Local estimation of the Hurst index of multifractional Brownian motion by increment ratio statistic method

We investigate here the central limit theorem of the increment ratio statistic of a multifractional Brownian motion, leading to a CLT for the time varying Hurst index. The proofs are quite simple relying on Breuer–Major theorems and an original freezing of time strategy. A simulation study shows the goodness of fit of this estimator

Local estimation of the Hurst index of multifractional Brownian motion by increment ratio statistic method

We investigate here the central limit theorem of the increment ratio statistic of a multifractional Brownian motion, leading to a CLT for the time varying Hurst index. The proofs are quite simple relying on Breuer–Major theorems and an original freezing of time strategy. A simulation study shows the goodness of fit of this estimator

Douleurs latérales mécaniques du genou

National audienceLateral knee pain is a common presenting complaint with many possible causes. History and physical examination can decrease imaging indication and narrow the possible causes explained by an articular (lateral knee osteoarthritis, patellofemoral syndrome, proximal tibiofibular joint, lateral meniscus tear, discoid lateral meniscus), a musculotendinous (iliotibial band syndrome, biceps femoris, popliteus syndrome) or an osseous origin (osteonecrosis, complex regional pain syndrome, stress fracture…). Referred pain resulting from hip joint pathology, L4 or L5 radiculopathy also may cause lateral knee pain.Les douleurs latérales du genou constituent un motif de consultation fréquent avec de nombreuses causes. L’interrogatoire et l’examen clinique peuvent limiter les indications de l’imagerie et réduire le nombre de causes possibles expliquées par une origine articulaire (arthrose fémoro-tibiale latérale, syndrome fémoro-patellaire, articulation tibiofibulaire supérieure, ménisque latéral, discoïde), abarticulaire (syndrome de la bandelette iliotibiale, tendinopathie bicipitale, poplitée) ou osseuse (ostéonécrose, syndrome régional douloureux complexe, fractures de fatigue). Les douleurs référées résultant d’une coxopathie, d’une radiculopathie L4 ou L5 peuvent aussi être responsables de douleurs latérales du genou

Bone marrow edema of the sacroiliac joint and anatomical variations: Look back the posterior bony excess. Comment on: "Spine abnormalities associated with bone edema on sacroiliac joints MRI in patients with non-inflammatory chronic back pain" by Marnas et al. Joint Bone Spine 2022;89:105436

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Coracoid-like osteochondroma and painful giant thoracic bursitis

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Primary anterior cruciate ligament repair: magnetic resonance imaging characterisation of reparable lesions and correlation with arthroscopy

International audienceObjectives A recent treatment algorithm suggests that proximal anterior cruciate ligament (ACL) tears with good-to-excellent tissue quality are amenable to primary repair. Our primary objective was to assess the ability of MRI to determine the exact tear location and tissue quality, using arthroscopy as a reference standard. Methods In an initial sample of 71 patients with prior ACL surgery (repair or reconstruction), the diagnostic accuracy of MRI was assessed using arthroscopy as a reference standard. Each native ACL tear was graded according to Sherman's arthroscopic classifications during the surgical procedure. MRI scans were retrospectively reviewed for grading, blinded to arthroscopic findings and in consensus by two musculoskeletal radiologists. Tear location and tissue quality were graded using the MRI Sherman tear location (MSTL), MRI Sherman tissue quality (MSTQ) and simplified MRI Sherman tissue quality (S-MSTQ) classifications. Intra- and inter-observer agreement was assessed on a second sample of 77 patients. MRI classification accuracy was compared by McNemar's tests. Intra- and inter-observer agreement was assessed using Cohen's kappa coefficient. Results Regarding tear location, diagnostic accuracy was 70% (50/71) based on the MSTL classification. Diagnostic accuracy for tissue quality was 52% (15/29) based on the MSTQ classification and 90% (26/29) for the S-MSTQ classification (p = 0.003). Inter-observer agreement was good for MSTL (kappa = 0.78) and moderate-to-good for the MSTQ and S-MSTQ classifications (kappa = 0.44 and 0.63 respectively). Conclusions MRI seems to be accurate in assessing tear location and tissue quality and may help clinicians to predict the reparability of ACL tears

Giant synovial chondromatosis of the metacarpophalangeal joint

International audienceA 59-years-old man presented with a one-year history of a painless swelling of his second metacarpophalangeal (MCP) joint of his right hand..

How can we optimize anterior iliac crest bone harvesting? An anatomical and radiological study

International audiencePURPOSE: Anterior iliac crest bone is a widely used donor site for bone harvesting. It provides an autologous bone graft consisting of cancellous bone that can be packed or cortical bone with greater structural support. Uses include spinal fusion and fracture non-union surgery. Although its use is common, dedicated anatomical and radiological studies analysing graft dimensions and optimal harvesting site in relation to local anatomical landmarks [anterior superior iliac spine (ASIS), anterior iliac tubercle (AIT) and lateral femoral cutaneous nerve (LFCN)] have not been described. METHODS: Twenty-eight female hemipelvises were dissected for this study. The LFCN, ASIS and AIT were identified. Calliper measurements and CT scan analysis were undertaken to determine the optimum positions in obtaining a 5-mm-thickness tricortical graft whilst remaining safe for the LFCN. RESULTS: According to our measurements, the optimal location for harvesting a 5-mm-thick tricortical graft with 35-mm height and 47-mm width is situated anterior to a line passing at the level of the thickest point of the AIT. This thickest point was situated at a mean 67 mm from the centre of the EIAS in our study. CONCLUSION: This anatomical and radiographic study determined the anatomical iliac crest landmarks to avoid neurological injury when taking an optimal 5-mm-width tricortical bone graft