How reliable is MRI in diagnosing cartilaginous lesions in patients with first and recurrent lateral patellar dislocations?

<p>Abstract</p> <p>Background</p> <p>Lateral dislocation of the patella (LPD) leads to cartilaginous injuries, which have been reported to be associated with retropatellar complaints and the development of patellofemoral osteoarthritis. Therefore, the purpose of this study was to determine the reliability of MRI for cartilage diagnostics after a first and recurrent LPD.</p> <p>Methods</p> <p>After an average of 4.7 days following an acute LPD, 40 patients (21 with first LPDs and 19 with recurrent LPDs) underwent standardized 1.5 Tesla MRI (sagittal T1-TSE, coronal STIR-TSE, transversal fat-suppressed PD-TSE, sagittal fat-suppressed PD-TSE). MRI grading was compared to arthroscopic assessment of the cartilage.</p> <p>Results</p> <p>Sensitivities and positive predictive values for grade 3 and 4 lesions were markedly higher in the patient group with first LPDs compared to the group with recurrent LPDs. Similarly, intra- and inter-observer agreement yielded higher kappa values in patients with first LPDs compared to those with recurrent LPDs. All grade 4 lesions affecting the subchondral bone (osteochondral defects), such as a fissuring or erosion, were correctly assessed on MRI.</p> <p>Conclusions</p> <p>This study demonstrated a comparatively good diagnostic performance for MRI in the evaluation of first and recurrent LPDs, and we therefore recommend MRI for the cartilage assessment after a LPD.</p

Does osteoporosis reduce the primary tilting stability of cementless acetabular cups?

Background: Cementless hip cups need sufficient primary tilting stability to achieve osseointegration. The aim of the study was to assess differences of the primary implant stability in osteoporotic bone and in bone with normal bone density. To assess the influence of different cup designs, two types of threaded and two types of press-fit cups were tested. Methods: The maximum tilting moment for two different cementless threaded cups and two different cementless press-fit cups was determined in macerated human hip acetabuli with reduced (n=20) and normal bone density (n=20),determined using Q-CT. The tilting moments for each cup were determined five times in the group with reduced bone density and five times in the group with normal bone density, and the respective average values were calculated. Results: The mean maximum extrusion force of the threaded cup Zintra was 5670.5 N (max. tilting moment 141.8 Nm) in bone with normal density and. 5748.3 N (max. tilting moment 143.7 Nm) in osteoporotic bone. For the Hofer Imhof (HI) threaded cup it was 7681.5 N (192.0 Nm) in bone with normal density and 6828.9 N (max. tilting moment 170.7 Nm) in the group with osteoporotic bone. The mean maximum extrusion force of the macro-textured press-fit cup Metallsockel CL was 3824.6 N (max. tilting moment 95.6 Nm) in bone with normal and 2246.2 N (max. tilting moment 56.2 Nm) in osteoporotic bone. For the Monoblock it was 1303.8 N (max. tilting moment 32.6 Nm) in normal and 1317 N (max. tilting moment 32.9 Nm) in osteoporotic bone. There was no significance. A reduction of the maximum tilting moment in osteoporotic bone of the ESKA press-fit cup Metallsockel CL was noticed. Conclusion: Results on macerated bone specimens showed no statistically significant reduction of the maximum tilting moment in specimens with osteoporotic bone density compared to normal bone, neither for threaded nor for the press-fit cups. With the limitation that the results were obtained using macerated bone, we could not detect any restrictions for the clinical indication of the examined cementless cups in osteoporotic bone

Arthroscopy vs. MRI for a detailed assessment of cartilage disease in osteoarthritis: diagnostic value of MRI in clinical practice

<p>Abstract</p> <p>Background</p> <p>In patients with osteoarthritis, a detailed assessment of degenerative cartilage disease is important to recommend adequate treatment. Using a representative sample of patients, this study investigated whether MRI is reliable for a detailed cartilage assessment in patients with osteoarthritis of the knee.</p> <p>Methods</p> <p>In a cross sectional-study as a part of a retrospective case-control study, 36 patients (mean age 53.1 years) with clinically relevant osteoarthritis received standardized MRI (sag. T1-TSE, cor. STIR-TSE, trans. fat-suppressed PD-TSE, sag. fat-suppressed PD-TSE, Siemens Magnetom Avanto syngo MR B 15) on a 1.5 Tesla unit. Within a maximum of three months later, arthroscopic grading of the articular surfaces was performed. MRI grading by two blinded observers was compared to arthroscopic findings. Diagnostic values as well as intra- and inter-observer values were assessed.</p> <p>Results</p> <p>Inter-observer agreement between readers 1 and 2 was good (kappa = 0.65) within all compartments. Intra-observer agreement comparing MRI grading to arthroscopic grading showed moderate to good values for readers 1 and 2 (kappa = 0.50 and 0.62, respectively), the poorest being within the patellofemoral joint (kappa = 0.32 and 0.52). Sensitivities were relatively low at all grades, particularly for grade 3 cartilage lesions. A tendency to underestimate cartilage disorders on MR images was not noticed.</p> <p>Conclusions</p> <p>According to our results, the use of MRI for precise grading of the cartilage in osteoarthritis is limited. Even if the practical benefit of MRI in pretreatment diagnostics is unequivocal, a diagnostic arthroscopy is of outstanding value when a grading of the cartilage is crucial for a definitive decision regarding therapeutic options in patients with osteoarthritis.</p