• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.34-41
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• 2021

Purpose: To evaluate the long-term clinical results and survivorship of unicompartmental knee arthroplasty (UKA) in elderly patients older than 70 years by analyzing cases that have been implanted for >10 years ago. Materials and Methods: The long-term follow-up results were evaluated in 39 patients (46 cases) who underwent medial UKA from March 2002 to February 2004. The mean age of the patients at the time of surgery was 74.0 years, and the preoperative diagnosis was degenerative arthritis of the knee in all cases. Results: Of the 46 cases, reoperation occurred due to the complications in four cases. In 22 cases without 14 cases of death and six cases of follow-up loss, follow-up more than 10 years was possible. The mean Knee Society knee and function scores improved significantly from 53.0 and 52.5 points pre-operatively to 89.4 and 80.9 points at the last follow-up, respectively (p<0.001). The mean range of motion of the knee recovered to 132.5°, and the mean tibiofemoral angle changed to 5.9° of valgus at the last follow-up. Complications following the UKA occurred in four cases; the most prevalent complication was mobile bearing dislocation (n=2). One case of failure occurred due to aseptic loosening and degenerative arthritis of the lateral compartment, respectively. The cumulative survival rate of the implants was 95.0% at 10 years and 85.7% at 15 years. Of the 40 cases, excluding six cases of follow-up loss, 36 cases (90.0%) could be used without reoperation until death or at the last follow-up after surgery. Conclusion: These results showed the outstanding functions of the knee and satisfactory long-term survivorship after UKA. Therefore, UKA could be a useful method for the treatment of osteoarthritis of the knee in elderly patients older than 70 years of age.

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.169-177
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• 2020

Purpose: To assess the effectiveness of mixed grafts in lumbar posterolateral fusion (PLF) by comparing the bone union rates of an autobone with a bone substitute mixed graft. Materials and Methods: The patients were followed-up for at least two years after PLF and divided into four groups according to the mixed graft retrospectively. Group I was 48 cases using a femoral head allobone. Group II was 38 cases using β-tricalcium phosphate. Group III was 92 cases using biphasic calcium phosphate. Group IV was 38 cases using biphasic calcium phosphate and autologous bone marrow. Union was evaluated by the work up simple radiographs after two years from PLF. Union was defined if the radiographs demonstrated a bilateral continuity in the fusion mass between the cephalad and caudal transverse processes with less than 2° of angular motion and no translation between the vertebrae at the level of fusion on the lateral flexion-extension radiographs. Results: According to simple radiographs after two years from PLF, the rate of union was highest in Group IV using local autobone, biphasic calcium phosphate and autologous bone marrow mixed graft. Conclusion: Biphasic calcium phosphate is an osteoconductive bone substitute that increases the bio-absorbability and mechanical strength. Autologous bone marrow has osteoinductive and osteogenic properties. These features can increase the rate of bone union. Therefore, a local autobone, biphasic calcium phosphate and autologous bone marrow mixed graft can be considered an effective bone graft substitute for lumbar PLF instead of an autobone graft.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.57-61
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• 2012

Purpose: The multi-gated cardiac blood pool scan is to evaluate the function of left ventricle (LV) and usefully observe a value of ejection fraction (EF) for a patient who is receiving chemotherapy. To calculate LVEF, we should adjust an angle of left anterior oblique (LAO) view to separate both ventricles. And by overlapped ventricles, it is possible to affect LVEF. The purpose of this study is to investigate and compare quantitative indices by changing an angle of LAO view. Materials and methods: We analyzed the 49 patients who were examined by multi-gated cardiac blood pool scan in department of nuclear medicine at Asan Medical Center from June to September 2011. Firstly, we acquired "Best septal" view. And then, we got images by addition and subtraction of angle for LAO view to anterior and lateral. We compared three LAO views for 20 people by 5 degrees and 39 people by 10 degrees. And we analyzed quantitative indices, EF, end diastole and end systole counts, by automated and manual region of interest (ROI) modes. Results: Firstly, we analyzed quantitative indices by automated ROI mode. In case of 5 degrees, the averages of EF are $61.0{\pm}7.5$, $62.1{\pm}7.1$, $60.9{\pm}6.7%$ ($p$=0.841) in LAO, LAO $-5^{\circ}$ and LAO $+5^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). In case of 10 degrees, the averages of EF are $62.4{\pm}9.5$, $62.3{\pm}10.8$, $61.6{\pm}.9.3%$ ($p$=0.938) in LAO, LAO $-10^{\circ}$ and LAO $+10^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). Secondly, we analyzed quantitative indices by manual ROI mode. In case of 5 degrees, the averages of EF are $62.8{\pm}7.1$, $63.6{\pm}7.5$, $62.7{\pm}7.3%$ ($p$=0.903) in LAO, LAO $-5^{\circ}$ and LAO $+5^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). In case of 10 degrees, the averages of EF are $65.5{\pm}9.0$, $66.3{\pm}8.7$, $63.5{\pm}.9.3%$ (p=0.473) in LAO, LAO $-10^{\circ}$ and LAO $+10^{\circ}$ respectively. And there is no difference in end diastole and end systole counts ($p$<0.05). Conclusion: When an image is nearly "Best septal" view, the difference of LAO angle would not affect to change LVEF. Although there was no difference in quantitative analysis, deviations could happen when to interpret wall motion qualitatively by reading physicians.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.160-168
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• 2003

Purpose : To analyze the anterior stability and functional results after the arthroscopic ACL reconstruction and meniscectomy based on meniscus status at the time of surgery. Materials and Methods : From October 1997 to October 2002, 78 patients (male 64 female 14) were treated by arthroscopic ACL reconstruction and meniscectomy and followed more than 12 months (range, $12\~72$ months, average: 32 months). Average age was 32 years old (range, $18\~57$ years old). We divided the patients into 4 groups; Both menisci was intact (BMI, control group), lateral meniscus removed (LMR), medial meniscus removed (MMR) and both menisci removed (BMR). Anterior passive displacement (objective stability) was estimated using KT-2000 arthrometer under the loading of 15lb,20lb and 30lb and evaluated anterior drawer test, Lachman test, range of motion, thigh circumference. Functional evaluation system of IKDC, OAK and Lysholm knee score was used. Results : Average anterior displacement under the loading of 30lb were 2.47 mm, 2.96 mm, 2.96 mm and 3.57 mm in each group(BMI, LMR, MMR, BMR) and it was statistically significant difference (p<0.05). There is no statistically significant difference in average anterior displacement under the loading of 15lb and 20lb in each group but it has showed decreasing tendency in meniscal removed groups. The mean anterior displacement was within 3 mm in 21 cases, 15 cases, 24 cases and 12 cases (total 72 cases, $94\%$) under the loading of 15lb and 20 cases, 15 cases, 24 cases and 11 cases (total 70 cases, $91\%$) under the loading 20lb of in each group and postoperative knee joint stability has showed increasing tendency (p>0.05). The mean score was 94.5, 93.2, 92.2 and 90.4 points in each group and 71 cases $(91\%)$ were more than excellent or good with a OAK score and fair results were noted 4 cases in both meniscal removed group. There were 65 cases $(83\%)$ with a Lysholm knee score more than excellent or good, and IKDC grading were more than normal or nearly normal in 74 cases $(95\%)$ except 4 cases (2 cases in MMR group and 2 cases in BMR group). Conclusion : Long-term anterior stability and functional results of a successful ACL reconstruction affected by tile status of the menisci at the time of surgery and KT-2000 arthrometer was good for estimation of objective follow up.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.73-82
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• 1997

Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two-compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE $Advance^{TM}$ PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by the refined method incorporating myocardium geometric information into the two-compartment model using N-13 ammonia and PET.

• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.95-103
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• 1996

Reverse redistribution(RRD) refers to a perfusion defect that develops or becomes more evident on rest imaging compared with the stress imaging. This phenomenon was not uncommonly noted on myocardial perfusion single photon emission computed tomography (SPECT). However, the clinical significance and pathophysiological mechanism of RRD were unclear. The aim of this study was to evaluate the incidence and clinical significance of RRD on either dipyridamole T1-201 or Tc-99m MIBI myocardial perfusion SPECT. RRD was defined as ${\geq}10%$ decrease in relative T1-201 and Tc-99m MIBI uptakes on rest images compared to the stress images or as an appearance of new perfusion defects on rest images. It was observed in both T1-201 (44/463, 9.5%) and Tc-99m MIBI (124/999, 12.4%) myocardial SPECTs similarly, with an overall incidence of 11.5%(168/1462). Many apparent)y unrelated disease groups showed the finding: post-revascularization(53.9%), coronary artery disease(24.6%), myocardial infarction(12.3%), and those with normal coro-nary arteries (9.2%). Clinical and angiographic characteristics of 65 consecutive patients who underwent coronary arteriography in 168 patients who had RRD on myocardial perfusion SPECT were reviewed. Tc-99m MIBI was used in 44 patients, and T1-201 was used in 21 patients. Of the 81 myocardial segments analyzed which showed RRD, 32 segments(39.5%) were in septum, 24(29.5%) in inferior wallL, 12(14.8%) in anterior wall, 7(8.7%) in apex and 6(7.4%) in lateral wall. There was no clear association between RRD and coronary arterial stenosis or Presence of collateral circulations. Ventriculographical wall motion was evaluated in 27 regions with RRD; it was normal in 12 regions, hypokinetic in 12 regions and dyskinetic in 3 regions. In 14 of 21 patients who showed RRD on T1-201 myocardial SPECT, T1-201 reinjection was performed immediately after the 3-4 hour redistribution studies. Ten of 14 (71.4%) showed enhanced T1-201 activity(${\geq}10%$ increased) after reinjection. We conclude that RRD is not related to mode of stress or radiopharmaceuticals. RRD might represent many inhomogeneous pathophysiological processes.