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Knee Surgery, Sports Traumatology,... Aug 2023Medial meniscus extrusion (MME) refers to the protrusion of the medial meniscus beyond the tibial edge by more than 3 mm, leading to a deficiency of the hoop strain.... (Meta-Analysis)
Meta-Analysis Review
Radiographic OA, bone marrow lesions, higher body mass index and medial meniscal root tears are significantly associated with medial meniscus extrusion with OA or medial meniscal tears: a systematic review and meta-analysis.
PURPOSE
Medial meniscus extrusion (MME) refers to the protrusion of the medial meniscus beyond the tibial edge by more than 3 mm, leading to a deficiency of the hoop strain. MME commonly occurs in conjunction with osteoarthritis (OA) or medial meniscal tears (MMT). However, factors associated with concomitant MME in patients with OA or MMT have not been systematically reviewed. This study aims to perform a systematic review and meta-analysis to identify factors associated with concomitant MME in OA or MMT.
METHODS
The systematic review of the literature was performed according to PRISMA. A literature search was conducted in 4 databases. All original human studies that reported the available evidence on factors associated with concomitant MME in patients with OA or MMT were included. Pooled binary variables were analyzed by odds ratios (OR) and 95% CIs, and pooled continuous variables were evaluated by mean difference (MD) and 95% CIs.
RESULTS
Ten studies on OA (5993 patients) and eight studies on MMT (872 patients) met the inclusion criteria. The overall pooled incidence of MME was 43% (95% CI, 37-50%) for OA, 61% (95% CI 43-77%) for MMT, and 85% (95% CI 72-94%) for medial meniscal root tears (MMRT). For the population with OA, Factors significantly associated with MME included radiographic OA [OR 4.24; 95% CI 3.07-5.84; P < 0.0001], bone marrow lesions [OR, 3.35; 95% CI 1.61-6.99; P = 0.0013], cartilage damage [OR, 3.25; 95% CI 1.60-6.61; P = 0.0011], and higher body mass index (BMI) [MD, 1.81; 95% CI 1.15-2.48; P < 0.0001]. Factors strongly associated with increased risk of MME for MMT included medial meniscal root [OR, 8.39; 95% CI 2.84-24.82; P < 0.0001] and radial tears [OR, 2.64; 95% CI 1.18-5.92; P < 0.0001].
CONCLUSION
Radiographic OA, bone marrow lesions, cartilage damage, and higher BMI were significantly associated with concomitant MME with OA. Furthermore, medial meniscal root and radial tears were significantly associated with an increased risk of MME in patients with MMT.
LEVEL OF EVIDENCE
IV.
Topics: Humans; Menisci, Tibial; Body Mass Index; Bone Marrow; Retrospective Studies; Magnetic Resonance Imaging; Osteoarthritis; Cartilage Diseases; Bone Diseases
PubMed: 37099153
DOI: 10.1007/s00167-023-07418-8 -
The Knee Oct 2023This study was conducted with patients with anterior and medial extrusion of the medial meniscus (MM-AE, MM-ME) to investigate the relationship of the amount of...
BACKGROUND
This study was conducted with patients with anterior and medial extrusion of the medial meniscus (MM-AE, MM-ME) to investigate the relationship of the amount of extrusion with damage to the meniscus, meniscofemoral ligament (MFL), meniscotibial ligament (MTL), presence of effusion, osteoarthritis (OA) grade and other medial stablizers. A cut-off value for significant MM-ME was also suggested.
METHODS
All patients aged 18 and above who had measurable MM extrusion on knee MRI were included. Patients with acute injury detected on knee MRI and any disease that could disrupt the anatomy were not included. The relationship between the amount of MM-AE, MM-ME and the investigated comorbidities were evaluated. The patients were divided into two: those with and without positive findings for each comorbidities. The amount of MM-AE, MM-ME were evaluated. ROC analysis was undertaken for significant differences, and cut-off values were determined.
RESULTS
There was a correlation between MM-ME and age, weight, and BMI (p < 0.001, p = 0.027, p = 0.025, respectively). The amount of MM-ME was higher in the groups with OA (p = 0.007), MTL damage (p < 0.001), MFL damage (p < 0.001), meniscus damage (p < 0.001), effusion (p < 0.001), and the amount of MM-AE was higher in the groups with OA (p = 0.042), effusion (p = 0.002). The cut-off values of MM-ME were determined to be 2.69 mm (MTL), 2.65 mm (MFL), 2.49 mm (meniscus), and 2.85 mm (OA).
CONCLUSION
OA grade, effusion, and meniscus, MTL, and MFL damage were all found to be related to the amount of MM-ME. MM-ME values 2.49-2.85 mm may indicate meniscus, MFL, MTL damage and OA.
Topics: Humans; Menisci, Tibial; Tibial Meniscus Injuries; Knee Joint; Osteoarthritis; Magnetic Resonance Imaging; Osteoarthritis, Knee
PubMed: 37672909
DOI: 10.1016/j.knee.2023.08.015 -
The American Journal of Sports Medicine Apr 2023The discoid medial meniscus is a rare congenital anomaly of the knee. The literature is limited to small case series.
BACKGROUND
The discoid medial meniscus is a rare congenital anomaly of the knee. The literature is limited to small case series.
PURPOSE/HYPOTHESIS
Our purpose is to report the clinical manifestations and operative treatments of discoid medial menisci in children from multiple centers in North America. We hypothesized that symptoms and signs, arthroscopic findings, surgical treatments, and outcomes are similar to those for symptomatic discoid lateral menisci.
STUDY DESIGN
Case series; Level of evidence, 4.
METHODS
A retrospective review identified patients with a diagnosed discoid medial meniscus confirmed at surgery across 8 children's hospitals between January 2000 and June 2021. The literature on discoid lateral menisci was reviewed and summarized for comparison.
RESULTS
A total of 21 patients (9 female, 12 male) with 22 discoid medial menisci were identified. The mean ± SD age at the time of diagnosis was 12.8 ± 3.8 years. The most common symptoms and signs were locking and/or clunking, present in 12 of 22 knees (55%), similar to that reported in patients with discoid lateral menisci. Twelve discoid medial menisci were complete (55%); 8, incomplete (36%); and 2, indeterminate (9%). Tears were present in 13 knees, most commonly horizontal cleavage (54%). Five discoid medial menisci were unstable (23%): 3 for posterior tears and 2 for rim insufficiency. All 22 knees underwent arthroscopic saucerization, and of the 13 torn menisci, 7 (54%) were repaired. The median follow-up was 24 months (range, 2-82 months). Four knees underwent reoperation. All knees that required reoperation had undergone repair for a posteriorly located tear. There was a significant association between operative repair and need for reoperation ( = .0048). High rates of peripheral instability were also noted in case series of patients with discoid lateral menisci.
CONCLUSION
Patient presentations and treatments for those with discoid medial menisci were similar to those reported for patients with discoid lateral menisci. Knees with discoid medial menisci also demonstrated instability attributed to peripheral insufficiency and posterior tears. Tears were present in over half of knees with discoid medial menisci, and reoperation was more common in knees that underwent repair of tears than those without repair.
Topics: Humans; Child; Male; Female; Adolescent; Menisci, Tibial; Arthroscopy; Knee Joint; Joint Diseases; Rupture; Retrospective Studies
PubMed: 36876853
DOI: 10.1177/03635465231159671 -
Arthroscopy : the Journal of... Nov 2022While studies have shown significant clinical improvement after medial meniscus allograft transplantation (MMAT) with good long-term graft survivorship, progression to...
Editorial Commentary: Restoring Native Meniscal Anatomy With Medial Meniscus Allograft Transplantation and Augmentation of the Meniscotibial Ligament May Decrease Meniscal Graft Extrusion.
While studies have shown significant clinical improvement after medial meniscus allograft transplantation (MMAT) with good long-term graft survivorship, progression to osteoarthritis still occurs, even in the presence of intact grafts. Several factors can potentially explain the lack of chondroprotection despite graft survivorship, including meniscal degeneration, tearing, and remodeling after the initial procedure. A major factor contributing to progression of osteoarthritis is meniscal extrusion, which is seen in up to 60% of patients and seems to be more of an issue in medial meniscus transplantation compared to lateral and is present even immediately postoperatively. Grafts without extrusion provide protective effects similar to the native meniscus, while greater than 3 mm of extrusion leads to nearly complete loss of the protective effects. A reconstruction of the meniscotibial ligament, in addition to standard MMAT, may significantly decrease meniscal extrusion. Optimization of graft size, quality, and meniscal root positioning is best to prevent extrusion and restore native biomechanics.
Topics: Humans; Menisci, Tibial; Knee Joint; Ligaments, Articular; Osteoarthritis; Allografts; Magnetic Resonance Imaging
PubMed: 36344064
DOI: 10.1016/j.arthro.2022.07.011 -
Arthroscopy : the Journal of... Nov 2019The importance of the medial meniscus posterior root for preserving knee joint kinematics, joint contact pressures, and articular cartilage integrity is well recognized....
The importance of the medial meniscus posterior root for preserving knee joint kinematics, joint contact pressures, and articular cartilage integrity is well recognized. Medial meniscus root repair generally is associated with favorable clinical outcomes and radiographic changes compared with conservative treatment or subtotal meniscectomy; however, second-look arthroscopy often reveals some laxity at the repair site. Even in this latter situation of "failure with continuity" of the meniscus root repair, there may be benefit in delaying progression of radiographic degeneration changes. Given that the displacement of the repair often occurs with premature rehabilitative loading, it is important to delay the progression of weight-bearing until adequate healing has occurred.
Topics: Arthroscopy; Humans; Meniscectomy; Menisci, Tibial; Second-Look Surgery; Tibial Meniscus Injuries
PubMed: 31699260
DOI: 10.1016/j.arthro.2019.07.004 -
Arthroscopy : the Journal of... Mar 2023To systematically summarize the medial meniscus allograft transplantation (MAT) reported outcomes and evaluate whether the surgical technique is associated with... (Review)
Review
PURPOSE
To systematically summarize the medial meniscus allograft transplantation (MAT) reported outcomes and evaluate whether the surgical technique is associated with allograft extrusion and knee function.
METHODS
Systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were English-language clinical studies involving arthroscopically assisted medial MAT that reported the surgical technique and the presence of graft extrusion or functional outcomes after surgery. Studies in which outcomes for medial MAT could not be separated from lateral MAT were excluded. Surgical technique, allograft-related characteristics, and clinical outcomes were extracted.
RESULTS
Twenty-four studies with 328 medial MAT were included, 58.3% studies qualified as level 4 of evidence, 29.2% as level 3, and 12.5% as level 2. Allograft fixation techniques were bone plug (235/328 [71.6%]), bone bridge/trough (55/328 [16.8%]), and soft-tissue suture fixation only (38/328 [11.6%]). Relative percentage of extrusion after surgery ranged from 24.8% to 53.7%. Major extrusion (>3 mm) ranged from zero to 78%. Overall, functional scores improved after medial MAT. None of surgical techniques were associated with poor functional outcomes or extruded meniscus; however, nonanatomical placement of the anterior and posterior horns appeared to increase meniscus extrusion.
CONCLUSION
Medial MAT provides favorable outcomes, with acceptable rates of complication and failure regardless of surgical technique. Although allograft extrusion appears equivalent for both bone plug and soft-tissue fixation techniques, positioning allograft horns at the native meniscal footprint may be critical for preventing extrusion. However, the heterogeneity and low level of evidence of the studies included in this review prevent decisive conclusions regarding optimal MAT fixation techniques, clinical significance of allograft extrusion, or comparative clinical outcomes after medial MAT.
LEVEL OF EVIDENCE
Level IV - systematic review of Level II to IV studies.
Topics: Humans; Menisci, Tibial; Follow-Up Studies; Transplantation, Homologous; Allografts; Patient Reported Outcome Measures
PubMed: 36543661
DOI: 10.1016/j.arthro.2022.11.033 -
Knee Surgery, Sports Traumatology,... May 2016Although interest in medial meniscus posterior root tear (MMPRT) repair has increased, few case series have been reported. This meta-analysis aimed to examine the... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Although interest in medial meniscus posterior root tear (MMPRT) repair has increased, few case series have been reported. This meta-analysis aimed to examine the clinical and radiological effects of MMPRT repair by pooling pre- and post-operative data from case-series reports.
METHODS
A literature search was performed using MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE databases. Pre- and post-operative data were pooled to investigate the effects of MMPRT repair, including the Lysholm score improvement, meniscal extrusion (mm) reduction, progression of the Kellgren-Lawrence (K-L) grade, and cartilage status according to the Outerbridge classification. Treatment effects included paired standardized mean differences (difference in the pre- and post-operative mean outcomes divided by the standard deviation) for the Lysholm score and meniscal extrusion, as well as the pooled event rates of progression of K-L grade and cartilage status.
RESULTS
As treatment effects, the Lysholm score increased by as much as 3.675 (P < 0.001), whereas meniscus extrusion was not reduced (n.s.). The overall pooled event rates of progression of K-L grade and cartilage status were 10.6 and 17.3 % (P < 0.001), respectively.
CONCLUSIONS
According to the current literature, MMPRT repair resulted in significant improvements in the post-operative clinical subjective scores compared with the preoperative status. However, meniscus extrusion was not reduced. Considering the occurrence of progression of K-L grade and cartilage status, it did not prevent the progression of arthrosis completely. Based on these results, repair results in favourable outcomes for MMPRT.
LEVEL OF EVIDENCE
Meta-analysis, Level IV.
Topics: Arthroscopy; Disease Progression; Humans; Knee Injuries; Magnetic Resonance Imaging; Menisci, Tibial; Tibial Meniscus Injuries; Wound Healing
PubMed: 26493550
DOI: 10.1007/s00167-015-3832-0 -
Knee Surgery, Sports Traumatology,... Jun 2023As a simple and invasive treatment, arthroscopic medial meniscal posterior horn resections (MMPHRs) can relieve the obstructive symptoms of medial meniscus posterior...
PURPOSE
As a simple and invasive treatment, arthroscopic medial meniscal posterior horn resections (MMPHRs) can relieve the obstructive symptoms of medial meniscus posterior root tears (MMPRTs) but with the risk of aggravating biomechanical changes of the joint. The aim of this study was to analyze dynamic simulation of the knee joint after medial meniscus posterior root tear and posterior horn resection.
METHODS
This study established static and dynamic models of MMPRTs and MMPHRs on the basis of the intact medial meniscus model (IMM). In the finite element analysis, the three models were subjected to 1000 N axial static load and the human walking gait load defined by the ISO14243-1 standard to evaluate the influence of MMPRTs and MMPHRs on knee joint mechanics during static standing and dynamic walking.
RESULTS
In the static state, the load ratio of the medial and lateral compartments remained nearly constant (2:1), while in the dynamic state, the load ratio varied with the gait cycle. After MMPHRs, at 30% of the gait cycle, compared with the MMPRTs condition, the maximum von Mises stress of the lateral meniscus (LM) and the lateral tibial cartilage (LTC) were increased by 166.0% and 50.0%, respectively, while they changed by less than 5% during static analysis. The maximum von Mises stress of the medial meniscus (MM) decreased by 55.7%, and that of the medial femoral cartilage (MFC) increased by 53.5%.
CONCLUSION
After MMPHRs, compared with MMPRTs, there was no significant stress increase in articular cartilage in static analysis, but there was a stress increase and concentration in both medial and lateral compartments in dynamic analysis, which may aggravate joint degeneration. Therefore, in clinical treatments, restoring the natural structure of MMPRTs is first recommended, especially for physically active patients.
Topics: Humans; Menisci, Tibial; Meniscectomy; Tibial Meniscus Injuries; Knee Injuries; Biomechanical Phenomena; Knee Joint; Gait
PubMed: 36534149
DOI: 10.1007/s00167-022-07285-9 -
The Knee Jun 2022Spontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this...
PURPOSE
Spontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this study was to investigate the relationship of the type of meniscus tear and medial meniscus extrusion with SONK on the medial femoral condyle in patients who underwent surgical treatment with high tibial osteotomy due to severe knee pain.
METHODS
We enrolled 98 patients with 102 knees who underwent medial opening wedge high tibial osteotomy (OWHTO) under the diagnosis of medial femoral condyle osteonecrosis at our hospital from December 2003 to January 2020. Based on the Koshino classification, cases of SONK were classified as stage 1-4. The relationships of demographic data, X-rays and MRI images, including femorotibial angle (FTA), meniscus tear type, and medial meniscus extrusion (MME), with the stage and volume of SONK were investigated.
RESULTS
Ninety-eight patients (29 males and 69 females), with an average age at surgery of 69.2 ± 9.6 years and Body mass index(BMI) of 61.0 ± 17.6 kg/m. In 102 cases of SONK, 11 knees, 18 knees, 46 knees, and 27 knees were classified as stage 1-4, respectively. The mean SONK volume was 2161.61 µm (range 95.67-7484.68 µm) on preoperative MRI. The preoperative FTA (mean 180.86°, range 172-187°) was not associated with the stage or volume of SONK. Meniscus tears were found in all cases of SONK and consisted of 2 degenerations, 2 horizontal tears, 0 vertical tears, 40 radial tears, 4 complex tears, and 54 medial meniscus posterior root tears (MMPRTs). In addition, 99% (101/102) of knees showed more than 3 mm of meniscus extrusion. Although the meniscus tear type was not associated with SONK stage, there was a high rate of tears that caused disruption of the hoop strain, such as MMPRTs (52.9%) or radial tears (39.2%). MME was significantly related to SONK volume (r = 0.387, p < 0.001).
CONCLUSION
All patients with SONK had coexisting meniscus tears, most menisci had medial extrusion, and a positive correlation was observed between MME and SONK volume.
Topics: Female; Humans; Knee Joint; Magnetic Resonance Imaging; Male; Menisci, Tibial; Osteonecrosis; Osteotomy; Pain; Retrospective Studies; Tibial Meniscus Injuries
PubMed: 35533576
DOI: 10.1016/j.knee.2022.04.011 -
Knee Surgery, Sports Traumatology,... Apr 2020Assessment of medial meniscus extrusion (MME) has become increasingly popular in clinical practice to evaluate the dynamic meniscus function and diagnose meniscus...
PURPOSE
Assessment of medial meniscus extrusion (MME) has become increasingly popular in clinical practice to evaluate the dynamic meniscus function and diagnose meniscus pathologies. The purpose of this biomechanical study was to investigate the correlation between MME and the changes in joint contact pressure in varus and valgus alignment. It was hypothesized that varus alignment would result in significantly higher MME along with a higher joint contact pressure in the medial compartment.
METHODS
Eight fresh-frozen human cadaveric knees were axially loaded, with a 750 N compressive load, in full extension with the mechanical axis shifted to intersect the tibial plateau at 30% and 40% (varus), 50% (neutral), 60% and 70% (valgus) of its width (TPW). Tibiofemoral peak contact pressure (PCP), mean contact pressure (MCP) and contact area (CA) were determined using pressure-sensitive films. MME was obtained via ultrasound at maximum load.
RESULTS
MME was significantly increased from valgus (1.32 ± 0.22 mm) to varus alignment (3.16 ± 0.24 mm; p < 0.001). Peak contact pressure at 30% TPW varus alignment was significantly higher compared to 60% TPW valgus (p = 0.018) and 70% TPW valgus (p < 0.01). MME significantly correlated with PCP (r = 0.56; p < 0.001) and MCP (r = 0.47, p < 0.01) but not with CA (r = 0.23; n.s.).
CONCLUSION
MME was significantly increased in varus alignment, compared to neutral or valgus alignment, with an intact medial meniscus. It was also significantly correlated with PCP and MCP within the medial compartment. However, valgus malalignment and neutral axis resulted in reduced MME and contact pressure. Lower limb alignment must be taken into account while assessing MME in clinical practice.
LEVEL OF EVIDENCE
Controlled laboratory study.
Topics: Aged; Biomechanical Phenomena; Cadaver; Female; Humans; Knee Joint; Male; Menisci, Tibial; Pressure; Stress, Mechanical; Ultrasonography
PubMed: 31489460
DOI: 10.1007/s00167-019-05701-1