MRI evaluation of a new scaffold-based allogenic chondrocyte implantation for cartilage repair.

AIM: The present study was designed to evaluate the implantation of alginate beads containing human mature allogenic chondrocytes for the treatment of symptomatic cartilage defects of the knee. MRI was used for the morphological analysis of cartilage repair. The correlation between MRI findings and clinical outcome was also studied. METHODS: A biodegradable, alginate-based biocompatible scaffold containing human mature allogenic chondrocytes was used for the treatment of symptomatic chondral and osteochondral lesions in the knee. Twenty-one patients were prospectively evaluated with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Visual Analogue Scale (VAS) for pain preoperatively and at 3, 6, 9 and 12 months of follow-up. Of the 21 patients, 12 had consented to follow the postoperative MRI evaluation protocol. MRI data were analyzed based on the original MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) and modified MOCART scoring system. The correlation between the clinical outcome and MRI findings was evaluated. RESULTS: A statistically significant clinical improvement became apparent after 6 months and patients continued to improve during the 12 months of follow-up. One of the two MRI scoring systems that were used, showed a statistically significant deterioration of the repair tissue at 1 year of follow-up. Twelve months after the operation complete filling or hypertrophy was found in 41.6%. Bone-marrow edema and effusion were seen in 41.7% and 25% of the study patients, respectively. We did not find a consistent correlation between the MRI criteria and the clinical results. DISCUSSION: The present study confirmed the primary role of MRI in the evaluation of cartilage repair. Two MOCART-based scoring systems were used in a longitudinal fashion and allowed a practical and morphological evaluation of the repair tissue. However, the correlation between clinical outcome and MRI findings was poor. Further validation of these scoring systems is mandatory. The promising short-term clinical outcome of the allogenic chondrocytes/alginate beads implantation was not confirmed by the short-term MRI findings.

Health technology assessment of magnetic resonance imaging of the knee.

A search of the available literature was performed and the role of MR imaging of the knee is discussed. Based on this search the authors concluded that MR has a high sensitivity in detecting any abnormalities in the knee but it does not have the same diagnostic accuracy as a clinical investigation performed by a trained knee specialist when all knee injuries are taken together. It does lead to a decrease in the number of surgical interventions due to its high negative predictive value. For the detection of meniscal injury, MR has the same accuracy as arthroscopy and should be performed in order to avoid unnecessary surgical interventions. A negative MR also obviates further investigation in suspected cartilage damage. This is not true for anterior and posterior cruciate ligament problems where MRI is less accurate than clinical investigation.

Health technology assessment of magnetic resonance.

MR imaging has established itself as a reliable means of imaging pathology in many different regions of the body without the disadvantage of ionizing radiation. There was also hope that MRI might replace not only CT but also more invasive imaging techniques. Until now the substitution, especially that of CT has been less than expected. To evaluate the possible substitution of CT by MR imaging, it is paramount to have high quality evidence regarding the efficacy of MRI. This was collected by performing a systematic search of the available literature using Medical Subject Heading (MeSH) terms. The retrieved articles were classified according to the different levels of diagnostic efficacy as described by Fryback and Thornbury. Based on the available studies and the quality assessment, a level of evidence is attributed for the diagnostic efficacy of MRI in each indication.

Health technology assessment of magnetic resonance imaging of the spine and bone marrow.

The high spatial resolution and the lack of ionizing radiation, makes magnetic resonance imaging the method of choice for imaging most spinal pathology, especially if associated with neurological symptoms. However, due to the high sensitivity of MR imaging, careful correlation between imaging findings and clinical findings is important to ensure appropriate treatment. Substituting radiographic evaluations for rapid MRI in the primary care setting may offer little additional benefit to patients. It may even increase the costs of care but the decisions about the use of imaging depend on judgments concerning whether the small observed improvement in outcome justifies additional cost. Because the presence of an abscess is a major factor in deciding between conservative and surgical treatment, MRI plays an essential role in the decision-making process concerning the treatment of spondylodiscitis. MR is also the method of choice for quantitative evaluation of bone marrow in lymphoma patients when a crucial therapeutic decision has to be made or for the qualitative evaluation of the spinal cord if compression is suspected in primary spinal malignancy or metastatic disease.