Elbow stiffness: effectiveness of conventional radiography and CT to explain osseous causes.
Zubler Veronika,Saupe Nadja,Jost Bernhard,Pfirrmann Christian W A,Hodler Juerg,Zanetti Marco
AJR. American journal of roentgenology
OBJECTIVE:The purpose of our study was to evaluate the effectiveness of conventional radiography and CT for explaining the osseous causes of elbow stiffness. MATERIALS AND METHODS:Two independent readers analyzed loose bodies and osteophytes on conventional radiography and CT (or CT arthrography) of the elbow in 94 consecutive patients (71 men, 23 women; mean age, 41 years; range, 18-68 years). Arthroscopic or surgical correlation was available in 58 (62%) patients. In all 94 patients, the expected restriction of motion was measured on images and correlated (Pearson's correlation) with the clinical restriction of motion. Kappa statistics were performed for interobserver agreement. RESULTS:Accuracy for detecting loose bodies was 67% with conventional radiography and 79% with CT. Differences in accuracy were most pronounced for detecting loose bodies in the posterior joint space (64% for conventional radiography vs 79% for CT). Accuracy for detecting osteophytes was 69% with conventional radiography and 76% with CT. Expected restriction of motion on conventional radiography correlated significantly with clinical restriction for only one reader for flexion (R = 0.21, p = 0.04). Expected restriction of extension on CT correlated significantly with clinical restriction of motion by both readers (R = 0.34 and 0.33, p = 0.001 and 0.001, respectively). Expected restriction of flexion on CT correlated significantly by one reader (R = 0.24, p = 0.02). Interobserver agreement with regard to detection of both loose bodies and osteophytes was higher for CT (kappa = 0.83 and 0.76) than for conventional radiography (0.64 and 0.60). CONCLUSION:CT is more effective than conventional radiography in explaining the osseous causes of elbow stiffness.
10.2214/AJR.09.3741
Improved demonstration of cartilage narrowing in the knee joint using standing PA flexed radiographs.
Scott William W,Beall Douglas P,Eng John,Matthiesen Chance L,Prater Scott,Enis John
The Journal of the Oklahoma State Medical Association
OBJECTIVE:To compare standing PA flexed (SPAF) knee radiographs of the knees with standing full-extension AP(SAP) radiographs for demonstration of narrowing of the articular cartilage of the knee joint and the presence and size of osteophytes and to determine if sclerosis is a predictor of the severity of joint space narrowing. DESIGN:220 knees in 110 consecutive patients visiting the orthopaedic clinic with knee pain and having both SPAF radiographs and SAP radiographs at the same visit were evaluated by a musculoskeletal radiologist for cartilage narrowing in the knee joint using a scale 0-3 with 0= normal and 3= bone on bone. Osteophytes were also graded 0-3 and sclerosis as present or absent. PATIENTS:The subjects were patients of one of the authors (C.A.J) who ordered both types of radiographs on most of his patients. RESULTS:In 47% of knees the SPAF radiograph showed narrowing more severe than the SAP radiograph. In 5% the SAP view showed narrowing more severe than the SPAF view. In the medial compartment the SPAF view showed significantly larger osteophytes than the SAP view. The osteophyte size difference was not significant in the lateral compartment. If sclerosis was present on the AP view, there was a greater than 80% chance that the SPAF view would show greater narrowing. CONCLUSION:The SPAF radiograph frequently shows more cartilage narrowing in the knee joint than does the SAP view. It is valuable for routine use or when the clinical severity of arthritis in the knee joint seems to be greater than that demonstrated on the AP standing view. Sclerosis on the SAP view makes it especially likely that the SPAF view will show greater cartilage narrowing.
Magnetic resonance imaging of subjects with acute unilateral neck pain and restricted motion: a prospective case series.
Fryer Gary,Adams James Hughes
The spine journal : official journal of the North American Spine Society
BACKGROUND CONTEXT:Zygapophyseal joint injury and inflammation have been proposed as causes of acute benign spinal pain, but this etiology has not been investigated. PURPOSE:To investigate the presence of periarticular tissue inflammation and zygapophysial joint synovitis in the cervical region using magnetic resonance imaging (MRI) in subjects with acute unilateral cervical pain and limited motion (acute "crick in the neck" <48 hours from onset), as well as the feasibility of recruiting these subjects. STUDY DESIGN/SETTING:Three-month case series in a university setting and private radiology clinic. PATIENT SAMPLE:Five subjects (three women and two men; mean age, 31.6 years; standard deviation [SD], 12.4). METHODS:Each subject was examined by a researcher experienced in manual medicine to assess active range of neck movement and the side and symptomatic segmental level of pain. Subjects then underwent a blinded MRI investigation, which included sagittal images through the entire neck and cervical spine and axial images from C2 to T1. Evidence of capsule or periarticular edema and joint space T2 increase was recorded and scored. Additionally, signs of muscle edema, alignment, disc disease, facet arthritic change, and spinal stenosis were recorded. RESULTS:Subjects presented with mean current pain of 4.8 (SD, 1.6; visual analog scale, 0-10), worst pain since onset of 7.0 (SD, 0.7), and duration of symptoms of 12.4 hours (SD, 14.1). The plane of active motion most commonly limited was rotation to the painful side, followed by side bending to the painful side and extension. No MRI findings demonstrated clear evidence of synovial effusion or inflammation around the joints of the cervical spine. In some individuals, signs of muscle edema, altered alignment, disc and facet arthrosis, and spinal stenosis were noted, but these did not appear to be related to the side of pain or symptomatic level. CONCLUSIONS:No evidence of cervical joint inflammation was detected, and more sensitive imaging methods may be required to detect inflammatory changes in or around the cervical joints of subjects with acute benign neck pain. Recruitment of subjects with acute "crick in the neck" pain (<48 hours duration) is difficult but feasible over a long data collection period.
10.1016/j.spinee.2010.12.002
The posteroanterior 45 degrees flexion weight-bearing radiograph of the knee.
Mason R B,Horne J G
The Journal of arthroplasty
Biomechanical studies suggest that radiographs of the osteoarthritic knee taken in 30 degrees to 60 degrees of flexion more accurately demonstrate the true degree of articular cartilage loss than radiographs taken with the knee in full extension. Conventional anteroposterior weight-bearing full-extension radiographs were compared with posteroanterior 45 degrees flexion weight-bearing radiographs of 35 patients with 45 symptomatic knees (90 compartments) presenting with suspected osteoarthritis. In 35 compartments, there was a 2-mm or greater loss of joint space in the 45 degrees flexion views compared with those taken in full extension. Also, in 11 compartments (10 knees), there was a normal joint space on the full extension radiographs, but marked narrowing on the flexion view. Both results are statistically significant. It is concluded that the posteroanterior 45 degrees flexion weight-bearing radiograph is a useful additional tool in the assessment of knees with early degenerative change.
Posterior-anterior weight-bearing radiograph in 15 degree knee flexion in medial osteoarthritis.
Yamanaka Norio,Takahashi Toshiaki,Ichikawa Norikazu,Yamamoto Hiroshi
Skeletal radiology
OBJECTIVE:To evaluate the degree of knee flexion at which: (1) degenerative joint space narrowing is best seen, (2) the tibial plateau is best visualized and (3) the tibiofemoral angle is most correct, in order to assess the degree of flexion in the anteroposterior radiographic view that is most useful for assessing medial compartment osteoarthritis (OA) of the knee. DESIGN AND PATIENTS:We compared the conventional extended view of the knee and views at 15 degrees, 30 degrees, and 45 degrees of flexion with respect to joint space narrowing, alignment of the medial tibial plateau (MTP), and tibiofemoral angles in 113 knees of 95 patients with medial osteoarthritis of the knee (22 men, 73 women; mean age 67 years). RESULTS:At the midpoint and the narrowest point of the medial compartment, joint space narrowing values at 15 degrees, 30 degrees, and 45 degrees of flexion of the knee were smaller than that of the conventional extended view. Superimposition of the margins of the tibial plateau was satisfactory in 12% of patients in the conventional extended view, in 36% at 15 degrees of flexion, in 20% at 30 degrees of flexion, and in 19% at 45 degrees of flexion of the knee. When the knee was at 15 degrees of flexion there was a smaller difference in the tibiofemoral angle, in comparison with the knee extended, than was the case at 30 degrees and 45 degrees of flexion in patients with medial OA. CONCLUSION:A posteroanterior view with 15 degrees of flexion of the knee was able to detect joint space narrowing accurately, to achieve good alignment of the MTP in the medial compartment, and to reduce the difference in tibiofemoral angle compared with a view of the knee in conventional extension, and may be an alternative view in cases of medial OA of the knee.
10.1007/s00256-002-0574-0
Associations between pain, function, and radiographic features in osteoarthritis of the knee.
Szebenyi Béla,Hollander Anthony P,Dieppe Paul,Quilty Brian,Duddy John,Clarke Shane,Kirwan John R
Arthritis and rheumatism
OBJECTIVE:To assess the associations between pain, loss of function, and radiographic changes in knee osteoarthritis (OA), taking into account both the patellofemoral and tibiofemoral compartments. METHODS:Both knees of 167 community-based patients with OA in at least 1 of their knees were assessed. Pain was measured by visual analog scale, and function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index. Anteroposterior standing radiographs with the knee in extension and lateral 30 degrees flexion were obtained and assessed for the Kellgren/Lawrence score and for individual features (osteophytes, joint space narrowing, and subchondral bone sclerosis) in each compartment. RESULTS:Knees with structural changes in both compartments were more likely to be painful and to be associated with loss of function than were knees in which only 1 compartment was affected. The individual feature most strongly associated with pain was subchondral bone sclerosis. CONCLUSION:Studies exploring the associations between structural and symptomatic knee OA need to include an assessment of the patellofemoral compartment, and individual radiographic features rather than a global severity score should be considered in these studies.
10.1002/art.21534
Stress radiography for osteoarthritis of the knee: a new technique.
Eriksson Karl,Sadr-Azodi O,Singh C,Osti L,Bartlett J
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA
Stress radiographs have been used for several years to detect the amount of varus/valgus knee laxity and to evaluate the degree of compartmental involvement in degenerative osteoarthritis. However, the popularity of these radiographic methods has been affected by their technical limits due to the x-ray exposure for the personnel involved and the variability of the stress forces applied. A device was developed with the aim to create a constant varus or valgus stress force to the knee with the patient in a supine position. The device does not require personal assistance during the actual film taking. Sixty consecutive patients where included in the study and measured prior to their total knee replacement. All patients had standard weight-bearing AP and lateral views as well as stress views in varus and valgus. Both knees were examined in full extension and 30° of flexion. The joint space width in both the lateral and medial compartments were measured and subsequently compared with the standard weight-bearing films. A significant decrease in joint space distance in the affected compartment was found in the stress radiographs compared with the standard weight-bearing views. The medial compartment was best examined with the knee extended and varus stress force (P < 0.001) and for the lateral compartment 30° of flexion proved to be more efficient (P < 0.01). In conclusion, this stress radiographic device offers a possibility to enhance the varus/valgus force in a standardized way compared to standard weight-bearing views of the knee. The reliability and reproducibility is high. It is suitable for clinical practice and a valuable tool in research.
10.1007/s00167-010-1169-2
Reproducibility of joint space width and the intermargin distance measurements in patients with medial osteoarthritis of the knee in various degrees of flexion.
Takahashi Toshiaki,Yamanaka Norio,Ikeuchi Masahiko,Yamamoto Haruyasu
Skeletal radiology
OBJECTIVE:This study tested the variability and reproducibility of measurements of the joint space width (JSW) and intermargin distance (IMD) of the medial tibial plateau in specific positions of knee flexion in osteoarthritic knees in order to evaluate the most useful knee angle for radiographic measurements. DESIGN:Radiographs from 56 knees with osteoarthritis from 46 patients were taken with the knees in conventional full extension and 15 degrees , 30 degrees , and 45 degrees of flexion with weight bearing. Three orthopedic surgeons independently measured the JSW and IMD at the narrowest point and the midpoint of medial tibial plateau using a computer-assisted method. RESULTS:The JSW and IMD were smallest at 15 degrees flexion, both measured at the narrowest point and the midpoint of the medial compartment. Reproducibility of the IMD at the midpoint was better than at the narrowest point for all four flexion angles. CONCLUSION:Measurements of the medial JSW and IMD are smallest at 15 degrees of knee flexion indicating that radiographs should be obtained at this angle in order to best demonstrate the extent of osteoarthritis.
10.1007/s00256-008-0572-y
Quantitative evaluation of joint space width in femorotibial osteoarthritis: comparison of three radiographic views.
Piperno M,Hellio Le Graverand M P,Conrozier T,Bochu M,Mathieu P,Vignon E
Osteoarthritis and cartilage
OBJECTIVE:Quantitative evaluation of radiographic methods proposed to improve the detection of joint space narrowing (JSN) in femorotibial osteoarthritis (OA). METHODS:Thirty-two consecutive patients with knee OA and five normal controls had three different weight-bearing radiographs of the knee: (1) anteroposterior film of both knees in full extension (extended knees), (2) anteroposterior film of one knee in extension while the patient was standing on the homolateral foot (standing on homolateral foot), (3) posteroanterior film of both knees flexed at 30 degrees (schuss view). Joint space was analyzed blind using both an evaluation of JSN with a six-grade scale (JSN score) and an image analyser computer measurement of the mean joint space width (mean JSW). The medial compartment of medial femorotibial OA knees, the lateral compartment of lateral femorotibial OA knees, as well as both compartments of control knees, were measured. Extended knee and schuss views were made 1 year later in 10 patients for the evaluation of sensitivity to change. RESULTS:The JSN scores +/- S.D. in schuss, standing on the homolateral foot and extended knee views were 2.75 +/- 1.31, 1.95 +/- 1.3 and 1.66 +/- 1.27, respectively. The mean JSW +/- S.D. in schuss, standing on the homolateral foot, and extended knee views were 2.9 +/- 1.9 mm, 3.5 +/- 1.6 mm and 3.8 +/- 1.5 mm, respectively. Changes in JSN scores and mean JSW with schuss view increased with OA severity. In controls, JSW of the medial compartment did not vary in the three views. JSW of the lateral compartment of controls was significantly larger in the schuss view. The change in JSW after 1 year was -0.41 mm (P = 0.02) in the schuss view and -0.17 mm (P > 0.05) in the extended knee view. CONCLUSION:The schuss view is suggested as the most accurate method for the evaluation of JSW in femorotibial OA.
10.1053/joca.1998.0118
Joint space narrowing and Kellgren-Lawrence progression in knee osteoarthritis: an analytic literature synthesis.
Emrani P S,Katz J N,Kessler C L,Reichmann W M,Wright E A,McAlindon T E,Losina E
Osteoarthritis and cartilage
OBJECTIVE:While the interpretation of cartilage findings on magnetic resonance imaging (MRI) evolves, plain radiography remains the standard method for assessing progression of knee osteoarthritis (OA). We sought to describe factors that explain variability in published estimates of radiographic progression in knee OA. DESIGN:We searched PubMed between January 1985 and October 2006 to identify studies that assessed radiographic progression using either joint space narrowing (JSN) or the Kellgren-Lawrence (K-L) scale. We extracted cohort characteristics [age, gender, and body mass index (BMI)] and technical and other study factors (radiographic approach, study design, OA-related cohort composition). We performed meta-regression analyses of the effects of these variables on both JSN and K-L progression. RESULTS:Of 239 manuscripts identified, 34 met inclusion criteria. The mean estimated annual JSN rate was 0.13 +/- 0.15 mm/year. While we found no significant association between JSN and radiographic approach among observational studies, full extension was associated with greater estimated JSN among randomized control trials (RCTs). Overall, observational studies that used the semi-flexed approach reported greater JSN than RCTs that used the same approach. The overall mean risk of K-L progression by at least one grade was 5.6 +/- 4.9%, with higher risk associated with shorter study duration, OA definition (K-L > or = 2 vs K-L > or = 1) and cohorts composed of subjects with both incident and prevalent OA. CONCLUSION:While radiographic approach and study design were associated with JSN, OA definition, cohort composition and study duration were associated with risk of K-L progression. These findings may inform the design of disease modifying osteoarthritis drug (DMOAD) trials and assist clinicians in optimal timing of OA treatments.
10.1016/j.joca.2007.12.004
Are joint structure and function related to medial knee OA pain? A pilot study.
Zifchock Rebecca Avrin,Kirane Yatin,Hillstrom Howard,
Clinical orthopaedics and related research
BACKGROUND:Although the severity of knee osteoarthritis (OA) usually is assessed using different measures of joint structure, function, and pain, the relationships between these measures are unclear. PURPOSE:Therefore, we: (1) examined the relationships between the measures of knee structure (flexion-extension range of motion, radiographic tibiofemoral angle, and medial joint space), function (Knee Osteoarthritis Outcome Scores [KOOS], peak adduction angle, and moment), and pain (visual analog scale [VAS]); and (2) identified variables that best predicted knee pain. METHODS:We assessed 15 patients with medial knee OA using VAS pain, KOOS questionnaire, 3-D gait analysis, and radiographic examination. Parameter relationships were assessed using Pearson correlation, and variables most predictive of knee pain were determined using a stepwise multiple regression. RESULTS:Subjective measurements correlated (|r| ≥ 0.54) with one another, as did most of the objective measurements (|r| ≥ 0.56) except for adduction moment which did not correlate with any variable. All variables correlated (|r| > 0.54) with VAS knee pain except peak adduction moment. Medial joint space and peak adduction angle best predicted knee pain, accounting for approximately three-quarters of the model variance (r(2) = 0.73). CONCLUSIONS:Medial joint space and peak adduction angle may be useful for predicting knee pain in patients with medial knee OA. Therapies that target these structural and functional variables may reduce knee pain in this population. CLINICAL RELEVANCE:Increasing the medial joint space and limiting the peak knee adduction angle may be critical in achieving effective pain relief in patients with varus knee OA.
10.1007/s11999-011-1969-9
Knee pain reduces joint space width in conventional standing anteroposterior radiographs of osteoarthritic knees.
Mazzuca Steven A,Brandt Kenneth D,Lane Kathleen A,Katz Barry P
Arthritis and rheumatism
OBJECTIVE:A suspected, but heretofore undemonstrated, limitation of the conventional weight-bearing anteroposterior (AP) knee radiograph, in which the joint is imaged in extension, for studies of progression of osteoarthritis (OA) is that changes in knee pain may affect extension, thereby altering the apparent thickness of the articular cartilage. The present study was undertaken to examine the effect of changes in knee pain of varying magnitudes on radiographic joint space width (JSW) in the weight-bearing extended and the semiflexed AP views, in which radioanatomic positioning of the knee was carefully standardized by fluoroscopy. METHODS:Fifteen patients with knee OA underwent a washout of their analgesic/nonsteroidal antiinflammatory drug (NSAID) agents (duration 5 half-lives), after which standing AP and semiflexed AP knee radiographs of both knees were obtained. Examinations were repeated 1-12 weeks later (median 4.5 weeks, mean 6.0 weeks), after resumption of analgesic/NSAID therapy. Knee pain was measured with the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index (Likert scale). JSW was measured with a pair of calipers and a magnifying lens. Mixed model analyses of variance were used to test the significance of changes in pain and JSW within and between 2 groups of knees with mild-to-moderate radiographic severity of OA: (a) "flaring knees," in which the patient rated standing knee pain as severe or extreme after the washout and in which pain decreased to any degree after resumption of analgesics and/or NSAIDs (n = 12) and (b) "nonflaring knees," in which standing knee pain was absent, mild, or moderate after the washout or did not decrease after resumption of treatment (n = 15). RESULTS:After reinstitution of treatment, WOMAC pain scores decreased significantly in both flaring and nonflaring knees (-44%; P < 0.0001 and -18%; P < 0.01, respectively). After adjustment for the within-subject correlation between knees, mean JSW (+/-SEM) in the extended view of the flaring OA knee increased significantly from the first to second examination (0.20 +/- 0.06 mm; P = 0.005). In contrast, the change in adjusted mean JSW in the extended view of the nonflaring OA knee was negligible (-0.04 +/- 0.04 mm) and significantly smaller than that observed in flaring knees (P < 0.01). Mean JSW in the semiflexed AP view was unaffected by the severity or responsiveness of standing knee pain in flaring and nonflaring OA knees. CONCLUSION:JSW in weight-bearing extended-view radiographs of highly symptomatic OA knees can be altered significantly by changes in joint pain. In clinical trials and in epidemiologic studies of OA progression that use this radiographic technique, longitudinal variations in pain may confound changes in the apparent thickness of the articular cartilage.
10.1002/art.10256
Radiographic measurement of joint space height in non-osteoarthritic tibiofemoral joints. A comparison of weight-bearing extension and 30 degrees flexion views.
Deep K,Norris M,Smart C,Senior C
The Journal of bone and joint surgery. British volume
There have been many reports which suggest that in patients with tibiofemoral osteoarthritis, a reduction in joint space is demonstrated better on weight-bearing radiographs taken with the knee in semiflexion than in full extension. The reduction has been attributed to the loss of articular cartilage in the contact area in a semiflexed arthritic knee. None of these studies have, however, included normal knees. We have therefore undertaken a prospective, double-blind, randomised study in order to evaluate the difference in the joint-space of arthroscopically-proven normal tibiofemoral joints as seen on weight-bearing full-extension and 30 degrees flexion posteroanterior radiographs. Twenty-two knees were evaluated and the results showed that there may be a difference of up to 2 mm in the two views. This difference could be attributed to the inherent differential thickness of the articular cartilage in different areas of the femoral and tibial condyles and a change in the areas of contact between them.
Relief in mild-to-moderate pain is not a confounder in joint space narrowing assessment of full extension knee radiographs in recent osteoarthritis structure-modifying drug trials.
Pavelka K,Bruyere O,Rovati L C,Olejárova M,Giacovelli G,Reginster J-Y
Osteoarthritis and cartilage
OBJECTIVE:To assess whether improvement in knee pain biased the determination of the structure-modifying effect reported for glucosamine sulfate in two recent 3-year, randomised, placebo-controlled clinical trials, in which conventional standing antero-posterior full extension knee radiographs were used for the measurement of joint space narrowing, and in which pain relief might have improved knee full extension. DESIGN:Patients completing the 3-year treatment course were selected based on a WOMAC pain decrease at least equal to the mean improvement in the glucosamine sulfate arms in either of the original studies, irrespective of treatment with glucosamine sulfate or placebo (drug responders or placebo responders). In a second approach, 3-year completers were selected if their baseline standing knee pain (item #5 of the WOMAC pain scale) was 'severe' or 'extreme' and improved by any degree at the end of the trials. In both cases, changes in minimum joint space width were compared between treatment groups. RESULTS:Global knee pain was mild-to-moderate in the two study populations and in all patient subsets identified. There were obviously more pain improvers in the glucosamine sulfate subsets (N=76 in the two studies combined) than in the placebo subsets (N=57), but WOMAC pain scores improved to the same extent, which was as large as over 50% relative to baseline. Nevertheless, the placebo subsets in both studies underwent an evident mean (SD) joint space narrowing, which in the pooled analysis of both studies was -0.22 (0.80) mm, and was not observed with glucosamine sulfate: +0.15 (0.60) mm (P=0.003 vs placebo). Similar results were found in the smaller subsets with > or = severe baseline standing knee pain that improved after 3 years, with a joint space narrowing nevertheless of -0.28 (0.76) mm with placebo (N=26), not observed with glucosamine sulfate: +0.21 (0.68) mm (N=31; P=0.014 vs placebo). CONCLUSIONS:Knee pain relief did not bias the report of a structure-modifying effect of glucosamine sulfate in two recent long-term trials using conventional standing antero-posterior radiographs, possibly due to the mild-to-moderate patient characteristics.
10.1016/s1063-4584(03)00166-3
Difference in the joint space of the medial knee compartment between full extension and Rosenberg weight-bearing radiographs.
Miura Yugo,Ozeki Nobutake,Katano Hisako,Aoki Hayato,Okanouchi Noriya,Tomita Makoto,Masumoto Jun,Koga Hideyuki,Sekiya Ichiro
European radiology
OBJECTIVES:Radiographs are the most widespread imaging tool for diagnosing osteoarthritis (OA) of the knee. Our purpose was to determine which of the two factors, medial meniscus extrusion (MME) or cartilage thickness, had a greater effect on the difference in the minimum joint space width (mJSW) at the medial compartment between the extension anteroposterior view (extension view) and the 45° flexion posteroanterior view (Rosenberg view). METHODS:The subjects were 546 participants (more than 50 females and 50 males in their 30 s, 40 s, 50 s, 60 s, and 70 s) in the Kanagawa Knee Study. The mJSW at the medial compartment was measured from both the extension and the Rosenberg views, and the "mJSW difference" was defined as the mJSW in the Rosenberg view subtracted from the mJSW in the extension view. The cartilage region was automatically extracted from MRI data and constructed in three dimensions. The medial region of the femorotibial joint cartilage was divided into 18 subregions, and the cartilage thickness in each subregion was determined. The MME was also measured from MRI data. RESULTS:The mJSW difference and cartilage thickness were significantly correlated at 4 subregions, with 0.248 as the highest absolute value of the correlation coefficient. The mJSW difference and MME were also significantly correlated, with a significantly higher correlation coefficient (0.547) than for the mJSW difference and cartilage thickness. CONCLUSIONS:The MME had a greater effect than cartilage thickness on the difference between the mJSW at the medial compartment in the extension view and in the Rosenberg view. KEY POINTS:• The difference in the width at the medial compartment of the knee between the extension and the flexion radiographic views was more affected by medial meniscus extrusion than by cartilage thickness.
10.1007/s00330-021-08253-6