence interval (CI) -25.02 to -10.55) and patient global assessment (the RR was 1.44 (95% CI 1.13 to 1.82)) at one week post injection with an NNT of 3 to 4 for both, based on n=185 for pain on 100 mm visual analogue scale (VAS) and n=158 for patient global assessment. Data on function were sparse at one week post injection and neither statistically significant nor clinically important differences were detected. There was evidence of pain reduction between two weeks (the RR was 1.81 (95% CI 1.09 to 3.00)) to three weeks (the RR was 3.11 (95% CI 1.61 to 6.01), but a lack of evidence for efficacy in functional improvement. At four to 24 weeks post injection, there was lack of evidence of effect on pain and function (small studies showed benefits which did not reach statistical or clinical importance, i.e. less than 20% risk difference). For patient global, there were three studies which consistently showed lack of effect longer than one week post injection. However, all were fairly small sample sizes (less than 50 patients per group). This was supported by another study which did not find statistically significant differences, at any time point, on a continuous measure of patient global assessment (100 mm VAS). In comparisons of corticosteroids and HA products, no statistically significant differences were in general detected at one to four weeks post injection. Between five and 13 weeks post injection, HA products were more effective than corticosteroids for one or more of the following variables: WOMAC OA Index, Lequesne Index, pain, range of motion (flexion), and number of responders. One study showed a difference in function between 14 to 26 weeks, but no differences in efficacy were detected at 45 to 52 weeks. In general, the onset of effect was similar with IA corticosteroids, but was less durable than with HA products. Comparisons of IA corticosteroids showed triamcinolone hexacetonide was superior to betamethasone for number of patients reporting pain reduction up to four weeks post injection (the RR was 2.00 (95% CI 1.10 to 3.63). Comparisons between IA corticosteroid and joint lavage showed no differences in any of the efficacy or safety outcome measures.

AUTHORS' CONCLUSIONS

The short-term benefit of IA corticosteroids in treatment of knee OA is well established, and few side effects have been reported. Longer term benefits have not been confirmed based on the RevMan analysis. The response to HA products appears more durable. In this review, some discrepancies were observed between the RevMan 4.1 analysis and the original publication. These are likely the result of using secondary rather than primary data and the statistical methods available in RevMan 4.1. Future trials should have standardised outcome measures and assessment times, run longer, investigate different patient subgroups, and clinical predictors of response (those associated with inflammation and structural damage).

Viscosupplementation for the treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is the most prevalent chronic joint disorder worldwide and is associated with significant pain and disability.

OBJECTIVES

To assess the effects of viscosupplementation in the treatment of OA of the knee. The products were hyaluronan and hylan derivatives (Adant, Arthrum H, Artz (Artzal, Supartz), BioHy (Arthrease), Durolane, Fermathron, Go-On, Hyalgan, Hylan G-F 20 (Synvisc Hylan G-F 20), NRD-101, Orthovisc, Ostenil, Replasyn, SLM-10, Suplasyn, Synject and Zeel compositum).

SEARCH STRATEGY

MEDLINE, EMBASE, PREMEDLINE, Current Contents up to July 2003, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Specialised journals and reference lists of identified randomised controlled trials (RCTs) and pertinent review articles up to April 2004 were handsearched.

SELECTION CRITERIA

RCTs of viscosupplementation for the treatment of people with a diagnosis of OA of the knee were eligible. Single and double-blinded studies, placebo-based and comparative studies were eligible. At least one of the four OMERACT III core set outcome measures had to be reported (Bellamy 1997).

DATA COLLECTION AND ANALYSIS

Each trial was assessed independently by two reviewers (NB, JC) for its methodological quality using a validated tool. All data were extracted by one reviewer (JC) and verified by a second reviewer (VR). Continuous outcome measures were analysed as weighted mean differences (WMD) with 95% confidence intervals (CI). Dichotomous outcomes were analyzed by relative risk (RR).

MAIN RESULTS

Sixty-three trials with a median quality score of 3 (range 1 to 5) were identified. Follow-up periods varied between day of last injection and one year. Thirty-seven trials included comparisons of hyaluronan/hylan and placebo, nine trials included comparisons of intra-articular (IA) corticosteroids, and five trials included comparisons of nonsteroidal anti-inflammatory drugs (NSAIDs). The pooled analyses of the effects of viscosupplements against 'placebo' controls generally supported the efficacy of this class of intervention. In these same analyses, differential efficacy effects were observed for different products on different variables and at different timepoints. Of note is the 5 to 13 week post injection period which showed a percent improvement from baseline of 11 to 54% for pain and 9 to 15% for function. In general, comparable efficacy was noted against NSAIDs and longer-term benefits were noted in comparisons against IA corticosteroids. In general, few adverse events were reported in the hyaluronan/hylan trials included in these analyses.

AUTHORS' CONCLUSIONS

Based on the aforementioned analyses, viscosupplementation is an effective treatment for OA of the knee with beneficial effects: on pain, function and patient global assessment; and at different post injection periods but especially at the 5 to 13 week post injection period. It is of note that based on non-randomised groups, the magnitude of the clinical effect, as expressed by the WMD and standardised mean difference (SMD) from the RevMan 4.1 output, is different for different products, comparisons, timepoints, variables and trial designs. However, there are few randomised head-to-head comparisons of different viscosupplements and readers should be cautious, therefore, in drawing conclusions regarding the relative value of different products. The clinical effect for some products, against placebo, on some variables at some timepoints is in the moderate to large effect-size range. Readers should refer to relevant tables to review specific detail given the heterogeneity in effects across the product class and some discrepancies observed between the RevMan 4.1 analyses and the original publications. Overall, the analyses performed are positive for the HA class and particularly positive for some products with respect to certain variables and timepoints, such as pain on weight bearing at 5 to 13 weeks postinjection. In general, sample-size restrictions preclude any definitive comment on the safety of the HA class of products; however, within the constraints of the trial designs employed no major safety issues were detected. In some analyses viscosupplements were comparable in efficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events. In other analyses HA products had more prolonged effects than IA corticosteroids. Overall, the aforementioned analyses support the use of the HA class of products in the treatment of knee OA.

Injectable corticosteroids in modern practice

Long-lasting, crystalline suspensions of injectable corticosteroids have been used to treat joint and soft-tissue disorders for many years; they decrease inflammation by reducing local infiltration of inflammatory cells and mediators. Depot formulations differ in their characteristics. Compounds with low solubility are thought to have the longest duration of action but may cause tissue atrophy when used in soft tissues. Intra-articular corticosteroids are commonly used to treat osteoarthritis and inflammatory arthritis: meta-analyses confirm their benefit in reducing pain and symptoms. Intra-articular corticosteroid injections have been shown to be safe and effective for repeated use (every 3 months) for up to 2 years, with no joint space narrowing detected. Fewer clinical trials are available for extra-articular uses for injectable corticosteroids, although there is evidence of efficacy in a variety of soft-tissue conditions. The accuracy of injections affects outcomes. Postinjection flare, facial flushing, and skin and fat atrophy are the most common side effects. Systemic complications of injectable corticosteroids are rare.

Update on identification of pathogenic crystals in joint fluid

Crystal identification in joint fluid has been an essential part of diagnosis of joint disease. Recent advances have included progress in crystal identification on stained slides, attention to aspiration techniques, and arthrocenteses of asymptomatic joints. Challenges remain to increase use and optimize techniques.