Quantitative 3D MRI reveals limited intra-lesional bony overgrowth at 1 year after microfracture-based cartilage repair.

OBJECTIVE: Intra-lesional bony overgrowth (BO) identified during or following cartilage repair treatment is being frequently described through subjective reports focusing primarily on incidence. Our objective was to quantify the exact volume of intra-lesional BO at 12 months post-cartilage repair treatment, to determine if a correlation exists between the extent of BO and clinical outcomes, and to visualize and characterize the BO. DESIGN: MRI scans were systematically obtained during a randomized clinical trial for cartilage repair (Stanish et al., 2013) that compared two microfracture-based treatments in 78 patients. Semi-automated morphological segmentation of pre-treatment, 1 and 12 months post-treatment scans utilizing a programmed anatomical atlas for all knee bone and cartilage structures permitted three-dimensional reconstruction, quantitative analysis, as well as qualitative characterization and artistic visualization of BO. RESULTS: Limited intra-lesional BO representing only 5.8 ± 5.7% of the original debrided cartilage lesion volume was found in 78 patients with available MRIs at 12 months. The majority (80%) of patients had very little BO (<10%). Most occurrences of BO carried either spotty (56.4%) or planar (6.4%) morphological features, and the remaining balance (37.2%) was qualitatively unobservable by eye. Pre-existing BO recurred at 12 months in the same intra-lesional location in 36% of patients. No statistical correlations were found between BO and clinical outcomes. CONCLUSIONS: Intra-lesional BO following microfracture-based treatments may not be as severe as previously believed, its incidence is partly explained by pre-existing conditions, and no relationship to clinical outcomes exists at 12 months. Morphologically, observable BO was categorized as comprising either spotty or planar bone.

The effect of anterior cruciate ligament injury on bone curvature: exploratory analysis in the KANON trial.

OBJECTIVE: Investigate the 5-year longitudinal changes in bone curvature after acute anterior cruciate ligament (ACL) injury, and identify predictors of such changes. METHODS: In the KANON-trial (ISRCTN 84752559), 111/121 young active adults with an acute ACL tear to a previously un-injured knee had serial 1.5 T MR images from baseline (within 5 weeks from injury) to 5 years after injury. Of these, 86 had ACL reconstruction (ACLR) performed early or delayed, 25 were treated with rehabilitation alone. Measures of articulating bone curvature were obtained from computer-assisted segmentation of MR images. Curvature (mm(-1)) was determined for femur, tibia, medial/lateral femur, trochlea, medial/lateral tibia. Age, sex, treatment, BMI, meniscal injury, osteochondral fracture on baseline MR images were tested for association. RESULTS: Over 5 years, curvature decreased in each region (P < 0.001) suggesting flattening of convex shapes and increased concavity of concave shapes. A higher BMI was associated with flattening of the femur (P = 0.03), trochlea (P = 0.007) and increasing concavity of the lateral tibia (LT) (P = 0.011). ACLR, compared to rehabilitation alone, was associated with flatter curvature in the femur (P < 0.001), medial femoral condyle (P = 0.006) and trochlea (P = 0.003). Any meniscal injury at baseline was associated with a more flattened curvature in the femur (P = 0.038), trochlea (P = 0.039), lateral femoral condyle (P = 0.034) and increasing concavity of the LT (P = 0.048). CONCLUSION: ACL injury is associated with significant changes in articulating bone curvature over a 5 year period. Higher BMI, baseline meniscal injury and undergoing ACL reconstruction (as distinct from undergoing rehabilitation alone) are all associated with flattening of the articulating bone.

OARSI-FDA initiative: defining the disease state of osteoarthritis.

OBJECTIVE: To respond to a pre-specified set of questions posed by the United States Food and Drug Administration (FDA) on defining the disease state to inform the clinical development of drugs, biological products, and medical devices for the prevention and treatment of osteoarthritis (OA). METHODS: An Osteoarthritis Research Society International (OARSI) Disease State working group was established, comprised of representatives from academia and industry. The Working Group met in person and by teleconference on several occasions from the Spring of 2008 through the Autumn of 2009 to develop consensus-based, evidence-informed responses to these questions. A report was presented at a public forum in December 2009 and accepted by the OARSI Board of Directors in the Summer of 2010. RESULTS: An operational definition of OA was developed incorporating current understanding of the condition. The structural changes that characterize OA at the joint level were distinguished from the patients' experience of OA as the 'disease' and 'illness', respectively. Recommendations were made regarding the evaluation of both in future OA clinical trials. The current poor understanding of the phenotypes that characterize OA was identified as an important area for future research. CONCLUSIONS: The design and conduct of clinical trials for new OA treatments should address the heterogeneity of the disease, treatment-associated structural changes in target joints and patient-reported outcomes.