Drawing Guideline for JKMS Manuscripts (06): Scatter Plot.

The appropriate plot effectively conveys the author's conclusions to the readers. Journal of Korean Medical Science is providing a series of guidelines to show you how to make consistent and excellent plots more easily. In this article, we introduce scatter plots and more.

Drawing Guideline for JKMS Manuscripts (05): Plots for Numeric Data.

The appropriate plot effectively conveys the author's conclusions to the readers. Journal of Korean Medical Science will provide a series of special articles to show you how to more easily make consistent and excellent plots. In this article, we will cover plots with numeric data.

Implant Removal After Medial Opening Wedge High Tibial Osteotomy Provides Implant-Related Pain Relief and Functional Improvement.

PURPOSE: To (1) investigate the incidence of implant-related pain after medial opening wedge high tibial osteotomy (MOWHTO) using a locking plate, (2) determine whether implant removal provides pain relief and functional improvement, and (3) evaluate bone healing and loss of correction after implant removal. METHODS: Between March 2014 and September 2017, MOWHTO was performed without bone graft. The inclusion criteria were patients who underwent implant removal after MOWHTO and were followed up for a minimum of 2 years. Patients were evaluated for implant removal 1 and 2 years after surgery. Clinical and functional evaluations were conducted to investigate implant-related pain using the visual analog scale, Lysholm score, and Tegner score. The radiographic indices measured were the gap-filling rate, weightbearing line (WBL) ratio, hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), and posterior tibial slope angle (PTSA). RESULTS: A total of 55 patients were enrolled. Fifty-one (92.7%) patients experienced implant-related pain prior to implant removal, with 43 and 8 patients reporting mild pain and moderate pain, respectively. At 1 and 2 years after implant removal, mild pain occurred in 6 (10.9%) and 5 (9.1%) patients, respectively. The remaining patients reported no implant-related pain. Prior to implant removal and 1 year after implant removal, the Lysholm score improved from 77.0 ± 5.6 to 86.8 ± 5.7 (P < .001), and the Tegner score improved from 3.3 ± 1.2 to 3.9 ± 1.3 (P < .001). The mean gap-filling rate was 84.4% ± 9.6% at implant removal, and it significantly increased to 93.7% ± 5.4% and 97.4% ± 2.6% at 1 and 2 years after implant removal, respectively (P < .001). For the WBL ratio, HKAA, MPTA, and PTSA, no statistically significant differences were found after implant removal. CONCLUSIONS: The incidence of implant-related pain after MOWHTO using the medial proximal tibial locking plate was high. Implant removal provides pain relief and functional improvement (met minimal clinically important differences). Even after implant removal, bone healing progressed gradually without a loss of correction in all patients. LEVEL OF EVIDENCE: Level IV, case series.

Assessing local California trends in emergency physician opioid prescriptions from 2012 to 2020: Experiences in a large academic health system.

OBJECTIVES: There has been increased focus nationally on limiting opioid prescriptions. National data demonstrates a decrease in annual opioid prescriptions among emergency medicine physicians. We analyzed data from 2012 to 2020 from a large academic health system in California to understand trends in opioid prescribing patterns for emergency department (ED) discharged patients and assessed the potential impact of two initiatives at limiting local opioid prescriptions. METHODS: In 2012-2020, monthly ED visit data was used to evaluate the total number of outpatient opioid prescriptions and percent of ED visits with opioid prescriptions (as primary outcomes). Descriptive statistics, graphic representation, and segmented regression with interrupted times series were used based on two prespecified time points associated with intensive local initiatives directed at limiting opioid prescribing1) comprehensive emergency medicine resident education and 2) electronic health record (EHR)-based intervention. RESULTS: Between March 2012 and July 2020, a total of 41,491 ED discharged patients received an opioid prescription. The three most commonly prescribed drugs were hydrocodone (84.1%), oxycodone (10.8%), and codeine (2.8%). After implementing comprehensive emergency medicine resident education, the total number of opioid prescriptions, the percentage of opioid prescriptions over total ED visit numbers and the total tablet number showed decreasing trends (p's ≤ 0.01), in addition to the natural (pre-intervention) decreasing trends. In contrast, later interventions in the EHR tended to show attenuated decreasing trends. CONCLUSIONS: From 2012 to 2020, we found that total opioid prescriptions decreased significantly for discharged ED patients. This trend is seen nationally. However, our specific interventions further heightened this downward trend. Evidence-based legislation, policy changes, and educational initiatives that impact prescribing practices should guide future efforts.

Drawing Guideline for JKMS Manuscripts (03): Pyramid Charts.

The appropriate plot effectively conveys the author's conclusions to the readers. Journal of Korean Medical Science (JKMS) will provide a series of special articles to show you how to make consistent and excellent plots more easily. In this article, we will cover pyramid charts. A pyramid chart is a simple yet popular tool for looking at the structure of a population by age and gender. Other variables can also be applied. This article helps researchers use these charts more easily by introducing effective tools and explaining how to use them.

Bone healing on serial plain radiographs occurs slowly but adequately after medial opening wedge high tibial osteotomy without bone graft.

PURPOSE: The purpose of this study was to prospectively investigate osteotomy gap filling rates on serial plain radiographs, and to evaluate whether alignment correction is maintained after medial opening wedge high tibial osteotomy (MOWHTO) using a locking plate without bone graft. METHODS: Between March 2014 and June 2017, MOWHTO was performed without bone graft regardless of gap size. Radiographs were taken preoperatively, postoperatively, at 1, 3, 6, 12, 18, and 24 months after surgery. Radiographic examinations included a weight bearing long-standing anteroposterior (AP) view of the whole lower extremity, as well as, the AP, lateral, and both oblique views of the knee. Bone healing was measured on the medial oblique view of the knee. The postoperative alignment correction and its maintenance were assessed using the three radiologic parameters of the weight-bearing line (WBL) ratio, the hip-knee-ankle angle (HKAA), and the medial proximal tibial angle (MPTA) on the weight-bearing long-standing AP view of the lower extremity. RESULTS: Fifty-two consecutive patients underwent MOWHTO, but three patients failed to follow-up for more than 24 months. A total of 49 patients were assessed in this study. The median opening gap height was 10.0 mm (IQR, 8.0-12.0; range, 7-20). On immediate post-operative radiographs, the mean gap filling was 31.4 ± 3.6%. After 1, 3, 6, 12, 18, and 24 months, the mean gap filling rates increased to 38.7 ± 4.4%, 51.4 ± 6.6%, 66.5 ± 5.1%, 84.8 ± 7.0%, 92.4 ± 5.6%, and 97.8 ± 2.3%, respectively. Statistical differences were observed between all the follow-up evaluations (P < 0.001). Statistical differences in the WBL ratio, HKAA, and MPTA were observed between preoperatively and 1 month after surgery (P < 0.001). The mean PTSA increased significantly from preoperatively to postoperatively (P < 0.001). However, no statistical differences were found between the post-operative follow-up radiographs performed for these four values. CONCLUSION: MOWHTO using a locking plate without bone graft achieved at least 90% bone healing and had no loss in correction at 2 years postoperatively. LEVEL OF EVIDENCE: III.

Blinding, sham, and treatment effects in randomized controlled trials for back pain in 2000-2019: A review and meta-analytic approach.

BACKGROUND: Blinding aims to minimize biases from what participants and investigators know or believe. Randomized controlled trials, despite being the gold standard to evaluate treatment effect, do not generally assess the success of blinding. We investigated the extent of blinding in back pain trials and the associations between participant guesses and treatment effects. METHODS: We did a review with PubMed/OvidMedline, 2000-2019. Eligibility criteria were back pain trials with data available on treatment effect and participants' guess of treatment. For blinding, blinding index was used as chance-corrected measure of excessive correct guess (0 for random guess). For treatment effects, within- or between-arm effect sizes were used. Analyses of investigators' guess/blinding or by treatment modality were performed exploratorily. RESULTS: Forty trials (3899 participants) were included. Active and sham treatment groups had mean blinding index of 0.26 (95% confidence interval: 0.12, 0.41) and 0.01 (-0.11, 0.14), respectively, meaning 26% of participants in active treatment believed they received active treatment, whereas only 1% in sham believed they received sham treatment, beyond chance, that is, random guess. A greater belief of receiving active treatment was associated with a larger within-arm effect size in both arms, and ideal blinding (namely, "random guess," and "wishful thinking" that signifies both groups believing they received active treatment) showed smaller effect sizes, with correlation of effect size and summary blinding indexes of 0.35 (p = 0.028) for between-arm comparison. We observed uniformly large sham treatment effects for all modalities, and larger correlation for investigator's (un)blinding, 0.53 (p = 0.046). CONCLUSION: Participants in active treatments in back pain trials guessed treatment identity more correctly, while those in sham treatments tended to display successful blinding. Excessive correct guesses (that could reflect weaker blinding and/or noticeable effects) by participants and investigators demonstrated larger effect sizes. Blinding and sham treatment effects on back pain need due consideration in individual trials and meta-analyses.

Drawing Guideline for JKMS Manuscripts (03): Plots for Categorical Data.

The appropriate plot effectively conveys the author's conclusions to the readers. JKMS will provide a series of special articles to show you how to make consistent and excellent plots easier. In this article, we will cover plots with categorical data. We will show what 'Bubble Plot,' 'Matrix Bubble Plot,' and 'Matrix Bar Plot' are and how to make them.

Drawing Guidelines for Receiver Operating Characteristic Curve in Preparation of Manuscripts.

The appropriate plot effectively conveys the author's conclusions to the readers. The Journal of Korean Medical Science provides a series of special articles to show you how to make consistent and excellent plots easier. In the second article, drawing receiver operating characteristic (ROC) curve is introduced. A ROC curve is a graphic plot that illustrates the diagnostic ability as its discrimination threshold is varied. It is widely used as logistic regression analysis as machine learning becomes widespread. It has great visual effect in comparing various diagnostic tools.

Drawing Guideline for JKMS Manuscript (01) Kaplan-Meier Curve and Survival Analysis.

The appropriate plot effectively conveys the author's conclusions to readers. Journal of Korean Medical Science will provide a series of special articles to show you how to make consistent and excellent plots easier. In the first of this series of special articles, I will cover Kaplan-Meier curve (or Kaplan-Meier plot) and the ease tools. This plot, generated as a result of the Survival Analysis, provides a visualization of the 'Kaplan-Meier Survival Probability Estimate' for each group.

Arthroscopic Coracoclavicular Fixation Using Multiple Low-Profile Devices in Acute Acromioclavicular Joint Dislocation.

PURPOSE: To introduce an arthroscopically assisted coracoclavicular (CC) fixation technique using multiple low-profile devices to evaluate the clinical and radiologic outcomes in patients with acute high-grade acromioclavicular (AC) joint dislocation. METHODS: Between July 2014 and September 2015, cases of AC joint dislocation that were treated with arthroscopic CC fixation using multiple low-profile devices with a minimum follow-up of 24 months were included. We measured the vertical coracoclavicular distance (CCD) on the anteroposterior view and the horizontal acromioclavicular distance on 3-dimensional computed tomography images to evaluate the changes in radiologic outcomes before and after surgery. We compared final radiologic outcomes between initial AC reduction groups based on hierarchical clustering. Clinical outcomes were evaluated using the Constant-Murley score. RESULTS: We enrolled 27 patients in total, and the mean follow-up period was 27.2 months. The mean CCD of the injured shoulder was 13.68 ± 3.98 mm preoperatively and decreased to 5.72 ± 1.68 mm immediately postoperatively but increased to 7.32 ± 2.29 mm at last follow-up (P = .07). Horizontal displacement of the distal clavicle was 1.1 ± 1.0 mm immediately postoperatively but decreased to 0.9 ± 0.6 mm at last follow-up (P < .05). In particular, in the 2 groups that were determined using the hierarchical cluster analysis, patients with excellent recovery of the initial CCD (20 patients) showed less of an increase in the CCD at last follow-up than did those in the other group (7 patients) (P < .001). The Constant-Murley score was 93.5 ± 2.7 points on the injured side at last follow-up (P = .074). CONCLUSIONS: Our CC fixation technique with multiple low-profile devices exhibited satisfactory clinical and radiologic outcomes. In particular, ensuring good initial recovery of the CCD and the precise placement and location of the AC joints was important in maintaining the proper AC position at the final follow-up. LEVEL OF EVIDENCE: Level IV, case series.

Excess Readmission-Based Penalty: Is Arthroplasty Different From the Other Outcomes?

Whether factors not under a hospital's control affect readmissions remains intensely debated in the context of the Centers for Medicare & Medicaid Services' Hospital Readmission Reduction Program. This study aimed to evaluate the potential effects of poverty, race, and hospital volume on excess readmissions, with >3000 hospitals participating in "Hospital Compare." Correlations between excess readmission ratios for five eligible outcomes (including hip and knee arthroplasty) were assessed with the three area and hospital-level factors: poverty, race (percent of black population), and hospital volume (number of discharges). Correlation coefficients of the ratios with race were approximately r = 0.2, consistently larger than those with poverty (r = 0-0.1), and those with volume were r = 0 to -0.5. Hip and knee arthroplasty had unique findings: null correlation with poverty (r ≈ 0), largest variability, and strong monotonicity with volume (r ≈ -0.5). The percent of Hispanic population showed negligible correlations in secondary analysis. Penalty assessment and hospital profiling should consider areas with high percentages of black population and a small volume of hospitals and providers of hip and knee surgery. (Journal of Surgical Orthopaedic Advances 27(4):286-294, 2018).

Gastrointestinal stromal tumours: Preoperative imaging features to predict recurrence after curative resection.

PURPOSE: To identify whether preoperative factors could predict the recurrence after curative resection of gastrointestinal stromal tumours (GISTs) and evaluate the performance of a prediction model using preoperative factors for GIST recurrence compared to a model using preoperative/postoperative factors. METHOD: This retrospective study included patients who underwent curative resection and preoperative CT for GIST. CT imaging features as preoperative factors were analysed by two abdominal radiologists. Modified National Institutes of Health scores were accessed as a postoperative factor. Multiple logistic regression analysis was performed to assess the preoperative and postoperative factors in predicting GIST recurrence. Through the logistic regression, two prediction models using preoperative factors only and both preoperative/postoperative factors were constructed, respectively. The internal validation of the prediction models was performed using bootstrapping sampling. RESULTS: Data in 113 patients were evaluated. Among them, 14 patients had recurrence. The multiple logistic regression analysis demonstrated that non-gastric location (odds ratio [OR] = 5.12, p = 0.029), ill-defined margin (OR = 4.93, p = 0.023), and prominent vessels around tumour (OR = 6.78, p = 0.007) were significant factors. The prediction models using these preoperative factors and adding a postoperative factor showed an area under the receiver operating characteristic curve of 0.863 and 0.897, respectively, which were not statistically different. The bootstrapping sampling showed the two models were valid. CONCLUSION: The prediction model derived from non-gastric location, ill-defined margin, and prominent vessels around tumour can be used preoperatively to estimate the risk of recurrence after resection of GIST.

Performance of Diabetes and Kidney Disease Screening Scores in Contemporary United States and Korean Populations.

BACKGROUND: Risk assessment tools have been actively studied, and they summarize key predictors with relative weights/importance for a disease. Currently, standardized screening scores for type 2 diabetes mellitus (DM) and chronic kidney disease (CKD)-two key global health problems-are available in United States and Korea. We aimed to compare and evaluate screening scores for DM (or combined with prediabetes) and CKD, and assess the risk in contemporary United States and Korean populations. METHODS: Four (2×2) models were evaluated in the United States-National Health and Nutrition Examination Survey (NHANES 2015-2018) and Korea-NHANES (2016-2018)-8,928 and 16,209 adults. Weighted statistics were used to describe population characteristics. We used logistic regression for predictors in the models to assess associations with study outcomes (undiagnosed DM and CKD) and diagnostic measures for temporal and cross-validation. RESULTS: Korean adult population (mean age 47.5 years) appeared to be healthier than United States counterpart, in terms of DM and CKD risks and associated factors, with exceptions of undiagnosed DM, prediabetes and prehypertension. Models performed well in own country and external populations regarding predictor-outcome association and discrimination. Risk tests (high vs. low) showed area under the curve >0.75, sensitivity >84%, specificity >45%, positive predictive value >8%, and negative predictive value >99%. Discrimination was better for DM, compared to the combined outcome of DM and prediabetes, and excellent for CKD due to age. CONCLUSION: Four easy-to-use screening scores for DM and CKD are well-validated in contemporary United States and Korean populations. Prevention of DM and CKD may serve as first-step in public health, with these self-assessment tools as basic tools to help health education and disparity.

Efficacy of a Restrictive Diet in Irritable Bowel Syndrome: A Systematic Review and Network Meta-analysis.

Background/Aims: Dietary factors can aggravate the symptoms of irritable bowel syndrome (IBS). Many IBS patients try restrictive diets to relieve their symptoms, but the types of diets with an exacerbating factor are unknown. Therefore, this paper reports the results of a systematic review and network meta-analysis of randomized-controlled trials (RCTs) reviewing the efficacy of food restriction diets in IBS. Methods: The MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov databases were searched until July 21, 2021, to retrieve RCTs assessing the efficacy of restriction diets in adults with IBS. Two independent reviewers performed the eligibility assessment and data abstraction. RCTs that evaluated a restriction diet versus a control diet and assessed the improvement in global IBS symptoms were included. These trials reported a dichotomous assessment of the overall response to therapy. Results: A total of 1,949 citations were identified. After full-text screening, 14 RCTs were considered eligible for the systematic review and network meta-analysis. A starch- and sucrose-reduced diet and a diet with low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) showed significantly better results than a usual diet. Symptom flare-ups in patients on a gluten- free diet were also significantly lower than in those on high-gluten diets. Conclusions: These findings showed that the starch- and sucrose-reduced, low FODMAP, and gluten-free diets had superior effects in reducing IBS symptoms. Further studies, including head-to-head trials will be needed to establish the effectiveness of dietary restrictions on IBS symptoms.

Glenoid Orientation and Profile in Atraumatic or Microtraumatic Posterior Shoulder Instability: Morphological Analysis Using Computed Tomography Arthrogram.

BACKGROUND: Posterior shoulder instability (PSI) is a relatively uncommon condition that occurs in about 10% of patients with shoulder instability. PSI is usually associated with dislocations due to acute trauma and multidirectional instability, but it can also occur with or without recognizable recurrent microtrauma. The infrequency of atraumatic or microtraumatic PSI and the lack of a full understanding of the pathoanatomy and the knowledge of management can lead to misdiagnosis or delayed diagnosis. PURPOSE: To evaluate the morphologic factors of the glenoid that are associated with atraumatic or microtraumatic PSI. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Enrolled in this study were patients who underwent arthroscopic posterior labral repair between January 2013 and March 2017 and were diagnosed with posterior glenohumeral instability by means of preoperative computed tomography arthrography (CTA) (n = 39; PSI group). These patients did not have any significant dislocation or subluxation episodes. The morphologic factors of the glenoid as revealed using CTA were compared with the CTA images from a sex-matched control group (n = 117) of patients without PSI who had been diagnosed with adhesive capsulitis in an outpatient clinic. The glenoid version and shape were evaluated between the 2 groups using the CTA findings, and the degree of centricity of the humeral head to the glenoid was assessed in the PSI group. Multivariate logistic regression analysis was performed to identify factors associated with PSI. RESULTS: The results of the multivariate logistic regression analysis indicated no statistically significant difference between the PSI and control groups regarding glenoid version or a flat-shaped glenoid. However, statistically significant between-group differences were found regarding convex glenoid shape, with an odds ratio of 5.39 (95% CI, 1.31-23.35; P = .0207). The proportion of eccentricity was significantly higher in the PSI group (21/39; 54%) versus the control group (47/117; 40%) (P = .031). CONCLUSION: The presence of convex glenoid shape was significantly associated with atraumatic or microtraumatic PSI. Humeral head eccentricity accounted for a high percentage of convex glenoid shape. However, there was no significant correlation between PSI and glenoid retroversion.

Meta-Analysis of Correlations between Altmetric Attention Score and Citations in Health Sciences.

INTRODUCTION: In recent years, several controversial reports of the correlation between altmetric score and citations have been published (range: -0.2 to 0.8). We conducted a meta-analysis to provide an in-depth statistical analysis of the correlation between altmetric score and number of citations in the field of health sciences. METHODS: Three online databases (Web of Science, Scopus, and PubMed) were systematically searched, without language restrictions, from the earliest publication date available through February 29, 2020, using the keywords "altmetric," "citation," and "correlation." Grey literature was also searched via WorldCat, Open Grey, and Google Scholar (first 100 hits only). All studies in the field of health sciences that reported on this correlation were included. Effect sizes were calculated using Fisher's z transformation of correlations. Subgroup analyses based on citation source and sampling methods were performed. RESULTS: From 27 included articles, 8 articles comprise several independent studies. The total sample size was 9,943 articles comprised of 35 studies. The overall pooled effect size was 0.19 (95% confidence interval 0.13 to 0.26). Bivariate partial prediction of interaction between effect size, citation source, and sampling method showed a greater effect size with Web of Science compared with Scopus and Dimensions. Egger's regression showed a marginally nonsignificant publication bias (p = 0.055), and trim-and-fill analysis estimated one missing study in this meta-analysis. CONCLUSION: In health sciences, currently altmetric score has a positive but weak correlation with number of citations (pooled correlation = 0.19, 95% C.I 0.12 to 0.25). We emphasize on future examinations to assess changes of correlation pattern between altmetric score and citations over time.

Drawing Guideline for 'Hip and Pelvis': Plot with Error Bar.

The appropriate plots effectively convey the author's conclusions to the readers. 'Hip and Pelvis' will provide a series of special articles to show how to make consistent and excellent plots easier. In this article, we will cover plots with error bars.

Estimating Residual Native Kidney Urea Clearance in Hemodialysis Patients with and without 24-Hour Urine Volume.

RATIONALE AND OBJECTIVE: Quantification of residual native kidney function (RKF) is rarely performed in patients on hemodialysis. Methods of estimating residual kidney urea clearance (KRU) that use commonly available laboratory and clinical data, with or without urine volume information, may be useful tools. STUDY DESIGN: Retrospective, predictive modeling and model validation. SETTING AND PARTICIPANTS: Initial timed urine collections in 604 incident in-center hemodialysis patients on thrice weekly treatments from a single academic center where KRU is measured in usual care. PREDICTORS: Models using combination of serum creatinine and urea, age, weight, height, gender, race, fluid weight gains, and with and without 24-hour urine volume. OUTCOMES: Residual kidney urea clearance. ANALYTIC APPROACH: Generalized linear model was used for model development for KRU using the first urine collection in 604 patients, as both a continuous and binary outcome (for >2.5 mL/min). Model validation was done by bootstrap resampling of the development cohort and with 1093 follow-up measurements. RESULTS: Urine volume alone was the strongest predictor of KRU. The model that included 24-hour urine volume with common clinical data had a high diagnostic accuracy for KRU >2.5 mL/min (area under the curve 0.91 in both development and bootstrap validation) and R2 of 0.56 with outcome as a continuous KRU value. Our model that did not use urine volume performed less well (e.g., AUC 0.75). Analyses of follow-up urine collections in these same subjects yielded comparable or improved performance. LIMITATIONS: Data were retrospective from a single center, no external validation, not validated in 2 or 4 times weekly hemodialysis patients. CONCLUSIONS: Estimation equations for residual kidney urea clearance that use commonly available data in dialysis clinics, with and without urine volume, may be useful tools for evaluation of hemodialysis patients who still have RKF for individualization of dialysis prescriptions.

Collagenous Ultrastructure of the Torn Medial Meniscus Posterior Root: A Transmission Electron Microscopy Study.

BACKGROUND: The collagen ultrastructure of torn medial meniscus posterior roots (MMPRs) has not been precisely defined. PURPOSE: To investigate the ultrastructure of torn MMPRs, focusing on their collagen fibers, and to compare the collagen net architecture between intact and torn MMPRs using the Collagen Meniscal Architecture (CMA) scoring system. STUDY DESIGN: Descriptive laboratory study. METHODS: Forty-three human meniscal specimens were obtained from 32 patients with osteoarthritis during total knee arthroplasty between January 2018 and November 2018. There were 23 specimens taken from patients with an MMPR tear and 20 taken from patients without an MMPR tear served as a control group. The presence of an MMPR tear was defined as a complete radial tear within 9 mm of the posterior root attachment. The collagen ultrastructure of the meniscal specimens was assessed with transmission electron microscopy using the CMA scoring system. Patient demographics included sex, age, and body mass index, and radiographic assessments included the Kellgren-Lawrence (K-L) grading system and the mechanical axis angle. RESULTS: The median CMA score was significantly higher in torn MMPRs (5.5 [interquartile range, 3.5-6.0]) than in intact MMPRs (2.0 [interquartile range, 1.5-3.8]) (P < .001). When the CMA scores were converted to CMA grading, 23 torn MMPRs had 1 grade I, 9 grade II, and 13 grade III menisci. In 20 intact MMPRs, there were 12 grade I, 7 grade II, and 1 grade III menisci. No significant differences in sex, age, body mass index, K-L grade, or mechanical axis angle were found between groups. CONCLUSION: This study showed that torn MMPRs had decreased numbers and disorganized courses of collagen fibers. The structural problem of torn MMPRs can negatively affect meniscal healing, function, and long-term survival after root repair. CLINICAL RELEVANCE: These results might provide a histopathological reason for the low healing rate after MMPR repair.