Radiographic findings of osteoarthritis versus arthroscopic findings of articular cartilage degeneration in the tibiofemoral joint

Does MRI alter management in patients 60 years and older with chronic knee pain: correlation with radiographs and clinical parameters

OBJECTIVE

To determine if MRI altered management in patients ≥ 60 years old with chronic knee pain.

MATERIALS AND METHODS

Consecutive patients ≥ 60 years old with knee MRI and radiographs within 90 days were included. Exclusion criteria included mass/malignancy, recent trauma, and infection. Standing AP and PA flexion views were evaluated using Kellgren-Lawrence (KL) and International Knee Documentation Committee (IKDC) scales. Pertinent clinical history was recorded. MRIs were considered to alter management if subchondral fracture was identified or subsequent arthroscopy was performed due to an MRI finding.

RESULTS

Eighty-five knee MRI/radiograph exams were reviewed; mean 68.2 years (60-88), 47:38 F:M. Twenty knee MRIs (24%) had either a subchondral fracture (n = 9) or meniscal tear (n = 11) prompting arthroscopy. On PA flexion view, 0/20 of these studies had KL grade 4 and 70% (14/20) had KL grade 0-1 compared to the remaining MRIs having 15.4% (10/65) KL grade 4 and 38.5% (25/65) KL grade 0-1 (p = 0.03). A 10-pack-year tobacco history, 38% vs 18%, was associated with a subchondral fracture or arthroscopy (p = 0.06). Subchondral fractures were more prevalent in older patients (mean 72.4 vs 67.7 years; p = 0.03).

CONCLUSION

In patients ≥ 60 years old with chronic knee pain, MRI altered management in ~ 24% of cases; 70% in patients with KL grade 0-1, and none in patients with KL grade 4. MRI may benefit older patients with minimal osteoarthritis but not those with end-stage disease. Patients with ≥ 10 pack years of smoking may also benefit from MRI.

Investigation of periodontitis, halitosis, xerostomia, and serological characteristics of patients with osteoarthritis and rheumatoid arthritis and identification of new biomarkers

Rheumatoid arthritis (RA) and osteoarthritis (OA) are two different types of arthritis. Within RA, the subsets between seronegative RA (snRA) and seropositive RA (spRA) represent distinct disease entities; however, identifying clear distinguishing markers between them remains a challenge. This study investigated and compared the oral health conditions in patients with RA and OA to clarify the differences from healthy controls. In addition, we investigated the serological characteristics of the patients, the factors that distinguished patients with RA from those with OA, and the main factors that differentiated between snRA and spRA patients. A total of 161 participants (mean age: 52.52 ± 14.57 years, 32 males and 129 females) were enrolled in this study and categorized as: normal (n = 33), OA (n = 31), and RA (n = 97). Patients with RA were divided into the following two subtypes: snRA (n = 18) and spRA (n = 79). Demographics, oral health, and serological characteristics of these patients were compared. The prevalence of periodontal diseases was significantly higher in patients with OA (100%) and RA (92.8%) than in healthy controls (0.0%). However, the presence of periodontal diseases was not utilized as a distinguishing factor between OA and RA. Xerostomia occurred more frequently in patients with RA (84.5%) than in patients with OA (3.2%) and healthy controls (0.0%) (all p < 0.001). ROC analysis revealed that periodontal disease was a very strong predictor in the diagnosis of OA compared to healthy controls, with an AUC value of 1.00 (p < 0.001). Additionally, halitosis (AUC = 0.746, 95% CI 0.621-0.871, p < 0.001) and female sex (AUC = 0.663, 95% CI 0.529-0.797, p < 0.05) were also significant predictors of OA. The strongest predictors of RA diagnosis compared to healthy controls were periodontal diseases (AUC = 0.964), followed by xerostomia (AUC = 0.923), age (AUC = 0.923), female sex (AUC = 0.660), and halitosis (AUC = 0.615) (all p < 0.05). Significant serological predictors of RA were anti-CCP Ab (AUC = 0.808), and RF (AUC = 0.746) (all p < 0.05). In multiple logistic regression analysis, xerostomia (odds ratio, OR: 8124.88, 95% CI 10.37-6368261.97, p-value = 0.008) and Anti-CCP Ab (OR: 671.33, 95% CI 2.18-207,074.02, p = 0.026) were significant predictors for RA compared to OA. When diagnosing spRA compared to snRA, anti-CCP Ab (AUC = 1.000, p < 0.001) and RF (AUC = 0.910, 95%CI 0.854-0.967, p < 0.001) had outstanding predictive performances. Therefore, clinicians and researchers should thoroughly evaluate the oral status of both OA and RA patients, alongside serological factors, and consider these elements as potential predictors.

Comprehensive Study on Scoring and Grading Systems for Predicting the Severity of Knee Osteoarthritis

Knee Osteoarthritis (KOA) is a degenerative joint ailment characterized by cartilage loss, which can be seen using imaging modalities and converted into imaging features. The older population is the most affected by knee OA, which affects 16% of people worldwide who are 15 years of age and older. Due to cartilage tissue degradation, primary knee OA develops in older people. In contrast, joint overuse or trauma in younger people can cause secondary knee OA. Early identification of knee OA, according to research, may be a successful management tactic for the condition. Scoring scales and grading systems are important tools for the management of knee osteoarthritis as they allow clinicians to measure the progression of the disease's severity and provide suggestions on suitable treatment at identified stages. The comprehensive study reviews various subjective and objective knee evaluation scoring systems that effectively score and grade the KOA based on where defects or changes in articular cartilage occur. Recent studies reveal that AI-based approaches, such as that of DenseNet, integrating the concept of deep learning for scoring and grading the KOA, outperform various state-of-the-art methods in order to predict the KOA at an early stage.

Association of a femoral neck T score with knee joint osteophyte formation but not with skeletal muscle mass

BACKGROUND

Osteophyte formation is an important radiographic sign of osteoarthritis (OA) and limited joint motion in knee osteoarthritis patients. Some studies revealed relationships of osteophyte formation with a high bone mineral density and a high muscle mass, while others showed no correlations. The aim of this study was to identify relationships of osteophyte formation with bone mineral density and muscle mass.

METHODS

A cross sectional study of knee osteoarthritis was conducted. Cases were classified as patients with osteophyte formation, while controls were those without osteophytes. All subjects underwent a knee x-ray and bone mineral density and body composition evaluation. General patient characteristics, covariates, and the results of biochemical analyses were also recorded. Statistical analysis was conducted using SPSS Version 22.0. Logistic regression and the chi-square test were utilized to analyze the relationships between the presence of knee osteophytes and the study variables.

RESULTS

A total of 228 patients were enrolled, including 78 with osteophytes in the knee joint and 150 without. A total of 162/228 are females; knee OA is commonly explained among females. (p = 0.001). The mean age was 73.23 ± 11.10 years in the osteophyte group and 71.86 ± 12.23 in the no osteophyte group (p = 0.409). The mean body mass index was 24.15 ± 3.27 kg/m² in the osteophyte group and 23.37 ± 3.48 kg/m² in the no osteophyte group (p = 0.433). More patients in the osteophyte group had hypertension (p = 0.002), so the age group 73 years expected to have OA and hypertension along other metabolic diseases, and the femoral neck T score was higher in the osteophyte group (p = 0.044). Logistic regression analysis showed that the male gender was associated with less osteophyte formation (p = 0.001, odds ratio (OR) 0.11 (0.03-0.37)), and hypertension was associated with increased muscle loss (p = 0.005). Femoral neck T score was associated with the presence of osteophyte formation (p = 0.011, OR 1.98 (1.17-3.36)).

CONCLUSIONS

The results demonstrated an association of knee osteophyte formation with the femoral neck T score and hypertension, but no association with muscle mass. We speculated that in patients with osteophytosis and increased bone mass, metabolic factors such as hypertension should be considered. Further study of the molecular mechanisms regulating these processes is needed in the future. Key Points • Associations of knee osteophyte formation with the femoral neck T score, but not with muscle mass. • Those with osteophytosis and an increased bone mass and metabolic factors such as hypertension need to be assessed.

Interpretation of Cartilage Damage at Routine Clinical MRI: How to Match Arthroscopic Findings

This review is intended to aid in the interpretation of damage to the articular cartilage at routine clinical MRI to improve clinical management. Relevant facets of the histologic and biochemical characteristics and clinical management of cartilage are discussed, as is MRI physics. Characterization of damage to the articular cartilage with MRI demands a detailed understanding of the normal and damaged appearance of the osteochondral unit in the context of different sequence parameters. Understanding the location of the subchondral bone plate is key to determining the depth of the cartilage lesion. Defining the bone plate at MRI is challenging because of the anisotropic fibrous organization of articular cartilage, which is susceptible to the "magic angle" phenomenon and chemical shift artifacts at the interface with the fat-containing medullary cavity. These artifacts may cause overestimation of the thickness of the subchondral bone plate and, therefore, overestimation of the depth of a cartilage lesion. In areas of normal cartilage morphology, isolated hyperintense and hypointense lesions often represent degeneration of cartilage at arthroscopy. Changes in the subchondral bone marrow at MRI also increase the likelihood that cartilage damage will be visualized at arthroscopy, even when a morphologic lesion cannot be resolved, and larger subchondral lesions are associated with higher grades at arthroscopy. The clinical significance of other secondary features of cartilage damage are also reviewed, including osteophytes, intra-articular bodies, and synovitis. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Medial Tibial Osteophyte Width Strongly Reflects Medial Meniscus Extrusion Distance and Medial Joint Space Width Moderately Reflects Cartilage Thickness in Knee Radiographs

BACKGROUND

The presence of medial tibial osteophytes on knee radiographs suggests cartilage wear, but may be associated with medial meniscus extrusion (MME). The joint space width of the medial compartment consists anatomically of cartilage and the medial meniscus, but which is most responsible for joint space narrowing remains unclear. Magnetic resonance imaging (MRI) reveals MME and cartilage thickness.

PURPOSES

To determine which radiographic medial tibial osteophyte width correlates better with cartilage thickness or MME distance and which radiographic medial joint space width correlates better with cartilage thickness or MME distance.

STUDY TYPE

Cross-sectional.

POPULATION

Total of 527 subjects, 253 females and 274 males, aged 30-79 years, included in the Kanagawa Knee Study.

FIELD STRENGTH/SEQUENCE

3 T/fat-suppressed spoiled gradient echo and proton density weighted.

ASSESSMENT

The medial tibial osteophyte width and "the minimum joint space width at the medial compartment" (mJSW) were measured from plain radiographs. The cartilage region was automatically extracted from MRI data using software. The medial femoral and tibial cartilage regions were each divided into nine subregions, and the average thickness of the cartilage was determined in each region and subregion. MME was manually measured by two orthopedic surgeons using MRI coronal section images.

STATISTICAL TESTS

Pearson's correlation coefficient and their comparison, with P < 0.05 considered statistically significant.

RESULTS

The absolute values of the correlation coefficients were 0.33 at maximum between osteophyte width and cartilage thickness and 0.76 between osteophyte width and MME; the value was significantly higher with MME than with cartilage thickness (P < 0.001). The absolute values of the correlation coefficients were 0.50 at maximum between mJSW and cartilage thickness and 0.16 between mJSW and MME; the value was significantly higher with cartilage thickness than with MME (P < 0.001).

DATA CONCLUSION

The medial tibial osteophyte width strongly reflected MME and the medial joint space width moderately reflected cartilage thickness.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 3.

The Value of SPECT/CT for Knee Osteoarthritis: A Systematic Review

BACKGROUND

Single photon emission computed tomography (SPECT/CT) is a diagnostic option for knee osteoarthritis patients without osteoarthritic features on X-ray; however, the added value of SPECT/CT remains debatable in the diagnostic algorithm.

OBJECTIVE

To review the added value of SPECT/CT in the diagnostic algorithm of knee osteoarthritis.

STUDY DESIGN

Systematic review.

METHODS

A systematic search was carried out in the databases EMBASE, MEDLINE, and the Cochrane collaboration. The retrieved articles were screened for relevance on title and abstract. This was followed by a full-text study quality appraisal of the remaining articles. Finally, a total of 9 trials were included.

RESULTS

The use of SPECT/CT might objectify some clinical knee osteoarthritis symptoms. It could correlate with findings on plain radiography and magnetic resonance imaging. Furthermore, there is some evidence SPECT/CT gives additional information compared with these imaging modalities; however, superiority is not proven. The uptake on SPECT could predict the intraoperative macroscopic findings. Yet the clinical relevance remains unclear.

CONCLUSION

There is no strong evidence SPECT/CT should play a role in the diagnosing and decision-making processes of knee osteoarthritis. Yet there is evidence suggesting SPECT/CT might give additional information in the diagnosing process. More research would be of added value to answer this research question.

Severity of valgus knee osteoarthritis has no effect on clinical outcomes after total knee arthroplasty

INTRODUCTION

Advanced valgus osteoarthritis (OA) is one of the most challenging indications for total knee arthroplasty (TKA). There is no information in the literature about the optimal timing of surgery. The current study investigates the impact of the preoperative deformity and degree of arthritis on postoperative outcome after TKA.

MATERIAL AND METHODS

The study evaluated 133 knees in 107 patients with valgus OA that failed nonoperative treatment with a minimum 2-year follow-up. Mechanical alignment, Kellgren and Lawrence (K/L) score, and minimal joint space width (minJSW) were measured on AP- and hip-to-ankle radiographs. All knees had advanced OA (i.e., K/L grades 3 or 4 and less than 50% minJSW). Pre- and postoperative WOMAC, VR-12, UCLA, VAS, ROM were recorded.

RESULTS

There was no difference in clinical outcome (WOMAC, UCLA, VR-12, VAS or ROM) between patients with different degrees of valgus deformities (< 5.0 deg., 5.0-9.9 deg., 10.0-14.9 deg., ≥ 15.0 deg.). There was also no correlation between K/L score or minimal joint space width and any of the outcome parameters.

CONCLUSIONS

The degree of valgus deformity and the grade of osteoarthritis do not predict the outcome of TKA in patients with valgus OA. Since the risk of complication and the need for implant constraint increases with increasing deformity and instability of the knee, surgery appears to be justified in patients with advanced OA that failed nonoperative treatment, regardless of the degree of deformity.

Impact-induced cartilage damage assessed using polarisation-sensitive optical coherence tomography

Non-invasive determination of structural changes in articular cartilage immediately after impact and rehydration provides insight into the response and recovery of the soft tissue, as well as provides a potential methodology for clinicians to quantify early degenerative changes. In this study, we use polarisation-sensitive optical coherence tomography (PS-OCT) to examine subtle alterations of the optical properties in healthy and early-stage degenerate articular cartilage immediately after impact loading to identify structurally relevant metrics required for understanding the mechanical factors of osteoarthritic initiation and progression. A custom-designed impact testing rig was used to deliver 0.9 J and 1.4 J impact energies to bovine articular cartilage. A total of 52 (n=26 healthy, n=26 mildly degenerate) cartilage-on-bone samples were imaged before, immediately after, and 3 h after impact. PS-OCT images were analyzed to assess changes relating to surface irregularity, optical attenuation, and birefringence. Mildly degenerate cartilage exhibits a significant change in birefringence following 1.4 J impact energies compared to healthy samples which is believed to be attributable to degenerate cartilage being unable to fully utilise the fluid phase to distribute and dampen the energy. After rehydration, the polarisation-sensitive images appear to 'optically-recover' reducing the reliability of birefringence as an absolute metric. Surface irregularity and optical attenuation encode diagnostically relevant information and may serve as markers to predict the mechanical response of articular cartilage. PS-OCT with its ability to non-invasively image the sub-surface microstructural abnormalities of cartilage presents as an ideal modality for cartilage degeneration assessment and identification of mechanically vulnerable tissue.

Imaging of knee osteoarthritis: A review of current evidence and clinical guidelines

BACKGROUND

Knee osteoarthritis (OA) is one of the most common and debilitating degenerative joint diseases worldwide. While radiography is the most commonly used imaging modality, it is associated with drawbacks which newer modalities such as magnetic resonance imaging (MRI) and ultrasound could overcome. Nevertheless, the role of imaging in clinical practice and research in knee OA has not been clearly defined. Furthermore, guidelines on imaging in knee OA from different authoritative bodies have not been compared in previous studies. Therefore, the present review aims to summarise existing evidence and compare guidelines on the use of different imaging modalities in evaluating knee OA.

METHODS

This is a narrative review based on a search of published clinical guidelines and the PubMed database for articles published between 1 January 1990 and 31 May 2020.

RESULTS

There is no broad consensus on the value of imaging in patients with typical OA presentation. If imaging is required, current evidence and clinical guidelines support the use of radiography and MRI as first- and second-line diagnostic modalities respectively. Since radiographic OA features have limited sensitivity and do not manifest in early stages, MRI is the preferred option for whole-joint evaluation in OA research. Discrepancies exist regarding the use of alternative imaging modalities including ultrasound, computed tomography and nuclear medicine.

CONCLUSION

Radiography and MRI are the imaging modalities of choice. Other modalities have their respective advantages, and more research is warranted for the standardisation of image acquisition and interpretation methodology, in order to evaluate their validity, reliability and responsiveness in OA research.

Diagnostic Accuracy of Magnetic Resonance Images and Weight-Bearing Radiographs in Patients With Arthroscopic-Proven Medial Osteoarthritis of the Knee

Aims:

The aim of this study is to analyze the diagnostic value of weight-bearing radiographs, magnetic resonance images (MRI), and the combination of both in osteoarthritic knees when using arthroscopic findings as the “gold standard” to compare with.

Methods:

A total of 59 patients were studied because of chronic pain in 1 of their knees. Radiographs were classified according to Kellgren-Lawrence scale. Magnetic resonance images were classified according to Vallotton, and arthroscopic findings according to Outerbridge criteria.

Results:

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were, respectively, 75.0%, 60.0%, 56.2%, 77.8%, and 66.1% for weight-bearing radiographs, and 70.8%, 88.6%, 81.0%, 81.6%, and 81.4% for MRI. Logistic regression analysis showed that a weight-bearing radiograph added to MRI offered no additional diagnostic value compared with MRI alone (P < .001).

Conclusions:

Magnetic resonance images presented higher specificity, positive and negative predictive values, and accuracy than weight-bearing radiographs for knee osteoarthritis. The combination of radiographs and MRI did not improve the diagnostic accuracy, compared with MRI alone.

The impact of limb loading and the measurement modality (2D versus 3D) on the measurement of the limb loading dependent lower extremity parameters

Background

Deformity assessment and preoperative planning of realignment surgery are conventionally based on weight-bearing (WB) radiographs. However, newer technologies such as three-dimensional (3D) preoperative planning and surgical navigation with patient-specific instruments (PSI) rely on non-weight bearing (NWB) computed tomography (CT) data. Additionally, differences between conventional two-dimensional (2D) and 3D measurements are known. The goal of the present study was to systematically analyse the influence of WB and the measurement modality (2D versus 3D) on common WB-dependent measurements used for deformity assessment.

Methods

85 lower limbs could be included. Two readers measured the hip-knee-ankle angle (HKA) and the joint line convergence angle (JLCA) in 2D WB and 2D NWB radiographs, as well as in CT-reconstructed 3D models using an already established 3D measurement method for HKA, and a newly developed 3D measurement method for JLCA, respectively. Interrater and intermodality reliability was assessed.

Results

Significant differences between WB and NWB measurements were found for HKA (p < 0.001) and JLCA (p < 0.001). No significant difference could be observed between 2D HKA NWB and 3D HKA (p = 0.09). The difference between 2D JLCA NWB and 3D JLCA was significant (p < 0.001). The intraclass correlation coefficient (ICC) for the interrater agreement was almost perfect for all HKA and 3D JLCA measurements and substantial for 2D JLCA WB and 2D JLCA NWB. ICC for the intermodality agreement was almost perfect between 2D HKA WB and 2D HKA NWB as well as between 2D HKA NWB and 3D HKA, whereas it was moderate between 2D JLCA WB and 2D JLCA NWB and between 2D JLCA NWB and 3D JLCA.

Conclusion

Limb loading results in significant differences for both HKA and JLCA measurements. Furthermore, 2D projections were found to be insufficient to represent 3D joint anatomy in complex cases. With an increasing number of surgical approaches based on NWB CT-reconstructed models, research should focus on the development of 3D planning methods that consider the effects of WB on leg alignment.

The posterior-anterior-flexed view is essential for the evaluation of valgus osteoarthritis. A prospective study on 134 valgus knees

Background

Radiographic imaging is an important tool to assess osteoarthritis (OA). Lateral compartment osteoarthritis (valgus OA) usually starts with cartilage degeneration along the posterior aspect of the lateral femoral condyle. There is evidence that the posterior-anterior (PA)-flexed view is more sensitive when diagnosing early stages of valgus OA compared to the anterior-posterior (AP) view. The current paper analyzes the value of the PA-flexed view for patients scheduled for total knee arthroplasty (TKA).

Methods

Radiographs of 134 valgus knees were assessed prior to TKA. The minimal joint space width (minJSW) was measured on AP and PA-flexed views. The extent of mechanical deformity was measured on hip to ankle standing films.

Results

49 (36.6%) AP views showed Kellgren and Lawrence (K/L)-grade 4 osteoarthritis in the lateral compartment, 82 (63.4%) showed grade 3 or less. The PA-flexed view resulted in an increased K/L-grading to grade 4 for 53 knees (62.4%) that were considered grade 3 or less on standard AP-radiographs. There was a significant differences between lateral minJSW on AP and PA-flexed view for patients with up to 10 degrees of mechanical valgus deformity (p < 0.001), as well as 11 to 15 degrees of mechanical deformity (p = 0.021). Only knees with severe deformity of more than 15 degrees did not show a difference in minJSW between PA-flexed view and AP view (p = 0.345).

Conclusions

The PA-flexed view is superior to the standard AP view in quantifying the extent of valgus OA in patients with zero to fifteen degrees of valgus deformity. It is recommended for the initial assessment of patients with valgus osteoarthritis and better documents the extent of osteoarthritis prior to TKA.

Radiographic-based measurement of tibiofemoral joint space width and magnetic resonance imaging derived articular cartilage thickness are not related in subjects at risk for post traumatic arthritis of the knee

Joint space width (JSW), measured as the distance between the femoral and tibial subchondral bone margins on two-dimensional weight-bearing radiographs, is the initial imaging modality used in clinical settings to diagnose and evaluate the progression of osteoarthritis (OA). While, JSW is the only structural outcome approved by the FDA for studying the treatment of this disease in phase III clinical trials, recent reports suggest that magnetic resonance imaging (MRI)-based measurements of OA changes are superior due to increased sensitivity and specificity to the structural changes associated with progression of this disease. In the current study, we examined the relationship between radiographic JSW and MRI-derived articular cartilage thickness in subjects 4 years post anterior cruciate ligament reconstruction (ACLR) who were at increased risk for the onset and early progression of post-traumatic OA, and in uninjured subjects with normal knees (Control). In both ACLR and Control groups, there were large measurement biases, wide limits of agreement, and poor correlation between the two measurement techniques. Clinical significance: The finding from this study suggest that the two methods of examining changes associated with the onset and early progression of PTOA either characterize different structures about the knee and should not be used interchangeably, or two-dimensional JSW measurements are not sensitive to small changes in articular cartilage thickness. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Three-dimensional mapping of the joint space for the diagnosis of knee osteoarthritis based on high resolution computed tomography: Comparison with radiographic, outerbridge, and meniscal classifications

One of the most important characteristic of knee osteoarthritis (OA) is the joint space (JS) width narrowing. Measurements are usually performed on two dimensional (2D) X-rays. We propose and validate a new method to assess the 3D joint space at the medial knee compartment using high resolution peripheral computed tomography images. A semi-automated method was developed to obtain a distance 3D map between femur an tibia with the following parameters: volume, minimum, maximum, mean, standard deviation, median, asymmetry, and entropy. We analyzed 71 knee specimens (mean age: 85 years), radiographs were performed for the Kellgren Lawrence (KL) score grading. In a subgroup of 41 specimens, the histopathological Outerbridge and meniscal classifications were performed and then cores were harvested from the tibial plateau in three different positions (posterior, central, and peripheral) and imaged at 10 µm of resolution to measure the cartilage thickness. Minimum, maximum, mean, and median were statistically lower and entropy higher between knee specimens classified as KL = 0 and KL = 3-4. Gr1 and 2 were statistically different from Gr3-4 for minimum, asymmetry, entropy using the Outerbridge classification and Gr1 was statistically different from Gr3-4 using the meniscal classification. Asymmetry, minimum, mean, median and entropy were significantly correlated with cartilage thickness. Parameters extracted from a 3D map of the medial joint space indicate local variations of JS and are related to local measurements of tibial cartilage thickness, and could be consequently useful to identify early OA. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:2380-2391, 2018.

The posterior-anterior flexed view is better than the anterior-posterior view for assessing osteoarthritis of the knee

OBJECTIVE

The aim of this study is to determine whether the posterior-anterior (PA)-flexed view improves the radiographic assessment of patients with knee pain compared with the standard standing anterior-posterior radiograph.

MATERIALS AND METHODS

Three hundred and sixty-five patients with knee pain underwent anterior-posterior (AP), PA flexed, lateral, and Merchant radiographs of the knee. Knees were grouped as mild (Kellgren and Lawrence [K-L] 1-2) or severe (K-L 3-4) osteoarthritis (OA) and either varus (medial compartment), valgus (lateral compartment), or patellofemoral OA.

RESULTS

In knees with mild valgus OA on AP view (K-L 1-2), the PA flexed view was more sensitive than the AP view. The measured lateral minimal joint space width (minJSW) decreased more than 2 mm in 68% of the patients, resulting in an increase in K-L grade (3 or 4). In patients with severe valgus OA and in all patients with varus and patellofemoral OA, there was no difference between AP and PA flexed view with regard to radiographic measurements or KL grade. Based on the Medicare reimbursement rate using the PA flexed view alone instead of both views reduced imaging costs by 47%.

CONCLUSION

The PA flexed view better classifies the severity of lateral compartment disease in patients with mild valgus OA and provides comparable diagnostic sensitivity for joint space narrowing in varus- and patellofemoral OA. Using the PA flexed view alone was more cost effective than using the combination of AP and PA flexed imaging.

The Clinical Significance of Osteophytes in Compartments of the Knee Joint With Normal Articular Cartilage

OBJECTIVE

The purpose of this study is to determine whether marginal osteophytes in compartments with normal cartilage would be more frequently observed in knees with cartilage lesions and osteophytes in other compartments.

MATERIALS AND METHODS

This retrospective study reviewed 500 consecutive knee MRI examinations performed within 6 months of arthroscopic knee surgery conducted for 497 patients with symptoms (289 male patients and 208 female patients; age range, 17-74 years; median age, 43 years). The highest grade of cartilage lesion detected at MRI and arthroscopy was recorded. Marginal osteophytes were graded on MRI with use of a standardized scoring system, with grade 0 denoting no osteophyte; grade 1, small osteophyte; grade 2, medium-size osteophyte; and grade 3, large osteophyte). The frequency of false-positive osteophytes, defined as osteophytes present in compartments (the patellofemoral, medial tibiofemoral, and lateral tibiofemoral compartments) with normal cartilage observed on MRI and arthroscopy, was calculated. The Goodman and Kruskal gamma statistic was used to test the association of osteophyte size between compartments. Logistic regression was used to test the association between osteophyte size and the severity of the cartilage lesions.

RESULTS

Marginal osteophytes were seen in compartments with normal cartilage on MRI and arthroscopy in 60.5% of knees (75 of 124) with cartilage lesions and osteophytes in other compartments and accounted for all false-positive grade 2 and grade 3 osteophytes. Marginal osteophytes were seen in 12.7% of knees (13 of 102) that had no cartilage lesions in any compartment on MRI or arthroscopy, and all of these were grade 1 osteophytes. The presence of larger sized osteophytes in the compartments with cartilage lesions was associated with the presence of larger sized osteophytes in the compartments with normal cartilage. More severe cartilage lesions were associated with larger osteophyte size.

CONCLUSION

Compartments with marginal osteophytes and normal cartilage are commonly seen in knees that have other compartments with osteophytes and cartilage lesions.

Secondary use of hospital information system data for safe bedside radiography in terms of patient factors

OBJECTIVE:

The purpose of this study was to use patient data gathered by a hospital information system (HIS) to improve the safe performance of bedside radiography.

METHOD:

Hierarchical cluster analysis was used to investigate the factors of hospitalised patients who had undergone radiography in the X-ray room or at the bedside. Logistic regression analysis was then performed to quantify patient factors and calculate the probability of undergoing general radiography or bedside radiography.

RESULTS:

Patients were grouped into six clusters by hierarchical cluster analysis on the basis of their factors. We found a remarkable difference between clusters for the ratio of bedside radiography. Results indicated that "types of transportation" and "level of mobility" related to the ratio of bedside radiography. Logistic regression analysis of the associations between the probability of undergoing bedside radiography and patient factors indicated that type of transportation and level of mobility were highly correlated with bedside radiography or general radiography.

CONCLUSION:

Our results suggested that the secondary use of HIS data for the quantitative evaluation of patient factors and implementation of those quantitative values in medical records may be useful for the safe performance of bedside radiography as well as providing a method of decision support for doctors to order bedside radiography.

Dysregulation of both miR-140-3p and miR-140-5p in synovial fluid correlate with osteoarthritis severity

Objectives

This study looked to analyse the expression levels of microRNA-140-3p and microRNA-140-5p in synovial fluid, and their correlations to the severity of disease regarding knee osteoarthritis (OA).

Methods

Knee joint synovial fluid samples were collected from 45 patients with OA of the knee (15 mild, 15 moderate and 15 severe), ten healthy volunteers, ten patients with gouty arthritis, and ten with rheumatoid arthritis. The Kellgren–Lawrence grading (KLG) was used to assess the radiological severity of knee OA, and the patients were stratified into mild (KLG < 2), moderate (KLG = 2), and severe (KLG > 2). The expression of miR-140-3p and miR-140-5p of individual samples was measured by SYBR Green quantitative polymerase chain reaction (PCR) analysis. The expression of miR-140-3p and miR-140-5p was normalised to U6 internal control using the 2^-△△CT method. All data were processed using SPSS software.

Results

Expression of both miR-140-3p and miR-140-5p was downregulated in OA synovial fluid, showing a statistical difference between the OA and non-OA group, and increased OA severity was associated with a decreased expression of miR-140-3p or miR-140-5p. The Spearman rank correlation analysis suggested that the expression of miR-140-3p or miR-140-5p was negatively correlated with OA severity. In addition, the expression of miR-140-5p was 7.4 times higher than that of miR-140-3p across all groups.

Conclusion

The dysregulation of miR-140-3p and miR-140-5p in synovial fluid and their correlations with the disease severity of OA may provide an important experimental basis for OA classification, and the miR-140-3p/miR-140-5p are of great potential as biomarkers in the diagnosis and clinical management of patients with OA.

Cite this article: C-M. Yin, W-C-W. Suen, S. Lin, X-M. Wu, G. Li, X-H. Pan. Dysregulation of both miR-140-3p and miR-140-5p in synovial fluid correlate with osteoarthritis severity. Bone Joint Res 2017;6:612–618. DOI: 10.1302/2046-3758.611.BJR-2017-0090.R1.

Coexisting lateral tibiofemoral osteoarthritis is associated with worse knee pain in patients with mild medial osteoarthritis

OBJECTIVE

To examine the clinical impact of coexisting lateral osteoarthritis (OA) in knees with mild medial OA.

DESIGN

In patients with Kellgren/Lawrence (K/L) grade 2 OA in the medial compartment (n = 100; age: 56-89 years; 80.0% female), anteroposterior knee radiography was used to assess the presence of lateral OA, using grading systems from the Osteoarthritis Research Society International (OARSI) atlas and the K/L classification. The Japanese Knee Osteoarthritis Measure (JKOM), knee range of motion (ROM), and performance-based functional measures (10 m walk, timed up and go and five repetition chair stand maneuvers) were evaluated. The outcomes were compared between patients with and without lateral OA using an analysis of covariance (ANCOVA) or nonparametric rank ANCOVA. Furthermore, ordinal logistic regression analysis was performed, with responses on individual JKOM pain questionnaires as the outcomes and lateral OA as the predictor.

RESULTS

Knees with coexisting lateral OA had a significantly worse score of JKOM pain question compared with those without, after adjusting for covariates. The presence of lateral OA was significantly associated with knee pain while ascending/descending stairs and standing. These results were consistent between different definitions of the K/L and OARSI grading systems. The knee ROM and performance-based functional measures were not significantly different between patients with and without lateral OA.

CONCLUSION

Knees with concomitant lateral and mild medial OA may be more symptomatic compared to those without lateral OA. These findings might help to define a clinically distinct subgroup based on a simple radiographic finding in mild knee OA.

Comparison of tibiofemoral joint space width measurements from standing CT and fixed flexion radiography

The objective of this project was to determine the relationship between medial tibiofemoral joint space width measured on fixed-flexion radiographs and the three-dimensional joint space width distribution on low-dose, standing CT (SCT) imaging. At the 84-month visit of the Multicenter Osteoarthritis Study, 20 participants were recruited. A commercial SCT scanner for the foot and ankle was modified to image knees while standing. Medial tibiofemoral joint space width was assessed on radiographs at fixed locations from 15% to 30% of compartment width using validated software and on SCT by mapping the distances between three-dimensional subchondral bone surfaces. Individual joint space width values from radiographs were compared with three-dimensional joint space width values from corresponding sagittal plane locations using paired t-tests and correlation coefficients. For the four medial-most tibiofemoral locations, radiographic joint space width values exceeded the minimal joint space width on SCT by a mean of 2.0 mm and were approximately equal to the 61st percentile value of the joint space width distribution at each respective sagittal-plane location. Correlation coefficients at these locations were 0.91-0.97 and the offsets between joint space width values from radiographs and SCT measurements were consistent. There were greater offsets and variability in the offsets between modalities closer to the tibial spine. Joint space width measurements on fixed-flexion radiographs are highly correlated with three-dimensional joint space width from SCT. In addition to avoiding bony overlap obscuring the joint, a limitation of radiographs, the current study supports a role for SCT in the evaluation of tibiofemoral OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1388-1395, 2017.

Correlations of Medial Joint Space Width on Fixed-Flexed Standing Computed Tomography and Radiographs With Cartilage and Meniscal Morphology on Magnetic Resonance Imaging

OBJECTIVE

To assess whether medial tibiofemoral joint space width (JSW) on 3-dimensional (3-D) standing computed tomography (SCT) correlates more closely with magnetic resonance imaging cartilage morphology (CM) and meniscal scores than does radiographic 2-D JSW.

METHODS

Participants in the Multicenter Osteoarthritis Study, who had standing fixed-flexion posteroanterior knee radiographs, were recruited. Medial tibiofemoral 3-D JSW on SCT and 2-D JSW on fixed-flexion radiographs were compared with medial tibiofemoral cartilage and meniscal morphology using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Associations between the area of the articular surface with 3-D JSW <2.5 mm on SCT, radiographic minimal 2-D JSW, and the WORMS-CM and meniscal scores were assessed using Spearman's rho.

RESULTS

For the 19 participants included (33 knees), mean ± SD age was 66.9 ± 5.4 years, body mass index was 29.5 ± 4.4 kg/m(2) , 42.1% of participants were female, and the Kellgren/Lawrence grades were 0 (21.2%), 1 (36.4%), 2 (18.2%), and 3 (24.2%). The articular surface area with 3-D JSW <2.5 mm on SCT correlated with WORMS-CM scores for the central medial tibia (rs  = 0.84, P < 0.001), central medial femur (rs  = 0.60, P < 0.007), and posterior medial meniscal tear (rs  = 0.39, P < 0.026), as did other cut points for 3-D JSW. Correlations with radiographic minimal 2-D JSW were -0.66, -0.52, and -0.40, respectively, differing from SCT only for tibial cartilage (P = 0.001).

CONCLUSION

Greater surface area with a low JSW, measured by SCT, correlates more strongly with the severity of tibial cartilage lesions, while correlating with medial femoral cartilage and meniscal damage to a similar extent as radiographic minimal JSW. SCT may enable valid stratification of participants in clinical trials, through quickly and inexpensively characterizing osteoarthritis features.

Flexion Posteroanterior Radiographs Affect Both Enrollment for and Outcomes After Injection Therapy for Knee Osteoarthritis

BACKGROUND

Knee injection therapy is less effective for severe osteoarthritis (OA), specifically Kellgren-Lawrence (KL) grade 4. Patient selection for knee injection trials has historically been based on extension anteroposterior (AP) radiographic evaluation; however, emerging evidence suggests that KL grading using a flexion posteroanterior (PA) radiograph more accurately and reproducibly predicts disease severity. The impact of radiographic view on patient selection and outcome after knee injection therapy remains unknown.

HYPOTHESIS

A 45° flexion PA radiograph will reveal more advanced knee OA in certain patients. These patients will report worse pre- and postinjection outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Four raters independently graded extension AP and flexion PA radiographs from 91 patients previously enrolled in a knee injection trial. Patients determined to have KL grade 4 OA by any rater on extension AP radiographs were excluded. Among included patients, those upgraded to KL grade 4 on flexion PA radiographs by at least 2 raters constituted group 2, while all remaining patients constituted group 1. Demographic data and patient-reported outcome scores before injection and at 6 weeks, 3 months, 6 months, and 12 months postinjection were compared between groups.

RESULTS

Overall, 64 patients met the inclusion criteria, of which 19 patients (30%) constituted group 2. Compared with group 1, patients in group 2 were older (58.7 vs 52.3 years, P = .02), had worse visual analog scale pain scores before (6.6 vs 5.3, P = .03) and 6 months after injection (5.3 vs 3.5, P = .01), had less improvement in both Lysholm (8.5 vs 20.5, P = .02) and Short Form-12 physical component (-2.2 vs 1.7, P = .03) scores from preinjection to 6 months postinjection, and had less improvement in both Lysholm (1.6 vs 13.1, P = .03) and Knee injury and Osteoarthritis Outcome Score sport subscale (-2.1 vs 16, P = .01) scores from preinjection to 12 months postinjection.

CONCLUSION

One in 3 patients considered to have mild to moderate knee OA on extension AP radiography is upgraded to severe knee OA (KL grade 4) on flexion PA radiography. These patients report worse preinjection outcomes, worse pain scores at short-term follow-up, and decreased improvement in knee function scores between 6 months and 1 year postinjection.

Multimodality scoring of chondral injuries in the equine fetlock joint ex vivo

OBJECTIVE

We investigate the potential of a prototype multimodality arthroscope, combining ultrasound, optical coherence tomography (OCT) and arthroscopic indentation device, for assessing cartilage lesions, and compare the reliability of this approach with conventional arthroscopic scoring ex vivo.

DESIGN

Areas of interest (AIs, N = 43) were selected from equine fetlock joints (N = 5). Blind-coded AIs were independently scored by two equine surgeons employing International Cartilage Repair Society (ICRS) scoring system via conventional arthroscope and multimodality arthroscope, in which high-frequency ultrasound and OCT catheters were attached to an arthroscopic indentation device. In addition, cartilage stiffness was measured with the indentation device, and lesions in OCT images scored using custom-made automated software. Measurements and scorings were performed twice in two separate rounds. Finally, the scores were compared to histological ICRS scores.

RESULTS

OCT and arthroscopic examinations showed the highest average agreements (55.2%) between the scoring by surgeons and histology scores, whereas ultrasound had the lowest (50.6%). Average intraobserver agreements of surgeons and interobserver agreements between rounds were, respectively, for conventional arthroscope (68.6%, 69.8%), ultrasound (68.6%, 68.6%), OCT (65.1%, 61.7%) and automated software (65.1%, 59.3%).

CONCLUSIONS

OCT imaging supplemented with the automated software provided the most reliable lesion scoring. However, limited penetration depth of light limits the clinical potential of OCT in assessing human cartilage thickness; thus, the combination of OCT and ultrasound could be optimal for reliable diagnostics. Present findings suggest imaging and quantitatively analyzing the entire articular surface to eliminate surgeon-related variation in the selection of the most severe lesion to be scored.

Reproducibility assessment of different descriptions of the Kellgren and Lawrence classification for osteoarthritis of the knee

Objective

To assess the inter- and intraobserver reproducibility of the original version and different descriptions of the Kellgren and Lawrence classification used in epidemiological studies for osteoarthritis of the knee.

Methods

The study included 72 patients with osteoarthritis of the knee. Three medical members of the Brazilian Society of Knee Surgery were invited to evaluate the images. An intra- and interobserver analysis was conducted, with an interval of one month. The intraobserver agreement was analyzed using the weighted Cohen's Kappa coefficient. The interobserver agreement was analyzed using the Krippendorff alpha coefficient (α).

Results

The intraobserver assessment indicated conflicting results. In the interobserver analysis, the level of agreement was superficial.

Conclusions

The classification of Kellgren and Lawrence and its variants generated a low reproducibility between observers. The intraobserver analysis showed a lack of uniformity in the use of this classification and its variants, even among experienced observers.

Quantitative techniques for musculoskeletal MRI at 7 Tesla

Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage. Most of this work has been done in the knee or other extremities, due to technical difficulties associated with scanning areas such as the hip and torso at 7 Tesla. In this manuscript, we first provide some technical context for 7 Tesla imaging, including challenges and potential advantages. We then review the major quantitative MRI techniques being applied to musculoskeletal applications on 7 Tesla whole-body systems.

Absence of a relationship between joint space narrowing and osteophyte formation in early knee osteoarthritis among Japanese community-dwelling elderly individuals: A cross-sectional study

OBJECTIVES

Joint space narrowing and osteophyte formation, radiographic features of knee osteoarthritis (OA), are not necessarily synchronous processes. We evaluated the relationship between medial minimum joint space width (mJSW) and osteophyte formation.

METHODS

We conducted a retrospective study of 1050 individuals (424 males; 626 females; mean age 64.9 years) who underwent knee radiography as part of a health screening program, between 2011 and 2013. mJSW and tibial osteophyte area (OF) were quantified using automated software. The mJSW range was subdivided into tertiles, and OF, mJSW, and quality of life (QOL) were compared among them. Correlation between OF and mJSW was evaluated.

RESULTS

In females, OF was largest and correlated with mJSW only in the lowest tertile group. Patients in the lowest mJSW tertile group had a lower QOL and higher pain than those in the other two groups. Based on our generalized additive models and a receiver operating characteristic curve analysis, an mJSW cutoff point of 3.5 mm was apparent in females, with no significant cutoff identified in males.

CONCLUSIONS

OF correlates with mJSW below a cutoff value of about 3.5 mm in females. OA symptoms, namely physical function impairment and pain, increases significantly as mJSW decreases below the cutoff. .

Laterality of radiographic osteoarthritis of the knee

There are few reports of the laterality in radiological knee osteoarthritis (ROA). This study aimed to evaluate laterality in terms of the minimum joint space width (mJSW) and osteophyte areas (OFs) in a cross-sectorial general population screen and elucidate the association between laterality and risk of osteoarthritis. We enrolled 330 participants (mean age 64.6 years) and examined the presence of ROA (Kellgren-Lawrence grade ≧ 2) laterality in terms of the mJSW and OF on the medial tibia using auto-measuring software. Moreover, we examined the association between laterality and leg dominance. The right and left medial mJSWs were 4.02 ± 0.98 mm and 4.05 ± 1.01 mm, respectively, showing no laterality; the laterals were also similar. The participants who had osteophytes ≥1 mm² in the right, left, and bilateral knees were 15, 37, and 57 respectively, with osteophytes being significantly more common in the left knee. The OF was significantly larger in the left knee. Conversely, the medial and lateral mJSWs and OF did not differ according to leg dominance. The prevalence of ROA was higher and the OF was more pronounced in the left knee. However, the mJSW showed no laterality. Additionally, the mJSW and OF showed no differences according to leg dominance.

Metabolic analysis of knee synovial fluid as a potential diagnostic approach for osteoarthritis

Osteoarthritis (OA) is a leading cause of chronic joint pain in the older human population. Diagnosis of OA at an earlier stage may enable the development of new treatments to one day effectively modify the progression and prognosis of the disease. In this work, we explore whether an integrated metabolomics approach could be utilized for the diagnosis of OA. Synovial fluid (SF) samples were collected from symptomatic chronic knee OA patients and normal human cadaveric knee joints. The samples were analyzed using (1)H nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) followed by multivariate statistical analysis. Based on the metabolic profiles, we were able to distinguish OA patients from the controls and validate the statistical models. Moreover, we have integrated the (1)H NMR and GC-MS results and we found that 11 metabolites were statistically important for the separation between OA and normal SF. Additionally, statistical analysis showed an excellent predictive ability of the constructed metabolomics model (area under the receiver operating characteristic curve = 1.0). Our findings indicate that metabolomics might serve as a promising approach for the diagnosis and prognosis of degenerative changes in the knee joint and should be further validated in clinical settings.

Magnetic Resonance Imaging of the Hip

Hip pain is common in all age groups, and osteoarthritis of this joint is an increasingly recognized problem particularly in aging populations. One of the primary goals in the diagnostic evaluation in patients with hip pain is to identify and correct pathologies that could progress to osteoarthritis. Magnetic resonance imaging (MRI) has become an important noninvasive method for characterizing hip anatomy and pathology in these patients. Improvements in MRI hardware and techniques have allowed high spatial and contrast resolution imaging to detect subtle abnormalities, such as acetabular labral and articular cartilage injuries, which often contribute to patient symptoms. Newer MRI techniques, such as delayed gadolinium-enhanced MRI of cartilage and T2 mapping, can give insight into the biochemical structure of tissues such as the articular cartilage. In turn, these can allow quantitative assessment and enable imagers to more directly compare the findings of patients at earlier stages of disease. It is important to understand the fundamental principles of various MRI techniques and their limitations to know when these techniques can best be applied. In addition, understanding of normal hip anatomy and common anatomic variants is useful for being able to accurately detect and localize areas of pathology and to prevent misinterpreting normal structures as diseased. The aims of this work were to briefly review normal hip anatomy and common anatomic variants seen on routine MRI examination, to discuss principles often used in high-resolution hip MRI and newer techniques for biochemical evaluation, and to examine several intra-articular pathologic conditions of the hip joint that are of current clinical interest.

Radiographic assessment of leg alignment and grading of knee osteoarthritis: A critical review

Knee osteoarthritis (OA) is a progressive joint disease hallmarked by cartilage and bone breakdown and associated with changes to all of the tissues in the joint, ultimately causing pain, stiffness, deformity and disability in many people. Radiographs are commonly used for the clinical assessment of knee OA incidence and progression, and to assess for risk factors. One risk factor for the incidence and progression of knee OA is malalignment of the lower extremities (LE). The hip-knee-ankle (HKA) angle, assessed from a full-length LE radiograph, is ideally used to assess LE alignment. Careful attention to LE positioning is necessary to obtain the most accurate measurement of the HKA angle. Since full-length LE radiographs are not always available, the femoral shaft - tibial shaft (FS-TS) angle may be calculated from a knee radiograph instead. However, the FS-TS angle is more variable than the HKA angle and it should be used with caution. Knee radiographs are used to assess the severity of knee OA and its progression. There are three types of ordinal grading scales for knee OA: global, composite and individual feature scales. Each grade on a global scale describes one or more features of knee OA. The entire description must be met for a specific grade to be assigned. The Kellgren-Lawrence scale is the most commonly-used global scale. Composite scales grade several features of knee OA individually and sum the grades to create a total score. One example is the compartmental grading scale for knee OA. Composite scales can respond to change in a variety of presentations of knee OA. Individual feature scales assess one or more OA features individually and do not calculate a total score. They are most often used to monitor change in one OA feature, commonly joint space narrowing. The most commonly-used individual feature scale is the OA Research Society International atlas. Each type of scale has its advantages; however, composite scales may offer greater content validity. Responsiveness to change is unknown for most scales and deserves further evaluation.

Diagnostic performance of 3D standing CT imaging for detection of knee osteoarthritis features

OBJECTIVE

To determine the diagnostic performance of standing computerized tomography (SCT) of the knee for osteophytes and subchondral cysts compared with fixed-flexion radiography, using MRI as the reference standard.

METHODS

Twenty participants were recruited from the Multicenter Osteoarthritis Study. Participants' knees were imaged with SCT while standing in a knee-positioning frame, and with postero-anterior fixed-flexion radiography and 1T MRI. Medial and lateral marginal osteophytes and subchondral cysts were scored on bilateral radiographs and coronal SCT images using the OARSI grading system and on coronal MRI using Whole Organ MRI Scoring. Imaging modalities were read separately with images in random order. Sensitivity, specificity and accuracy for the detection of lesions were calculated and differences between modalities were tested using McNemar's test.

RESULTS

Participants' mean age was 66.8 years, body mass index was 29.6 kg/m(2) and 50% were women. Of the 160 surfaces (medial and lateral femur and tibia for 40 knees), MRI revealed 84 osteophytes and 10 subchondral cysts. In comparison with osteophytes and subchondral cysts detected by MRI, SCT was significantly more sensitive (93 and 100%; p < 0.004) and accurate (95 and 99%; p < 0.001 for osteophytes) than plain radiographs (sensitivity 60 and 10% and accuracy 79 and 94%, respectively). For osteophytes, differences in sensitivity and accuracy were greatest at the medial femur (p = 0.002).

CONCLUSIONS

In comparison with MRI, SCT imaging was more sensitive and accurate for detection of osteophytes and subchondral cysts than conventional fixed-flexion radiography. Additional study is warranted to assess diagnostic performance of SCT measures of joint space width, progression of OA features and the patellofemoral joint.

Imaging strategies for assessing cartilage composition in osteoarthritis

Efforts to reduce the ever-increasing rates of osteoarthritis (OA) in the developed world require the ability to non-invasively detect the degradation of joint tissues before advanced damage has occurred. This is particularly relevant for damage to articular cartilage because this soft tissue lacks the capacity to repair itself following major damage and is essential to proper joint function. While conventional magnetic resonance imaging (MRI) provides sufficient contrast to visualize articular cartilage morphology, more advanced imaging strategies are necessary for understanding the underlying biochemical composition of cartilage that begins to break down in the earliest stages of OA. This review discusses the biochemical basis and the advantages and disadvantages associated with each of these techniques. Recent implementations for these techniques are touched upon, and future considerations for improving the research and clinical power of these imaging technologies are also discussed.

Classification of histologically scored human knee osteochondral plugs by quantitative analysis of magnetic resonance images at 3T

This work evaluates the ability of quantitative MRI to discriminate between normal and pathological human osteochondral plugs characterized by the Osteoarthritis Research Society International (OARSI) histological system. Normal and osteoarthritic human osteochondral plugs were scored using the OARSI histological system and imaged at 3 T using MRI sequences producing T1 and T2 contrast and measuring T1, T2, and T2* relaxation times, magnetization transfer, and diffusion. The classification accuracies of quantitative MRI parameters and corresponding weighted image intensities were evaluated. Classification models based on the Mahalanobis distance metric for each MRI measurement were trained and validated using leave-one-out cross-validation with plugs grouped according to OARSI histological grade and score. MRI measurements used for classification were performed using a region-of-interest analysis which included superficial, deep, and full-thickness cartilage. The best classifiers based on OARSI grade and score were T1- and T2-weighted image intensities, which yielded accuracies of 0.68 and 0.75, respectively. Classification accuracies using OARSI score-based group membership were generally higher when compared with grade-based group membership. MRI-based classification--either using quantitative MRI parameters or weighted image intensities--is able to detect early osteoarthritic tissue changes as classified by the OARSI histological system. These findings suggest the benefit of incorporating quantitative MRI acquisitions in a comprehensive clinical evaluation of OA.

Sensitivity of standing radiographs to detect knee arthritis: a systematic review of Level I studies

PURPOSE

The purpose of this study was to perform a systematic review of the available literature to define the level of quality evidence for determining the sensitivity and specificity of different radiographic views in detecting knee osteoarthritis and to determine the impact of different grading systems on the ability to detect knee osteoarthritis.

METHODS

A systematic review of the literature was conducted to identify studies that evaluated the standing anteroposterior (AP) and 45° posteroanterior (PA) views for tibiofemoral and patellofemoral arthritis and those comparing the use of the Kellgren-Lawrence versus the joint space narrowing (JSN) radiographic grading systems using arthroscopy as the gold standard. A comprehensive search of PubMed, Scopus, CINAHL, the Cochrane Database, Clinicaltrial.gov, and EMBASE was performed using the keywords "osteoarthritis," "knee," "x-ray," "sensitivity," and "arthroscopy."

RESULTS

Six studies were included in the evaluation. The 45° flexion PA view showed a higher sensitivity than the standing AP view for detecting severe arthritis involving either the medial or lateral tibiofemoral compartment. There was no difference in the specificities for the 2 views. The direct comparison of the Kellgren-Lawrence and the JSN radiographic grading systems found no clinical difference between the 2 systems regarding the sensitivities, although the specificity was greater for the JSN system.

CONCLUSIONS

The ability to detect knee osteoarthritis continues to be difficult without using advanced imaging. However, as an inexpensive screening tool, the 45° flexion PA view is more sensitive than the standing AP view to detect severe tibiofemoral osteoarthritis. When evaluating the radiograph for severe osteoarthritis using either the Kellgren-Lawrence or JSN grading system, there is no clinical difference in the sensitivity between the 2 methods; however, the JSN may be more specific for ruling in severe osteoarthritis in the medial compartment.

LEVEL OF EVIDENCE

Level I, systematic review of Level I studies.

Inferior outcomes of total knee replacement in early radiological stages of osteoarthritis

BACKGROUND

Total knee replacement (TKR) for osteoarthritis (OA) is a common and successful operation; the severity of radiographic changes plays a key role as to when it should be performed. This study investigates whether an early radiological grade of OA has an adverse effect on the outcome of TKR in patients with arthroscopically confirmed OA.

METHODS

Between January 2006 and January 2011 data was collected prospectively on all patients undergoing a primary TKR for OA. We included all patients with a Kellgren-Lawrence score of two or less on their pre-operative radiograph who had had an arthroscopy to confirm significant OA. Our primary outcomes were the Oxford Knee Score (OKS) and a satisfaction rating.

RESULTS

Over the study period 1708 primary TKRs were performed in 1381 patients. We identified 44 TKRs in 43 patients with a Kellgren-Lawrence score of two or less on their pre-operative radiograph. In this group the mean age was 63 years, 66% were female and the mean BMI was 31.7 kg/m(2). At a mean follow-up of 37 months the mean OKS was only 30 points compared to 36 in all TKRs performed over the same period (p=0.0004). Only 68% were either satisfied or very satisfied. Eight knees (18%) underwent further surgery, three (6.8%) of which were revision procedures, compared to a revision rate of 1.6% in all patients.

CONCLUSION

The outcomes of TKR in patients with early radiological changes of OA are inferior to those with significant radiological changes and should be performed with caution.

LEVEL OF EVIDENCE

Level IV case-series.

Imaging following acute knee trauma

Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma.

The forward problem of electroarthrography: modeling load-induced electrical potentials at the surface of the knee

Electroarthrography (EAG) is a novel technology recently proposed to detect cartilage degradation. EAG consists of recording electrical potentials on the knee surface while the joint is undergoing compressive loading. Previous results show that these signals originating from streaming potentials in the cartilage reflect joint cartilage health. The aim of this study is to contribute to the understanding of the generation of the EAG signals and to the development of interpretation criteria using computer models of the human knee. The knee is modeled as a volume conductor composed of different regions characterized by specific electrical conductivities. The source of the EAG signal is the load-induced interstitial fluid flow that transports ions within the compressed cartilage. It is modeled as an impressed current density in different sections of the articular cartilage. The finite-element method is used to compute the potential distribution in two knee models with a realistic geometry. The simulated potential distributions correlate very well with previously measured potential values, which further supports the hypothesis that the EAG signals originate from compressed cartilage. Also, different localized cartilage defects simulated as a reduced impressed current density produce specific potential distributions that may be used to detect and localize cartilage degradation. In conclusion, given the structural and electrophysiological complexity of the knee, computer modeling constitutes an important tool to improve our understanding of the generation of EAG signals and of the various factors that affect the EAG signals so as to help develop the EAG technology as a useful clinical tool.

Quantitative MRI techniques of cartilage composition

Due to aging populations and increasing rates of obesity in the developed world, the prevalence of osteoarthritis (OA) is continually increasing. Decreasing the societal and patient burden of this disease motivates research in prevention, early detection of OA, and novel treatment strategies against OA. One key facet of this effort is the need to track the degradation of tissues within joints, especially cartilage. Currently, conventional imaging techniques provide accurate means to detect morphological deterioration of cartilage in the later stages of OA, but these methods are not sensitive to the subtle biochemical changes during early disease stages. Novel quantitative techniques with magnetic resonance imaging (MRI) provide direct and indirect assessments of cartilage composition, and thus allow for earlier detection and tracking of OA. This review describes the most prominent quantitative MRI techniques to date-dGEMRIC, T2 mapping, T1rho mapping, and sodium imaging. Other, less-validated methods for quantifying cartilage composition are also described-Ultrashort echo time (UTE), gagCEST, and diffusion-weighted imaging (DWI). For each technique, this article discusses the proposed biochemical correlates, as well its advantages and limitations for clinical and research use. The article concludes with a detailed discussion of how the field of quantitative MRI has progressed to provide information regarding two specific patient populations through clinical research-patients with anterior cruciate ligament rupture and patients with impingement in the hip. While quantitative imaging techniques continue to rapidly evolve, specific challenges for each technique as well as challenges to clinical applications remain.

Comparative analysis between radiographic views for knee osteoarthrosis (bipedal AP versus monopedal AP)

Objective

A comparative analysis by applying the criteria of the original classification Ahlbäck in the anteroposterior (AP) bipedal knee in extension and anteroposterior (AP) monopodal knee in symptomatic knee arthrosis. With this analysis we intend to observe the agreement, any advantage or difference between the incidence and degree of joint involvement between the orthopedic surgeons and radiologists with the referring physician.

Methods

From January 2012 to March 2012, was a prospective study of 60 symptomatic arthrosis knees (60 patients), clinically selected group of outpatient knee and radiographic proposals submitted to the search. Of the 60 patients, 39 were female and 21 male, mean age 64 years (ranging from 50 to 84 years). Of the 60 knees studied, 37 corresponded to the right side and 23 on the left side. Statistical analysis was performed by Kappa statistics, which evaluates the interobserver agreement for qualitative data.

Results

According to the scale of Ahlbäck, there was a significant agreement (p < 0.0001) intra-observer in the classification of knee osteoarthritis among the five evaluators. There was a significant agreement (p < 0.0001) with inter-observer referring physician in the incidence of AP monopodal and AP bipedal for the four raters.

Conclusion

The study found no difference between the incidence in the AP monopodal versus AP bipedal in osteoarthritis of the knee.

Relationship between radiological grading and clinical status in knee osteoarthritis. A multicentric study

BACKGROUND

Controversy exists regarding the relationship between radiographic findings and clinical status in knee osteoarthritis. Although the surgical indication for total knee arthroplasty (TKA) should be based on pain, clinical status, and the deterioration of quality of life, the radiographic study is the most commonly used criterion for preoperative evaluation. The objective of this study is to find out the relationship between the Ahlbäck classification and clinical status in patients undergoing TKA.

METHODS

1329 protocols were collected from preoperative studies in four multicentric working groups (the Interax, Duracon, Scorpio, and Triathlon Spanish groups) in 30 Spanish hospitals. Mean age was 70.4 years (SD: 6.8; range: 35 to 98); 76.3% of patients were women. Patients entered the study whenever the surgeon found that medical treatment was insufficient to control pain and functional limitation. Data were collected using electronic Case Report Forms, and included Ahlbäck grading scores, Hospital for Special Surgery Knee Score (HSS), SF-12, and other clinical and epidemiologic variables.

RESULTS

According to the Ahlbäck grading system, patients were divided as follows: 243 grade I (18.3%), 358 grade II (26.9%), 416 grade III (31.3%), 241 grade IV (18.1%), and 71 grade V (5.3%). As for HSS, the following scores were obtained: <60 points in 925 patients (69.6%), 60 to 69 points in 286 patients (21.5%), 70 to 84 points in 112 patients (8.4%) and 85 to 100 points in 6 patients (0.5%). Scores showed a statistically significant difference depending on Ahlbäck grade, with a clear tendency towards decrease in HSS scores as the Ahlbäck grade increases (p<0.001). However, the HSS score difference between Ahlbäck grades I and V was of 9.56 points only. Comparing the status of the patients at the start (1994) and at the end (2010) of the data collection process, we observed that patients who underwent surgery in the last years were older and showed a lower Ahlbäck grade.

CONCLUSIONS

We found a relationship between Ahlbäck grading and the preoperative clinical score. The range of variability of the HSS score between the different Ahlbäck grades is small.