Femoroacetabular impingement is a major cause for early "primary" osteoarthritis of the hip. It can easily be recognized on conventional radiographs of the pelvis and the proximal femur.

A high indirect correlation between the density of openings in the osseous endplate (particularly of the size of the capillary buds) and the morphologic degeneration grade of the disc support the hypothesis that occlusion of these openings may deprive the cells of nutrients, leading to insufficient maintenance of the extracellular matrix and disc degeneration.

Selective imaging parameters and a newly created scoring scheme were found to correlate with disc degeneration as determined in a morphological manner. Surprisingly, radiographic parameters were able to distinguish different stages of degeneration, whereas MRI could only detect advanced stages of disc degeneration. We conclude that X-rays may remain a cost-effective, non-invasive in vivo-grading method to detect early disc degeneration, and, combined with MRI, correlate best with morphological and biochemical assessment of disc degeneration.

Axial T2 mapping provides a more T2-based classification. The new system may be able to detect early degenerative changes before the conventional classification systems can.

Purpose: To perform baseline T 2 mapping of the hips of healthy volunteers, focusing on topographic variation, because no detailed study has involved hips. T 2 mapping is a quantitative magnetic resonance imaging (MRI) technique that evaluates cartilage matrix components. Materials and Methods:Hips of 12 healthy adults (six men and six women; mean age ϭ 29.5 Ϯ 4.9 years) were studied with a 3.0-Tesla MRI system. T 2 measurement in the oblique-coronal plane used a multi-spin-echo (MSE) sequence. Femoral cartilage was divided into 12 radial sections; acetabular cartilage was divided into six radial sections, and each section was divided into two layers representing the superficial and deep halves of the cartilage. T 2 of these sections and layers were measured.Results: Femoral cartilage T 2 was the shortest (-20°to 20°a nd -10°to 10°, superficial and deep layers), with an increase near the magic angle (54.7°). Acetabular cartilage T 2 in both layers was shorter in the periphery than the other parts, especially at 20°to 30°. There were no significant differences in T 2 between right and left hips or between men and women. Conclusion:Topographic variation exists in hip cartilage T 2 in young, healthy adults. These findings should be taken into account when T 2 mapping is applied to patients with degenerative cartilage.

The dimensions of the cervical spinal canal and cord in healthy individuals are associated with spinal level, sex, age, and height. Online supplemental material is available for this article.

Fifty-nine cases of lesions presenting in the patella were identified after review of the databases of four European bone tumour registries. Of the 59 cases, 46% were non neoplastic, 39% were benign and 15% were malignant. The commonest benign neoplasm was giant cell tumour (GCT) (11 cases). Younger patients were more likely to have a benign neoplasm. Lesions in patients less than 40 years of age included giant cell tumour, chondroblastoma, aneurysmal bone cyst (ABC), osteomyelitis, osteoid osteoma and solitary bone cyst. In patients older than 40 years, the following were common lesions: intra-osseous gout, metastasis and intra-osseous ganglion. Expansion of the patella with thinning of cortex was seen more commonly in GCT and brown tumour in hyperparathyroidism. There was associated soft tissue extension in gout and malignant lesions.

Objective: To investigate the ability of delayed gadolinium-enhanced magnetic resonance (MR) imaging of cartilage (dGEMRIC) and T2 mapping to evaluate the quality of repair tissue after microfracture. Design: Twelve knees from 12 goats were studied. An osteochondral defect (diameter, 6 mm; depth, 3 mm) with microfracture was created in the weight-bearing aspect of both the medial and lateral femoral condyles. Goats were euthanized at 24 weeks (n ¼ 6) and 48 weeks (n ¼ 6) postsurgery. Pre-contrast R1 (R1pre) and post-contrast R1 (R1post) measurements for dGEMRIC and a pre-contrast T2 measurement for T2 mapping were performed with a 3 T MR imaging system. MR imaging findings were compared with histological and biochemical assessments. Results: In native cartilage, significant correlations were observed between the R1post and the glycosaminoglycan (GAG) concentration, as well as DR1 (difference between the R1pre and R1post) and the GAG concentration (P < 0.05). In repair tissue, a significant correlation was observed between DR1 and the GAG concentration (P < 0.05), but not between the R1post and the GAG concentration. In both repair tissue and native cartilage, no correlation was observed between T2 and the water concentration or between T2 and the hydroxyproline (HP) concentration. A zonal variation of T2 and a clear dependence of T2 on the angles relative to B0 were observed in native cartilage, but not in repair tissue. Conclusion: dGEMRIC with DR1 measurement might be useful for the evaluation of the GAG concentration in repair tissue after microfracture. T2 mapping might be useful for the differentiation of repair tissue after microfracture from native cartilage; however, its potential to assess the specific biochemical markers in native cartilage as well as repair tissue may be limited.