Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and morphologic MRI of cartilage in the long-term follow-up after Legg-Calvé-Perthes disease (LCPD)

T1ρ and T2 MRI show hip cartilage damage in adolescents with healed Legg-Calvé-Perthes disease

Legg-Calvé-Perthes disease (LCPD) is a juvenile hip disorder associated with residual femoral head deformity, cartilage degeneration and a high risk of early onset hip osteoarthritis. Assessing management of LCPD in the healed phase requires an understanding of when and where hip cartilage damage happens. While it has been shown that cartilage is degenerated in healed LCPD hips in adults, it is not clear when this degeneration begins. Our research question was: Are the MR markers of cartilage degeneration T1ρ and T2 increased in healed LCPD hips in adolescents? Twelve adolescents [10-17 years old (mean 14); 3 female 9 male] with healed LCPD (Stulberg 2-5; 8 unilateral and 4 bilateral) and 15 age- and sex-matched controls were imaged in a 3T MRI using a T1ρ and a T2 sequence. We applied a mixed-effects model adjusted for age and nested by subject to determine the effect of Stulberg grade on overall and regional mean T1ρ and T2 values. T1ρ was significantly higher overall and in the medial region of Stulberg ≥3 hips, and in the medial region of Stulberg 2 hips than in the control group. T2 was significantly higher in the medial region of Stulberg ≥3 hips than in the control group. Our results suggest that cartilage damage in LCPD has begun by adolescence and that T1ρ can detect early changes in cartilage associated with LCPD.

Assessment of Articular Cartilage Disorders After Distal Radius Fracture Using Biochemical and Morphological Nonenhanced Magnetic Resonance Imaging

PURPOSE

To assess radiocarpal articular cartilage after distal radius fracture, with and without intra-articular extension, compared with healthy controls using multiparametric, nonenhanced magnetic resonance imaging (MRI).

METHODS

In this prospective study, multiparametric MRI of the radiocarpal articular cartilage was performed in 26 participants (16 males and 10 females; mean age, 39.5 ± 14.7 years; range, 20-70 years) using 3T MRI. The cohort consisted of 14 patients with a distal radius fracture and 12 healthy volunteers. The radiocarpal articular cartilage was assessed using morphological (Double Echo Steady-State [DESS] and True Fast Imaging With Steady-State Precession [TrueFISP]) and biochemical (T2∗) MRI sequences without an intravenous contrast agent. The modified Outerbridge classification system for morphological analyses and region-of-interest biochemical analysis were applied to assess the degree of articular cartilage damage in each patient.

RESULTS

Morphological articular cartilage assessment showed no difference between the DESS sequence and the reference standard, TrueFISP. In the morphological (DESS and TrueFISP) and biochemical (T2∗) assessments, patients with intra-articular fractures did not show articular cartilage damage different from those with extra-articular fractures. Greater articular cartilage degradation was observed after distal radius fracture compared with controls.

CONCLUSIONS

Posttraumatic radiocarpal articular cartilage damage did not differ between fractures with intra-articular and extra-articular extension, but patients with fractures had notably higher articular cartilage degradation compared with healthy controls. Magnetic resonance imaging using advanced multiparametric sequences may facilitate accurate, noninvasive assessment of articular cartilage changes after distal radius fracture without the need for a contrast agent.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Viewing arthrography images affects treatment preferences for Legg-Calvé-Perthes disease among medical professionals

Objectives

We explored how experience of arthrography affects treatment preferences for Legg-Calvé-Perthes disease (LCPD) patients. We also examined changes in surgical procedure preferences after examining arthrography images. In addition, we analysed the effect of experience with arthrography on treatment and surgical modality preferences.

Methods

A case-based questionnaire was completed by 26 participants. Information on age, symptoms, hip range of motion (ROM), and extremity length differences were provided for eight LCPD cases. Based on these data and roentgenography images of the cases, the respondents were questioned regarding diagnostic, treatment, and surgical preferences. A slide was shown of arthrography images of each case and the same questions were asked to determine any changes in treatment preferences. The participants were divided into arthrography-experienced (Group 1, n = 16) and -inexperienced (Group 2, n = 10) groups to determine differences in treatment preferences in association with experience.

Results

After the participants had examined the arthrography images, a significant decrease in the number of additional examination requests was observed (p < 0.001). A significant group difference was also found in the rate of change of preference in diagnostic modality (p < 0.001).After arthrography images were examined, the tendency towards a preference for surgery increased in all participants. However, no significant difference between the experience groups was observed (p = 0.193). In addition, after arthrography images were examined, there was an increased tendency towards a preference for femoral valgisation and Salter osteotomy among participants who chose surgical treatments (p = 0.408). The treatment preferences difference between the two experience groups were not significant, and nor was the preference regarding surgical procedures (p = 0.999).

Conclusions

Previous studies have shown that arthrography is useful for planning treatment and informing decisions regarding surgical modality for LCPD. However, no study has explored changes in treatment preferences after viewing arthrography images. This study explored such changes in choices regarding the diagnostic method and treatment modality. Our study showed that experience with arthrography decreased the preference for additional diagnostic tests (p < 0.001). Experience of arthrography increased the preference for surgery, though not significantly (p = 0.193).

Differences of radiocarpal cartilage alterations in arthritis and osteoarthritis using morphological and biochemical magnetic resonance imaging without gadolinium-based contrast agent administration

OBJECTIVES

To identify differences of radiocarpal cartilage alterations in osteoarthritis and arthritis using multiparametrical magnetic resonance imaging (MRI) comprising morphological and biochemical sequences without gadolinium-based contrast agent administration.

METHODS

In this prospective study, multiparametrical MRI of the radiocarpal cartilage was performed in 47 participants (mean age, 46.6 ± 17.6 years; min., 20 years; max., 79 years) on a 3 Tesla MRI. The cohort consisted of 11 patients suffering from arthritis, 10 patients with osteoarthritis, 14 patients after distal radius fracture, and 12 healthy volunteers. The radiocarpal cartilage was assessed using morphological (DESS, TrueFISP) and biochemical (T2*) MRI sequences without the application of intravenous contrast agent. The modified Outerbridge classification system for morphological and region-of-interest analyses for biochemical analysis was applied to assess the degree of cartilage damage in each patient before data were statistically tested for significant difference between the groups using a post hoc Tukey test.

RESULTS

In morphological imaging, cartilage damage was significantly more frequent in arthritis and osteoarthritis than in healthy volunteers (DESS: p = 0.01, p = 0.0004; TrueFISP: p = 0.02, p = 0.0001). In T2* imaging, patients with osteoarthritis showed higher cartilage damage compared to patients with arthritis (p = 0.01).

CONCLUSION

With multiparametrical MRI, it is possible to identify differences of radiocarpal cartilage alterations of patients with arthritis and osteoarthritis using the combination of morphological and biochemical MR imaging of the radiocarpal cartilage without the application of contrast agent. Multiparametrical MRI without the usage of contrast agent may be a potential tool helping to distinguish both entities.

KEY POINTS

• Multiparametrical MRI with morphological and biochemical sequences allows the differentiation of patients with arthritis and osteoarthritis. • High-resolution MRI of radiocarpal cartilage is possible without administration of contrast agent.

T2*-Mapping of Acetabular Cartilage in Patients With Femoroacetabular Impingement at 3 Tesla: Comparative Analysis with Arthroscopic Findings

Objective To evaluate the diagnostic accuracy of T2*-mapping for detecting acetabular cartilage damage in patients with symptomatic femoroacetabular impingement (FAI). Design A total of 29 patients (17 females, 12 males, mean age 35.6 ± 12.8 years, mean body mass index 25.1 ± 4.1 kg/m², 16 right hips) with symptomatic FAI underwent T2* MRI and subsequent hip arthroscopy. T2* values were obtained by region of interest analysis in seven radially reformatted planes around the femoral neck (anterior, anterior-superior, superior-anterior, superior, superior-posterior, posterior-superior, posterior). Intraoperatively, a modified Outerbridge classification was used for assessment of the cartilage status in each region. T2* values and intraoperative data were compared, and sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV) as well as the correlation between T2*-mapping and intraoperative findings, were determined. The mean time interval between MRI and arthroscopy was 65.7 ± 48.0 days. Results Significantly higher T2* values were noted in arthroscopically normal evaluated cartilage than in regions with cartilage degeneration (mean T2* 25.6 ± 4.7 ms vs. 19.9 ± 4.5 ms; P < 0.001). With the intraoperative findings as a reference, sensitivity, specificity, NPV and PPV were 83.5%, 67.7%, 78.4% and 74.4%, respectively. The correlation between T2*-mapping and intraoperative cartilage status was moderate (ρ = -0.557; P < 0.001). Conclusions T2*-mapping enabled analysis of acetabular cartilage with appropriate correlation with intraoperative findings and promising results for sensitivity, specificity, PPV, and NPV in this cohort. Our results emphasize the value of T2*-mapping for the diagnosis of hip joint cartilage pathologies in symptomatic FAI.

3D double-echo steady-state sequence assessment of hip joint cartilage and labrum at 3 Tesla: comparative analysis of magnetic resonance imaging and intraoperative data

OBJECTIVES

To assess the diagnostic accuracy of a high-resolution, three-dimensional (3D) double-echo steady-state (DESS) sequence with radial imaging at 3 Tesla (T) for evaluating cartilage and labral alterations in the hip.

METHODS

Magnetic resonance imaging (MRI) data obtained at 3 T, including radially reformatted DESS images and intraoperative data of 45 patients (mean age 42 ± 13.7 years) who underwent hip arthroscopy, were compared. The acetabular cartilage and labrum of the upper hemisphere of the acetabulum and the central femoral head cartilage were evaluated. Sensitivity, specificity, accuracy, and negative and positive predictive values were determined.

RESULTS

Sensitivity, specificity and accuracy of the DESS technique were 96.7%, 75% and 93.7% for detecting cartilage lesions and 98%, 76.2% and 95.9% for detecting labral lesions. The positive and negative predictive values for detecting or ruling out cartilage lesions were 96% and 78.9%. For labral lesions, the positive and negative predictive values were 97.5% and 80%.

CONCLUSION

A high-resolution, 3D DESS technique with radial imaging at 3 T demonstrated high accuracy for detecting hip cartilage and labral lesions with excellent interobserver agreement and moderate correlation between MRI and intraoperative assessment.

KEY POINTS

• High-resolution, 3D DESS with radial imaging allows accurate cartilage and labrum evaluation. • DESS demonstrated high sensitivity, specificity, accuracy for detecting cartilage and labral lesions. • Highly accurate sequence may influence treatment decisions in patients with hip pain.

The fate of the joint space in Legg-Calvé-Perthes' disease

OBJECTIVE

This study was undertaken to identify variations in the hip joint space in patients with healed Legg-Calvé-Perthes' disease (LCPD) and to correlate these changes with the radiological outcome of treatment.

METHODS

The width of the joint space was measured on radiographs of 121 skeletally mature individuals with healed LCPD. The joint space width at the stage of healing in 79 patients was compared with the joint space at skeletal maturity. The hips were graded by the Stulberg classification and the femoral head radius was measured. Associations between the joint space width, the Stulberg class and the femoral head radius were tested. The reproducibility of measurement was tested by measuring 30 radiographs twice and computing the intra-class correlation coefficient (ICC). The joint space width was measured on radiographs of 25 patients taken both while recumbent and standing, to determine if the joint space alters on weight-bearing.

RESULTS

The reproducibility of measurements was satisfactory; no difference was noted in the joint space in recumbent and weight-bearing films. Increased joint space was noted both at healing of the disease and at skeletal maturity; the width was minimally increased in Stulberg Class I hips and considerably increased in Class III, IV and V hips. There was a significant correlation between the increase in joint space and enlargement of the femoral head.

CONCLUSIONS

An increase in joint space width occurs quite frequently following LCPD; the increase is most evident in hips with a poor outcome. The implications of this observation need to be elucidated.