• Clinics in Shoulder and Elbow
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• v.11 no.1
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• pp.29-36
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• 2008

Purpose: We wanted to evaluate the relationship between the clinical outcomes and cuff integrity after open rotator cuff repair and we wanted to analyze the causes of rotator cuff retear. Materials and Methods: 78 patients who underwent open rotator cuff repair were enrolled from 2004 to 2006. All the patients were observed for a minimum follow-up of 12 months and they were evaluated by magnetic resonance imaging (MRI). The clinical outcomes were accessed by dividing the patients into the retear group and the intact group. The groups were also compared to analyze the cause of rotator cuff retear according to the preoperative tear size, the symptom duration, and so on. Results: The clinical outcome of the retear group (n=22) was improved significantly after operation (p<0.001, p<0.001), but the muscle power was not improved significantly (p=0.099, p=0.243). More retears were found in the patients who had a larger preoperative tear (p<0.001) and the symptom duration of the retear group was longer (p=0.027). Conclusion: Although there were retear after rotator cuff repair, the clinical outcomes were improved. Yet the muscle power of the supraspinatus and external rotator were not improved significantly. There were more retears for the cases that had a larger preoperative tear size and a longer duration of symptoms.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.1
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• pp.50-57
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• 2006

Purpose: The purpose of this study was to evaluate the tendon healing of arthroscopic repair in full-thickness supraspinatus tears. We evaluate the effectiveness of the arthroscopic repair of full-thickness supraspinatus tears by assessing functional improvement. Materials and Methods: Thirty consecutive full-thickness supraspinatus tears were repaired arthroscopically in 19 patients with a one row of anchor and 11 patients with two rows of anchors. Patients ranged in age from 51 to 79 years (average 63 years). Average follow-up was 16 month (range, 12 to 28 months). To evaluate the effectiveness of the arthroscopic repair of full-thickness supraspinatus tears by assessing functional improvement, we calculate the Constant, ASES, UCLA scores. The 30 patients had either an MR Arthrogram (25 cases) or an MRI (5 cases), performed between 5 months and 20 months (mean 10 months) after surgery. Results: The cuff was healed in 21/30 cases (70%) and partially torn in 3 cases (10%) after the arthroscopic repair of full-thickness supraspinatus tear. Although the supraspinatus tendon was totally torn to the tuberosity in 6 cases(20%) after the arthroscopic repair, the size of the tear was smaller than the initial in 5 cases. The Constant score improved from an average of $55.7{\pm}7.1$ points preoperatively to $77.7{\pm}9.7$ points at the last follow-up (p<0.001), and the average ASES score improved from $39.2{\pm}7.4\;to\;72.4{\pm}12.6$ (p<0.001), and the average UCLA score improved from $17.9{\pm}2.2\;to\;26.8{\pm}5.0$ (p<0.001). Strength of elevation was significantly better $(7.1kgs{\pm}2.4)$ in the shoulders with a healed tendon that in those with an total or partial re-tear tendon $(4.5kgs{\pm}1.0)$ (p<0.05). Factors adversely affecting tendon healing were increasing age, Only 41.7% of the repairs completely healed in patients over 65 years (p<0.05). Conclusion: Arthroscopic repair of isolated full-thickness tear of the supraspinatus leads to completely healing in 70% of the cases. Total or partial re-tear of the repaired rotator cuff is associated with a decreased strength. Older patients had significantly lower healing rates.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.20-26
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• 2010

Purpose: To evaluate clinical features and surgical results for rotator cuff tear secondary to shoulder dislocation in middle-aged and elderly patients. Materials and Methods: We reviewed 19 patients over 50 years of age who had rotator cuff tears combined with shoulder dislocation between October 2004 and October 2008. There were 7 males and 12 females with a mean age 64.7 years (range, 50 to 78 years). The average follow-up duration was 22 months (range, 8 to 56 months). We investigated the number of dislocations, the size of the cuff tear, the presence of Bankart lesions and the time interval from dislocation to surgery. We also investigated the ASES score, UCLA score, SST score, and shoulder range of motion before and after surgery. We analyzed clinical outcomes and contributing factors. Results: ASES scores improved from 30.2 preoperatively to 72.3 postoperatively; UCLA scores improved from 12.9 to 26.5; SST scores improved from 2.4 to 7.3. Range of motion improved significantly: forward flexion, abduction, external rotation and internal rotation were, respectively, $110.8({\pm}39.3)^{\circ}$, $107.7({\pm}40)^{\circ}$, $22.5({\pm}17.6)^{\circ}$ and L5 level preoperatively; postoperatively they were $153.6({\pm}20.6)^{\circ}$, $152.1({\pm}20.8)^{\circ}$, $36.4({\pm}22.7)^{\circ}$ and L1 level. Age, the presence of Bankart lesions and the number of dislocations were not correlated with clinical outcomes. But the size of the cuff tear was correlated with clinical results. Also, the duration from dislocation to surgery was correlated with postoperative UCLA and SST scores (p=0.039, p=0.038). Conclusion: For shoulder dislocation, it is important to achieve early diagnoses of rotator cuff tears in middle-aged and elderly patients. If these injuries are both present, early rotator cuff repair should be performed for better clinical results.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.961-967
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• 1998

In order to improve the optical properties and printability of paper, various fillers are used in papermaking. This study was performed to investigate several fillers-precipitated calcium carbonate(PCC), ground calcium carbonate(GCC), and blends(PCC/talc or micro-talc(MVP) and GCC/talc or micro-talc(MVP)-for their effects on various newsprint properties. Results obtained from the study were summarized as follows ; 1) PCC treatment gave about 16.8% higher retention than GCC treatment at the filler level of 5% and the retention of filler in the handsheet increased as average particle size of mixed filler was increasing($PCC{\leq}GCC<MVP<talc$). 2) PCC treatment kept opacity more highly than no filler treatment and opacity decreased as average particle size of mixed filler was increasing. 3) Independent treatment of PCC kept tear strength more effectively than GeC did, and tear strength increased as average particle size of mixed filler was increasing. 4) Independent treatment of pee kept tensile strength more highly than other treatments and Gee treatment kept tensile strength highly than pee treatment under mixed filler treatment. 5) Burst strength under PCC treatments decreased linearly as average particle size of mixed filler was increasing. 6) Compared "With non-filler treatment, filler treatment gave much better printability.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.35-40
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• 2010

Purpose: To compare the outcome of patients who underwent rotator cuff repair using all-arthroscopic mini-open repair techniques. Materials and Methods: We retrospectively reviewed 44 patients who underwent either arthroscopic (group I) or mini-open (group II) rotator cuff repair. 23 patients underwent an arthroscopic repair and 21 patients had a mini-open repair. The mean age was 50.4 years in the arthroscopic group and 56.7 years in the mini-open group. The outcomes for the 2 groups were evaluated using ROM, VAS, ASES, UCLA scale. Statistical analysis was performed using correlations, T-test, Paired T-test. The mean follow-up period in the arthroscopic and mini-open groups were 24.1months and 26.1months, respectively. Results: The group I (arthroscopic group) had 2 small-sized tears, 10 medium sized tears, and 11 large sized tears (3~5 cm). The group II (mini-open group) had 1 small sized tears, 8 medium sized tears, and 12 large sized tears. The mean cuff tear size of the group I and Group II were 3.8 cm and 4.2 cm, respectively. At last follow-up periods, ROM and functional scores were improved. In the group I and group II, there were no significant difference in ROM, VAS, ASES, UCLA score. Conclusion: The size of the tear did not produce different results at arthroscopic repair group but larger tear size was associated with a worse outcome in mini-open group. There were no significant clinical results between the arthroscopic and mini-open group.

• Elastomers and Composites
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• v.41 no.3
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• pp.157-163
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• 2006

In this study, the wettability and mechanical properties of silicone rubber impression material were studied by using precipitated silica and fumed silica with different particle size and polarity (hydrophilic/hydrophobic). Curing time of impression material depended on the particle size of fumed silica. The curing time delayed about 9 minutes by using A300, which was the fumed silica with the smallest particle size among the silica used in this study. Wettability of rubber impression material improved with the introduction oi hydrophobic fumed silica(R972). Also, the optimum flow and mechanical properties could be obtained by using blended silica with the 90: 10 ratio of precipitated and fumed silica.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.333-343
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• 2004

Impression cytology refers to application of cellulose acetate filter material to the ocular surface to remove the superficial layers of the conjunctival epithelium. The technique is non-invasive, is easy to perform, causes minimal discomfort to the patient, and can be used to follow changes in the conjunctival ocular surface over time. With this method, the morphology of the conjunctival ocular surface can be studied and the degree of squmaous metaplasia assessed. This study was performed to evaluate the conjunctival surface by impression cytology in dry eye patients. A total of 70 students with no contact lens wearing history were recruited. Subjects were required to fill in a McMonnies dry eye symptom questionnaire. The non-invasive tear thinning time(TIT) test of each subject was measured, followed by Schirmer tear test(STI), tear film break-up time(TBUT) tests and Rose-bengal staining were performed as a baseline. Conjunctival epithelial cells from the inferior bulbar conjunctiva were harvested by the impression cytology technique. The specimens collected were labelled and stained with PAS(Periodic Acid Schift)-haematoxylin. The goblet cells and conjunctival epithelial cells were observed under a light microscope of 400x magnification. The specimens were classified according to the Nelson Grading scale which was based on the degree of squamous metaplasia such as changes of goblet cells density, size/form, N:C(nucleus : cytoplasm) ratio. Dry eye patients were observed morphological changes of the epithelial cells, different nuclear alterations, decrease of the goblet cells density. The degree of cytological changes was related to severity of dry eye conditions. When the epithelial cell morphology was graded according to the system described by Nelson, specimens from the control group revealed 91.43% of the eyes to be grade 0 and 8.57% to be grade 1, whereas of the dry eye patients, 20% were grade 0, 42.86% grade 1, 34.29% grade 2 and 2,86% grade 3. Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. This technique is a safe, simple method and may help increase understanding of various ocular surface alterations in dry eye patients.

• Journal of Ocean Engineering and Technology
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• v.28 no.1
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• pp.28-33
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• 2014

The Korean icebreaking research vessel "Araon" performed four sea trials in the Arctic and Antarctic Seas. The ice properties, such as the ice thickness, floe size, ice strength, and power of the vessel were quite different in these trials. To compare the speeds of ship with the same ice strength and power, the AARC (Arker Arctic Research Center) method is used with a vessel power of 10 MW and an ice strength of 630 Pa in this paper. Based on the analysis results, the speed of the ship was 1.62 knots (0.83 m/s) with a 1.02-m ice thickness and 2.5-km floe size, 5.3 knots (2.73 m/s) with a 1.2-m ice thickness and 1.0-km floe size, and 13.8 knots (7.10 m/s) with a 1.1-m ice thickness and 200-m floe size. The analysis results showed that the ship speed and floe size have an inversely proportional relationship. Two reasonable reasons are given in this paper for the final result. One is an ice breaking phenomenon, and the other is the effect of the ice floe mass. For the breaking phenomenon, the ice breaking force is very small because the ice floe is not breaking but tearing when a ship is passing through a small ice floe. Regarding the effect of the ice floe mass, it is impossible for a ship to push and tear an ice floe if the mass of the ice floe is too large compared to the mass of the ship. The velocity of the ship decreases when the ice floe has a large mass and a large size because the ship has to break the ice floe to move forward.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.17-25
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• 2012

Purpose: The aim of this retrospective study was to evaluate the relationship between appearance and size of bone bruise and severity of anterior cruciate ligament (ACL) injury with magnetic resonance imaging (MRI), furthermore, to identify the mechanism of ACL injury by analyzing the footprint of bone bruise. Materials and Methods: Sixty-five subjects who was taken an MRI within 6 weeks after acute ACL injury were studied. All MRI showed ACL injury and associated bone bruises. Bone bruises were analyzed using Costa-Paz classification based on appearance and location and also scored using Kornaat bone bruise grading system based on size and location. The severity of the ACL injury was graded using a 4-point system (ie, grade 0-3) with oblique coronal MRI. Results: There was statistically significant correlation between Costa-Paz classification of bone bruises in lateral femoral condyle and grade of ACL injury. There were more type 2 lesions in partial tear group (grade 1, 2), however, type 3 lesions of Costa-Paz classification in complete tear group (P=0.037). Significant positive correlations were observed between Kornaat total bone bruise score and grade of ACL injury (P=0.014). Most common ACL injury mechanism was pivot shift injury. Other mechanisms were clip valgus injury, phantom foot injury, and hyperextension injury. Conclusion: It is highly suggested that appearance and size of bone bruise is related to severity of ACL injury after acute ACL injury. The foot print of bone bruise provides valuable clues to identify ACL injury mechanism.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.67-74
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• 2018

Background: Fatty degeneration of rotator cuff is a well-known predictor of postoperative outcome. The purpose of this study was to evaluate the clinical features of rotator cuff tears involving subscapularis, and investigate whether fatty degeneration quantified from only the upper subscapularis correlates better with clinical outcomes than quantified from the whole subscapularis. Methods: We retrospectively analyzed 315 consecutive patients who underwent arthroscopic repair for rotator cuff tears involving subscapularis with a minimum follow-up of 1 year. Preoperative and postoperative visual analogue score for pain, range of motion and functional scores were assessed. Integrity of the repaired tendon was assessed at the 1-year follow-up with either magnetic resonance imaging or ultrasonography. Results: The mean Goutallier grade of whole cross-section was significantly lower than that of upper cross-section (1.59 vs. 1.71, p<0.05), but significantly higher than that of lower cross-section (1.59 vs. 1.01, p<0.05). In analysis of 37 re-tears, the occupancy of severe fatty degeneration in upper cross-section was 86.5%, which was significantly higher than that seen in whole cross-section (56.8%, p<0.05). We calculated the cut-off tear size for prediction of re-tears as 19.0 mm for retraction and 11.0 mm for superior-inferior. The cut-off Goutallier grade was 2.5 for both whole and upper cross-sections, but area under the curve was greater in the upper cross-section than the whole (0.911 vs. 0.807). Conclusions: As fatty degeneration of upper subscapularis demonstrated a more distinct spectrum than whole subscapularis, we suggest that measuring fatty degeneration of upper subscapularis can be a more useful method to predict clinical prognosis.