Feasibility of Loop-Mediated Isothermal Amplification for Rapid Detection of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus in Tissue Samples

Background@#To date, few studies have investigated the feasibility of the loop-mediated isothermal amplification (LAMP) assay for identifying pathogens in tissue samples. This study aimed to investigate the feasibility of LAMP for the rapid detection of methicillin-susceptible or methicillin-resistant Staphylococcus aureus (MSSA or MRSA) in tissue samples, using a bead-beating DNA extraction method. @*Methods@#Twenty tissue samples infected with either MSSA (n = 10) or MRSA (n = 10) were obtained from patients who underwent orthopedic surgery for suspected musculoskeletal infection between December 2019 and September 2020. DNA was extracted from the infected tissue samples using the bead-beating method. A multiplex LAMP assay was conducted to identify MSSA and MRSA infections. To recognize the Staphylococcus genus, S. aureus, and methicillin resistance, 3 sets of 6 primers for the 16S ribosomal ribonucleic acid (rRNA) and the femA and mecA genes were used, respectively. The limit of detection and sensitivity (detection rate) of the LAMP assay for diagnosing MSSA and MRSA infection were analyzed. @*Results@#The LAMP result was positive for samples containing 10 3 colony-forming unit (CFU)/mL for 16S rRNA, 10 4 CFU/mL for femA, and 10 5 CFU/mL formecA. The limits of detection for 16S rRNA and femA were not different between MSSA and MRSA. For the 10 MSSA-positive samples, the LAMP assay showed 100% positive reactions for 16S rRNA and femA and a 100% negative reaction for mecA. For the 10 MRSA-positive samples, the LAMP assay showed 100% positive reactions for 16S rRNA and mecA but only 90% positive reactions for femA. The sensitivity (detection rate) of the LAMP assay for identifying MSSA and MRSA in infected tissue samples was 100% and 90%, respectively. @*Conclusions@#The results of this study suggest that the LAMP assay performed with tissue DNA samples can be a useful diagnostic method for the rapid detection of musculoskeletal infections caused by MSSA and MRSA.

Development of Predictive Models in Patients with Epiphora Using Lacrimal Scintigraphy and Machine Learning / 대한핵의학회잡지

PURPOSE@#We developed predictive models using different programming languages and different computing platforms for machine learning (ML) and deep learning (DL) that classify clinical diagnoses in patients with epiphora. We evaluated the diagnostic performance of these models.@*METHODS@#Between January 2016 and September 2017, 250 patients with epiphora who underwent dacryocystography (DCG) and lacrimal scintigraphy (LS) were included in the study. We developed five different predictive models using ML tools, Python-based TensorFlow, R, and Microsoft Azure Machine Learning Studio (MAMLS). A total of 27 clinical characteristics and parameters including variables related to epiphora (VE) and variables related to dacryocystography (VDCG) were used as input data. Apart from this, we developed two predictive convolutional neural network (CNN) models for diagnosing LS images. We conducted this study using supervised learning.@*RESULTS@#Among 500 eyes of 250 patients, 59 eyes had anatomical obstruction, 338 eyes had functional obstruction, and the remaining 103 eyes were normal. For the data set that excluded VE and VDCG, the test accuracies in Python-based TensorFlow, R, multiclass logistic regression in MAMLS, multiclass neural network in MAMLS, and nuclear medicine physician were 81.70%, 80.60%, 81.70%, 73.10%, and 80.60%, respectively. The test accuracies of CNN models in three-class classification diagnosis and binary classification diagnosis were 72.00% and 77.42%, respectively.@*CONCLUSIONS@#ML-based predictive models using different programming languages and different computing platforms were useful for classifying clinical diagnoses in patients with epiphora and were similar to a clinician's diagnostic ability.

Arthroscopic Treatment of Popliteal Cysts with and without Cystectomy: A Systematic Review and Meta-Analysis

PURPOSE: To compare the clinical outcomes of the arthroscopic treatments for popliteal cysts with and without cystectomy. METHODS: PubMed/MEDLINE, EMBASE, KoreaMed, and Cochrane Library were searched from the earliest available date of indexing through August 2016. The methodological quality of all articles was assessed according to the Coleman methodology score (CMS). Studies were grouped according to the surgical method, and a meta-analysis was conducted to identify the unsuccessful clinical outcome and complication rates. RESULTS: Nine studies were included; the mean CMS was 67.33 (standard deviation, 8.75 points). Cystectomy was reported in five studies; cystectomy was not performed in four studies. The odds ratio of unsuccessful clinical outcomes evaluated by Rauschning and Lindgren score was 122.05 (p<0.001) with cystectomy and 58.12 (p<0.001) without cystectomy. The effect size of complications was 0.16 (p<0.001) with cystectomy and 0.03 (p<0.001) without cystectomy. The recurrence rate was 0% with cystectomy and 6.4% without cystectomy. CONCLUSIONS: All the currently available studies showed satisfactory outcomes in both with and without cystectomy groups. However, arthroscopic cystectomy concurrently performed with management of intra-articular lesions was associated with a relatively low recurrence rate and a relatively high incidence of complications.

Development of Predictive Models in Patients with Epiphora Using Lacrimal Scintigraphy and Machine Learning / 대한핵의학회잡지

PURPOSE: We developed predictive models using different programming languages and different computing platforms for machine learning (ML) and deep learning (DL) that classify clinical diagnoses in patients with epiphora. We evaluated the diagnostic performance of these models.METHODS: Between January 2016 and September 2017, 250 patients with epiphora who underwent dacryocystography (DCG) and lacrimal scintigraphy (LS) were included in the study. We developed five different predictive models using ML tools, Python-based TensorFlow, R, and Microsoft Azure Machine Learning Studio (MAMLS). A total of 27 clinical characteristics and parameters including variables related to epiphora (VE) and variables related to dacryocystography (VDCG) were used as input data. Apart from this, we developed two predictive convolutional neural network (CNN) models for diagnosing LS images. We conducted this study using supervised learning.RESULTS: Among 500 eyes of 250 patients, 59 eyes had anatomical obstruction, 338 eyes had functional obstruction, and the remaining 103 eyes were normal. For the data set that excluded VE and VDCG, the test accuracies in Python-based TensorFlow, R, multiclass logistic regression in MAMLS, multiclass neural network in MAMLS, and nuclear medicine physician were 81.70%, 80.60%, 81.70%, 73.10%, and 80.60%, respectively. The test accuracies of CNN models in three-class classification diagnosis and binary classification diagnosis were 72.00% and 77.42%, respectively.CONCLUSIONS: ML-based predictive models using different programming languages and different computing platforms were useful for classifying clinical diagnoses in patients with epiphora and were similar to a clinician's diagnostic ability.

Evaluation parameters of graft maturation on second-look arthroscopy following anterior cruciate ligament reconstruction: a systematic review

PURPOSE@#The purpose of this systematic review was to investigate and summarize the evaluation methods of graft maturation on second-look arthroscopy following anterior cruciate ligament (ACL) reconstruction.@*METHODS@#A literature search was performed on articles before December 2017 to identify the literature that has evaluated graft maturation on second-look arthroscopy following ACL reconstruction. Only studies using human grafts, evaluating graft maturation with two or more gross findings were included. Study design, grafts, surgical techniques, follow-up period, evaluation parameters, and categories were compiled.@*RESULTS@#Twenty-eight studies were included in this study. All studies evaluated graft maturation with two or more of the following three findings: graft integrity, tension, and synovial coverage. Two to four categories were used for evaluating each parameter, but the criteria for classification were slightly different for each study. Several studies reported neo-vascularization of grafts and the total maturation score by summing up the scores assigned to each evaluation parameter. Three studies reported that there was no correlation between second-look findings and patient-reported outcomes.@*CONCLUSIONS@#Graft integrity, tension, and synovial coverage were the most frequently evaluated for graft maturation on second-look arthroscopy. However, there is no uniform criterion for evaluation. Therefore, development of a valid, uinform criterion is required.LEVEL OF EVIDENCE: Level IV, systematic review of level I–IV investigations.

Medial patellofemoral ligament reconstruction using an autograft or allograft for patellar dislocation: a systematic review

PURPOSE@#The purpose of this study is to review the use of an allograft or autograft in medial patellofemoral ligament (MPFL) reconstruction.@*MATERIALS AND METHODS@#Various electronic databases were searched for relevant articles published from January 2000 to September 2017 that evaluated clinical outcomes of MPFL reconstruction using an autograft or allograft. Data search, extraction, analysis, and quality assessments were performed based on Cochrane Collaboration guidelines.@*RESULTS@#The study of 21 autografts and one allograft was included in this review. Although direct comparative studies were unavailable, the Kujala score and subjective results were reported in the majority of these studies. While the use of an autograft for MPFL reconstruction yielded satisfactory clinical outcomes with few perioperative complications, no new outcome has been drawn from the use of allografts.@*CONCLUSIONS@#Although many studies have shown favorable clinical results for MPFL reconstruction using an autograft, the clinical results of MPFL reconstruction using an allograft have not yet been sufficient to achieve meaningful clinical results due to low levels of evidence. Direct comparisons were not conducted because there were very few studies on allografts; thus, further research in this area should be performed in the future.

High incidence of subsequent re-operation following treatments for medial meniscus tears combined with anterior cruciate ligament reconstruction: second-look arthroscopic study

BACKGROUND@#The Multicenter Orthopaedic Outcomes Network (MOON) group recently reported that medial meniscus (MM) repairs are associated with more frequent re-operations when compared to lateral meniscus (LM) repairs. The purpose of this study was to compare the meniscal healing and the incidence of subsequent re-operation of medial and lateral meniscal tears that occurred concurrently with anterior cruciate ligament (ACL) injuries.@*METHODS@#We retrospectively reviewed patients who underwent second-look arthroscopy after primary ACL reconstruction (ACLR) between June 2005 to December 2016. The healing of meniscal tears following repair or left in situ, and re-tear following partial meniscectomy, were evaluated via second-look arthroscopy and compared between medial and lateral meniscus. Moreover, the incidence of subsequent meniscal re-operation after the index ACLR were investigated and compared between medial and lateral meniscus. Subsequent meniscal re-operation was performed in cases of the following three symptomatic meniscus tears: re-tears at the meniscectomy site; new tears; and failed healing of repaired or left in situ meniscus.@*RESULTS@#There were 148 meniscal tears in 121 patients at index ACLR. There were 62 MM tears, 38 LM tears, and 24 bilateral meniscus tears. At second-look arthroscopy, the “successful healing” rate for tears following repair was higher in LM tears (91.2%) compared to MM tears (80.0%), although it was not statistically significant (p > 0.05). No significant differences were observed in the healing of left in situ tears or re-tear of meniscectomy site between medial and lateral meniscus. Patients with MM tears combined with ACL injuries had a higher incidence of subsequent meniscal re-operation compared to patients with LM tears (25.6% vs 16.1%, p = 0.025).@*CONCLUSIONS@#There was a trend for the successful healing rate to be higher in LM repairs than MM repairs. Subsequent meniscal re-operations after ACLR were more frequent in patients with medial meniscal tears concurrently with ACL injuries in comparison to patients with lateral meniscal tears.LEVEL OF STUDY: Level IV, retrospective case series.

Inverse Prognostic Relationships of ¹⁸F-FDG PET/CT Metabolic Parameters in Patients with Distal Bile Duct Cancer Undergoing Curative Surgery / 대한핵의학회잡지

PURPOSE@#As there were few previous studies with a small number of subjects, the purpose of this was to evaluate the prognostic significance of ¹⁸F-FDG PET/CT in patients with distal bile duct cancer undergoing curative surgery.@*METHODS@#The study included 40 patients (M/F = 24:16; age 68.0 ± 8.0 years) who underwent preoperative ¹⁸F-FDG PET/CT followed by curative surgical resection. The participant's age, sex, Eastern Cooperative Oncology Group performance-status score, baseline serum CA 19-9 level, stage, pathologic T and N stages, tumor size, tumor grade, tumor growth pattern, R0 resection, and adjuvant therapy were included as clinicopathological variables for predicting overall survival. The PET variables were maximum standardized uptake value (SUV(max)), average SUV (SUV(avg)), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the tumor. The Kaplan-Meyer method and Cox proportional hazards model were used for the survival analysis.@*RESULTS@#A total of 15 of 40 patients (37.5%) died during the follow-up period. In univariate analysis, low SUVmax (≤ 2.7, p = 0.0005) and low SUV(avg) (≤ 2.6, p = 0.0034) were significant predictors of poor overall survival. In multivariate analyses, only low SUV(max) (HR = 6.7016, 95% CI 1.9961–22.4993, p = 0.0047) was an independent prognostic factor associated with poor overall survival.@*CONCLUSION@#The SUVmax of the primary tumor measured by ¹⁸F-FDG PET/CT was an independent significant prognostic factor for overall survival in patients with distal bile duct cancer. However, different results from a previous study warrant further large sample-sized study.

Inverse Prognostic Relationships of ¹⁸F-FDG PET/CT Metabolic Parameters in Patients with Distal Bile Duct Cancer Undergoing Curative Surgery / 대한핵의학회잡지

PURPOSE: As there were few previous studies with a small number of subjects, the purpose of this was to evaluate the prognostic significance of ¹⁸F-FDG PET/CT in patients with distal bile duct cancer undergoing curative surgery.METHODS: The study included 40 patients (M/F = 24:16; age 68.0 ± 8.0 years) who underwent preoperative ¹⁸F-FDG PET/CT followed by curative surgical resection. The participant's age, sex, Eastern Cooperative Oncology Group performance-status score, baseline serum CA 19-9 level, stage, pathologic T and N stages, tumor size, tumor grade, tumor growth pattern, R0 resection, and adjuvant therapy were included as clinicopathological variables for predicting overall survival. The PET variables were maximum standardized uptake value (SUV(max)), average SUV (SUV(avg)), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the tumor. The Kaplan-Meyer method and Cox proportional hazards model were used for the survival analysis.RESULTS: A total of 15 of 40 patients (37.5%) died during the follow-up period. In univariate analysis, low SUVmax (≤ 2.7, p = 0.0005) and low SUV(avg) (≤ 2.6, p = 0.0034) were significant predictors of poor overall survival. In multivariate analyses, only low SUV(max) (HR = 6.7016, 95% CI 1.9961–22.4993, p = 0.0047) was an independent prognostic factor associated with poor overall survival.CONCLUSION: The SUVmax of the primary tumor measured by ¹⁸F-FDG PET/CT was an independent significant prognostic factor for overall survival in patients with distal bile duct cancer. However, different results from a previous study warrant further large sample-sized study.

Redislocation after Bearing Exchange for the Treatment of Mobile Bearing Dislocation in Medial Unicompartmental Knee Arthroplasty

PURPOSE: This study was conducted to investigate the outcomes of bearing exchange for the treatment of mobile bearing dislocation in medial unicompartmental knee arthroplasty (UKA). MATERIALS AND METHODS: We retrospectively reviewed 18 patients (15 females and 3 males, mean age of 65 years) treated with bearing exchange following mobile bearing dislocation in medial UKA. The occurrence of bearing redislocation, the Oxford Knee Score, and radiographic changes at the last follow-up were investigated. RESULTS: Bearing redislocation after bearing exchange occurred in 9 of 18 patients (50%). Of these 9 patients, 7 underwent conversion to total knee arthroplasty after bearing redislocation. The 9 patients without bearing redislocation showed good to excellent clinical outcomes at a mean follow-up of 55 months after bearing exchange. The non-redislocation group had a higher percentage of posterior dislocation of the bearing than the redislocation group (55.5% vs. 22.2%, p=0.040). Univariate logistic regression analysis showed no significant risk factors for bearing redislocation. CONCLUSIONS: This study showed a high rate of bearing redislocation after isolated, mobile bearing exchange for bearing dislocation following medial UKA. Therefore, bearing exchange as a sole treatment should be carefully considered in selected patients with correctable causes of bearing dislocation.

Arthroscopic Meniscectomy for Medial Meniscus Horizontal Cleavage Tears in Patients under Age 45

PURPOSE: The purpose of this study was to evaluate the demographics, clinical features, and outcomes of arthroscopic partial meniscectomy (APM) for isolated medial meniscus horizontal cleavage tears (MMHCTs) in patients under 45 years of age. MATERIALS AND METHODS: We retrospectively reviewed 98 patients (100 knees) under 45 years who underwent APM for MMHCTs. Clinical outcomes were assessed using International Knee Document Committee (IKDC) subjective core, Tegner activity scale, visual analog scale (VAS) pain score, and a question on the symptom relief. RESULTS: 79% were male and 70% had no trauma. The mean symptom duration was 10 months. At arthroscopy, a flap tear was identified in 75%. At a mean of 19-month follow-up, the IKDC subjective score, Tegner activity scale, and VAS pain score were significantly improved compared to the preoperative values (p=0.025, p=0.043, and p=0.032, respectively). While 85% were free of symptoms, 15% had persistent pain. No significant differences in outcomes were observed based on the tear type and the presence of flap tears. No progression or development of radiographic degenerative changes was observed in all knees. CONCLUSIONS: Demographics of MMHCTs under age 45 showed a male dominance and higher frequency of non-traumatic tears. APM was beneficial to symptomatic HCTs in this cohort during the short-term follow-up. Type of HCTs and combined flap tears did not affect clinical outcomes.

In vivo Kinematics of the Knee after a Posterior Cruciate-Substituting Total Knee Arthroplasty: A Comparison between Caucasian and South Korean Patients

PURPOSE: This study compared in vivo kinematic differences between Caucasian and South Korean patients after a posterior-substituting total knee arthroplasty (PS-TKA). MATERIALS AND METHODS: In vivo motions of 9 Caucasian and 13 South Korean knees with a PS-TKA during weight bearing single leg lunge were determined using a dual fluoroscopic imaging technique. Normalized tibiofemoral condylar motions and articular contact locations were analyzed. RESULTS: Femoral condylar motions of the two groups showed a similar trend in anteroposterior translation, but the South Korean patients were more anteriorly positioned than the Caucasian patients at low flexion and maximal flexion angles in both medial and lateral compartments (p<0.05). Mediolateral femoral condyle translations were similar between the two groups. For tibiofemoral articular contact kinematics, the South Korean patients had significantly more anterior contact locations at the medial compartment at low flexion angles, and more lateral contact locations at the lateral compartment at 0° and 90° flexion compared to the Caucasian patients (p<0.05). The South Korean patients had significantly larger distances between the medial and lateral contact locations at 60° and 90° flexion compared to the Caucasian patients (p<0.05). CONCLUSIONS: The study revealed that while the Caucasian and South Korean knees had similar femoral condylar motions, after PS-TKA the South Korean patients showed different articular contact point kinematics compared to the Caucasian patients.

Non-Operative Treatment of the Degenerative Medial Meniscus Posterior Root Tear / 대한정형외과학회잡지

Degenerative medial meniscus posterior root tear is commonly seen in middle or old age populations. Because the biomechanical status of the meniscus root tear is similar to total menisectomy state, medial meniscus posterior root tear can cause early osteoarthritis. Treatment options for the medial meniscus posterior root tear include non-operative treatment, meniscectomy, repair, and high tibia osteotomy. There is still debate regarding the exact indication of each treatment, because the natural course of the medial meniscus posterior root tear and long-term results of each treatment is not known. However, non-operative treatments provide symptomatic relief and functional improvement in patients who are not indicated for operative treatment or before operative treatment.

The Parameters Affecting the Success of Irrigation and Debridement with Component Retention in the Treatment of Acutely Infected Total Knee Arthroplasty

BACKGROUND: The aims of our study were to evaluate the success rate of irrigation and debridement with component retention (IDCR) for acutely infected total knee arthroplasty (TKA) (< 4 weeks of symptom duration) and to analyze the factors affecting prognosis of IDCR. METHODS: We retrospectively reviewed 28 knees treated by IDCR for acutely infected TKA from 2003 to 2012. We evaluated the success rate of IDCR. All variables were compared between the success and failure groups. Multivariable logistic regression analysis was also used to examine the relative contribution of these parameters to the success of IDCR. RESULTS: Seventeen knees (60.7%) were successfully treated. Between the success and failure groups, there were significant differences in the time from primary TKA to IDCR (p = 0.021), the preoperative erythrocyte sedimentation rate (ESR; p = 0.021), microorganism (p = 0.006), and polyethylene liner exchange (p = 0.017). Multivariable logistic regression analysis of parameters affecting the success of IDCR demonstrated that preoperative ESR (odds ratio [OR], 1.02; p = 0.041), microorganism (OR, 12.4; p = 0.006), and polyethylene liner exchange (OR, 0.07; p = 0.021) were significant parameters. CONCLUSIONS: The results show that 60.7% of the cases were successfully treated by IDCR for acutely infected TKA. The preoperative ESR, microorganism, and polyethylene liner exchange were factors that affected the success of IDCR in acutely infected TKA.

Biomechanical Properties of a New Anatomical Locking Metal Block Plate for Opening Wedge High Tibial Osteotomy: Uniplane Osteotomy

PURPOSE: The purpose of this study was to evaluate the biomechanical properties of a new anatomical locking metal block plate by comparing the initial biomechanical stability of three different fixation constructs for open wedge high tibial osteotomy (HTO). MATERIALS AND METHODS: Sawbones composite tibiae were used to make a 10-mm opening osteotomy model with uniplane technique. The osteotomy was secured with three different types of plates: Group I, new osteotomy plate without a metal block (n=5); Group II, new osteotomy plate with a 10-mm metal block (n=5); and Group III, two short metal block plates (n=5). Single load to failure test and staircase load-controlled cyclical failure test were performed. In the single load to failure test, the yield load, maximum failure load, and the displacement of the osteotomy gap were measured. In the staircase cyclical load to failure test, the total number of cycles to failure was recorded. Failure modes were observed during both single and cyclic load tests. RESULTS: Group II showed the highest yield and ultimate loads (1829+/-319 N, 3493+/-1250 N) compared to Group I (1512+/-157 N, 2422+/-769 N) and Group III (1369+/-378 N, 2157+/-210 N, p<0.05). The displacement of the opening gap in Group II (0.34+/-0.35 mm) was significantly lesser than the other groups (p<0.05). In the staircase cyclical load to failure test, the total number of cycles to failure was 12,860 at 950 N in Group III, 20,280 at 1,140 N in Group I, and 42,816 at 1,330 N in Group II (p<0.05). All the specimens showed complete fracture of the intact lateral sawbones area and slight displacement of the distal fragment of the specimens in the single load to test. None of the specimens showed deformed or broken screws and plates during the single load to test. During the fatigue test with staircase cyclic loading, no fracture of the lateral sawbones area was observed. CONCLUSIONS: This study demonstrated that the new anatomical locking metal block plate could provide sufficient primary stability for open wedge HTO. The addition of a metal block to this new plate can increase the stability of the osteotomy compared to the one without a metal block.

Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

BACKGROUND: The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. METHODS: Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction. RESULTS: Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30degrees of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees. CONCLUSIONS: Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction.

Intra-articular Patterns of Bucket Handle Meniscal Tears and Its Relation to Reducibility

BACKGROUND: The purpose of this study was to assess the intra-articular patterns in the rotational deformities of bucket handle meniscal tears (BHMTs) based on arthroscopic findings and their clinical relevance. METHODS: From 2004 to 2009, 42 patients with a BHMT diagnosed by magnetic resonance imaging underwent arthroscopic surgery. The arthroscopic data (all procedures were recorded) were evaluated retrospectively, and BHMTs were classified according to the rotational directions of centrally displaced fragments. To assess the reliability of the agreement in this classification, 2 orthopedic surgeons re-classified BHMTs, 1 week after first trial. Intra- and interobserver reliabilities were assessed using kappa statistics. In addition, we address specific tear patterns, associated anterior cruciate ligament injury, medio-lateral difference, reducibility, chronicity, and reparability. RESULTS: Most of the tears could be categorized into one of 3 morphologic patterns. Of the tears, 4.8% could not be categorized. BHMTs were classified, based on the rotational directions of centrally displaced fragments, as follows; the upward rotation group (type 1), the downward rotation group (type 2) and the reverse group (type 3). The most common intra-articular pattern was type 1 (29 patients, 69%). The occurrence of the other patterns was: type 2 in 7 patients (16.7%), type 3 in 4 patients (9.5%); we were not able to make a classification of type in 2 patients (4.8%). Intra-observer reliability was 0.86 in terms of kappa statistics, which implies almost perfect agreement. Mean interobserver reliability (0.73) showed substantial agreement. Type 1 and 2 tears were easily reduced, whereas all type 3 tears (4/4) needed additional procedures to achieve reduction. CONCLUSIONS: Based on arthroscopic findings, we describe a comprehensive BHMT classification scheme that encompasses 95.2% of all tears. Tear type was correlated with reducibility.

Fracture of a Polyethylene Tibial Post in a Scorpio Posterior-Stabilized Knee Prosthesis

We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articulation. This is the first report of a polyethylene tibial post fracture of a Scorpio PS prosthesis.

Treatment of Spontaneous Osteonecrosis of the Knee Using the Oxford Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the clinical and radiographic outcomes of unicompartmental knee arthroplasty (UKA) in patients with spontaneous osteonecrosis. MATERIALS AND METHODS: Between September 2002 and March 2005, 15 patients with 16 knees were treated with UKA for the treatment of spontaneous osteonecrosis. There were thirteen women and two men with a mean age of 64 years old. The clinical assessment was performed using the American Knee Society Score system. The preoperative radiography was analyzed according to the size and stage of the osteonecrotic lesion and the osteoarthritic changes. Postoperatively, the presence of new osteonecrotic lesion, loosening of the implant, subsidence and arthritic changes was recorded. RESULTS: The mean preoperative knee score and the knee function score was improved from 52.5 to 89.2 and 56.0 to 85.2, respectively. There was no new necrotic lesion in the lateral compartment, loosening of the implant, subsidence or arthritic change. CONCLUSION: UKA in patients with spontaneous osteonecrosis provided satisfactory clinical and radiological results in the short to medium term.

Aspects of Patients Injured While Attending Street Rallies in Seoul During the Period of the 2002 World Cup

PURPOSE: An appropriate emergency medical support system is required at sites of large-scale congregations because different kinds of emergencies may be encountered. My colleagues and I initiated this project to present the information required for the process of devising an onsite plan for large crowds. The basic structure is based on an analysis of patients who were injured while attending large scale street-cheering demonstrations in Seoul during the period of the 2002 World Cup. METHOD: The analysis concentrated on the period from May 31, 2002, to June 30, 2002, during the 2002 Korean-Japan World Cup. Seven soccer games involving the Korean team and 8.91 million people from 116 places were considered. The following report was generated from the supporting schedules and the activity reports of emergency rescue crews from fire departments. It is largely based on rescue activity journals and transportation records. RESULT: There were 796 patients among the in 8.91 million people. Male patients were 383 (42.8%) and female 413 (51.2%). Patients in their 20's were 267, and that was the largest age group. In Korean game against Germany, 183 patients were treated, and that was the largest among the seven games involving Korean's team. There was one patient in every 10,000 people on average. Sicknesses were not that serious, and most of them were headaches, stomachaches and exhaustion. CONCLUSION: The frequency and pattern of generation of patients were affected by the scale of the cheering crowd, the sex and age composition of the crowd, and the weather. In planning future medical support for similar events, the structure of the plan should be based on the site and the size of the crowd, after which the plan can be finalized by considering details such as the importance of the game and the weather.