| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Musculoskeletal Imaging |
1 From the Departments of Radiology (T.M.L., L.S.S., S.G., Y.L., S.M.), Orthopedic Surgery (M.R.), and Medicine (N.L.), University of California, San Francisco. Received January 22, 2002; revision requested March 20; revision received April 30; accepted June 25. Supported by National Institutes of Health grants RO1-AR46905 and RO1-AG17762. Address correspondence to T.M.L., Department of Radiology, Technische Universitaet Muenchen, Ismaninger Str 22, 81675 Munich, Germany (e-mail: tmlink@roe.med.tu-muenchen.de).
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
MATERIALS AND METHODS: Radiographs in 50 patients with varying degrees of osteoarthritis of the knee were assessed by using the the Western Ontario and McMaster University (WOMAC) osteoarthritis index and the Kellgren-Lawrence (KL) scale. MR images were obtained and analyzed by two readers for cartilage lesions, bone marrow edema pattern, and ligamentous and meniscal lesions.
RESULTS: Thirteen of 16 knees with a KL score of 4 showed full-thickness cartilage lesions and bone marrow edema pattern. Cruciate ligament tears were found in five of 12 knees with a KL score of 3 and in nine of 16 knees with a KL score of 4. While the KL score correlated significantly (P < .05) with the grade of cartilage lesions, and a substantially higher percentage of lesions with higher KL scores were found on MR images, the correlations between MR imaging findings and KL score versus clinical findings were not significant (P > .05). Significant differences between WOMAC scores were found only for the grades of cartilage lesions (P < .05).
CONCLUSION: Cartilage lesions, bone marrow edema pattern, and meniscal and ligamentous lesions were frequently demonstrated on MR images in patients with advanced osteoarthritis. Clinical findings showed no significant correlations with KL score and extent of findings at MR imaging.
© RSNA, 2003
Index terms: Arthritis, degenerative, 452.4851, 452.711 • Cartilage, MR, 4521.121412, 4521.121415 • Knee, arthritis, 452.4851, 452.711 • Knee, ligaments, menisci, and cartilage, 452.4851 • Knee, MR, 4521.121412, 4521.121415
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
Radiography is still standard for assessment of the progression of osteoarthritis, and the Kellgren-Lawrence (KL) scale (12,13) is used most frequently by clinicians. The KL scale was also adopted by the World Health Organization as the reference standard for cross-sectional and longitudinal epidemiologic studies. As yet, however, it is not well known what abnormalities to expect at magnetic resonance (MR) imaging at different stages of disease and whether MR imaging may be useful as an additional diagnostic tool, given a specific grade of osteoarthritis.
In addition, since pain, stiffness, and limited function are the most clinically important problems in patients with osteoarthritis, it is important to correlate these symptoms with abnormal MR imaging and radiographic findings. Clinical scores for osteoarthritis have been developed to measure relevant patient outcome in drug trials. One of the most well established scores is the Western Ontario and McMaster University (WOMAC) osteoarthritis index, a multidimensional health status instrument (14,15) that quantifies pain, stiffness, and limited function in patients with osteoarthritis of the knee and hip.
The purpose of this study was to analyze findings on MR images of the knee obtained at different stages of osteoarthritis and to determine whether pain, stiffness, and limited function correlate with the degree of disease assessed on MR images and radiographs.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
All patients were examined clinically, and WOMAC scores (14) were determined. The WOMAC system was developed to quantify symptoms related to osteoarthritis and to assess relevant patient outcome in drug trials. This well-established clinical grading system quantifies the degree of pain, functional impairment, and stiffness in patients with osteoarthritis.
The patients were interviewed by an orthopedic surgeon (M.R.), and questions concerning the amount of knee pain and stiffness the patients were currently experiencing were answered by using a five-point scale (none, slight, moderate, severe, and extreme). In addition, patients answered questions to assess physical function—that is, the ability to move around and take care of themselves. These questions focused on the ability of the patients to perform such functions as descending and ascending stairs, standing, walking, rising from bed, and going shopping. On the basis of the answers to these questions, the overall WOMAC scores were determined. The scores varied from 0 (no pain, stiffness, or functional impairment) to 500 (extreme pain, stiffness, and functional impairment).
Imaging
In all patients, radiographs of the knee were obtained in lateral and anteroposterior planes. In addition, a sunrise view of the patellofemoral joint was obtained. MR imaging of the knee was performed with a 1.5-T MR imager (Signa; GE Medical Systems, Waukesha, Wis) by using a bilateral dual phased-array coil (USA Instruments, Cleveland, Ohio) for signal reception. Since patients with symptomatic knees were examined by using a fairly long acquisition protocol, reduction of motion artifacts and accuracy of patient and coil positioning were optimized by positioning the knee flexed (30°–35°) on a dedicated holder (machined in-house, 152° angle). Patients were immobilized by using hook-and- loop straps.
The MR imaging protocol included five pulse sequences. The first was a sagittal high-spatial-resolution volumetric fat-suppressed spoiled gradient-echo sequence. Imaging parameters were as follows: 30/8 (repetition time msec/echo time msec), flip angle of 30°, matrix of 512 x 256, field of view of 12 cm, one signal acquired, and acquisition time of 9 minutes 31 seconds with 64 sections. The in-plane spatial resolution was 0.234 x 0.234 mm2, and the section thickness was 2 mm.
The second and third sequences were coronal and sagittal, respectively, T2-weighted fat-suppressed fast spin-echo sequences with 3,000/70, echo train length of eight, matrix of 256 x 192, field of view of 14 cm, one signal acquired, bandwidth of 16 kHz, acquisition time of 2 minutes 36 seconds, and section thickness of 4 mm.
The fourth and fifth sequences were coronal and sagittal, respectively, T1-weighted spin-echo sequences with 500/9, matrix of 256 x 192, field of view of 14 cm, one signal acquired, bandwidth of 16 kHz, acquisition time of 3 minutes 28 seconds, and section thickness of 4 mm.
Image Analysis
All radiographs and MR images were analyzed by two radiologists (L.S.S., T.M.L.) in consensus without knowledge of patient age or sex. To obviate recall bias, MR images and radiographs were analyzed separately in random order. The radiographic findings were scored according to the KL scale, which is a standard radiologic grading system for osteoarthritis (12,13). Features considered evidence of osteoarthritis were osteophytes in the joint margins, narrowing of joint spaces, and subchondral sclerosis. On the basis of these features, the following KL scores were defined (Fig 1): 0, no features of osteoarthritis; 1, doubtful osteoarthritis, with minute osteophytes of doubtful importance; 2, minimal osteoarthritis, with definite osteophytes but unimpaired joint space; 3, moderate osteoarthritis, with osteophytes and moderate diminution of joint space; and 4, severe osteoarthritis, with greatly impaired joint space and sclerosis of subchondral bone.
|
Cartilage lesions were graded in a manner analogous to the Noyes and Stabler (16) classification, which was modified for MR imaging by Recht et al (3): Grade I lesions were defined as having areas of inhomogeneous signal intensity on high-spatial-resolution spoiled gradient-echo images; grade IIa lesions, as cartilage defects that involved less than half of the articular cartilage thickness; grade IIb lesions, as cartilage defects involving more than half of the cartilage but less than full thickness; and grade III lesions, as cartilage defects exposing the bone.
Bone marrow edema pattern was defined as diffuse subchondral low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Edema pattern was mild when it was less than 1 cm in diameter in the long axis on fat-suppressed T2-weighted images. It was moderate when its diameter was 1–2 cm and severe when its diameter was larger than 2 cm in the long axis. Osteophytes were classified as mild when they were located in the joint margins and were less than 0.5 cm in diameter when measured from the base to the tip on T1-weighted images; when osteophytes were larger than 0.5 cm in diameter, they were defined as severe.
For correlation with KL and WOMAC scores, the most advanced cartilage lesions and the most severe bone marrow edema patterns or other findings in the individual joint were used. Meniscal lesions included meniscal tears and intrasubstance degeneration. Meniscal tears ranged from minor tears that did not change the shape of the menisci to severe tears in which the meniscus was substantially deformed and torn or it could no longer be depicted. Intrasubstance degeneration was defined as signal intensity changes of the meniscus without tears. Cruciate ligament tears were diagnosed when the ligament was interrupted by abnormal signal intensity on T2-weighted images, had abnormal alignment, or was completely absent. Pathologic changes of the collateral ligaments included edematous changes, such as collateral ligament sprains and tears.
Data Analysis
Contingency table analysis was performed when the data were either nominal or ordinal. These results were presented in crosstabs tables. A 
2 or Fisher exact test was used to examine the associations. Since the values showed an abnormal distribution, the medians and interquartile ranges (IQRs) of the WOMAC scores were determined for the KL scores and the individual abnormalities on MR images, such as cartilage defects and bone marrow edema pattern. The significance of differences between the groups was calculated by using a Wilcoxon rank sum test at the .05 significance level. Spearman correlations between the scores were determined. All statistical computations were processed by using Statview 4.1 software (Abacus, Berkeley, Calif), JMP software (SAS Institute, Cary, NC), and S-plus software (Insightful, Seattle, Wash).
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
Cartilage lesions were found on MR images in 43 of 50 knees (Table 1). All knees without cartilage lesions except for one were given a KL score of 1 or 2. The grade of cartilage lesions increased with increasing KL scores (r = 0.55, P < .01). Thirteen of 16 knees with a KL score of 4 showed full-thickness cartilage lesions. Figure 2 depicts cartilage lesions with different KL scores.
|
|
|
|
|
|
|
WOMAC Scores versus KL Scores and MR Imaging Findings
WOMAC scores were determined for pain (median, 115.5; IQR, 48–200), stiffness (median, 119; IQR, 44–200), and function (median, 173.5; IQR, 100–272). There was no significant correlation between WOMAC scores for pain and stiffness versus age, but there was a moderate correlation between WOMAC scores for function and age (r = 0.38, P < .05). Significant differences between men and women were not found.
While the KL score correlated well with the extent of MR imaging findings in the knee, the correlations between MR imaging and clinical findings were limited. Correlations between WOMAC and KL scores were not significant. While the WOMAC pain score tended to be lower in knees with a KL score of 1, the stiffness score was higher in knees with a KL score of 4 compared with those in knees with other scores (Table 5). Differences between the individual groups, however, were not significant (P > .05). The function score showed no significant differences between the groups. Figure 5 shows radiographic and MR imaging findings in a patient with high WOMAC scores and a KL score of 2, and Figure 6 shows findings in a patient with low WOMAC scores and a KL score of 4.
|
|
|
|
|
Median WOMAC pain and stiffness scores were higher in patients with meniscal tears (n = 42; pain: median, 120; IQR, 80–200) than in those without meniscal tears (n = 8; median, 83; IQR, 41–242.75); however, differences were not significant (P > .05). WOMAC pain scores were also not significant (P > .05) between patients with anterior cruciate ligament tears (n = 14; median, 110; IQR, 85–180) and patients without tears (n = 36; median, 127; IQR, 43.25–215). WOMAC pain and stiffness scores tended to be higher in patients with collateral ligamentous lesions (n = 7; median, 150; IQR, 100–200) than in those without lesions (n = 43; median, 77.5; 26.5–153), but again, these differences were not significant (P > .05).
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
Although our findings appear difficult to comprehend initially, they are not completely surprising. In a recent study by Hannan et al (17), similar results were reported in an analysis of the cross-sectional data of the National Health and Nutrition Examination Survey, or NHANES I, with regard to three indicators of osteoarthritis of the knee: radiographic signs of osteoarthritis, self-reported knee pain, and a self-reported diagnosis of arthritis by a physician. These authors classified osteoarthritis in a manner analogous to the KL scale and found disease with a KL score of 2–4 in only 319 of the 6,880 (3.7%) patients enrolled in the study. Only 47% of this subset of patients reported knee pain, and only 61% were told by their physician that they had osteoarthritis. However, knee pain was reported by 1,004 of the 6,880 (14.6%) patients enrolled in their study, and only 15% of patients had osteoarthritis with a KL score of 2–4 on the basis of radiographic assessment, but 59% reported having a diagnosis of osteoarthritis assigned by a physician. Similar results were published by Meding et al (18), who analyzed 1,888 patients undergoing 2,759 knee arthroplasties and found that the degree of osteoarthritis as assessed on preoperative radiographs was independent of pain.
On the other hand, results of several studies (19–21) showed that radiographic features of osteoarthritis of the knee were significantly associated with pain. Lethbridge-Cejku et al (19) examined patients who reported ever having knee pain or having current knee pain and found that pain, as reported, was associated with definite radiographic osteoarthritis (KL score 
2); this pain definition, however, appears relatively vague. Since most of the patients in our study actually had (minor or major) pain (n = 47), and the degree of pain was not scored in most of those previous studies, these results are difficult to compare.
In our study, we used a well-established clinical scale (14,15) and correlated the calculated scores not only with radiographic signs but also with a number of typical MR imaging features of osteoarthritis (8,11). Investigators in most previous studies correlated radiographic signs of osteoarthritis and clinical findings, but again, these clinical findings were frequently not well defined or graded.
In contrast to KL scores, scores derived from cartilage findings at MR imaging were significantly associated with WOMAC scores. WOMAC pain and function scores were significantly lower in patients without cartilage defects than in those with cartilage defects. An interesting finding was the high WOMAC scores in the patients with grade IIa cartilage lesions; it may be hypothesized that clinical symptoms are most substantial at the onset of osteoarthritis, when cartilage defects occur. As cartilage damage progressed, a trend toward lower WOMAC pain and stiffness scores was shown in the present cross-sectional study, which may potentially be explained by the knee becoming more accustomed to the cartilage damage. The function score, however, stayed on a relatively high level.
In the present study, knee pain, function, and stiffness scores were not significantly associated with the presence or the amount of bone marrow edema. These findings are in contrast to results of a previous study by Felson et al (9). In their cross-sectional study, 401 patients with radiographically diagnosed osteoarthritis were analyzed; 351 had knee pain, and 50 had no knee pain. Seventy-eight percent of the patients with knee pain had bone marrow lesions, and 30% of those without knee pain had bone marrow lesions. Still, there is a substantial overlap. Since only three patients in our study had no knee pain, and two of these had no bone marrow edema, the comparison of the results of our study with those of Felson et al (9) is limited. As in our study, however, those authors showed that in patients with pain, severity of pain and bone marrow lesions were not associated.
Hill et al (10) showed that knee pain and the presence and amount of joint effusion on MR images were significantly associated. In a study population of 381 subjects with radiographically determined osteoarthritis and pain, as well as in 52 patients with signs of osteoarthritis but no pain, severe or moderate joint effusion was present in 55% of patients with pain but in only 16% of patients without pain. Distributions of popliteal cysts in patients with and patients without pain, however, were similar. In our study, neither the presence nor the amount of joint effusion or the presence of popliteal cysts was significantly associated with the clinical findings. However, there was a trend toward higher pain scores in patients with joint effusion.
The comparison of clinical, radiographic, and MR imaging findings in osteoarthritis may appear to be of more interest for the rheumatologist or orthopedic surgeon than for the radiologist. However, the radiologist must be aware of these associated findings when evaluating MR images, since the clinician will use the report and the MR images for therapeutic decision making. Even in a relatively advanced stage of osteoarthritis, a patient can be relatively free of symptoms, in which case, surgery may not be indicated.
Many osseous, cartilage, and ligamentous derangements are associated with osteoarthritis. One of the most eminent signs of osteoarthritis on MR images is changes in the hyaline cartilage. In our study, all knees with a KL grade of 4 showed advanced cartilage defects (groups IIb and III). Only seven of 50 knees showed no cartilage lesions. Fifteen of 21 knees with a KL grade of 1 or 2 showed cartilage lesions. These findings are in agreement with those in other studies concerning the sensitivity of MR imaging in the diagnosis of hyaline cartilage lesions as an early marker in osteoarthritis (22–25). In our study, the grading of cartilage defects also correlated best with clinical findings.
A number of studies have been performed to improve the imaging of hyaline cartilage, including the application of optimized sequences, such as driven equilibrium (26), high-spatial-resolution techniques (27,28), T2 maps at 3 T (1), and contrast material–enhanced techniques (2). In the present study, we used a high-spatial-resolution fat-suppressed spoiled gradient-echo sequence for cartilage imaging, which is a standard sequence and is well suited to depict surface defects of cartilage (3,24,29) but may have limitations in depicting the cartilage structure. This may explain the small number of grade I cartilage lesions diagnosed in our study.
With the development of more sophisticated techniques for cartilage repair in osteoarthritis, such as new articular cartilage replacement techniques, including chondrocyte transplantation, improved osteochondral transplantation, chondroprotective agents, and cartilage growth stimulating factors (25,30), optimized MR imaging for diagnosis and therapy planning in osteoarthritis and for monitoring of these interventions is of growing importance.
In addition to cartilage lesions, another important finding in osteoarthritis is bone marrow edema. In our study, 13 of 16 knees with a KL score of 4 but only three of 10 knees with a KL score of 1 showed bone marrow edema pattern. Other investigators (9,11) also reported bone marrow edema pattern in advanced osteoarthritis. Zanetti et al (11) correlated bone marrow edema pattern and histologic findings in 16 patients with advanced osteoarthritis who underwent total knee replacement. At histologic examination, however, most of the areas with bone marrow edema pattern consisted of normal bone marrow, and only 11% of the analyzed areas showed bone marrow necrosis; 8%, abnormal trabeculae; 4%, bone marrow edema; 4%, bone marrow fibrosis; and 2%, bone marrow bleeding. Studies performed to classify prevalence and degree of bone marrow edema according to osteoarthritis stage, to our knowledge, have not yet been performed.
As shown by results of other studies (8,10), in addition to cartilage lesions and bone marrow edema, meniscal lesions, joint effusion, and popliteal cysts are associated with osteoarthritis. While Fernandez-Madrid et al (8) found meniscal degeneration and tears in 52% of 52 patients with a clinical and radiologic diagnosis of osteoarthritis, 92% (46 of 50) of patients in our study showed meniscal lesions, and 84% (42 of 50) showed meniscal tears. All of the knees with a KL score of 3 or 4 showed meniscal tears in our study. Joint effusion was found in 60% of patients in the study of Fernandez-Madrid et al (8) versus 76% in our study population.
Additional MR findings in osteoarthritis described in the literature include synovial thickening, subarticular cysts, bone attrition (flattening and depression), and central osteophytes (10,22,31,32). McCauley et al (32) analyzed MR images of the knee in 193 patients and found 35 central osteophytes in 29 patients. These patients were older and had more cartilage defects and osteophytes. As in that study, all except one of our patients with central osteophytes had grade IIb or III cartilage lesions. Central osteophytes were found most frequently in osteoarthritis with a KL score of 4.
In our study, we also demonstrated a large number of ligamentous lesions (anterior cruciate ligament tears and collateral ligament sprains or tears) associated with advanced osteoarthritis. Since none of these patients had a history of trauma that would explain an anterior cruciate ligament tear, a degenerative cause is most likely. Collateral ligament sprains were located at the most severely damaged joint compartment (mostly medially) and may be explained by stress due to altered biomechanical loading of the knee.
Potential limitations of the present study are that a relatively small number of patients were examined in each group and that arthroscopy to confirm the presence or absence of a meniscal tear, cartilage defect, or ligament injury was not performed.
In conclusion, results of the present study show that a number of osseous, cartilaginous, synovial, ligamentous, and meniscal lesions depicted on MR images are associated with osteoarthritis and that the extent of these lesions correlates with radiographically determined KL scores. However, radiologists should be aware that these findings do not correlate with clinical findings (represented by the WOMAC scores in our study). Radiographic KL scores and clinical WOMAC scores were not associated, while among the MR imaging findings, only cartilage lesions were significantly associated with clinical findings.
|
ACKNOWLEDGMENTS |
|---|
|
FOOTNOTES |
|---|
Author contributions: Guarantors of integrity of entire study, T.M.L., S.M., L.S.S.; study concepts and design, T.M.L., S.M., L.S.S.; literature research, T.M.L., S.G.; clinical studies, M.R., N.L., T.M.L., L.S.S.; data acquisition, T.M.L., L.S.S., S.G.; data analysis/interpretation, T.M.L., L.S.S., S.G., Y.L., S.M.; statistical analysis, Y.L., T.M.L., S.G.; manuscript preparation, T.M.L., S.M.; manuscript definition of intellectual content, editing, and revision/review, T.M.L., L.S.S., S.M., Y.L.; manuscript final version approval, T.M.L., L.S.S., S.M.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  J. Bernstein, J. L Esterhai, M. Staska, S. Reinhardt, and M. E Mitchell The prevalence of occult peripheral arterial disease among patients referred for orthopedic evaluation of leg pain Vascular Medicine, August 1, 2008; 13(3): 235 - 238. [Abstract] [PDF]
|
|
|
|
 |
|
 J-P Raynauld, J Martel-Pelletier, M-J Berthiaume, F Abram, D Choquette, B Haraoui, J F Beary, G A Cline, J M Meyer, and J-P Pelletier Correlation between bone lesion changes and cartilage volume loss in patients with osteoarthritis of the knee as assessed by quantitative magnetic resonance imaging over a 24-month period Ann Rheum Dis, May 1, 2008; 67(5): 683 - 688. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. McCulloch Joint modelling of mixed outcome types using latent variables Statistical Methods in Medical Research, February 1, 2008; 17(1): 53 - 73. [Abstract] [PDF]
|
|
|
|
 |
|
 S. S. Boks, D. Vroegindeweij, B. W. Koes, R. M. D. Bernsen, M. G. M. Hunink, and S. M. A. Bierma-Zeinstra MRI Follow-Up of Posttraumatic Bone Bruises of the Knee in General Practice Am. J. Roentgenol., September 1, 2007; 189(3): 556 - 562. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. S. Boks, D. Vroegindeweij, B. W. Koes, R. M. D. Bernsen, M.G. M. Hunink, and S. M. A. Bierma-Zeinstra Clinical Consequences of Posttraumatic Bone Bruise in the Knee Am. J. Sports Med., June 1, 2007; 35(6): 990 - 995. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. R. Kornaat, J. L. Bloem, R. Y. T. Ceulemans, N. Riyazi, F. R. Rosendaal, R. G. Nelissen, W. O. Carter, M.-P. Hellio Le Graverand, and M. Kloppenburg Osteoarthritis of the Knee: Association between Clinical Features and MR Imaging Findings. Radiology, June 1, 2006; 239(3): 811 - 817. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. G. Potter and L. F. Foo Magnetic Resonance Imaging of Articular Cartilage: Trauma, Degeneration, and Repair Am. J. Sports Med., April 1, 2006; 34(4): 661 - 677. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Ding, F. Cicuttini, F. Scott, H. Cooley, C. Boon, and G. Jones Natural history of knee cartilage defects and factors affecting change. Arch Intern Med, March 27, 2006; 166(6): 651 - 658. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Kijowski, P. Stanton, J. Fine, and A. De Smet Subchondral Bone Marrow Edema in Patients with Degeneration of the Articular Cartilage of the Knee Joint Radiology, March 1, 2006; 238(3): 943 - 949. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Wang, C. Ding, A. E. Wluka, S. Davis, P. R. Ebeling, G. Jones, and F. M. Cicuttini Factors affecting progression of knee cartilage defects in normal subjects over 2 years Rheumatology, January 1, 2006; 45(1): 79 - 84. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. W. Hayes, D. A. Jamadar, G. W. Welch, M. L. Jannausch, L. L. Lachance, D. C. Capul, and M. R. Sowers Osteoarthritis of the Knee: Comparison of MR Imaging Findings with Radiographic Severity Measurements and Pain in Middle-aged Women Radiology, December 1, 2005; 237(3): 998 - 1007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. E. Wluka, C. Ding, G. Jones, and F. M. Cicuttini The clinical correlates of articular cartilage defects in symptomatic knee osteoarthritis: a prospective study Rheumatology, October 1, 2005; 44(10): 1311 - 1316. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Schmid, C. W. A. Pfirrmann, P. Koch, M. Zanetti, B. Kuehn, and J. Hodler Imaging of Patellar Cartilage with a 2D Multiple-Echo Data Image Combination Sequence Am. J. Roentgenol., June 1, 2005; 184(6): 1744 - 1748. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C Ding, F Cicuttini, F Scott, H Cooley, and G Jones Association between age and knee structural change: a cross sectional MRI based study Ann Rheum Dis, April 1, 2005; 64(4): 549 - 555. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M-J Berthiaume, J-P Raynauld, J Martel-Pelletier, F Labonte, G Beaudoin, D A Bloch, D Choquette, B Haraoui, R D Altman, M Hochberg, et al. Meniscal tear and extrusion are strongly associated with progression of symptomatic knee osteoarthritis as assessed by quantitative magnetic resonance imaging Ann Rheum Dis, April 1, 2005; 64(4): 556 - 563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Alford and B. J. Cole Cartilage Restoration, Part 1: Basic Science, Historical Perspective, Patient Evaluation, and Treatment Options Am. J. Sports Med., February 1, 2005; 33(2): 295 - 306. [Abstract] [Full Text] [PDF] |
