Genetics of patella hypoplasia/agenesis.

The patella is a sesamoid bone, crucial for knee stability. When absent or hypoplastic, recurrent knee subluxations, patellofemoral dysfunction and early gonarthrosis may occur. Patella hypoplasia/agenesis may be isolated or observed in syndromic conditions, either as the main clinical feature (Nail-patella syndrome, small patella syndrome), as a clue feature which can help diagnosis assessment, or as a background feature that may be disregarded. Even in the latter, the identification of patella anomalies is important for an appropriate patient management. We review the clinical characteristics of these rare diseases, provide guidance to facilitate the diagnosis and discuss how the genes involved could affect patella development.

Correlation between primary flat foot and lower extremity rotational misalignment in adults.

PURPOSE: The goal of this study was to identify rotational abnormalities of the lower limb in adult patients with primary symptomatic flatfoot. MATERIALS AND METHODS: From September 2009 to May 2012, 24 patients (12 women, 12 men; mean age: 40 years) were prospectively included in the study. Each patient underwent radiographs of the flat foot and weight-bearing upright EOS® examination. Three-dimensional reconstructions of the lower extremities were performed with derived measurements (length, hip and knee parameters, rotations). A total of 31 symptomatic primary flat feet (bilateral flat foot, n=7 patients; unilateral flat foot, n=17 patients) were studied and compared to 30 control subjects matched for age and gender. A comparison between the two groups was made with the Student t-test. RESULTS: No significant differences were found between patients and control subjects on the coronal and sagittal planes. Similarly, no significant differences were observed between the 2 groups for rotation of the lower limbs (femoral torsion, tibial torsion, tibiofemoral rotation). CONCLUSION: There are no rotational abnormalities of the lower extremities in adult patients with primary symptomatic flat foot.

Imaging features of lower limb malformations above the foot.

Lower limb malformations are generally isolated or sporadic events. However, they are sometimes associated with other anomalies of the bones and/or viscera in patients with constitutional syndromes or disorders of the skeleton. This paper reviews the main imaging features of these abnormalities, which generally exhibit a broad spectrum. This paper focuses on several different bone malformations: proximal focal femoral deficiency, congenital short femur and femoral duplication for the femur, tibial hemimelia (aplasia/hypoplasia of the tibia) and congenital bowing for the tibia, fibular hemimelia (aplasia/hypoplasia) for the fibula, and aplasia, hypoplasia and congenital dislocation for the patella.

Botulinum toxin treatment of pes cavovarus in a child suffering from autosomal recessive axonal Charcot-Marie-Tooth neuropathy (AR-CMT2).

In a 12-year old girl suffering from autosomal recessive axonal Charcot-Marie-Tooth (CMT) neuropathy, pes cavovarus was treated with botulinum toxin injection in the tibialis posterior. The patient underwent a clinical evaluation, video analysis of spatiotemporal gait parameters and dynamic foot plantar pressure assessment before treatment and then two weeks, three months and six months thereafter. The video gait analysis revealed a decrease in varus during the swing phase of gait. The dynamic foot plantar pressure decreased by 50% in the excessive pressure at the side of the foot six months after the injection (maximal pressure=42.6N/cm2 before treatment and 18.9 N/cm2 after 6 month). Botulinum toxin injection appears to be an efficacious means of correcting pes cavovarus in CMT disease. A larger-scale clinical trial is now required to evaluate the putative longer-term preventive effect of this treatment on the pes cavus deformity.

Congenital high scapula (Sprengel's deformity): four cases.

We report a series of four cases of congenital high scapula (or Sprengel's deformity) diagnosed and followed in our establishment. The main feature of this very rare congenital malformation of the pectoral girdle is an abnormally high, more or less dysmorphic scapula. A congenitally high scapula is often discovered in young children, when consequences for aesthetics, and sometimes functional difficulties, are brought to light. When surgical treatment is envisaged, imaging is recommended to diagnose a supernumerary structure, ossified (an omovertebral bone) or not (a fibrous and/or cartilaginous connection), extending from the scapula to the cervical spine. This needs to be resected. A CT scan is essential for detecting an omovertebral bone and the vertebral bone abnormalities that are often associated with it. MRI and ultrasound are very useful for assessing any fibrous and/or cartilaginous components. An ultrasound examination has the undeniable advantage of being quick and easy in these young children.

Progressive anterior vertebral fusion: a report of three cases.

We report a series of three cases of progressive anterior vertebral fusion diagnosed and monitored in our establishment. This very rare condition was discovered in young children while exploring a spinal deformity. With X-rays of the thoracolumbar spine it was possible to make a positive diagnosis and ensure follow-up. The radiographic semeiotics are characteristic and combine anterior pinching of the disc, well-delimited erosion of the anterior vertebral corners and anterior then posterior intervertebral ankylosis. MRI is very useful for assessing the extent of the intervertebral ankylosis and the condition of the residual discs, without irradiation. The condition develops over several months or years. Conservative treatment is usually sufficient.

[Spinal infections: typical and atypical imaging features]. / Infections rachidiennes: aspects typiques et atypiques.

While the imaging features of established spondylodiscitis are well known, other presentations may be misleading. The purpose of this article is to review the typical imaging features of spondylodiscitis as well as some more atypical and unusual imaging features (early spondylodiscitis, sceptic spondylitis, septic arthritis of facet joints, primary epidural abscess, unusual germs, neonate).

[Contribution of ultrasonography in inflammatory rheumatic disorders (rheumatoid arthritis, polymyalgia rheumatica and spondyloarthropathies)]. / Apport de l'échographie dans les rhumatismes inflammatoires (polyarthrite rhumatoïde, pseudopolyarthrite rhizomélique et spondylarthropathies).

Ultrasonography may be very useful for the positive and differential diagnosis of inflammatory rheumatic disorders (rheumatoid arthritis [RA], polymyalgia rheumatica [PMR] and spondylarthropathies) and if necessary, for the treatment response evaluation (RA). Later in the course of the disease, ultrasonography may help in diagnosing some peripheral complications (tendinous ruptures, synovial cysts, superficial bursitis...) and is useful to guide corticosteroid injections (RA, spondylarthropathies). This article addresses the main ultrasonographic features of inflammatory rheumatic disorders and the role of ultrasonography relative to other imaging modalities (especially magnetic resonance [MR] imaging).

[Value of imaging in posterolateral corner injuries of the knee]. / Apport de l'imagerie dans les lésions du point d'angle postéro-latéral du genou.

Lesions of the posterolateral corner are usually post-traumatic in etiology. They are most frequently associated with tear of the ACL and/or PCL. When unrecognized, they may lead to short-term failure of cruciate ligament reconstruction or long-term knee joint degeneration. Early detection of such lesions, especially in the preoperative period, is important since more severe injuries usually require dedicated early surgical management. The anatomy of the posterolateral corner will be reviewed and the normal and abnormal imaging features on MRI and US will be illustrated. The main clinical and surgcal features will also be presented.

[Plain radiographs of the wrist and hand]. / Les radiographies simples du poignet et de la main.

The purpose of this review is to describe the value of the different radiographic projections of the wrist and hand, provide criteria for quality control and key interpretation points. Plain radiographs of the hand and wrist are still, in this era of cross-sectional imaging, of great importance in the assessment and understanding of bone and joint disorders, particularly in the setting of trauma. Indeed postero-anterior and lateral views have to be completed with additional projections depending on the suspected lesion and clinical presentation.

[Tendons: inflammatory and degenerative pathology]. / Les tendons: lésions inflammatoires et dégénératives.

Tendons may be affected by a variety of pathologic conditions, including those caused by overuse and inflammatory diseases. Sonography is a very sensitive means of detecting tendonous pathology because of its spatial resolution and its comparative and dynamic capabilities. Moreover its wide availability makes it the preferred first-line imaging modality in these cases. This paper reviews the inflammatory and degenerative conditions that may involve the tendons and their sonographic appearances.

Normal anatomy of the heel entheses: anatomical and ultrasonographic study of their blood supply.

The purpose of this study was first to determine the normal blood supply of the heel entheses with cadaver injection, and second, to identify by means of ultrasound (US) this blood supply in healthy volunteers before and after the intravenous injection of a US contrast agent (SonoVue). Twenty cadaver lower limbs were cut into sagittal, coronal, or axial sections after the injection of a red-colored gelatin solution. Ten anatomical samples were selected for histology. Then 10 healthy volunteers were enrolled in a contrast-enhanced ultrasonography study (CUS). Calcaneal tendon and plantar aponeurosis entheses were studied first without any contrast-agent (B-mode, power Doppler). A single dose (2.4 ml) of the contrast agent was then administered for studying each enthesis of the right foot. The operators had to look for blood flow within the entheses and in the adjacent soft tissues. Anastomotic transverse branches were seen macroscopically at the back of the calcaneal tendon, giving some capillaries penetrating the enthesis. None of these vessels could be seen with CUS. In contrast, a high-density vascular network could be detected in Kager's triangle with CUS. No blood vessel could be seen within the plantar aponeurosis enthesis, either macroscopically or microscopically. No evidence of entheseal vascularization was found with any contrast-enhanced imaging technique. Inferior branches of the lateral plantar artery were seen on coronal and sagittal sections of the hindfoot, and could be detected with CUS. These arterioles were running toward the anterior aspect of the calcaneal tuberosity, near the plantar aponeurosis insertion. In conclusion, no vascularization was detected with CUS at the cortical bone insertion of normal heel entheses. However, some vascularization could be seen in the immediate vicinity of heel entheses. The latter feature has to be kept in mind, as it may represent a pitfall for the diagnosis of early inflammatory changes in patients, especially those with seronegative spondylarthropathies.

Relationship between computed tomographic image analysis and histomorphometry for microarchitectural characterization of human calcaneus.

The present study aimed to characterize the relationships between several variables reflecting bone microarchitecture assessed by both computed tomographic (CT) image analysis and histomorphometry (conventional CT system) at the calcaneus. A total of 24 cadaveric specimens were studied. The mean age at death was 78 +/- 10 years (range, 53-93 years). A total of 15 sagittal sections (1 mm in width and spaced 2 mm apart) were selected for CT analysis; 6 undecalcified sections (7 microm) were analyzed for histomorphometry. The histomorphometric analysis was performed on a Leica Quantimet Q570 image analyzer. Features measured by both methods were: bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), interconnectivity index (ICI), number of nodes (N Nd), number of terminus (N Tm), node-to-node strut count (NNS), node-to-terminus strut count (NTS), terminus-to-terminus strut count (TTS), marrow space star volume (SV), Euler number (EN), and fractal dimension (FD). The coefficient of correlations' values (simple linear regression) between histomorphometry and CT image analysis varied according to the parameters selected. R values were high for BV/TV, Tb.N, and Tb.Sp (range, 0.69-0.90; P < 0.01). R values were less significant for some variables also obtained from the binary image: SV (0.5, P < 0.05) and EN (0.43, P < 0.05). Finally R values were also significant for (two) variables obtained from skeletonized images, i.e., N Nd (0.4, P < 0.05) and N Tm (0.61, P < 0.01). Other correlations were not statistically significant. Moreover, for some variables the relationships between the two methods (CT analysis and histomorphometry) seemed best-described by using nonlinear models. For example, a logarithmic model was more appropriate for SV (r = 0.71, P < 0.01), N Nd (r = 0.52, P < 0.01). Finally the relationship between apparent (App) N Tm and N Tm was most satisfying when using an exponential model (r = 0.64, P < 0.01). In conclusion, trabecular bone structure measures determined on CT images show highly significant correlations with those determined using histomorphometry. The level of correlation varies according to the type of method used for characterizing bone structure, however, and the strongest correlations were found for the most basic features (Parfitt's parameters). Finally, for some variables, nonlinear models seem more appropriate.

Does quantitative ultrasound of bone reflect more bone mineral density than bone microarchitecture?

Relationships among quantitative ultrasound of bone (QUS), bone mineral density (BMD) and bone microarchitecture have been poorly investigated in human calcaneus.Twenty-four specimens, from 12 men and 12 women (mean age 78 +/- 10 years; range 53-93), removed from cadavers were studied. The feet were axially sectioned above the ankle. Two variables were measured for QUS (Achilles, Lunar): broadband ultrasound attenuation (BUA) and speed of sound (SOS). A third variable, the stiffness index (SI), which is a combination of both BUA and SOS, was also calculated. BMD (a lateral view) was measured on a QDR 2000 densitometer (Hologic). Bone microarchitecture was assessed by computed tomography (CT) using a conventional CT-system. Fifteen sagittal sections (1 mm in width and 2 mm apart) were selected for CT. Methods used for characterizing bone microarchitecture consisted in structural (trabecular network characterization) and a fractal analyses. The relationships between QUS and bone microarchitecture were assessed by simple linear regression analysis with and without adjustment for BMD (partial correlation) and by backward stepwise regression analysis. Strong relationships were found between BMD and QUS. Adjusted r(2) values were 0.545 for SOS and 0.717 for SI. Two microarchitectural variables were also significantly correlated with both SOS and SI: apparent trabecular separation (App Tr Sp) and trabecular bone pattern factor (App TBPF). After adjustment for BMD few correlations between QUS and microarchitectural variables were always significant. Adjusted squared semipartial coefficients of correlation (rsp2) values between SOS and bone microarchitecture were 6%, 6.8%, 13.2% and 4.6% for App BV/TV, App Tr Sp, App TBPF and fractal dimension (FD), respectively. For SI, corresponding figures were 3.7%, 4.1%, 5.2% and 3.2%. Backward stepwise regression analysis using BMD and microarchitecture showed a slight increase of r(2) values that varied from 8.4% for SI to 17.8% for SOS, compared with BMD alone. The current study suggests that although BMD is a major determinant of acoustic properties of human calcaneus, significant density independent relationships with bone microarchitecture should also be taken into account.

[Pseudo-winging of the scapula and snapping scapula secondary to solitary exostosis: two cases]. / Scapula alata statique et accrochage scapulaire secondaires à une exostose solitaire. A propos de 2 cas.

Pseudo-winging of the scapula and scapular snapping are two clinical signs of upper girdle insufficiency. The association of these two signs is highly suggestive, if not pathognomonic, of exostosis of the ventral aspect of the scapula. Resection of the exostosis is recommended to prevent pain and sarcomatous degeneration.