Regional prevalence of non-alcoholic fatty liver disease in Seoul and Gyeonggi-do,Korea

Background/Aims

The prevalence of nonalcoholic fatty liver disease (NAFLD) in Korea has increased recently. The aim of the present study was to determine the regional differences in the prevalence and characteristics of NAFLD.

Methods

From January 2009 to December 2010, 161,891 Seoul and Gyeonggi-do residents receiving a health examination at our institution were enrolled in this cross-sectional study. After applying exclusion criteria, the data of 141,610 subjects (80,943 males, 60,667 females) were analyzed. The presence of NAFLD was established by ultrasound examination.

Results

The overall prevalence of NAFLD was 27.3% (38.3% in men, 12.6% in women). When standardized according to age, area, and sex, the prevalence of NAFLD was 25.2%. The age and area standardized prevalence of NAFLD was higher for men (34.4%) than for women (12.2%; P<0.001). The overall prevalence of NAFLD was higher in Gyeonggi-do (27.7%) than in Seoul (26.9%; P<0.001). Among the men, the prevalence of NAFLD was higher in Gyeonggi-do (39.2%) than in Seoul (37.4%; P<0.001), while for the women it was higher in Seoul (13.2%) than in Gyeonggi-do (12.0%; P<0.001).

Conclusions

The regional prevalence of NAFLD differed between Seoul and Gyeonggi-do. Further studies are needed to establish the etiology of this difference.     

Bone temperature elevation by drilling friction and neurological outcome in the cervical spino-laminoplasty

Background

Drill-induced heat has been suspected as a cause of tissue injury, and there are ample experimental data to substantiate the implication. However, no clinical results have been presented with measurement of temperature in the vicinity of neural structures during the actual spinal procedures.

Methods

Using a thermocouple, temperature in the gutters drilled in the midline and the lateral margins of the lamina was monitored closely in 61 patients, who underwent the French-door style of cervical spino-laminoplasty. The drilling was performed intermittently for a duration of 5 or 10 seconds, using 3- or 5-mm diamond burrs with sufficient continuous cooling irrigation. The correlations between bone temperature elevation and postoperative sensorimotor symptoms were then analyzed.

Results

In the lateral gutters at the most cephalad level (typically C3), where the drilling was performed underneath an overlying bundle of muscle attached to C2's spinous process, the temperature rose significantly. This occurred even with 5-second drilling sessions. The average peak temperature was 44 °C at this level. At all other sites, the temperature was maintained below 40 °C. In three patients, transient neurological deficit developed postoperatively, which did not correlate with the incidence of bone temperature elevation.

Conclusions

Intermittent drilling with sufficient irrigation can prevent thermal neuronal damage generated by high-speed drills. Drilling with small diamond burrs in deep and narrow spaces covered by overlying muscles predisposes to inadequate irrigation and thermal elevation. Continuous, protracted drilling without frequent irrigation may result in excessive heat generation and nerve injury.     

Repairing the annular ligament is not necessary in the operation of Mason type 2, 3 isolated radial head fractures if the lateral collateral ligament is intact: Minimum 5 years follow-up

Introduction

The repair of annular ligament after open reduction and internal fixation of radial head fracture could produce the irritation or crepitation during range of motion exercise. The purpose of this study is to evaluate the significance of unrepaired annular ligament during fixation of isolated radial head fractures.

Materials and methods

Retrospectively we reviewed the twenty-five patients who underwent surgical fixation with a plate for Mason type 2, 3 isolated radial head fracture without annular ligament repair. All the radial head fracture did not have the associated injuries which could cause the elbow instabilities. The average length of follow-up was 6.9 years. The outcomes were evaluated clinically (range of motions, instabilities, pain VAS, Broberg & Murrey functional rating score, DASH score) and radiographically (bony union, arthritic change, lateral translation of the radial head, humero-ulnar angle with maximum varus stress of elbow, ulnar variance).

Results

The range of motions between affected and contralateral side were not significantly different at last follow-up. No one showed the instabilities of elbow. The mean pain VAS, Broberg & Murrey functional rating score, and DASH score were 2.7 ± 0.5, 95.3 ± 2.5, and 14.8 ± 5.3 points respectively. Bony union was observed for all cases. There was no significant difference in the lateral translation of the radial head, humero-ulnar angle with maximum varus stress of elbow, and ulnar variance between the affected and the contralateral arm.

Conclusion

The isolated role of the annular ligament seems overestimated. We scrutinize that the annular ligament repair is not essential in the operative treatment of isolated radial head fractures if the lateral collateral ligament is intact.     

Finite Element Modeling of Stress Distribution in Intervertebral Spacers of Different Surface Geometries

Intervertebral disc spacers using bioactive ceramics have been used to treat degenerative spinal disease. Tooth‐shaped spacers are commonly used to prevent migration, but there is a possibility of fracture when inserted or after insertion. Intervertebral disc spacers with either an isosceles triangle‐shaped tooth (T1) or a right triangle‐shaped tooth (T2) were used as a control group. The design factors for the experimental group were modified to prevent fractures induced by stress concentration, and the surfaces of the spacers were designed as either an isosceles triangle‐shaped valley (V1) or a right triangle‐shaped valley (V2). Linear analysis using finite element model (FEM) was performed, and Von Mises stress distribution was calculated by applying 1000 N of uniformly distributed load. Samples of the V2 design were made with bioactive glass‐ceramics (BGS‐7) and evaluated for compressive strength, fatigue degree, and impact strength. Von Mises stress was highest at the first tooth from the posterior side for the control group and at the center for the experimental group. Compared with the control group, the experimental group showed 18.4% and 82.5% reduction (V1 vs. T1 and V2 vs. T2, respectively) in the maximum stress at the bottom of the valleys. The FEM analysis revealed that the V2 design had the most even load distribution. The V2 samples with bioactive glass‐ceramics were evaluated for compressive strength, and all six samples were not fractured up to 24 000 N. However, the average impact strength was 19.42 kN, suggesting that momentary force caused damage at a lower load than compression with a steady speed. The BGS‐7 intervertebral disc spacer with V2 design was not fractured during the fatigue test at maximum pressure of 8000 N, R ≥10, 5 Hz, and 5 million cycles. These data confirm that the BGS‐7 spacer with the V2 design may be clinically applicable. Collectively, the modified surface geometry of the experimental group significantly lowered Von Mises stress values at the bottom of the valleys, and thus the possibility of fracture by compressive load was greatly reduced. Also, impact during insertion was confirmed to cause fracture more easily, as the impact strength was lower than the compressive strength in the experimental group.