Computed Tomographic Morphometric Analysis of C1 and C2 for Lamina Cross Screw Placement in Malay Ethnicity

Study Design

This is an observational study of computed tomography (CT) data.

Purpose

The C1 and C2 laminas in the Malaysian Malay population were analyzed for the feasibility of fitting 3.5-mm laminar screws in a cross configuration.

Overview of Literature

Morphometric analysis of the C1 and C2 laminas has been performed for various populations but not for the Malaysian Malay population.

Methods

A total of 330 CT cervical images were measured to establish the bicortical diameter of the C1 and C2 laminas as well as their height and length. The C1 posterior tubercle bicortical diameter and height were also determined from these images. All parameters were measured up to 0.1 mm, and statistical analysis was performed using IBM SPSS Statistics ver. 24.0 (IBM Corp., Armonk, NY, USA). An independent t -test and the Pearson chi-square test were used to determine the mean difference and screw acceptance.

Results

The means of the C1 lamina measurements were 5.79±1.19 mm in diameter, 9.76±1.51 mm in height, and 20.70±1.86 mm in length. The means of the measurements of the posterior tubercle were 7.20±1.88 mm in diameter and 10.51±1.68 mm in height. The means of the C2 lamina measurements were 5.74±1.31 mm in diameter, 11.76±1.69 mm in height, and 24.96±2.56 mm in length. Overall 65.5% of C1 and 80.3% of C2 laminas are able to accept 3.5-mm screws in a cross configuration. Screw acceptability is similar between the right and left sides (p>0.05). However, males have a higher screw acceptability compared with females (p<0.05), except for the C2 left lamina.

Conclusions

It is feasible to insert a 3.5-mm screw in a cross configuration in the C1 and C2 laminas of the Malaysian Malay population, especially in males. However, a CT scan should be performed prior to the operation to determine screw acceptability and to estimate screw sizes.

Risk factors of long bone fracture in non-ambulatory cerebral palsy children

OBJECTIVES

To identify the risk factors for long bone fractures in non-ambulatory cerebral palsy children. DESIGN. Case-control study.

SETTING

A residential rehabilitation centre in Hong Kong.

PATIENTS

The fracture group comprised 19 (13 male, 6 female) cerebral palsy children aged 4 years 5 months to 18 years 11 months (mean, 10 years; standard deviation, 3 years 9 months), who had their first long bone fracture during the period June 1992 to May 2001 inclusive. The control group was composed of 90 (46 male, 44 female) concomitant cerebral palsy residents aged 6 years 1 month to 16 years 11 months (mean, 9 years 11 months; standard deviation, 2 years 4 months) with no history of long bone fracture.

MAIN OUTCOME MEASURES

Presence of features considered relevant to the risk of fracture, namely: anthropometry, feeding practice, orthopaedic surgery and duration of postoperative immobilisation, extremity contracture, anti-epileptic medications, and general health status in the 12 months prior to the fracture.

RESULTS

Of the 19 fracture episodes, 18 occurred in the femur and one in the tibia/fibula. Multivariate analysis revealed that weight for age Z scores (adjusted odds ratio=0.41, 95% confidence interval, 0.19-0.86) and recent postoperative immobilisation (weeks) [adjusted odds ratio=1.35, 95% confidence interval, 0.97-1.89] were independent predictors for fracture occurrence.

CONCLUSION

Early intervention targeting these risk factors may reduce the fracture risk in non-ambulatory cerebral palsy children.

Congenital absence of portal vein presenting as hepatopulmonary syndrome

A 9-year-old girl presented with cyanosis and decreased exercise tolerance. Chest X-ray, lung function and echocardiogram were normal. Contrasted echocardiogram showed intrapulmonary right to left shunt and computerized tomography of the thorax showed dilated pulmonary vasculature. There was no arteriovenous malformation. Computerized tomography of the abdomen revealed absence of the intrahepatic portion of the portal vein. The superior mesenteric and splenic veins joined as a common trunk, bypassed the liver and drained into the right atrium. We concluded that the patient had hepatopulmonary syndrome secondary to absence of the portal vein. This is the first report of hepatopulmonary syndrome in a female paediatric patient with a congenital absence of the portal vein. As all portal blood entered directly into systemic circulation, the condition was equivalent to congenital portosystemic shunt. Cases of congenital portosystemic shunt complicated by hepatopulmonary syndrome were also reviewed.

Paediatric stroke: case series

Five cases of paediatric stroke are reported. Two patients presented with idiopathic stroke, another following vertebral artery dissection, one secondary to Moyamoya disease, and one patient with the syndrome of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes. The presentation, investigation, and management of paediatric stroke are discussed.