Avascular Necrosis of Left Femoral Head Following Trivial Trauma and the Need for Early Magnetic Resonance Imaging

Trivial Trauma is one of the causes of avascular necrosis of the femoral head. Even trivial trauma can cause loss of blood supply to the femoral head and results in ischemia and aseptic necrosis. A 68 year old male patient came with 2 month history of left hip pain. X-ray pelvis (fig-1) with both hips which was taken immediately after the trauma, showed no significant bony abnormality and patient was managed conservatively with analgesics. Patient had persisting pain for 2 months which increased in severity and patient developed difficulty walking. Therefore a Magnetic Resonance Imaging (MRI) L hip (fig-2) was done and which showed avascular necrosis grade III of left femoral head. Total hip replacement was then carried out for the patient and patient improved symptomatically. Earlier MRI imaging following trauma could have resulted in early diagnosis and intervention to prevent progression of the disease and salvage the femoral head.

Anterior lengthening in scoliosis occurs only in the disc and is similar in different types of scoliosis

Relative anterior spinal overgrowth (RASO) was proposed as a generalized growth disturbance and a potential initiator of adolescent idiopathic scoliosis (AIS). However, anterior lengthening was also observed in neuromuscular (NM) scoliosis, was shown to be restricted to the apical areas and to be located in the intervertebral discs, not in the bone. In this study the goal was to determine if other scoliotic curves of known origin exhibit the similar mechanism of anterior lengthening without changes in the vertebral body. Therefore CT-scans of 18 patients in whom a short segment congenital malformation had led to a long thoracic compensatory curve without bony abnormality were included. Of each vertebral body and intervertebral disc in the compensatory curve, the anterior and posterior length was measured on CT-scans in the exact mid-sagittal plane, corrected for deformity in all three planes. The total AP% of the compensatory curve in congenital scoliosis showed a lordosis (+1.8%) that differed from the kyphosis in non-scoliotic controls (-3.0%; p<0.001), and was comparable to AIS (+1.2%) and NM scoliosis (+0.5%). This anterior lengthening was not located in the bone; the vertebral body AP% showed a kyphosis (-3.2%), similar to non-scoliotic controls (-3.4%), as well as AIS (-2.5%) and NM scoliosis (-4.5%; p=1.000). However, the disc AP% showed a lordosis (+24.3%), which sharply contrasts to the kyphotic discs of controls (-1.5%; p<0.001), but was similar to AIS (+17.5%) and NM scoliosis (+20.5%). The results demonstrate that anterior lengthening is part of the three-dimensional deformity in different types of scoliosis and is exclusively located in the intervertebral discs. The bony vertebral bodies maintain their kyphotic shape, which indicates that there is no active bony overgrowth. Anterior lengthening appears to be a passive result of any scoliotic deformity, rather than being related to the specific cause of AIS.

C.04 Dynamic MRI in the evaluation of the craniocervical junction of pediatric down syndrome patients

Background: Down syndrome is the most common inherited disorder. Some patients develop craniocervical instability. Existing screening guidelines were developed prior to direct imaging of the neuraxis. We present parameters for potential instability using dynamic MRI of the craniocervical junction. Methods: A retrospective review from 2001 – 2015 was carried out. Patients were symptomatic if they had myelopathy or signal changes at the craniocervical junction. Radiographic measurements were taken. Data analysis was performed with SPSS. Results: 36 patients were included. Symptomatic patients had smaller CCD (9.4 mm vs 13.8 mm; p=0.003) and greater ADI (4.4mm vs 3.0 mm; p=0.01) on resting MRI . During dynamic imaging, symptomatic patients had greater changes in CCD (5.2 vs 2.7 mm; p <0.001) and ADI (2.8 vs 1.3 mm; p=0.04). These patients were also more likely to have a bony anomaly (0.5 vs 0.13; p=0.03). Conclusions: This study identifies parameters that can be used to distinguish unstable patients. A CCD of less than 5 mm or ADI greater than 4.4 mm on static MRI; change greater than 3 mm in ADI or 5mm on CCD during dynamic MRI; or any bony abnormality warrants further investigation. Asymptomatic patients should be followed although most do not progress.

Morphometric analysis of posterior fossa and foramen magnum

ABSTRACT Introduction: Configuration and size of the foramen magnum and posterior fossa plays an important role in the pathophysiology of the posterior fossa and craniovertebral junction disorders. This study is aimed to find out various dimensions of the foramen magnum and posterior fossa. Materials and Methods: This is a prospective study of 100 consecutive normal computerized tomography (CT) scans of posterior fossa and 100 dry adult skulls without any bony abnormality. The posterior fossa volume was calculated by abc/2 in method 1 and by advanced work station of CT scan in method 2. Various dimensions of posterior fossa and foramen magnum were also studied. Results: Age ranged from 16 to 89 years with a mean of 51.3 years. Mean height of posterior fossa were 3.01 cm (±0.22) and 3.52 (±0.43) cm in dry skull and CT scan group, respectively (P < 0.0001). Mean volume of posterior fossa were 157.88 (±27.94) cm3 and 159.58 (±25.73) cm3 by method 1 and method 2, respectively (P > 0.05). All the dimensions of posterior fossa and foramen magnum were larger in male as compared to female. Mean anteroposterior (AP), transverse diameter and surface area of the foramen magnum were 3.31 (±0.35) cm, 2.76 (±0.31) cm, and 729.15 (±124.87) mm2, respectively, in CT scan group as compared to 3.41 (±0.29) cm, 2.75 (±0.25) cm, and 747.67 (±108.60) mm2, respectively, in dry skull group. Conclusion: Normal values of posterior fossa and foramen magnum could serve as a future reference. Dry skull dimensions could be different from CT scan measurement. More studies are needed as there could be variations in dimensions in different regions in India