Knee Images Research Articles

Optimizing isotropic three-dimensional fast spin-echo methods for imaging the knee.

To optimize acquisition parameters for three dimensional fast spin-echo (3D FSE) imaging of the knee. The knees of eight healthy volunteers were imaged in a 3 Tesla MRI scanner using an eight-channel knee coil. A total of 146 intermediate weighted isotropic resolution 3D FSE (3D-FSE-Cube)images with varied acquisition parameter settings were acquired with an additional reference scan performed for subjective image quality assessment. Images were graded for overall quality, parallel imaging artifact severity and blurring. Cartilage, muscle, and fluid signal-to-noise ratios and fluid-cartilage contrast-to-noise ratios were quantified by acquiring scans without radio frequency excitation and custom-reconstructing the k-space data.Mixed effects regression modeling was used to determine statistically significant effects of different parameters on image quality. Changes in receiver bandwidth, repetition time and echo train length significantly affected all measurements of image quality (P < 0.05). Reducing band width improved all metrics of image quality with the exception of blurring. Reader agreement was slight to fair for subjective metrics, but overall trends in quality ratings were apparent. We used a systematic approach to optimize 3D-FSE-Cube parameters for knee imaging. Image quality was overall improved using a receiver bandwidth of 631.25 kHz, and blurring increased with lower band width and longer echo trains.

Haemophilia Joint Health Score in healthy adults playing sports

To evaluate outcome of prophylactic clotting factor replacement in children with haemophilia, the Haemophilia Joint Health Score (HJHS) was developed aiming at scoring early joint changes in children aged 4-18. The HJHS has been used for adults on long-term prophylaxis but interpretation of small changes remains difficult. Some changes in these patients may be due to sports-related injuries. Evaluation of HJHS score in healthy adults playing sports could improve the interpretation of this score in haemophilic patients. The aim of this study was to evaluate the HJHS scores in a cohort of young, healthy men participating in sports. Concomitant with a project collecting MRI images of ankles and knees in normal young adults, HJHS scores were assessed in 30 healthy men aged 18-26, participating in sports one to three times per week. One physiotherapist assessed their clinical function using the HJHS 2.1. History of joint injuries was documented. MRI images were scored by a single radiologist, using the International Prophylaxis Study Group additive MRI score. Median age of the study group was 24.3 years (range 19.0-26.4) and median frequency of sports activities was three times per week (range 1-4). Six joints (five knees, one ankle) had a history of sports-related injury. The median overall HJHS score was 0 out of 124 (range 0-3), with 60% of subjects showing no abnormalities on HJHS. All joints were normal on MRI. These results suggest that frequent sports participation and related injuries are not related with abnormalities in HJHS scores.

Diz manyetik rezonans görüntüleme bulguları ve fizik muayene bulgularının artroskopik bulgular ile karşılaştırılması

Comparison of magnetic resonance imaging and pysical examination of knee with arthroscopic findings Objective: To determine the effects of physical examination findings with the results of manyetik rezonans imaging (MRI) on the decision for arthroscopic surgery. Methods: Preoperative physical examination findings and MRI results of the patients undergoing knee arthroscopy in our clinic were evaluated statistically by reference of arthroscopy retrospectively. Results: The mean age of patients in the study is 47.2 (22.73), respectively. 25 of the patients were female, 20 of them were male. Arthroscopic surgery was performed for 27 left knee and 18 right knee. Mc Murray test sensitivity in patients with medial meniscus tear is 69.8%. The medial joint line tenderness sensitivity is 97.7% in the patients with medial meniscus tear. Sensitivity of MRI is determined as 93% in the group with medial meniscus tear. Mc Murray test sensitivity in patients with lateral meniscal tear is 71.4%. The lateral joint line tenderness sensitivity is 100% in the patients with lateral meniscus tear. Sensitivity of MRI is determined as 85.7% in the group with lateral meniscus tear. Mc Murray test sensitivity is 68.9%, joint line tenderness sensitivity is 97.8% and sensitivity of MRI is determined as 93.3% without discrimination on the medial and lateral meniscal tear. Conclusion: A careful physical examination is the most effective diagnostic method to determine meniscal pathologies. We think that careful physical examination could reduce the rates of

Custom-fit total knee arthroplasty: our initial experience with 30 knees

We report our initial experience of total knee arthroplasty (TKA) using customized cutting block technology in 30 TKAs from December 2010 to September 2012. Customized blocks were generated for each of the knees using preoperative magnetic resonance imaging of knee and long-leg weight-bearing radiographs. At 30 days, long-leg radiographs were obtained to evaluate the coronal alignment. Twenty-six of the 30 knees had a mechanical axis restored to within 3° of neutral. We conclude that this technology can be safely used in most of the cases of osteoarthritis.

Tibial subchondral bone mineral density: sources of variability and reproducibility

It has been shown that subchondral bone mineral density (sBMD) measurement may be a relevant parameter of osteoarthritis (OA) progression. However, factors implicating the reproducibility and contributing to the variability of the measurement have not been fully described. Thus, the aim of this study was to explore the reproducibility of sBMD by Dual energy X-ray Absorptiometry (DXA) and to further examine its sources of variability. In this study, short-term, intra and inter-observer reproducibility of sBMD was examined on knee images obtained on DXA scans. The influence of software (lumbar spine and forearm modes), knee positioning (flexion or extension), site and size of regions of interest (ROI) and use of rice, on both lateral and medial tibial sBMD, were assessed. Root mean square coefficient of variation (RMS CV) and least significant changes (LSC) were calculated. The short-term precision of sBMD ranged between 2.24% and 5.12% for RMS CV and between 0.053 and 0.135g/cm(2) for LSC. Good intra-observer precision was found for knee flexion conditions whatever the software used (RMS CV ranging from 0.43 to 1.41%). The reproducibility was dependant from the ROI size (the ROI including joint space exhibiting better precision results than ROI including solely the subchondral plate). For a constant size of the ROI, the precision results were site-dependant. Inter-observer RMS CV results ranged from 0.59 to 5.01% according to ROI and software used. For the specific task of monitoring medial sBMD in the ROI including solely subchondral plate, forearm flexion condition produced the highest intra-observer and short-term precision (respectively RMS CV: 0.45% and 2.77%; LSC: 0.013 and 0.080g/cm(2)). Taking account into the excellent precision of the sBMD measurements expressed as RMS CV with the protocol proposed in the present study, clinical application of these measurements might be envisaged.

Total glucosides of paeony prevents juxta-articular bone loss in experimental arthritis

BackgroundTotal glucosides of paeony (TGP) is a biologically active compound extracted from Paeony root. TGP has been used in rheumatoid arthritis therapy for many years. However, the mechanism by which TGP prevents bone loss has been less explored.MethodsTGP was orally administered for 3 months to New Zealand rabbits with antigen-induced arthritis (AIA). Digital x-ray knee images and bone mineral density (BMD) measurements of the subchondral knee bone were performed before sacrifice. Chondrocytes were observed using transmission electron microscopy (TEM). Histological analysis and mRNA expression of receptor activator of nuclear factor-B ligand (RANKL) and osteoprotegerin (OPG) were evaluated in joint tissues.ResultsThe BMD value in TGP rabbits was significantly higher compared with that seen in the AIA model rabbits. In addition, the subchondral bone plate was almost completely preserved by TGP treatment, while there was a decrease in bone plate integrity in AIA rabbits. There was less damage to the chondrocytes of the TGP treated group. Immunohistochemical examination of the TGP group showed that a higher percentage of TGP treated chondrocytes expressed OPG as compared to the chondrocytes isolated from AIA treated animals. In contrast, RANKL expression was significantly decreased in the TGP treated group compared to the AIA group. In support of the immunohistochemistry data, the expression of RANKL mRNA was decreased and OPG mRNA expression was enhanced in the TGP group when compared to that of the AIA model group.ConclusionThese results reveal that TGP suppresses juxta-articular osteoporosis and prevents subchondral bone loss. The decreased RANKL and increased OPG expression seen in TGP treated animals could explain how administration of TGP maintains higher BMD.

Sodium imaging of the human knee using soft inversion recovery fluid attenuation

Sodium signal strength in MRI is low when compared with 1H. Thus, image voxel volumes must be relatively large in order to produce a sufficient signal-to-noise ratio (SNR). The measurement of sodium in cartilage is hindered by conflation with signal from the adjacent fluid spaces. Inversion recovery can be used to null signal from fluid, but reduces SNR. The purpose of this work was to optimize inversion recovery sodium MRI to enhance cartilage SNR while nulling fluid. Sodium relaxation was first measured for knee cartilage (T1=21±1ms, T2fast∗=0.8±0.2ms, T2slow∗=19.7±0.5ms) and fluid (T1=48±3ms, T2∗=47±4ms) in nine healthy subjects at 4.7T. The rapid relaxation of cartilage in relation to fluid permits the use of a lengthened inversion pulse to preferentially invert the fluid components. Simulations of inversion pulse length were performed to yield a cartilage SNR enhancing combination of parameters that nulled fluid. The simulations were validated in a phantom and then invivo. B0 inhomogeneity was measured and the effect of off-resonance during the soft inversion pulse was assessed with simulation. Soft inversion recovery yielded twice the SNR and much improved sodium images of cartilage in human knee with little confounding signal from fluid.

Observer agreement in the reporting of knee and lumbar spine magnetic resonance (MR) imaging examinations: Selectively trained MR radiographers and consultant radiologists compared with an index radiologist

PurposeTo assess agreement between trained radiographers and consultant radiologists compared with an index radiologist when reporting on magnetic resonance imaging (MRI) examinations of the knee and lumbar spine and to examine the subsequent effect of discordant reports on patient management and outcome. MethodsAt York Hospital two MR radiographers, two consultant radiologists and an index radiologist reported on a prospective, random sample of 326 MRI examinations. The radiographers reported in clinical practice conditions and the radiologists during clinical practice. An independent consultant radiologist compared these reports with the index radiologist report for agreement. Orthopaedic surgeons then assessed whether the discordance between reports was clinically important. ResultsOverall observer agreement with the index radiologist was comparable between observers and ranged from 54% to 58%; for the knee it was 46–57% and for the lumbar spine was 56–66%. There was a very small observed difference of 0.6% (95% CI −11.9 to 13.0) in mean agreement between the radiographers and radiologists (P=0.860). For the knee, lumbar spine and overall, radiographers’ discordant reports, when compared with the index radiologist, were less likely to have a clinically important effect on patient outcome than the radiologists’ discordant reports. Less than 10% of observer's reports were sufficiently discordant with the index radiologist's reports to be clinically important. ConclusionCarefully selected MR radiographers with postgraduate education and training reported in clinical practice conditions on specific MRI examinations of the knee and lumbar spine to a level of agreement comparable with non-musculoskeletal consultant radiologists.

Three-Dimensional Characterization of the Anterior Cruciate Ligament's Femoral Footprint

There is increasing use of three-dimensional (3D) computed tomography (CT) for researching anterior cruciate ligament (ACL) reconstructions and tunnel placement. However, there is limited 3D CT data on the ACL footprint. The purpose of this study is to define the native ACL femoral footprint using 3D surface reconstructions of computed tomography (CT) imaging of cadaveric knees. The femoral insertion of the ACL was meticulously dissected and marked with drill holes in seven cadaveric knees. CT scans were performed on each specimen, and 3D computer models were created. Distance from the condyle edges to the margins of the footprint were referenced to the total condylar size. This was performed both parallel and perpendicular to the femoral axis as well as the intercondylar notch. The mean condylar depth (c/C) ratios along the axis of the femur were 0.45 ± 0.06 for the anterior border, 0.44 ± 0.08 for the posterior border, 0.26 ± 0.07 for the proximal border, and 0.63 ± 0.08 for the distal border. The mean notch (n/N) ratios for the four margins were 0.37 ± 0.04 for the anterior border, 0.67 ± 0.08 for the posterior border, 0.49 ± 0.07 for the proximal margin, and 0.50 ± 0.06 for the distal border. The mean c/C ratios parallel the intercondylar notch measured 0.23 ± 0.03 for the anterior border, 0.27 ± 0.04 for the posterior border, 0.37 ± 0.04 for the proximal border, and 0.12 ± 0.02 for the distal border. The mean n/N ratios perpendicular to the intercondylar notch measured 0.11 ± 0.06 for the anterior border, 0.52 ± 0.09 the posterior border, 0.29 ± 0.06 for the proximal border, and 0.30 ± 0.06 for the distal border. This study provides reference measures of the femoral footprint of the ACL using 3D CT. It will assist future studies that use advanced imaging to evaluate accuracy of ACL reconstruction.

FRI0323 The association of fat mass and skeletal muscle mass with knee OA: The neo study

BackgroundBody mass index (BMI) is an important risk factor for knee osteoarthritis (OA), but BMI depends only upon height and weight and gives no insight in underlying causal pathways.ObjectivesTo investigate...

AB1168 Clinical disease activity scores of knee joints in newly diagnosed JIA predicts reduction in bone pixel value detected by computed radiography

ObjectivesTo evaluate the relationship between Computed Radiography (CR) Pixel values and disease activity scores obtained for the knees of newly diagnosed Juvenile Idiopathic Arthritis (JIA) children.MethodsChildren with newly diagnosed untreated...

SP0159 The Check Cohort, What have we Learned so Far?

CHECK (Cohort Hip & Cohort Knee) is a cohort of 1002 subjects with pain and/or stiffness of one or both knee(s) and/or hip(s), age between 45 and 65 years, that...

OP0030 Identifying radiographic phenotypes of early knee osteoarthritis using separate quantitative features might improve patient selection for more targeted treatment

BackgroundOsteoarthritis (OA) is a degenerative joint disease characterized by pain and functional disability. The expression of OA varies significantly between individuals and over time, implying the existence of different phenotypes.ObjectivesThis...

AB1289 What is the influence of variation in knee positioning during image acquisition on separate quantitative radiographic parameters of osteoarthritis?

BackgroundThe clinical application of quantitative measurement of separate radiographic parameters of knee osteoarthritis (OA) might be hampered by a lack of reproducible joint positioning during acquisition of the radiographs.ObjectivesTo evaluate...

THU0437 Evaluation of separate quantitative radiographic features adds to the prediction of incident radiographic osteoarthritis in individuals with recent onset of knee pain: Five-year follow-up in the check cohort

BackgroundDetailed quantitative evaluation of knee radiographs might enable the identification of osteoarthritis (OA) earlier in the disease.ObjectivesTo evaluate whether and which separate features of radiographic damage, measured quantitatively in knees...

Identifying Phenotypes of Knee Osteoarthritis by Separate Quantitative Radiographic Features May Improve Patient Selection for More Targeted Treatment

Expression of osteoarthritis (OA) varies significantly between individuals, and over time, suggesting the existence of different phenotypes, possibly with specific etiology and targets for treatment. Our objective was to identify phenotypes of progression of radiographic knee OA using separate quantitative features. Separate radiographic features of OA were measured by Knee Images Digital Analysis (KIDA) in individuals with early knee OA (the CHECK cohort: Cohort Hip & Cohort Knee), at baseline and at 2-year and 5-year followup. Hierarchical clustering was performed to identify phenotypes of radiographic knee OA progression. The phenotypes identified were compared for changes in joint space width (JSW), varus angle, osteophyte area, eminence height, bone density, for Kellgren-Lawrence (K-L) grade, and for clinical characteristics. Logistic regression analysis evaluated whether baseline radiographic features and demographic/clinical characteristics were associated with each of the specific phenotypes. The 5 clusters identified were interpreted as "Severe" or "No," "Early" or "Late" progression of the radiographic features, or specific involvement of "Bone density." Medial JSW, varus angle, osteophyte area, eminence height, and bone density at baseline were associated with the Severe and Bone density phenotypes. Lesser eminence height and bone density were associated with Early and Late progression. Larger varus angle and smaller osteophyte area were associated with No progression. Five phenotypes of radiographic progression of early knee OA were identified using separate quantitative features, which were associated with baseline radiographic features. Such phenotypes might require specific treatment and represent relevant subgroups for clinical trials.

Anatomic Double-Bundle Reconstruction Techniques Result in Graft Obliquities That Closely Mimic the Native Anterior Cruciate Ligament Anatomy

Background: It has been reported previously that single-bundle anterior cruciate ligament (ACL) reconstruction with more accurate restoration of the footprint of the native ACL fails to restore the graft obliquity of the native ACL in the coronal plane. Whether double-bundle ACL reconstruction restores the graft obliquity of each bundle of the native ACL has not yet been determined. Hypothesis: Anatomic double-bundle ACL reconstruction using transportal (TP) and outside-in (OI) techniques can restore the graft obliquities of both anteromedial (AM) and posterolateral (PL) bundles in the native ACL in both sagittal and coronal planes. Study Design: Cohort study; Level of evidence, 2. Methods: Seventy-six patients underwent anatomic double-bundle ACL reconstruction. Patients were randomized to 2 groups to undergo either TP or OI tibial tunnel–independent anatomic ACL reconstruction. All participants underwent postoperative magnetic resonance imaging of both knees, and the native ACL obliquity was determined using the participant’s contralateral knee. Graft obliquities were determined by measuring the angles between the center line of the graft and the surface line of the tibial plateau, and the obliquities of paired knees were compared. Graft obliquities were analyzed in each group. Results: In the sagittal plane, the mean AM graft obliquity was 54.2° on the operated side and 54.6° on the nonoperated side, and the difference between sides was not statistically significant (P = .352). The mean PL graft obliquity in the sagittal plane was 54.1° on the operated side and 53.0° on the nonoperated side, and the difference between sides was also not statistically significant (P = .228). In the coronal plane, the mean AM graft obliquity was 73.8° on the operated side and 73.4° on the nonoperated side, and the mean PL graft obliquity was 65.5° on the operated side and 66.4° on the nonoperated side. There were no statistically significant differences between sides (P = .418 for AM graft; P = .328 for PL graft). Differences in the paired graft obliquities in each group were also statistically insignificant between the TP and OI groups. Conclusion: Both TP and OI anatomic double-bundle reconstruction techniques can result in graft obliquities in both bundles that resemble the native ACL in both sagittal and coronal planes. Clinical Relevance: Double-bundle ACL reconstruction techniques might more closely restore the normal kinematics of the native ACL by restoring the normal obliquity of both ACL bundles.

New Applications in Anatomical Education Using Soft‐Embalmed Cadavers

Soft embalming (Thiel, W. Annals of Anatomy 174:185–195; 184:267–269) began at VSAP in June, 2012. The method shares with fresh bodies and a commercial no‐formaldehyde embalming procedure the highly desirable characteristics of absence of formaldehyde fumes, natural tissue color, and flexibility of structures, but it also offers an extended time of utilization because of its superior preservational and antimicrobial properties, without mold or deterioration for at least six months. Soft‐embalmed bodies require a “cure time” of 3 to 4 weeks and also cause a superficial epidermal desquamation with occasional fluid‐filled bullae, easily removed after embalming. Dissections on a soft‐embalmed female demonstrate the didactic advantages of the method: palmar aspect of the hand, especially the relationships of the deep and superficial flexors; infratemporal fossa and superolateral neck elucidating multi‐level relationships of the glossopharyngeal nerve and related structures; urogenital and anal triangles of the perineum with clear visualization of the urogenital diaphragm, pelvic diaphragm, and pudendal canal; and clear ultrasound imaging of knee and wrist joints, severely limited on formalized specimens. The relative ease of dissection, ready identification of structures, and formaldehyde‐free environment strongly recommend soft embalming for active learning in anatomical education.

Bone marrow lesion regression is associated with worsening peri-articular bone: data from the Osteoarthritis Initiative

Bone marrow lesion regression is associated with worsening peri-articular bone: data from the Osteoarthritis Initiative

Automatic segmentation of articular cartilage from combined assessment of sodium and proton MR knee images

Automatic segmentation of articular cartilage from combined assessment of sodium and proton MR knee images