• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.2
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• pp.65-68
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• 2010

Acromio-clavicular (AC) joint cyst have been reported in small series of the orthopedics literature in association with extensive rotator cuff tear, pseudotumor, infection of the shoulder or chondrocalcinosis. Authors experienced one case of AC joint cyst with rotator cuff re-tear after arthroscopic rotator cuff repair, clinicians may need pay attention to AC joint bulging or mass lesion after arthroscopic rotator cuff repair as an important sign to check follow-up imaging study for the cuff integrity. Especially, ultrasonography is recommended for this follow up study, because it is simple to be operated, economic, easily accessible.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.21-27
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• 2019

Composite motor cases fabricated by the filament winding method are structurally weak in the dome when they are required to withstand the internal pressure of the combustion gas. In this study, a finite element analysis is conducted to compare the burst pressure of a composite dome according to the variation of the pressure distribution ratio(PDR). The performance of the composite motor case was compared quantitatively by calculating the stress on the inner and outer dome surfaces and metal boss volume. As a result, the critical point of the failure mode was observed at a PDR between 2.5 and 3.0. A design at a PDR of 2.5­-3.5 can reduce the weight of metal boss without fluctuation in the burst pressure of the combustion motor case. Moreover as the design reference value changes according to the dome shape and opening size, further analysis and testing are necessary.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.106-111
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• 2007

Purpose: The purpose of this paper is to clinically evaluate the usefulness of all arthroscopic repair with biceps incorporation in massive sized full thickness rotator cuff tears. Materials and Methods: This is a prospective comparative outcome study evaluating a series of all arthroscopic rotator cuff repairs with biceps incorporation on massive(range: $5{\sim}\;cm6$ sized) from March 2003 to May 2006. Group I was twenty two cases of arthroscopically repaired with biceps incorporation, twenty cases of group II without biceps incorporation were analyzed. The average age of the patients was 58 years(range, $41{\sim}74$ years), and mean follow-up was 24 months(range, $12{\sim}36$ months). Results were statistically compared by Mann-Whitney test. Results: Average VAS for pain, ADL, UCLA score were not significantly different between group I and group II (P>0.05 for each). Forward elevation strength was 4.3 in group I, 3.5 in group II(P<0.05). On postoperative follow up ultrasound, retear was 10 cases in the middle of 19 cases at group I, 15 cases in the middle of 17 cases at group II (P<0.05). Conclusion: This study reveals that all arthroscopic repairs with biceps incorporation in massive sized full thickness rotator cuff tears is an effective surgical method and reduced retear and enhanced strength.

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.135-142
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• 2020

Purpose: This paper presents the long term follow-up results of arthroscopic partial repair for massive irreparable rotator cuff tears using a biceps long head auto graft. Materials and Methods: Forty-one patients with massive irreparable rotator cuff tear, who underwent arthroscopic repair, were reviewed retrospectively. Patients who underwent arthroscopic partial repair using a biceps long head auto graft were assigned to group 1, and patients in group 2 underwent arthroscopic partial repair alone. Patients with a less than 50% partial tear of the long head biceps tendon were included in this study. The clinical scores were measured using a visual analogue pain scale (VAS) for pain, range of motion (ROM), The University of California, Los Angeles shoulder score (UCLA), American Shoulder and Elbow Surgeons Shoulder Score (ASES), and Korean Shoulder Scoring System (KSS) scores preoperatively and at the final follow-up. The acromiohumeral interval (AHI) was measured using plain radiographs taken preoperatively and at the final follow-up, and re-tear was evaluated using postoperative ultrasound or magnetic resonance imaging at the last follow-up. Results: The mean age of the patients was 62.1±12.7 years, and the mean follow-up period was 90.3±16.8 months. No significant differences in the VAS and ROM (forward flexion, external rotation, internal rotation) were found between the two groups (p=0.179, p=0.129, p=0.098, p=0.155, respectively). The UCLA (p=0.041), ASES (p=0.023), and KSS (p=0.019) scores showed functional improvements in group 1 compared to group 2. At the last follow-up, the measured AHI values were 9.46±0.41 mm and 6.86±0.64 mm in group 1 and 2, respectively (p=0.032). Re-tear was observed in six out of 21 cases (28.6%) in group 1 and nine out of 20 cases (45.0%) in group 2; the retear rate was significantly lower in group 1 than in group 2 (p=0.011). Conclusion: Arthroscopic partial repair for a massive irreparable rotator cuff tear using a biceps long head auto graft has significant clinical usefulness in functional recovery and decreases the re-tear rates after surgery than arthroscopic partial repair alone, showing favorable results after a long-term follow-up.

• Journal of the Korean Institute of Gas
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• v.23 no.5
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• pp.1-7
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• 2019

Although the rupture pressure is evaluated from remaining strength when a flaw is defected to cylinder surface, but the rupture pressure can be not easy to estimate for the composite cylinders. In this study, the area capacity method is developed for the type-3 cylinders that is based on the result applied area capacity method of type-1 cylinders. And the reliability is validated by bursting test with artificial flaw at the cylinder surface. The predicted data of area capacity method and experimental results have very similar tendency. This method and results will be a very important records in field of rupture pressure estimations.

• 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.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.77-81
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• 2009

In patients with full-thickness tears of the rotator cuff, the tendon is usually detached from its bony insertion in the greater or lesser tuberosity. We experienced an unusual pattern of rotator cuff tear in two cases, in which complete rotator cuff tears occurred at the tendinous portion (i.e., intrasubstance tears) with more than a 1cm remnant attached to the greater tuberosity. Arthroscopic tendon-totendon repair was performed without remnant removal in both cases. Follow-up MRI at 6 months showed re-tear of the rotator cuff at the previous tear site in both of our patients. To prove the availability of arthroscopic tendon-to-tendon repair in such cases, a larger case follw-up and biomechanical studies are required.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.27-32
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• 2007

Purpose: To investigate the validity of positive signs of supraspinatus test. Materials and Methods: The empty can test and full can test were performed on 200 shoulders which were diagnosed with magnetic resonance imaging or surgical findings as full thickness tear, partial thickness tear and no tear. Presence of pain, weakness, pain or weakness, and both pain and weakness were recorded as positive signs separately. The two tests with positive signs were compared and analyzed. Results: Pain and weakness were severity-dependent, and the empty-can test had a higher incidence of pain. The sensitivities of the two supraspinatus tests in all positive signs were higher when including partial-thickness tears in the tear group; however, their specificities were higher when excluding partial-thickness tears. The sensitivities of an empty-can test in 'pain', 'pain or weakness', 'both pain and weakness' were higher than those of the full-can test, otherwise, the specificity of the full-can test for 'pain' and 'pain or weakness' were higher. Concordance rate between 'pain or weakness' and 'pain' was the highest in all categorization. Conclusion: Both empty can and full can test were valuable for detecting torn rotator cuff.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.82-82
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• 2009

• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.71-75
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• 2000

Purpose : To introduce arthroscopic partial meniscectomy fur bucket handle tear of medial meniscus using posteromedial portal, which is superior to arthroscopic partial meniscectomy using standard anterior portals commonly used. Method : After arthroscopic examination of the knee, we reduce the torn meniscus, advance the arthroscope into posteromedial compartment under arthroscopic visualization, we make posteromedial portal with reexamination of the compartment and perform arthroscopic partial meniscectomy. Conclusion : With the technique of arthroscopic partial meniscectomy using standard anterior portals, accurate partial meniscectomy can not be done because of inadequate visual field, associated meniscal injuries of posterior horn and cartilage lesion of posterior aspect of the medial femoral condyle can be missed, commonly posterior cruciate ligament can be injured and artificial damage to weight bearing surface of medial femoral condyle is possible. An arthroscopic partial meniscectomy using posteromedial portal is an excellent method fur bucket handle tear of medial meniscus.