The orthopaedic approach to managing osteoarthritis of the knee

The Mechanisms and Efficacy of Photobiomodulation Therapy for Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) and osteoarthritis (OA) have a significant impact on the quality of life of patients around the world, causing significant pain and disability. Furthermore, the drugs used to treat these conditions frequently have side effects that add to the patient's burden. Photobiomodulation (PBM) has emerged as a promising treatment approach in recent years. PBM effectively reduces inflammation by utilizing near-infrared light emitted by lasers or LEDs. In contrast to photothermal effects, PBM causes a photobiological response in cells, which regulates their functional response to light and reduces inflammation. PBM's anti-inflammatory properties and beneficial effects in arthritis treatment have been reported in numerous studies, including animal experiments and clinical trials. PBM's effectiveness in arthritis treatment has been extensively researched in arthritis-specific cells. Despite the positive results of PBM treatment, questions about specific parameters such as wavelength, dose, power density, irradiation time, and treatment site remain. The goal of this comprehensive review is to systematically summarize the mechanisms of PBM in arthritis treatment, the development of animal arthritis models, and the anti-inflammatory and joint function recovery effects seen in these models. The review also goes over the evaluation methods used in clinical trials. Overall, this review provides valuable insights for researchers investigating PBM treatment for arthritis, providing important references for parameters, model techniques, and evaluation methods in future studies.

Hyaluronic Acid: A Valid Therapeutic Option for Early Management of Genitourinary Syndrome of Menopause in Cancer Survivors?

Genitourinary syndrome of menopause (GSM) is a chronic condition affecting a large number of women, with a major impact on their urogenital health and sexual function. It occurs at midlife because estrogen levels decline with menopause enhancing aging-related changes of the functional anatomy of the urogenital system. Unfortunately, GSM may occur early in the lifespan of women or be exacerbated following anticancer treatments, such as chemotherapy, ionizing radiation, or surgical removal of reproductive organs. Symptoms of GSM are often under-reported by women, under-estimated and under-diagnosed by health care providers (HCPs), and subsequently under-treated, despite their profound negative impact on the quality of life. The mainstay of vaginal treatments is local estrogen therapy (LET) ensuring an effective management of moderate to severe symptomatic GSM. However, LET is generally contraindicated in women with a history of hormone receptor positive cancer, due to the fear of increased recurrence or possible interference with endocrine adjuvant therapies. Among non-hormonal treatments, hyaluronic acid-based moisturizers have shown promising clinical results both in healthy women and in cancer patients or survivors. Its strong water-binding properties provide lubricating and moisturizing effects, which contribute to maintaining a proper level of hydration and viscoelasticity in several body parts, including the urinary tract and genital tissues. Hyaluronic acid-based moisturizers are effective, safe, and well tolerated; therefore, they may represent a valid option for the early management of GSM-associated symptoms in every woman with a history of cancer who is unable or unwilling to undergo hormone-based therapies. Hence, the aim of this review was to provide an overview of GSM etiology and treatment in women with natural or iatrogenic menopause, with a focus on the use of hyaluronic acid as a prophylactic treatment in the context of an integrated management protocol for cancer patients.

Correlation between Magnetic Resonance Imaging and Arthroscopic Findings in Knee Lesions

Background: Magnetic resonance imaging (MRI) is a noninvasive diagnostic method with no known side effects and a high sensitivity for detecting meniscal lesions as well as lesions of the anterior and posterior cruciate ligaments. For a correct and complete diagnosis, MRI results must be interpreted in the context of clinical examination and anamnesis. MRI results can support the surgical indication for arthroscopy, which is a minimally invasive intervention that facilitates the visualization, investigation, diagnosis, and treatment of intra-articular lesions of the knee. The purpose of this study was to assess the correlation between MRI results and the intra-articular lesions detected arthroscopically.

Material and methods: This retrospective study evaluated a total of 60 patients admitted and treated between January 1, 2013 and January 1, 2014 in the Clinic of Orthopedics and Traumatology of Mureș County Hospital, Târgu Mureș, Romania.

Results: In the 43 patients with lesion of the anterior cruciate ligament, the lesions were seen on MRI in 40 patients (93%) and confirmed arthroscopically in 37 patients (86%). In 34 cases (79.1% of the total of 43), the MRI and arthroscopic results were similar, the Kappa coefficient showing a high degree of correlation (0.90).

Conclusion: By assessing the Kappa coefficient to highlight the correlation between MRI results and arthroscopic diagnosis for knee injuries, a statistically relevant correlation between the two methods was found. This suggests that a correct diagnosis can be achieved by both methods.

The efficacy of local liposomal bupivacaine infiltration on pain and recovery after Total Joint Arthroplasty: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Total Joint Arthroplasty (TJA) is gradually emerging as the treatment of choice for end-stage osteoarthritis. In the past, Perioperative liposomal bupivacaine treatment is still a controversial subject in TJA. Therefore, we write this systematic review and meta-analysis to evaluate the efficacy of liposomal bupivacaine on pain and recovery after TJA.

MATERIALS AND METHODS

Embase, Pubmed, and Cochrane Library were comprehensively searched. Randomized controlled trials (RCTs), cohort studies were included in our meta-analysis. Twelve studies that compared liposomal bupivacaine groups with placebo groups were included in our meta-analysis. The research was reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. RCTs were included in our meta-analysis.

RESULTS

Our study demonstrated that liposomal bupivacaine group was as effective as the placebo group in term of VAS score at 24 h (P = .09), 48 h (P = .97); Postoperative nausea (P = .72); and LOS (0.27). There was significant difference in terms of total morphine consumption at 24 h (P < .0001), 48 h (P = .0008).

CONCLUSION

Our meta-analysis demonstrated that liposomal bupivacaine has similar pain control and functional recovery after TJA which compared with the control group. However, we still need large sample size, high-quality studies to explore the relationship between complications and dose response to give the final conclusion.

The efficacy of tranexamic acid using oral administration in total knee arthroplasty: a systematic review and meta-analysis

Background

Total knee arthroplasty (TKA) is gradually regarded as an effective choice for end-stage osteoarthritis or rheumatic arthritis. In the past, the management of tranexamic acid (TXA) using intravenous injection or topical application has been extensively researched. However, several studies have reported that oral TXA has an effect on blood loss. Therefore, a meta-analysis should be performed to determine whether oral TXA helps to prevent blood loss.

Methods

Randomized controlled trials or retrospective cohort studies about relevant studies were searched in PubMed (1996–April 2017), Embase (1980–April 2017), and the Cochrane Library (CENTRAL, April 2017). Six studies that compared oral TXA to non-TXA were included in our meta-analysis. Meta-analyses (PRISMA) guidelines, the Cochrane Handbook, and the Jadad scale were used to evaluate the included studies and the results to ensure that the meta-analysis was viable.

Results

In accordance with inclusion and exclusion, six studies with 2553 patients (oral TXA = 1386, without TXA = 1167) were eligible and accepted into this meta-analysis. Pooled data indicated that the oral TXA group was effective compared to the without TXA group in terms of hemoglobin (Hb) drop (P < 0.05), blood loss at 24 h (P < 0.05), total blood loss (P < 0.05), and the transfusion rate (P < 0.05). No significant differences were found in the length of hospital stay (P = 0.96) and complications (P = 0.39).

Conclusion

Compared to the non-TXA group, the oral TXA group showed effects of blood sparing. Considering the cost and effectiveness, oral TXA is useful for TKA.

The Efficacy of Liposomal Bupivacaine Using Periarticular Injection in Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Total knee arthroplasty (TKA) is gradually emerging as the treatment of choice for end-stage osteoarthritis. In the past, the method of liposomal bupivacaine by periarticular injection (PAI) showed better effects on pain reduction and opioid consumption after surgery. However, some recent studies have reported that liposomal bupivacaine by PAI did not improve pain control and functional recovery in patients undergoing TKA. Therefore, this meta-analysis was conducted to determine whether liposomal bupivacaine provides better pain relief and functional recovery after TKA.

METHODS

Web of Science, PubMed, Embase, and the Cochrane Library were comprehensively searched. Randomized controlled trials, controlled clinical trials, and cohort studies were included in our meta-analysis. Eleven studies that compared liposomal bupivacaine using the PAI technique with the conventional PAI method were included in our meta-analysis. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and Cochrane Handbook were applied to assess the quality of the results published in all included studies to ensure that the results of our meta-analysis were reliable and veritable.

RESULTS

Our pooled data analysis demonstrated that liposomal bupivacaine was as effective as the control group in terms of visual analog scale score at 24 hours (P = .46), 48 hours (P = .43), 72 hours (P = .21), total amount of opioid consumption (P = .25), range of motion (P = .28), length of hospital stay (P = .53), postoperative nausea (P = .34), and ambulation distance (P = .07).

CONCLUSION

Compared with the conventional PAI method, liposomal bupivacaine shows similar pain control and functional recovery after TKA. Considering the cost for pain control, liposomal bupivacaine is not worthy of being recommended as a long-acting alternative analgesic agent using the PAI method.

Intraoperative platelet-rich plasma does not improve outcomes of total knee arthroplasty

This randomized controlled study was conducted to assess the effects of platelet-rich plasma (PRP) on outcomes of total knee arthroplasty (TKA). Forty patients who underwent unilateral TKA were evaluated prospectively; 20 received intraoperative PRP and 20 served as control subjects. The results showed no significant differences in reduction of bleeding, range of motion, swelling around the knee joint, muscle power recovery, pain, Knee Society Scores, and Knee Injury and Osteoarthritis Outcome Score between the 2 groups. Additionally, no distinct clinical characteristics were found in patients who received intraoperative PRP. Therefore, we conclude that intraoperative PRP does not improve outcomes of TKA.

The effects of knee arthroplasty on walking speed: a meta-analysis

Background

Patients with knee osteoarthritis patients have problems with walking, and tend to walk slower. An important aim of knee arthroplasty is functional recovery, which should include a post-operative increase in walking speed. Still, there are several problems with measuring walking speed in groups of knee osteoarthritis patients. Nevertheless, test-retest reliability of walking speed measurements is high, and when the same investigators monitor the same subjects, it should be possible to assess the walking speed effects of knee arthroplasty. The present study reports a meta-analysis of these effects.

Methods

A total of 16 independent pre-post arthroplasty comparisons of walking speed were identified through MEDLINE, Web of Science, and PEDro, in 12 papers, involving 419 patients.

Results

For 0.5–5 months post-operatively, heterogeneity was too large to obtain a valid estimate of the overall effect-size. For 6–12 and 13–60 months post-operatively, heterogeneity was absent, low, or moderate (depending on estimated pre-post correlations). During these periods, subjects walked on average 0.8 standard-deviations faster than pre-operatively, which is a large effect. Meta-regression analysis revealed significant effects of time and time squared, suggesting initial improvement followed by decline.

Conclusion

This meta-analysis revealed a large effect of arthroplasty on walking speed 6–60 months post-operatively. For the first 0.5–5 months, heterogeneity of effect-sizes precluded a valid estimate of short-term effects. Hence, patients may expect a considerable improvement of their walking speed, which, however, may take several months to occur. Meta-regression analysis suggested a small decline from 13 months post-operatively onwards.

Targeted delivery of non-viral vectors to cartilage in vivo using a chondrocyte-homing peptide identified by phage display

Gene therapy is a promising method for osteoarthritis and cartilage injury. However, specifically delivering target genes into chondrocytes is a great challenge because of their non-vascularity and the dense extracellular matrix of cartilage. In our study, we identified a chondrocyte-affinity peptide (CAP, DWRVIIPPRPSA) by phage display technology. Subsequent analysis suggests that the peptide can efficiently interact specifically with chondrocytes without any species specificity. Polyethylenimine (PEI) was covalently modified with CAP to construct a non-viral vector for cartilage-targeted therapy. To investigate the cartilage-targeting property of the CAP-modified vector, FITC-labeled CAP conjugated PEI/DNA particles were injected into rabbit knee joints, and visualized under confocal microscope. Higher concentrations of CAP-modified vector were detected in the cartilage and specifically taken up by chondrocytes compared with a randomly scrambled peptide (SP)-modified vector. To evaluate cartilage-targeting transfection efficiency, the GFP and luciferase genes were delivered into knee joints using CAP- and SP-modified PEI. Cartilage transfections mediated by CAP-modified PEI were much more efficient and specific than those by SP-modified PEI. This result suggests that CAP-modified PEI could be used as a specific cartilage-targeting vector for cartilage disorders.

Arthroscopy vs. MRI for a detailed assessment of cartilage disease in osteoarthritis: diagnostic value of MRI in clinical practice

BACKGROUND

In patients with osteoarthritis, a detailed assessment of degenerative cartilage disease is important to recommend adequate treatment. Using a representative sample of patients, this study investigated whether MRI is reliable for a detailed cartilage assessment in patients with osteoarthritis of the knee.

METHODS

In a cross sectional-study as a part of a retrospective case-control study, 36 patients (mean age 53.1 years) with clinically relevant osteoarthritis received standardized MRI (sag. T1-TSE, cor. STIR-TSE, trans. fat-suppressed PD-TSE, sag. fat-suppressed PD-TSE, Siemens Magnetom Avanto syngo MR B 15) on a 1.5 Tesla unit. Within a maximum of three months later, arthroscopic grading of the articular surfaces was performed. MRI grading by two blinded observers was compared to arthroscopic findings. Diagnostic values as well as intra- and inter-observer values were assessed.

RESULTS

Inter-observer agreement between readers 1 and 2 was good (kappa = 0.65) within all compartments. Intra-observer agreement comparing MRI grading to arthroscopic grading showed moderate to good values for readers 1 and 2 (kappa = 0.50 and 0.62, respectively), the poorest being within the patellofemoral joint (kappa = 0.32 and 0.52). Sensitivities were relatively low at all grades, particularly for grade 3 cartilage lesions. A tendency to underestimate cartilage disorders on MR images was not noticed.

CONCLUSIONS

According to our results, the use of MRI for precise grading of the cartilage in osteoarthritis is limited. Even if the practical benefit of MRI in pretreatment diagnostics is unequivocal, a diagnostic arthroscopy is of outstanding value when a grading of the cartilage is crucial for a definitive decision regarding therapeutic options in patients with osteoarthritis.

Variation of mesenchymal cells in polylactic acid scaffold in an osteochondral repair model

OBJECTIVE

To achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted cells in the repair process. The objectives of this study were to elucidate the survival of mesenchymal cells (MCs). In a polylactic acid (PLA) scaffold and assess the possibility of MC/PLA constructs for osteochondral repair.

DESIGN

Bone marrow from mature male rabbits was cultured for 2 weeks, and fibroblast-like MCs, which contain mesenchymal stem cells (MSCs), were obtained. A cell/scaffold construct was prepared with one million MCs and a biodegradable PLA core using a rotator device. One week after culturing, the construct was transplanted into an osteochondral defect in the medial femoral condyle of female rabbits and the healing process examined histologically. To examine the survivability of transplanted MCs, the male-derived sex-determining region Y (SRY) gene was assessed as a marker of MCs in the defect by polymerase chain reaction (PCR).

RESULTS

In the groups of defects without any treatment, and the transplantation of PLA without cells, the defects were not repaired with hyaline cartilage. The cartilaginous matrix by safranin O staining and type II collagen by immunohistochemical staining were recognized, however the PLA matrix was still present in the defects at 24 weeks after transplantation of the construct. During the time passage, transplanted MCs numbers decreased from 7.8 x 105 at 1 week, to 3.5 x 105 at 4 weeks, and to 3.8 x 104 at 12 weeks. Transplanted MCs were not detectable at 24 weeks.

CONCLUSIONS

MCs contribute to the osteochondral repair expressing the cartilaginous matrix, however the number of MCs were decreasing with time (i.e. 24 weeks). These results could be essential for achieving cartilage regeneration by cell transplantation strategies with growth factors and/or gene therapy.

Maximum recovery after knee replacement--the MARKER study rationale and protocol

Background

There is little scientific evidence to support the usual practice of providing outpatient rehabilitation to patients undergoing total knee replacement surgery (TKR) immediately after discharge from the orthopaedic ward. It is hypothesised that the lack of clinical benefit is due to the low exercise intensity tolerated at this time, with patients still recovering from the effects of major orthopaedic surgery. The aim of the proposed clinical trial is to investigate the clinical and cost effectiveness of a novel rehabilitation strategy, consisting of an initial home exercise programme followed, approximately six weeks later, by higher intensity outpatient exercise classes.

Methods/Design

In this multicentre randomised controlled trial, 600 patients undergoing primary TKR will be recruited at the orthopaedic pre-admission clinic of 10 large public and private hospitals in Australia. There will be no change to the medical or rehabilitative care usually provided while the participant is admitted to the orthopaedic ward. After TKR, but prior to discharge from the orthopaedic ward, participants will be randomised to either the novel rehabilitation strategy or usual rehabilitative care as provided by the hospital or recommended by the orthopaedic surgeon. Outcomes assessments will be conducted at baseline (pre-admission clinic) and at 6 weeks, 6 months and 12 months following randomisation. The primary outcomes will be self-reported knee pain and physical function. Secondary outcomes include quality of life and objective measures of physical performance. Health economic data (health sector and community service utilisation, loss of productivity) will be recorded prospectively by participants in a patient diary. This patient cohort will also be followed-up annually for five years for knee pain, physical function and the need or actual incidence of further joint replacement surgery.

Discussion

The results of this pragmatic clinical trial can be directly implemented into clinical practice. If beneficial, the novel rehabilitation strategy of utilising outpatient exercise classes during a later rehabilitation phase would provide a feasible and potentially cost-effective intervention to optimise the physical well-being of the large number of people undergoing TKR.

Trial Registration

ACTRN12609000054213

Effect of home exercise of quadriceps on knee osteoarthritis compared with nonsteroidal antiinflammatory drugs: a randomized controlled trial

OBJECTIVES

To examine the effect of home-based exercise on knee osteoarthritis among Japanese in comparison with that of nonsteroidal antiinflammatory drugs (NSAIDs).

DESIGN

An open-labeled, randomized, controlled, multiclinic trial compared home-based quadriceps exercise with NSAIDs. Treatments were basically evaluated after 8 wks and compared with the baseline scores. Outcomes were evaluated with a set of psychometric measurements including the Western Ontario and McMaster Universities Arthritis Index (WOMAC), 36-Item Short-Form Health Survey (SF-36), Japanese Knee Osteoarthritis Measure (JKOM), and pain with the visual analog scale.

RESULTS

A total of 142 patients entered this trial to provide the baseline data. After 21 cases withdrew, the final number analyzed was 121 cases: 63 for the exercise group and 58 for the NSAIDs group. Between these two groups, there was no significant difference in gender, age, body height and weight, body mass index, or each score at baseline. The subjects in both groups showed improvements in all scores at the end of intervention. The difference in improvement rate of each score between the two groups was not statistically significant, though the mean rank score measured with JKOM in the exercise was slightly better than that of the NSAIDs.

CONCLUSIONS

Home-based exercise using quadriceps strengthening improves knee osteoarthritis no less than NSAIDs.

Hyaluronic Acid: An Effective Alternative Treatment of Interstitial Cystitis, Recurrent Urinary Tract Infections, and Hemorrhagic Cystitis?

OBJECTIVES

Hyaluronic acid is a protective barrier of the urothelium. A damaged glycosaminoglycan layer may increase the possibility of bacterial adherence and infection. This damage is proposed to be a causative factor in the development of interstitial cystitis, common urinary tract infections, and hemorrhagic cystitis due to posthematopoietic stem cell transplantation. The aim of this article was to review the available data regarding the use of hyaluronic acid as an alternative treatment of the above-mentioned conditions.

METHODS

Articles relevant to our review that were archived by September 2006 were retrieved from PubMed.

RESULTS

Nine relevant studies were identified and evaluated. Hyaluronic acid was administered intravesically at a dose of 40 mg every week for 4-6 wk; patients with noted improvement received two additional monthly doses. Short-term responses of patients with interstitial cystitis, hemorrhagic cystitis, and recurrent urinary tract infections were 30-73% (7 studies), 71% (1 study), and 100% (1 study), respectively. The treatment was well tolerated except for occasional development of bacterial cystitis. The cost of each intravesical installation of hyaluronic acid is 120 UK pounds (excluding the cost of the urinary catheterization).

CONCLUSIONS

The available clinical data regarding the effectiveness of hyaluronic acid as a potential treatment of patients with interstitial cystitis, recurrent urinary tract infections, and hemorrhagic cystitis are limited. There is need for randomized controlled trials for further investigation of this important therapeutics question; these clinical trials should be disease-specific, blinded, and controlled, and of a sufficient number of patients. Until such studies are available, intravesical instillation of hyaluronic acid cannot be unquestionably endorsed for use for the aforementioned diseases.

Unicompartmental knee arthroplasty for the treatment of unicompartmental osteoarthritis: a systematic study

Unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA) and high tibial osteotomy (HTO) may all be used to treat unicompartmental osteoarthritis, but they are often used for different patient groups. However, there is considerable overlap in indications for all three options. The aim of this review was to assess the safety and efficacy of UKA compared with TKA and HTO in unicompartmental osteoarthritis. Studies that compared UKA with either TKA or HTO were identified and included for review. For knee function and postoperative pain, UKA appeared similar to TKA and HTO at 5 years follow up. Range of motion was better in UKA compared with TKA. Complication rates after UKA and TKA appeared similar, although deep vein thrombosis was reported more often after TKA. There were more complications after HTO than UKA. Survival of UKA prostheses was approximately 85-95%, compared with at least 90% for TKA at 10 years follow up. Survivorship for HTO appeared to be less than 85%. It was not clear whether there were more revisions after UKA than TKA, but there appeared to be fewer revisions in UKA compared with HTO. UKA is considered at least as safe as TKA and HTO. For function, UKA appears to be at least as efficacious as TKA and HTO. The survival of UKA compared with TKA and HTO cannot be determined based on the available evidence.

Development of a diagnostic system for osteoarthritis using a photoacoustic measurement method

BACKGROUND AND OBJECTIVES

We demonstrated that photoacoustic measurement enables viscoelastic characterization of biological tissue. The purpose of this study was to develop a practical photoacoustic measurement system for diagnosis of osteoarthritis (OA) by viscoelastic characterization of articular cartilage.

STUDY DESIGN/MATERIALS AND METHODS

The portable system consists of a commercially available 3rd harmonic Q-switched Nd:YAG laser as a light source and a transducer, which is arranged coaxially with an optical fiber. Cell proliferation tests were performed to study the effect of laser irradiation on chondrocytes. Photoacoustic measurements were performed using enzymatically treated cartilage as a model of OA.

RESULTS

There was no significant damage of chondrocytes caused by laser irradiation (100 microJ/mm2, 5 Hz, 30 shots). The change in relaxation times measured by the photoacoustic measurement had a positive correlation with time of enzymatic treatment, that is, the degree of cartilage degeneration.

CONCLUSIONS

We have developed a noninvasive photoacoustic measurement system designed for arthroscopic use and have demonstrated the applicability of this system to the diagnosis of OA-like cartilage degeneration.

Magnetic resonance imaging (MRI) of articular cartilage in knee osteoarthritis (OA): morphological assessment

OBJECTIVE

Magnetic resonance imaging (MRI) is a three-dimensional imaging technique with unparalleled ability to evaluate articular cartilage. This report reviews the current status of morphological assessment of cartilage with quantitative MRI (qMRI), and its relevance for identifying disease status, and monitoring progression and treatment response in knee osteoarthritis (OA).

METHOD

An international panel of experts in MRI of knee OA, with direct experience in the analysis of cartilage morphology with qMRI, reviewed the existing published and unpublished data on the subject, and debated the findings at the OMERACT-OARSI Workshop on Imaging technologies (December 2002, Bethesda, MA) with scientists and clinicians from academia, the pharmaceutical industry and the regulatory agencies. This report reviews (1) MRI pulse sequence considerations for morphological analysis of articular cartilage; (2) techniques for segmenting cartilage; (3) semi-quantitative scoring of cartilage status; and (4) technical validity (accuracy), precision (reproducibility) and sensitivity to change of quantitative measures of cartilage morphology.

RESULTS

Semi-quantitative scores of cartilage status have been shown to display adequate reliability, specificity and sensitivity, and to detect lesion progression at reasonable observation periods (1-2 years). Quantitative assessment of cartilage morphology (qMRI), with fat-suppressed gradient echo sequences, and appropriate image analysis techniques, displays high accuracy and adequate precision (e.g., root-mean-square standard deviation medial tibia=61 microl) for cross-sectional and longitudinal studies in OA patients. Longitudinal studies suggest that changes of cartilage volume of the order of -4% to -6% occur per annum in OA in most knee compartments (e.g., -90 microl in medial tibia). Annual changes in cartilage volume exceed the precision errors and appear to be associated with clinical symptoms as well as with time to knee arthroplasty.

CONCLUSIONS

MRI provides reliable and quantitative data on cartilage status throughout most compartments of the knee, with robust acquisition protocols for multi-center trials now being available. MRI of cartilage has tremendous potential for large scale epidemiological studies of OA progression, and for clinical trials of treatment response to structure modifying OA drugs.