Search Results (14)

Background and Objectives: Subcortical bone cysts at the tibial attachment of the medial meniscus posterior root (MMPR) may reflect chronic degenerative changes; however, their clinical significance in medial meniscus posterior root tear (MMPRT) remains unclear. This study assessed whether bone cysts are associated with symptom duration and whether their presence influences healing status or medial meniscus extrusion (MME) after transtibial pullout repair (TPR). Materials and Methods: Seventy-four consecutive patients who underwent arthroscopic TPR for MMPRT between January 2022 and December 2024 were retrospectively reviewed. After applying exclusion criteria, 50 patients were included and divided into cyst-positive (n = 20) and cyst-negative (n = 30) groups based on preoperative MRI findings. Clinical outcomes, MME, and second-look arthroscopic healing status at 6 months postoperatively were compared between groups. Multivariable linear regression analysis was performed to identify independent predictors of postoperative MME. Results: The cyst-positive group had significantly longer symptom duration than the cyst-negative group (13.8 ± 3.0 vs. 8.8 ± 2.8 weeks, p < 0.001) and demonstrated higher grades of MMPR degeneration (p < 0.05). Complete healing was observed in 60.0% of patients in each group, and no failed healing cases were noted. Postoperative MME at 6 months was comparable between groups (3.8 ± 0.8 vs. 3.8 ± 1.0 mm). Multivariable regression analysis identified baseline MME as the strongest independent predictor of postoperative MME (β = 0.67, p < 0.001), whereas bone cyst presence was not independently associated with postoperative extrusion. Conclusions: Subcortical bone cysts at the MMPR attachment are associated with longer symptom duration and more advanced root degeneration. However, their presence was not significantly associated with healing status or postoperative MME after MMPRT repair. These findings suggest that bone cyst formation may be associated with chronic degenerative changes at the root attachment, but should not discourage surgeons from performing root repair. Full article

Background/Objectives: Medial meniscus extrusion (MME) is a quantitative marker of altered meniscal containment and load sharing. Although ultrasonography enables dynamic assessment under functional loading, it remains unclear whether generalized ligamentous hypermobility influences physiologic extrusion behavior in healthy knees. The aim of this study was to quantify load-dependent MME in healthy adults and to determine whether generalized hypermobility is associated with greater physiologic extrusion under progressive loading conditions. Methods: In this prospective observational study, 106 healthy adults aged 18–40 years were evaluated between October and December 2025. Generalized joint hypermobility was defined as a Beighton score ≥5. MME was measured by standardized ultrasonography on the dominant limb in three conditions: sitting (unloaded), bipedal stance, and unipedal stance. Patellar tendon shear-wave elastography (SWE) was recorded in kilopascals (kPa). Interobserver reliability was assessed in the first 25 participants using ICC (2,1). Group comparisons, multivariable linear regression for loading-related Δ-extrusion (Unipedal−Sitting and Bipedal−Sitting), and a linear mixed-effects model for repeated MME measures, including a Position × Hypermobility interaction, were performed. Results: Twenty-eight participants (26.4%) were classified as hypermobile. The hypermobile group showed significantly lower patellar tendon SWE than controls (23.8 ± 7.0 vs. 37.6 ± 9.7 kPa, p < 0.001). MME increased stepwise with loading in both groups and remained consistently higher in hypermobile participants across sitting, bipedal, and unipedal conditions (all p < 0.001). Loading-related extrusion was also greater in the hypermobile group for both Bipedal−Sitting (p = 0.037) and Unipedal−Sitting (p = 0.002). In multivariable regression, lower patellar tendon SWE independently predicted greater loading-related extrusion, whereas hypermobility status did not remain an independent predictor. In the mixed model, the Position × Hypermobility interaction was significant and was most pronounced during the unipedal stance. Conclusions: In healthy adults, medial meniscus extrusion increases stepwise from unloaded sitting to bipedal and unipedal weight bearing. Participants with generalized hypermobility demonstrated higher physiologic MME values and a more pronounced load-dependent pattern, particularly during unipedal stance. However, in adjusted analyses, lower patellar tendon stiffness on SWE, rather than hypermobility status itself, independently predicted greater loading-related extrusion. These findings support a contextual interpretation of ultrasound-based MME measurements in relation to loading condition and hypermobility phenotype. Full article

Background: This study evaluated time-dependent changes in anchor hole width (AHW) and their association with postoperative medial meniscus extrusion (MME) in patients undergoing open-wedge high tibial osteotomy (OWHTO) with medial meniscus posterior root tear (MMPRT) repair and meniscal centralization. Methods: Thirty knees treated with combined OWHTO and MMPRT repair using the centralization technique were retrospectively reviewed. MRI, CT, and second-look arthroscopy were performed preoperatively and postoperatively. AHW of the MMPRT anchor and two centralization anchors (midbody and midbody–posterior, M-anchor and MP-anchor) were measured on multiplanar reconstruction CT images at 1, 3, and 6 months, and 1 year, and their correlations with postoperative MME were analyzed. Results: AHW increased up to 3 months and gradually decreased with surrounding sclerosis by 1 year. The M-anchor showed significantly greater mediolateral (ML) expansion than the MP-anchor and demonstrated a moderate positive correlation between 1-year AHW and MME (r ≈ 0.5, p < 0.01). Second-look arthroscopy confirmed a 90% healing rate of the repaired root. Conclusions: Although OWHTO combined with MMPRT repair and centralization achieved favorable root healing, postoperative MME progression was not fully prevented. Time-dependent ML anchor hole expansion around the M-anchor may indicate persistent micromotion, elongation of the meniscotibial ligament, and degenerative stretch of the repaired meniscus following healing, suggesting that even after successful root healing, ML motion remains difficult to control, highlighting the need for biomechanically optimized fixation. Full article

Background: It is known that meniscus root tears affect the biomechanics of the knee in a way that is equivalent to a total meniscectomy. Therefore, repair is increasingly favored for meniscal root tears. In our study, we aimed to investigate the clinical and radiological outcomes of meniscal root repairs with suture anchors. Materials and Methods: Patients who had undergone surgery for medial meniscus posterior root tear (MMPRT) using suture-anchors between 2018 and 2023 were retrospectively analyzed. Patients were excluded if they had a previous infection, a fracture and an operation on the same knee, or osteoarthritis and a follow-up period under one year. The MMPRTs were classified according to the LaPrade classification system. For the functional classification, the range of motion (ROM), the Visual Analog Scale (VAS), the Lysholm Knee Score (LKS), and the International Knee Documentation Committee (IKDC) Subjective Knee Form were used for the postoperative functional assessments. The radiological assessment was performed by measuring the medial meniscus extrusion (MME) and evaluating the signal changes in the magnetic resonance imaging (MRI) of the knee, which was recorded during the last follow-up examination. Results: Thirty-two patients (6M/26F) were included in the study. The mean age was 49.9 ± 5.4 years old, and the follow-up period was 29.6 ± 24.1 months. The LKS improved from 53.7 ± 6.9 to 83.6 ± 5.2 and the IKDC improved from 46.1 ± 6.9 to 83.0 ± 5.5 at the final follow-up control (p < 0.001 and p < 0.001). The VAS score decreased from 8.4 ± 0.5 to 2.5 ± 0.9 (p < 0.001). The MRI scan of the knee performed at the last follow-up examination showed no improvement in only one patient. While the MME before surgery was 5.0 ± 2.1 mm, it was 4.6 ± 2.1 mm at the last follow-up examination (p = 0.178). An increase in the Kellgren–Lawrence stage was observed in 4 of our patients (from stage 1 to stage 2 in one patient, from stage 0 to stage 1 in 3 patients). Conclusions: The results of this study suggest that repairing MMPRTs using suture-anchors is a valid solution for treatment and prevention in patients with poor prognoses in order to achieve positive results in reducing pain, restoring mobility, improving functional outcomes and avoiding a significant increase in progression to arthrosis. Full article

Background/Objectives: While arthroscopic repair is established for the treatment of medial meniscus posterior root tears (MMPRT), the relationship between physiotherapy (PT) exposure, meniscal extrusion (ME), and structural healing remains unclear. The aim of this study was to evaluate short-term functional and structural results after transtibial pull-out (TPO) repair of isolated MMPRT and to explore the influence of patient age and postoperative physiotherapy volume. Methods: A retrospective single-center case series with 14 adults (64% women, age 59 years, body mass index (BMI) 31.0 kg/m²) who underwent TPO repair (April 2022–June 2024). Mean follow-up was 18.4 months. Outcomes included range of motion (ROM), pain levels using visual analog scale (VAS), International Knee Documentation Committee (IKDC), the Western Ontario Meniscal Evaluation Tool (WOMET), the 36-Item Short Form Survey (SF-36), and MRI-based ME, cartilage grade, and root-healing status. Postoperative PT volume was assessed with a self-developed, custom questionnaire. Correlations and subgroup analyses (<60 vs. ≥60 years) were performed. Results: Mean postoperative ROM was 121° and IKDC 63.4. Median PT exposure was 25.9 h, and the mean duration from symptom to repair was 215 days. MRI demonstrated complete healing in 70% of cases. A positive correlation was observed between postoperative ME and ROM (p = 0.008), while higher PT volume was associated with greater pain scores. Conclusions: TPO repair appears to be a viable treatment option for selected patients with MMPRT, showing acceptable early outcomes, even in older individuals with higher BMIs or delayed repair. Meniscal healing was frequent, although extrusion progression remained common and may influence the function. The observed links between ME, ROM, and PT-related pain highlight the need for standardized rehabilitation assessment. Larger, prospective studies are warranted to validate these exploratory findings and refine postoperative management. Full article

Introduction: Popliteal cysts (PCs) are occasionally accompanied by knee osteoarthritis (OA) and varus malalignment. However, whether concomitant arthroscopic excision of PCs with medial open-wedge high tibial osteotomy (MOWHTO) improves the osteoarthritic environment remains unclear. Therefore, this study assessed serial changes in C-size, medial meniscus extrusion (MME), and cartilage status for up to 2 years following an MOWHTO. Methods: This study retrospectively used serial magnetic resonance imaging (MRI) evaluations to assess 26 consecutive patients who underwent MOWHTO. Of the 26 patients, six with preoperative PCs were included. Based on the arthroscopic findings at the time of the MOWHTO, concomitant meniscal and chondral lesions, and whether or not partial meniscectomy was performed, were evaluated. All patients underwent second-look arthroscopy with plate removal 2 years postoperatively. The PC size, MME, and cartilage sub-scores in the medial compartment of the whole-organ MRI score (WORMS) were assessed by serial MRI preoperatively and at 3, 6, 18, and 24 months postoperatively. The recurrence of PCs and clinical outcomes, including the Rauschning–Lindgren grade, were also evaluated when serial MRI was performed. Moreover, changes in cartilage status were assessed using two-stage arthroscopy. Results: All patients underwent concomitant partial meniscectomy for medial meniscal tears in the posterior horn. A significant decrease in the mean size of preoperative PCs (27.4 ± 22.3 mm) was noted from 3 months postoperatively (8.7 ± 7.6 mm, p = 0.018), and thereafter. The mean size of PCs further decreased with time until 2 years (1.5 ± 4.0 mm, p = 0.018) following an MOWHTO with partial meniscectomy. Moreover, significant improvements in the MME and WORMS values were noted from 3 to 24 months postoperatively. Meanwhile, no PC recurrence occurred during the follow-up period and the preoperative Rauschning–Lindgren grade improved significantly with time after MOWHTO (p = 0.026). Furthermore, the two-stage arthroscopic assessments showed significant improvements in ICRS grade in the medial femoral condyle (p = 0.038). Conclusions: After an MOWHTO with partial meniscectomy, PCs decreased with time up to 2 years postoperatively; no recurrence occurred during the follow-up period, although cyst excision was not concomitantly performed. Furthermore, the reduction in PCs corresponded with improvements in MME and chondral lesions in the knee joint following the MOWHTO. Full article

Purpose: The aim of this study was to investigate how meniscal extrusion, assessed either with ultrasounds or magnetic resonance (MR), correlates with clinical symptoms in knee osteoarthritis (OA). Methods: One hundred patients with symptomatic knee OA were enrolled (60.3 ± 9.7 years). Patients underwent MR evaluation and ultrasound analyses (clinostatic and orthostatic positions). Patients were clinically evaluated through IKDC, KOOS, WOMAC, VAS, and Tegner scores. Correlation analyses were performed between meniscal extrusion extent and clinical scores. Lower (<4 mm) and higher extrusion (≥4 mm) groups were also compared. Results: The identification of low/high extrusion was 56/44 (MR) and 45/55 (ultrasounds) for patients with medial meniscus and 72/28 (MR) and 57/43 (ultrasounds) for patients with lateral meniscus. Meniscal extrusion correlated with symptoms (p < 0.05) with worse clinical findings in patients with higher extrusion, particularly for the lateral meniscus. For the medial meniscus, more differences were found between lower and higher extrusion groups with ultrasounds than MR, especially in the orthostatic position, while for the lateral meniscus, similar trends were documented with both methods. Conclusions: Extrusion of both menisci correlates with knee OA symptoms, with a stronger correlation for the lateral meniscus. Ultrasounds performed in the standing position identify more patients with meniscal extrusion and correlate better than MR with clinical findings. Full article

Background/Objectives: The aim of this study was the investigation of any correlation between medial meniscal extrusion (MME) and T2 relaxation times. Furthermore, the impact of different meniscal morphologies on the femoral cartilage was assessed. Methods: Fifty-nine knees of fifty-five patients (twenty-four female, thirty-one male) with a mean age of 33.7 ± 9.2 years and without risk factors for MME or osteoarthritis were examined in a 3.0T MRI. MME was assessed quantitatively in accordance with BLOKS score. T2 maps were calculated from sagittal 2D MESE sequences. The region of interest was defined as the load-bearing cartilage at the medial femoral condyle and analysis was performed on two consecutive slices. T2 values were correlated to MME; furthermore, mean T2 values were compared in different grades of MME. Results: T2 values showed a strong correlation with increasing MME (r = 0.635; p < 0.001) in an exponential pattern. Analogously, knees with MME ≥ 3 mm showed statistically significant higher T2 values (p < 0.001) compared to knees with MME ≤ 2 mm and 2.1–2.9 mm; between the latter two, no differences in T2 values were found. Conclusions: T2 values showed a strong correlation with increasing MME. Consequently, MME ≥ 3 mm has a detectable impact on the cartilage of the femur. Full article

Background/Objectives: MRI is the gold standard for detecting meniscal tears; however, ultrasound may readily detect meniscal changes, obviating the need for MRI. We aim to (1) determine ultrasound sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in detecting meniscal changes, and (2) describe characteristic meniscal changes in US and their prevalence. Methods: A retrospective analysis of knee ultrasound scans for the presence of medial and lateral meniscal tears was conducted. Meniscal changes were characterized into five US appearances (cleft, diminutive, cyst, displaced fragment, and extrusion) by the consensus of two musculoskeletal radiologists. Ultrasound findings were then compared to MRI results. Results: In total, 249 patients were included. Ultrasound sensitivity, specificity, PPV, NPV, and accuracy for medial meniscal tears were 79%, 97.3%, 95.3%, 86.6%, and 90%, respectively, and for lateral meniscal tears the ultrasound sensitivity, specificity, PPV, NPV, and accuracy were 63%, 99.5%, 96%, 93%, and 93.6%, respectively. The false negative and false positive rates for medial meniscal tears were 13.4% and 4.7%, respectively, and for the lateral meniscus, the false negative and false positive rates were 6.7% and 3.8%, respectively. Meniscal clefts were the most prevalent appearance in the medial meniscus followed by extrusions. Meniscal extrusions were the most prevalent appearance in the lateral meniscus followed by clefts. Conclusions: Community-based US is highly accurate in the detection of meniscal tears when compared with MRI, making it a valuable diagnostic imaging tool for detecting meniscal tears in a community setting where accessibility to MRI is limited or if there are MRI contraindications. Full article

Recently, there has been increasing interest in medial meniscal extrusion (MME), but few reports have evaluated MME via X-ray. In this study, the amount of MME and meniscal height at the medial border of the tibia were measured via X-ray with gradation processing. The extrusion length divided by the meniscal height yields the meniscal extrusion ratio, which was used as an index. In addition, the medial meniscal length of the part protruding from the medial border of the tibia on MRI was measured as an absolute value. Then, the correlation between the meniscal extrusion ratio and the amount of MME on MRI was examined, and there was a strong correlation between the meniscal extrusion ratio via X-ray and the amount of MME on MRI (correlation coefficient 0.860, p < 0.0001). The cut-off value of the meniscal extrusion ratio via X-ray for positive meniscal extrusion on MRI was 0.50, with an AUC of 0.9825, sensitivity of 0.9063, and specificity of 0.8663. From the present study, it was possible to measure the extrusion length and meniscal height via gradation processing, with X-ray and without MRI, and to calculate the meniscal extrusion ratio, which strongly correlates with the amount of MME on MRI. Full article

Background: With a growing understanding of biomechanical disadvantages following medial meniscus posterior root tear (MMPRT), recent studies have focused on surgical repair of MMPRT. Because not all tears are repairable, surgical indications can be properly established when the outcomes of conservative treatments are revealed. This study tried to identify risk factors for osteoarthritis progression after conservative treatments for isolated MMPRT. Materials & Methods: Patients who had conservative treatments for isolated MMPRT during 2013–2016 were retrospectively reviewed. To evaluate osteoarthritis progression, those who were followed up for ≤3 years and those who already showed advanced osteoarthritis of Kellgren--Lawrence (K-L) grade 4 at the time of diagnosis were excluded. Because patients with varus malalignment were candidates for realignment osteotomy, conservative treatments for MMPRT were applied to patients with well-aligned knees. Osteoarthritis progression was determined based on the K-L grading system, and risk factors including age, sex, body mass index, lower limb alignment, preoperative K-L grade, meniscal extrusion, and the presence of subchondral bone marrow lesion (BML) were analyzed using logistic regression analyses. Results: A total of 42 patients were followed up for 57.4 ± 26.8 months. During that period, osteoarthritis progression was noted in 17 (40.5%) patients. Based on univariate analyses for each risk factor, age, meniscal extrusion, and the presence of subchondral BML were included in the multivariate logistic regression analysis. The results showed that age (p = 0.028, odds ratio = 0.87) and meniscal extrusion (p = 0.013, odds ratio = 9.65) were significant risk factors. A receiver operating characteristic curve found that the cutoff age was 63.5 years, with the area under the curve being 0.72 (sensitivity, 68.0%; specificity, 70.6%). Conclusions: About two-fifths of patients who had conservative treatments for MMPRT underwent osteoarthritis progression in the mid to long term. Age and meniscal extrusion were determining factors of osteoarthritis progression. The risk for osteoarthritis progression was decreased when the age of patients was over 63.5 years. Full article

Background and Objectives: Root repair can prevent osteoarthritis (OA) by restoring hoop tension in medial meniscus posterior root tears (MMPRTs). This study aims to investigate bone marrow edema (BME) lesions known to be associated with OA following MMPRTs. Methods: Thirty patients with transtibial pull-out repair were recruited. Subchondral BME lesions were evaluated using magnetic resonance imaging (MRI) at 1-year follow-ups. Participants were categorized into three groups: no change of BME lesions (group one), improved BME lesions (group two) and worsened BME lesions (group three). Clinical scores and radiological outcomes, specifically Kellgren–Lawrence grade, medial joint space width and cartilage grade and meniscal extrusion were evaluated and compared between groups. Results: After surgery, twenty-three patients with no BME, three patients with BME lesions on the medial femoral condyle, one patient with BME lesions on the medial tibia plateau and three patients with BME lesions on both were investigated. A total of 20 patients in group one (66.7%) showed no change in BME lesions. In group two, seven patients (23.3%) presented with improved BME lesions. Only three patients (10%) showed worsened BME lesions (group three). Moreover, Lysholm scores and the rate of progression of cartilage grades were significantly worse in group three patients. Meniscal extrusion was significantly reduced in group two, whereas extrusion was significantly progressed in group three. Conclusions: Patients with worsened BME lesions showed less favorable outcomes than other patients. A decrease in meniscal extrusion can have a positive effect on BME lesions after root repair. Full article

Knee osteoarthritis is a common degenerative joint disease characterized by chronic knee pain and disability in daily living. The lesion can involve the cartilage as well as the synovium, bone, ligaments, and meniscus, indicating a complicated pathology for knee osteoarthritis. The association with the meniscus has recently attracted much attention. Meniscal tears can initiate and progress knee osteoarthritis, with deleterious effects on the important roles of the meniscus in load distribution, shock absorption, and stability of the knee joint. Degenerative meniscus lesions are commonly observed in elderly people, but they have less impact on the prognosis of osteoarthritis. However, they are often accompanied by meniscal extrusion, which substantially decreases the hoop function of the meniscus and increases the risk of knee osteoarthritis. When surgical treatment is necessary, meniscal tears should be repaired to the greatest extent possible to preserve meniscus function. Long-term studies show better clinical outcomes and less degenerative osteoarthritis changes following meniscal repair than following partial meniscectomy. For meniscal extrusion repair, centralization techniques have been proposed that involve suturing the meniscus-capsule complex to the edge of the tibial plateau. Advancements in orthobiologics, such as platelet-rich plasma or stem cell therapy, have the potential to prevent the initiation or progression of osteoarthritis. Full article

Meniscal tear is a common reason for patients to undergo knee operation, and the medial meniscus posterior root tear (MMPRT) is one of the most frequent kinds of meniscal tears. The purpose of this study was to analyze participants’ factors (anthropometric and medical) to the fate of the MMPRT based on the treatment strategy. The hypothesis of this study was that treatment modalities from conservative treatment to final arthroplasty would be affected by participants’ affecting factors. From July 2003 to May 2018, 640 participants were included. Groups were categorized according to the treatment strategies such as conservative treatment, arthroscopic surgery, high tibial osteotomy (HTO) and arthroplasty surgery. Participants’ affecting factors were analyzed by one-way analysis of variance according to the four different treatment strategies and a correlation between affecting factors was also analyzed. Participants with K-L (Kellgren–Lawrence) Grade 4 and high BMI > 28.17 were appropriate candidates for arthroplasty, with K-L Grade 4 being a greater determining factor than high BMI. Participants with alignment factors such as low initial weight bearing line (WBL) (26.5%) and high delta WBL ratio (5.9%) were appropriate candidates for HTO, with the delta WBL ratio being a greater determining factor than initial WBL. Longer MRI-event times (1.44 year) and a lesser extent of meniscal extrusion (2.98 mm) were significantly associated with conservative treatment. Understanding the correlation of each affecting factor to the treatment strategy will help clinicians decide on the appropriate treatment for patients with MMPRT. Full article