Moon Jong Chang

PURPOSE: To evaluate the effectiveness of all-inside repair of posterior lateral meniscus root full-thickness tears with preoperative and postoperative magnetic resonance imaging (MRI) and to propose a system of classifying posterior lateral meniscus root tears. METHODS: From June 2003 to March 2007, 27 (6.95%) of a consecutive series of 388 anterior cruciate ligament reconstructions had a concomitant posterior lateral meniscus root tear. Of the patients, 25 (92.6%) were followed up for a more t

PURPOSE: The purpose of this study was to evaluate the accuracy of the characteristic magnetic resonance imaging (MRI) findings of medial meniscal root tear in the coronal, sagittal and axial planes. METHODS: Thirty arthroscopically diagnosed patients who had undergone preoperative knee MRI were included in this study. They were compared to 30 age-matched patients with medial meniscus tears without root tears. The findings used for imaging analysis were as follows: the radial tear on the menisca

Instability following total knee arthroplasty is one of the major causes of revision surgery. In most cases, it can be prevented by using an appropriate prosthesis and a good surgical technique. Particular attention should be given to confirmation of diagnosis for which thorough history taking, complete physical examination and radiographic evaluation are needed. With regard to treatment, identification of the etiology of instability is crucial for establishing proper treatment plans; instabilit

BACKGROUND: The objectives of this study were to describe changes in physical activity profiles of Korean patients after TKA and to determine whether the postoperative physical activity level is influenced by patient socio-demographic factors and postoperative functional outcomes. We also sought to determine whether regular postoperative physical activity is associated with greater patient satisfaction after TKA. METHODS: This observational study included 369 patients. Physical activity profiles

The purposes of this study were to report degenerative changes that coexist with a symptomatic torn discoid lateral meniscus in adults and to analyze the factors associated with the accompanied degenerative changes. From 1997 to 2008, 329 knees in the 305 patients were included. Associations between the status of the meniscus and the coexisting degenerative changes on the images and the arthroscopic findings were statistically analyzed. Marginal osteophyte was seen on conventional radiography in

Dimensional variations often cause expensive problems in the assembly of mechanical products especially during new product deployment. Currently, the time and labour spent on the removal of variation-related assembly problems are considerable. This paper proposes a computational method to identify the causes of variation-related problems in assemblies. In the proposed method, the relationship between causes and symptoms is computed via simulation of the assembly process, and they are represented

BACKGROUND: We sought to document the incidences of deep vein thrombosis (DVT) before and after total knee arthroplasty (TKA). In addition, we aimed to explor whether routine preoperative DVT evaluation was useful to establish DVT treatment strategies after TKA. Finally, we wanted to evaluate whether the incidences of DVT differed between patients undergoing unilateral and staged bilateral TKA within the same hospitalization period. METHODS: The retrospective study included 153 consecutive patie

The convex approach to the absolute stability problem is considered. Gapski and Geromel's algorithm for computing Zames-Falb multipliers, used in determining stability, treats the problem as an optimization problem. It is found that their algorithm may terminate prematurely in some cases, failing to find the optimal multiplier. We propose an improvement that always finds an ascent direction and a multiplier that improves the objective function whenever one exists.

PURPOSE: The aim of this study was to determine the outcomes of bursoscopic ossicle excision in young and active patients with unresolved Osgood-Schlatter disease. METHODS: This retrospective study included 18 male military recruits. A direct bursoscopic ossicle excision was performed using low anterolateral and low anteromedial portals. Outcomes were evaluated using the Lysholm knee score, pain score on a visual analog scale (VAS) (from 0 to 10), and Tegner activity scale score. In addition, pa

PURPOSE: To determine whether there are differences between adjustable-length loop and fixed-length loop devices in terms of the amount of displacement, temporal pattern of displacement, and ultimate failure load when tested using 4,500 cycles of sinusoidal loading with high loads (100-400 N). METHODS: Two cortical suspension devices with a fixed- or adjustable-length loop were tested. For our comparisons, a 20-mm fixed-length loop device and a fixed-length loop device with the same loop length

BACKGROUND: The present study was performed to determine whether MRI findings can predict the degree of knee joint laxity in patients undergoing ACL reconstruction and whether the accuracy of the prediction is affected by the MRI acquisition time. METHODS: We assessed prospectively collected data of 154 knees with ACL tears. The presence or absence of four primary findings of ACL tears, i.e., nonvisualization, discontinuity, abnormal signal intensity, and abnormal shape of the ACL, and five seco

BACKGROUND: We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) and clinical outcomes following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system. METHODS: This retrospective study included 130 consecutive patients (184 knees)

The purpose of this study was to assess the overall clinical results and range of motion (ROM) after total knee arthroplasty (TKA) in patients with preoperative stiffness. We also aimed to determine whether the severity or cause of the stiffness can affect the clinical outcome after surgery. This retrospective study included 122 knees (117 patients) with follow-up of more than 2 years (mean age, 64.3 years). TKA was performed using posterior-stabilized, varus-valgus constrained (VVC), and hinged