Meniscus Posterior Root Tear Research Articles

Varus stress MRI in diagnosis of medial meniscal posterior root tear

BackgroundEarly and accurate diagnosis of medial meniscal posterior root tear (MMPRT) via magnetic resonance imaging (MRI) is crucial to prevent the development of medial meniscus extrusion (MME) and subsequent osteoarthritic changes. The study aims to assess the role of MRI in diagnosing the medial meniscal posterior root tear (MMPRT) as well as to investigate the additive value of a new MRI technique (varus stress position technique) in measuring the accurate degree of a truly extruded meniscus, during normal daily activities like standing or walking. This prospective study included 70 patients who had an episode of posteromedial knee pain. All patients underwent conventional MRI, whereas only 35 of them underwent MRI with varus stress loading position.ResultsThe study included 70 patients, of which 56 were female (80.0%), with a mean age of 49.1 ± 8.5 years. According to duration onset of MMPRT, 39 patients were in the chronic stage (4–12 months), 16 patients were in the acute stage (early < 1 month), and 15 patients were in the subacute stage (1–3 months). It was found that varus stress position could detect 100% of the patients (35/35) with positive medial meniscus extrusion (MME) (≥ 3 mm), whereas the MRI with the traditional position could detect only 62.9% of the cases (22/35) (P < 0.000). Regarding the chronicity of MMPRT, a significant increase was observed in the amount of MME in post-varus MRI compared with that in pre-varus MRI for each stage (acute, subacute, and chronic) (P < 0.000).ConclusionMRI is considered a superior imaging modality in diagnosing MMPRT through several characteristic MRI findings. The varus stress position showed a valuable role in assessing the presence and degree of severity of true extruded meniscus using positional varus stress load.

Quantifying the differential functional behavior between the medial and lateral meniscus after posterior meniscus root tears.

Meniscus tears of the knee are among the most common orthopedic knee injury. Specifically, tears of the posterior root can result in abnormal meniscal extrusion leading to decreased function and progressive osteoarthritis. Despite contemporary surgical treatments of posterior meniscus root tears, there is a low rate of healing and an incidence of residual meniscus extrusion approaching 30%, illustrating an inability to recapitulate native meniscus function. Here, we characterized the differential functional behavior of the medial and lateral meniscus during axial compression load and dynamic knee motion using a cadaveric model. We hypothesized essential differences in extrusion between the medial and lateral meniscus in response to axial compression and knee range of motion. We found no differences in the amount of meniscus extrusion between the medial and lateral meniscus with a competent posterior root (0.338mm vs. 0.235mm; p-value = 0.181). However, posterior root detachment resulted in a consistently increased meniscus extrusion for the medial meniscus compared to the lateral meniscus (2.233mm vs. 0.4705mm; p-value < 0.0001). Moreover, detachment of the posterior root of the medial meniscus resulted in an increase in extrusion at all angles of knee flexion and was most pronounced (4.00mm ± 1.26mm) at 30-degrees of knee flexion. In contrast, the maximum mean extrusion of the lateral meniscus was 1.65mm ± 0.97mm, occurring in full extension. Furthermore, only the medial meniscus extruded during dynamic knee flexion after posterior root detachment. Given the differential functional behaviors between the medial and lateral meniscus, these findings suggest that posterior root repair requires reducing overall meniscus extrusion and recapitulating the native functional responses specific to each meniscus.

Effect of concurrent repair of medial meniscal posterior root tears during high tibial osteotomy for medial osteoarthritis during short-term follow-up: a systematic review and meta-analysis

BackgroundMedial meniscal posterior root tears (MMPRTs) are frequently associated with medial compartment osteoarthritis, leading to loss of meniscal hoop tension. This study aimed to evaluate the efficacy of concurrent MMPRT repair during high tibial osteotomy (HTO) compared to HTO alone in patients with medial osteoarthritis and MMPRTs.MethodsThe MEDLINE/PubMed, EMBASE, and Cochrane Library databases were searched for studies reporting on concurrent MMPRT repair during HTO. Pre- and postoperative data were pooled to investigate the treatment effects of concurrent MMPRT repair during HTO, and compare postoperative clinical, radiological, and arthroscopic outcomes including cartilage status and healing event rates according to the arthroscopic classification of MMPRT healing (complete, partial [lax or scar tissue], or failed healing) between HTO patients with and without concurrent MMPRT repair. The random-effect model was used to pool the standardized mean differences, odds ratios (ORs), 95% confidence intervals (CIs), and event rates.ResultsSeven patient subgroups in six articles divided according to meniscal repair techniques were included in the final analysis. Concurrent MMPRT repair during HTO significantly improved the Lysholm score, while no intergroup differences were observed in the postoperative Lysholm and WOMAC scores, as well as radiological and arthroscopic outcomes. Those who underwent concurrent MMPRT repair showed a higher rate of complete meniscal healing (OR: 4.792, 95% CI, 1.95–11.79), with a pooled rate of complete meniscal healing of 0.327 (95% CI, 0.19–0.46).ConclusionConcurrent MMPRT repair during HTO for medial osteoarthritis with MMPRTs has little benefits on the clinical, radiological, and arthroscopic outcomes during short-term follow-up. Further accumulation of evidence is needed for long-term effects.

A Simple Way to Fix a Lateral Meniscal Root Tear

Background: Meniscal posterior root tears, which are often associated with anterior cruciate ligament (ACL) injury, lead to the loss of normal biomechanical and kinematic behavior of menisci. Several arthroscopic techniques have been introduced to address this kind of injury. In this video, a simple all-inside technique to repair posterior lateral root tear (PLRT) is presented. Indications: To repair type 1, type 2, and type 4 PLRT. Technique: The torn lateral meniscus root is sutured to the medial fibers of the posterior cruciate ligament (PCL), with an arthroscopic all-inside repair system, with the purpose of reproducing the stabilizing function of the meniscofemoral ligaments. Results: This procedure allows restoration of the correct position of the detached horn, and restores meniscal stability with satisfactory clinical outcomes. Discussion/Conclusion: The technique described represents a simple and fast arthroscopic all-inside procedure to repair PLRT in association with concomitant procedure, such as ACL reconstruction. However, outcome reports of this technique are still lacking in the literature, and further studies are needed to confirm the authors’ results.

MAGNETIC RESONANCE IMAGING OF LATERAL MENISCAL POSTERIOR ROOT TEARS IN THE ADOLESCENT KNEE: IS THE DIAGNOSIS MISSED, MENTIONED, OR MADE?

Background:The meniscal roots play a vital role in maintaining proper knee kinematics. Neglected meniscal root tears place excess stress on the articular cartilage and increase the risk of premature osteoarthritis. As opposed to medial meniscal root tears, lateral meniscal posterior root tears (LMPRTs) are more likely to be associated with anterior cruciate ligament (ACL) pathology. Failure to identify and address meniscal root tears may place undue loads on ACL grafts and lead to inferior post-surgical outcomes.Purpose:To examine preoperative knee magnetic resonance imaging (MRI) radiologist interpretations for the identification of lateral meniscal root pathology in children and adolescents.Methods:We performed a retrospective review of children and adolescents that underwnent knee arthroscopy between 3/1/2010 and 4/1/2020 and had an arthroscopically confirmed LMPRT. Arthroscopic findings were compared to the reading radiologist’s preoperative MRI interpretations. LMPRTs were graded using the LaPrade classification. ANOVA was performed to assess if body mass index (BMI), open physes, time from injury to MRI, time from MRI to surgery, MRI magnet field strength, musculoskeletal radiologist designation, insurance type and tear grade were associated with the preoperative MRI identification of a LMPRT.Results:During the study period, 1285 knee arthroscopies were performed. 607 of which were ACL reconstructions. 54 children were found to have a LMPRT arthroscopically and all were associated with an ACL tear 54/607 (9%). One patient had 2 preoperative MRIs for a total of 55 MRIs in 54 pateints. Average age was 16 years (range 14-21). Preoperative MRI diagnosis of a LMPRT was made in only 14/55 (25%) and missed in 22/55 (40%). In 19/55 (35%), pathology of the lateral meniscus nonspecific to the root was mentioned. Lateral joint line tenderness was present in 23/54 (46%). There was no statistical significance found in regards to patient BMI, skeletal maturity, time from injury to MRI, time from MRI to surgery, MRI magnet strength, if the radiologist was musculoskeletal fellowship-trained, or insurance type, with a reliable diagnosis. (Table)Conclusion:The final interpretation of preoperative MRIs did not provide a clear definitive diagnosis of a LMPRT in 75 % in patients. As the intraoperative management of LMPRTs can be involved and diverge from standard meniscal work, preoperative diagnosis would be advantageous. All LMPRTs in this study were associated with a concomitant ACL tear. Surgeons caring for ACL tears in children and adolescents should be prepared to treat a LMPRT regardless of a inconclusive MRI interpretation for meniscal root pathology.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients.

While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear. Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity. One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping. In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs. IV.

Higher Incidence of Complete Lateral Meniscal Root Tears in Revision Compared With Primary Anterior Cruciate Ligament Reconstruction

PurposeTo evaluate the incidence of complete lateral meniscal posterior root tears (LMPRTs) repaired at revision as compared with primary anterior cruciate ligament (ACL) reconstruction (PACLR) and to determine whether other demographic or surgical characteristics were associated with LMPRTs needing repair.MethodsA chart review was performed to identify the PACLR and revision ACL reconstruction (RACLR) cohorts. Demographic and surgical characteristics were recorded. Cases with concurrent lateral meniscal posterior root repair were identified. Cases were classified as acute (<5 months) or chronic (>5 months) based on the time from reported injury to surgery. Tunnel malposition in revision cases was recorded if either tunnel or both tunnels were malpositioned on radiographs and magnetic resonance imaging.ResultsData from 167 cases, 140 PACLR and 27 RACLR cases, were included. The cohorts had similar demographic characteristics including age, sex, and lateral meniscal injury. The overall incidence of lateral meniscal root repair in ACL reconstruction patients was 12.6% (21 of 167 patients). The incidence of LMPRT repair was 7.1% (10 of 140 patients) in the PACLR cohort versus 40.7% (11 of 27 patients) in the RACLR cohort. The revision cohort was significantly more likely to have a chronic injury (66.7% [18 of 27 patients] vs 31.4% [44 of 140 patients]). The most significant predictor of concurrent lateral meniscal posterior root repair was RACLR versus PACLR for both univariate and multivariate logistic regression analyses (χ2 = 20.603; P < .0001; odds ratio, 13.887; 95% confidence interval, 1.531-125.993). Analysis of tunnel positions for the revision group revealed that PACLR tunnel malposition was a significant predictor of LMPRTs (χ2 = 4.91, P = .027).ConclusionsComplete LMPRTs warranting repair are encountered with a significantly greater frequency at RACLR as compared with PACLR. The overall incidence of LMPRT repair at RACLR is high. In this cohort, LMPRT repair in RACLR cases was associated with tunnel malposition of the PACLR.Level of EvidenceLevel III, retrospective cohort study.

Partial meniscectomy does not affect the biomechanics of anterior cruciate ligament reconstructed knee with a lateral posterior meniscal root tear.

The purpose of this study was to determine the effects of a lateral meniscus posterior root tear, partial meniscectomy, and total meniscectomy on knee biomechanics in the setting of anterior cruciate ligament (ACL) reconstruction. Thirteen fresh-frozen cadaver knees were tested with a robotic testing system under an 89.0-N anterior tibial load at full extension (FE), 15°, 30°, 60° and 90° of knee flexion and a simulated pivot-shift loading (7.0 Nm valgus and 5.0 Nm internal tibial rotation) at FE, 15° and 30° of knee flexion. Anterior tibial translation (ATT) and the in-situ force of ACL graft under the different loadings were measured in four knee states: (1) ACL reconstruction with intact lateral meniscus (Intact meniscus), (2) ACL reconstruction with lateral meniscal posterior root tear (Root tear), (3) ACL reconstruction with lateral posterior partial meniscectomy (Partial meniscectomy) and (4) ACL reconstruction with total lateral meniscectomy (Total meniscectomy). Under anterior tibial loading, compared with an intact meniscus, root tear significantly increased ATT at 15° and 30° of knee flexion (p < 0.05) and partial meniscectomy had almost same increased ATT as with root tear at any knee flexion between FE and 90°. Under simulated pivot-shift loading, total meniscectomy increased ATT compared with intact meniscus, root tear, partial meniscectomy at FE (p < 0.05). Under anterior tibial and simulated pivot-shift loading, partial meniscectomy has no significant effect on the stability of ACL-reconstructed knee with lateral meniscal posterior root tear, while total meniscectomy increased laxity at less than 30° of knee flexion. Clinically, in cases of irreparable meniscal root tears or persistent pain a partial meniscectomy can be considered in the setting of ACL reconstruction.

Remodified Mason-Allen suture technique concomitant with high tibial osteotomy for medial meniscus posterior root tears improved the healing of the repaired root and suppressed osteoarthritis progression.

To evaluate the results of the remodified Mason-Allen suture technique concomitant with high tibial osteotomy (HTO) for medial meniscal posterior root tears (MMPRTs). The hypothesis was that this procedure would improve clinical results, prevent progression of knee osteoarthritis and increase the healing rate of the repaired root. Total 17 patients of mean 51.5 ± 4.4years who were underwent this combined procedure for MMPRT completed this study. Lysholm and Hospital for Special Surgery (HSS) scores, Kellgren-Lawrence (KL) grade reflecting osteoarthritis progression were evaluated preoperatively and at the last follow-up. Medial meniscus extrusion (MME) was measured on magnetic resonance imaging preoperatively and at mean 26.1 ± 2.3months postoperatively. Second-look arthroscopy was performed at mean 25.1 ± 5.3months postoperatively. The healing status of the repaired root was classified as complete, partial and failed healing. The Outerbridge (OB) grade of the medial femoral condyle (MFC) was compared between index surgery and second-look arthroscopy. Mean follow-up duration was 66.4 ± 6.5months. Mean Lysholm and HSS mean scores improved significantly from preoperatively to the last follow-up: Lysholm: 56.9 ± 5.4 to 83.5 ± 6.0 (P < 0.001); HSS: 56.1 ± 6.0 to 81.7 ± 7.7 (P < 0.001). The mean mechanical alignment of the lower extremity was corrected from varus to the neutral range at the last follow-up. The preoperative KL grade was not significantly different from the KL grade at the last follow-up (P = 0.071). On MRI, mean MME increased from 3.0 ± 0.7mm to 3.1 ± 0.7mm (P = 0.046). Second-look arthroscopy showed 64.7% complete, 29.4% partial and 5.9% failed healing of the repaired root. The initial OB grade of the MFC showed no progression (P = 0.103). The remodified Mason-Allen suture technique concomitant with HTO for MMPRTs significantly improved clinical outcomes and suppressed OA progression at 66.4months. However, this procedure produced limited complete healing of the repaired roots in 64.7% of patients. IV.

Outcomes after Surgical Repair of Medial Meniscal Root Tears: A Review.

At the present time, there is a paucity of literature regarding medial meniscal posterior root repair and outcomes. This review seeks to examine the currently available data to further elucidate the clinical risks and benefits and any associated risks of medial meniscal posterior root repair. A systematic literature search was performed up to July 2018 in the databases of Medline via PubMed, EBSCOhost, and EMBASE. The results were reviewed independently by two authors and appropriate articles were reviewed and eligibility determined based on established criteria. The best-evidence synthesis was subsequently used. Thirteen studies (324 patients) were included in this review with a mean patient age of 54 years. There were no control studies with nonoperative treatment of medial meniscal posterior root tears. All studies included a minimum of 10 patients in a case series or case-control manner. Of patients treated with medial meniscal posterior root repair, 62.43% demonstrated complete healing on follow-up magnetic resonance imaging (MRI) or second-look arthroscopy. Among them, 32.60% demonstrated incomplete healing, loosening of the construct, or excessive scar tissues formation. Also, 4.97% demonstrated complete failure or retearing of the construction. At a mean follow-up period of 33 months, patients demonstrated a mean improvement in Lysholm's score of 30.5 (p < 0.00001), International Knee Documentation Committee (IKDC) score of 31.9 (p < 0.00001), and HSS Knee Score of 38.3 (p < .00001). Surgical repair of medial meniscus posterior root tears appears to result in highly satisfying subjective outcomes. Patients included in this review meet criteria for both statistically and clinically significant improvement, based on published guidelines for minimal clinically important difference. Despite this, however, postoperative MRI and second-look arthroscopy demonstrate a relatively high rate of incomplete healing (32.60%) or retearing and failure of the construct (4.97%). More highly powered studies are required to confirm these findings.

Outcomes of Medial Meniscal Posterior Root Repair During Proximal Tibial Osteotomy: Is Root Repair Beneficial?

To compare the clinical and radiologic outcomes and arthroscopic findings of proximal tibial osteotomy (PTO) alone versus PTO combined with medial meniscal posterior root repair (MMPRR). Between October 2010 and September 2016, patients who underwent PTO and second-look arthroscopy at a minimum of 24 months postoperatively were reviewed. Patients were divided into group I (isolated PTO), group P (PTO with MMPRR using the pull-out technique), and group F (PTO and MMPRR using the side-to-side repair method). The subjective knee scores were assessed. Radiologic evaluation was based on the Kellgren-Lawrence grade. Healing of medial meniscal posterior root tears (good/loose/scar tissue/failed) and cartilage regeneration (excellent/good/poor) were assessed by arthroscopic examination. Mean clinical follow-up duration of group I (n= 22), P (n= 25), and F (n= 24) was 28.5 ± 5.7, 27.9 ± 6.2, and 26.3 ± 5.3 months, respectively. At final follow-up, Lysholm score, International Knee Documentation Committee subjective score, and Tegner activity scale significantly improved in all groups (P < .001), and subjective scores did not differ among the groups. The Kellgren-Lawrence grade progression showed no significant differences among 3 groups (P= .461). Good healing of medial meniscal posterior root tears was found in 24% and 12.5% of patients in groups P and F, respectively, and 0 in group I; there were significant differences between groups I and P (P < .001) and groups I and F (P < .001). Excellent cartilage regeneration in the medial femoral condyle and medial tibial plateau was found in 13.6% and 9.1% in group I, 24% and 12% in group P, and 16.7% and 8.3% in group F, respectively, without significant differences. Concurrent MMPRR during PTO appears to improve the arthroscopic appearance (healing of MMRPTs and cartilage regeneration) during second-look arthroscopy. However, concurrent MMPRR does not significantly improve clinical and radiologic outcomes at short-term follow-up. Level III, retrospective comparative study.

Outcomes of Arthroscopic All-Inside Repair Versus Observation in Older Patients With Meniscus Root Tears

Background: Meniscus root tears lead to de-tensioning of the meniscus, increased contact forces, and cartilage damage. Management of older patients with root tears is controversial and the efficacy of different treatment options is unclear. Purpose: To compare the clinical outcomes of patients with moderate knee osteoarthritis who underwent an all-inside meniscus root repair technique versus nonoperative management for either medial or lateral meniscus root tears. Study Design: Cohort study; Level of evidence, 2. Methods: Patients with a diagnosed posterior meniscus root tear who underwent arthroscopic repair (AR: 30 knees) or nonoperative treatment with observation (O: 18 knees) were followed for a minimum of 2 years (mean follow-up, 4.4 years). The arthroscopic repair included all-inside sutures to reduce the root back to its remnant (reduction sutures), thereby re-tensioning the meniscus, and 1 mattress suture to strengthen the repair by reapproximating the construct to the posterior capsule. The data collected included the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and Veterans RAND 12-Item Health Survey (VR-12) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores and conversion to total knee arthroplasty (TKA). Results: Medial meniscus root tears comprised 80.0% of the AR group and 77.8% of the O group. The average Kellgren-Lawrence grade was 2 in both groups. The baseline scores for the KOOS Symptoms subscale were lower for AR (50.2 ± 19.3) than for O (66.5 ± 16.1) (P = .003), as were the KOOS Knee-Related Quality of Life scores (AR, 26.7 ± 16.1; O, 39.6 ± 22.1) (P = .046). No differences were found between groups for the absolute values at follow-up except that follow-up Tegner scores were lower in the O group than in the AR group (P = .004). Significant improvements were seen in the AR group from baseline to ultimate follow-up in average KOOS subscale scores (P < .001), Lysholm scores (P < .001), Tegner scores (P = .0002), and VR-12 PCS scores (P < .001), whereas the O group had a significant improvement only in average KOOS Pain (P = .003), KOOS Function in Daily Living (P = .006), and VR-12 PCS (P = .038) scores. Compared with the O group, the AR group had a significantly larger improvement from baseline to follow-up in average KOOS Pain (P = .009), KOOS Symptoms (P = .029), and Lysholm scores (P = .016). During follow-up, 3.3% of the AR group underwent a TKA compared with 33.3% of the O group (P = .008). The hazard ratio of TKA conversion was 93.2% lower for the AR group compared with the O group (P = .013). Conclusion: All-inside medial or lateral meniscus root repair showed improved functional outcomes and decreased TKA conversion rates compared with nonoperative treatment and may be considered as a treatment option for the management of meniscus root tears in older patients with moderate osteoarthritis.

Progression of radiographic osteoarthritis after partial meniscectomy in degenerative medial meniscal posterior root tears was greater in varus- than in neutral-aligned knees: a minimum 5-year follow-up

To perform a radiographic assessment of osteoarthritis, progression after partial meniscectomy (PM) in degenerative medial meniscus posterior root tears (MMPRTs) in relation to preoperative mechanical axis (MA). The hypothesis is that neutral-aligned knees with degenerative MMPRTs have better radiographic outcomes than those of varus-aligned knees after arthroscopic PM. Records of 114 patients with degenerative MMPRTs and Kellgren-Lawrence (KL) grade ≤ 2 osteoarthritis, who underwent PM, had preoperative weight-bearing hip-to-ankle radiographs from 2004 to 2014, and were followed-up for at least 5 years were reviewed retrospectively. The mean follow-up period was 8.3 ± 2.8years. Preoperative MA values were used to classify the patients into either a Neutral (N valgus 3° to varus 3°; n = 60) or Varus-aligned group (V varus > 3°; n = 54). Joint space width (JSW; mm) and KL grade (0/1/2/3/4) were measured preoperatively and finally on weight-bearing 45° flexion posteroanterior and anteroposterior radiographs, respectively. Preoperative JSW and KL grade did not differ significantly between the groups (N vs V; JSW 3.64 ± 0.83 vs 3.44 ± 0.81, P = 0.201; KL grade, 2/31/27/0/0 vs 0/22/32/0/0, P = 0.162); however, the final JSW and KL grade differed significantly between the groups (N vs V; JSW 3.03 ± 0.78 vs 2.07 ± 0.87; KL grade, 0/21/23/13/3 vs 0/10/26/21/6, both P < 0.001). The N group showed significantly less KL progression compared with the V group (N vs V; progression/no progression, 27/33 vs 42/12, P = 0.001). The progression of radiographic osteoarthritis after PM for degenerative MMPRTs was greater in varus-aligned knees than in neutral-aligned knees. PM should be considered cautiously in patients with varus-aligned knees. Retrospective comparative study, Level III.

The association between high-grade pivot-shift and complete lateral meniscus posterior root tear after anterior cruciate ligament ruptures

Objective To investigate the association between high-grade pivot-shift and complete lateral meniscus posterior root (LMPR) tear in patients with anterior cruciate ligament (ACL) ruptures. Methods From January 2013 to December 2017, a total of 86 ACL injured patients with LMPR tears were reviewed retrospectively. There were 66 males and 20 females with an average age of 27.8±8.3 years (range 16-49 years) and an mean BMI of 25.1±3.2 kg/m2 (range 17.4-33.9 kg/m2). The average duration from injury to surgery was 33.5±79.4 weeks (range 3 days to 11 years). All patients were classified into high-grade pivot-shift group (60 patients of IKDC grade II-III) and low-grade pivot-shift group (26 patients of IKDC grade 0-I) according to the results of pivot-shift tests under anesthesia before ACL reconstructions. Predictive factors of high-grade pivot-shift were analyzed by multivariable Logistic regression, involving degree of LMPR tear, integrity of meniscofemoral ligament, width of lateral meniscal extrusion, KT-1000 arthrometer side-to-side difference, age, sex, and BMI. Results The prevalence of complete LMPR tear in high-grade pivot-shift group was higher than that in low-grade pivot-shift group. High-grade pivot-shift was associated to complete LMPR tear [OR=4.096, 95% CI(1.339, 12.371), P=0.013] and KT-1000 arthrometer side-to-side difference [OR=9.632, 95% CI (3.095, 29.975), P 0.05). Conclusion In patients with ACL ruptures, complete LMPR tear was an independent risk factor of high-grade pivot-shift, especially for patients with 12 weeks at least duration from injury to surgery. Key words: Anterior cruciate ligament; Menisci, tibial; Joint instability; Risk factors; Case-control studies

Biomechanical comparison of meniscus-suture constructs for pullout repair of medial meniscus posterior root tears

BackgroundTranstibial pullout repair for posterior meniscus root tear is widely performed to restore meniscal function. However, it is sometimes technically difficult to pass the suture through the posterior medial meniscus root in narrow joint space. To address this limitation, a new suture technique using an all-inside meniscal suture device through the tibial tunnel was proposed. The purpose of the present study was to compare the biomechanical properties of a meniscus-suture construct prepared using an all-inside meniscal suture device and those of the construct prepared using conventional suture techniques.MethodsA total of 18 fresh-frozen porcine medial menisci were used and randomly divided into three groups according to the type of suturing technique applied. Three suturing methods were evaluated: suturing with all-inside meniscal suture device, single simple suture, and double simple sutures. All specimens were subjected to cyclic loading of 300 cycles followed by a load-to-failure test. The displacement after cyclic loading, the ultimate failure load, and the mode of failure were evaluated.ResultsThere was no significant difference among the three suturing techniques regarding both displacement after cyclic loading and ultimate failure load. Suture breakage was the most common failure mode in each group.ConclusionsThe biomechanical properties of meniscus-suture construct with the all-inside meniscal suture device were equivalent to those obtained using conventional suture techniques. Our results suggest that pullout repair using the all-inside meniscal suture device through the tibial tunnel could serve as an alternative suture technique for the repair of posterior meniscus root tears.

Characteristic location and rapid progression of medial femoral condylar chondral lesions accompanying medial meniscus posterior root tear

BackgroundThis study aimed to demonstrate the characteristics of the chondral lesion at the medial femoral condyle (MFC) in patients with medial meniscal posterior root tear (MMPRT), and to compare the progression rate of accompanying chondral disease in MMPRT with that in degenerative non-radial tear. MethodsThirty-one patients who underwent arthroscopic surgery for MMPRT and 31 controls who underwent arthroscopic surgery for degenerative medial meniscus posterior horn horizontal tear (MMPHT) were included. Accompanying chondral lesions in the MFC were evaluated by magnetic resonance imaging (MRI) at initial diagnosis and from video taken at arthroscopic surgery using the International Cartilage Repair Society (ICRS) classification system. The difference in severity and extent of the chondral lesion between initial diagnosis and surgery was measured. ResultsTwenty-five patients with MMPRT (80.6%) and 29 patients (93.5%) with MMPHT had ICRS grade ≥2 chondral injuries at MFC. In the MMPRT and MMPHT groups, the most severely injured areas of the MFC were the far medial compartment (52%) and central compartment (51%), respectively. Comparing MRI and arthroscopy, 12 patients (39%) in the MMPRT group showed progression of chondral disease after a mean of 3.5 months, whereas only three patients (10%) in the MMPHT group showed progression after a mean of 3.1 months. ConclusionsMFC lesions accompanying MMPRT were located more medially and progressed faster than those with non-root horizontal tear. Earlier intervention such as repair of MMPRT or high tibial osteotomy, if malalignment is present, may be considered in order to prevent the progression of chondral lesion.

Partial Meniscectomy for Degenerative Medial Meniscal Root Tears Shows Favorable Outcomes in Well-Aligned, Nonarthritic Knees

Background: Arthroscopic meniscectomy has been commonly performed for persistent pain caused by degenerative medial meniscal posterior root tears (MMPRTs). However, risk factors that affect long-term outcomes and joint survivorship after meniscectomy are unclear. Purpose: To identify the risk factors associated with end-stage osteoarthritis after arthroscopic meniscectomy for degenerative MMPRT for middle-aged or elderly patients and to determine the joint survivorship according to the identified risk factors. Study Design: Case-control study; Level of evidence, 3. Methods: Data from 288 patients (24 male and 264 female), followed for at least 5 years after arthroscopic meniscectomy for degenerative MMPRTs performed between 1999 and 2010, were examined retrospectively. The modified Lysholm score was used for clinical evaluation. Cox proportional hazards regression analysis was used to assess factors that affect joint survivorship when conversion to total knee arthroplasty (TKA) was taken as the endpoint; these factors were age, sex, body mass index (BMI), preoperative tibiofemoral alignment (varus [<2° valgus] vs well-aligned [2°-10° valgus]), preoperative Kellgren-Lawrence grade (0 or 1 vs 2 or 3), and the modified Outerbridge grade of the medial compartment. Kaplan-Meier survival analysis and the log-rank test were used to compare overall survivorship with respect to each significant risk factor. Results: Mean age at the time of surgery was 58.9 years (range, 43-78 years). Sixty (20.8%) patients underwent TKA at 7.0 ± 3.6 years (range, 1.1-14.4 years) postoperatively. The mean follow-up time for those who did not undergo TKA was 8.9 ± 2.9 years (range, 4.5-16.5 years). The overall modified Lysholm score improved from 64.4 to 81.3 (P < .001), but progression of radiographic arthritis was noted in 156 (61.9%) patients (P < .001) at 2 years postoperatively. Age (hazard ratio [HR] = 1.049), BMI (HR = 1.092), varus alignment (HR = 2.283), and Kellgren-Lawrence grade 2 or higher (HR = 2.960) were significant risk factors for end-stage arthritis requiring TKA. Well-aligned nonarthritic knees (n = 131, 45.5%) survived significantly longer before requiring TKA than did knees with varus alignment or radiographic arthritis (P < .05). The 5- and 10-year survival rates in these low-risk groups were 97.7% (95% CI, 95.2%-100.2%) and 89.1% (95% CI, 82.4%-95.8%), respectively. Conclusion: Arthroscopic meniscectomy is an effective treatment for degenerative MMPRTs, with favorable long-term survival in well-aligned nonarthritic knees. However, meniscectomy should be undertaken cautiously in patients with varus alignment and preoperative radiographic osteoarthritis.

Lateral Meniscal Posterior Root Repair With Anterior Cruciate Ligament Reconstruction Better Restores Knee Stability

Background: The effect of lateral meniscal posterior root tear and repair—commonly seen in clinical practice in the setting of anterior cruciate ligament (ACL) reconstruction—is not known. Purpose/Hypothesis: This study evaluated the effect of tear and repair of the lateral meniscal posterior root on the biomechanics of the ACL-reconstructed knee. It was hypothesized that anterior tibial translation would increase under anterior loading and simulated pivot-shift loading with the root tear of the posterior lateral meniscus, while repair of the root tear would reduce it close to the noninjured state. Study Design: Controlled laboratory study. Methods: Thirteen fresh-frozen adult human knees were tested with a robotic testing system under 2 loading conditions: (1) an 89.0-N anterior tibial load applied at full extension and 15°, 30°, 60°, and 90° of knee flexion and (2) a combined 7.0-N·m valgus and 5.0-N·m internal tibial torque (simulated pivot-shift test) applied at full extension and 15° and 30° of knee flexion. The following knee states were tested: intact knee, ACL reconstruction and intact lateral meniscus, ACL reconstruction and lateral meniscal posterior root tear, and ACL reconstruction and lateral meniscal posterior root repair. Results: In the ACL-reconstructed knee, a tear of the lateral meniscal posterior root significantly increased knee laxity under anterior loading by as much as 1 mm. The transosseous pullout suture root repair improved knee stability under anterior tibial and simulated pivot-shift loading. Root repair improved the ACL graft force closer to that of the native ACL under anterior tibial loading. Conclusion: Lateral meniscal posterior root injury further destabilizes the ACL-reconstructed knee, and root repair improves knee stability. Clinical Relevance: This study suggests a rationale for surgical repair of the lateral meniscus, which can restore stability close to that of the premeniscal injury state.

L’arthrose du compartiment fémoral tibial médial précède la lésion de la racine méniscale médiale exprimée par un épisode douloureux soudain

BackgroundAn event of painful popping is a highly predictive clinical sign of medial meniscal posterior root tears (MMPRTs) in middle-aged to older patients. There are lack of studies about the prevalence of a painful popping event and the condition of the medial compartment at the time of popping event in MMPRTs. HypothesisWe hypothesized that most of MMPRTs with a single painful popping event would show pre-existed pathologic medial meniscal extrusion (MME) and articular cartilage degeneration, and larger contact area of medial femoral condyle to medial tibial plateau could affect the MME. In addition, MME would be correlated with knee osteoarthritis. Patients and MethodsThirty-eight patients (mean age 58.5±10.5) who had painful popping within 3 weeks were included. On MRIs, absolute MME, relative percentage of extrusion (RPE), MME-medial femoral condyle (MFC)/medial tibial condyle (MTC) at 0̊ ratio, and medial compartments’ Modified Outerbridge Scale (MOS) were evaluated. Kellgren-Lawrence (K-L) grade was also assessed. ResultsThe MME parameters including absolute MME, RPE, and the ratio between MME and MFC/MTC at 0̊ were 2.9±1.2mm, 22.0±10.3%, and 3.2±1.3. Patients with MOS and K-L grade≥2 were 33 (86.8%) and 32 (84.2%). Patients were divided into MME ≥3mm (group G, n=20) and MME<3mm (group L, n=18). The MME parameters were significantly greater in group G than group L (all, p<0.001). The group G had worse osteoarthritis progression in terms of MOS and K-L grade than the group L (p=0.035 and 0.077, respectively) MME≥3mm showed significantly association with MOS≥3 (p=0.045). DiscussionMore than 80% of MMPRT patients with an event of painful popping within 3 weeks showed that medial compartment degeneration preceded the event of popping. Therefore, identification of MME and articular cartilage degeneration at the time of painful popping in MMPRTs could be helpful when the surgeon determines the most appropriate treatment. Level of EvidenceIV, Case-series.

Medial knee osteoarthritis precedes medial meniscal posterior root tear with an event of painful popping

BackgroundAn event of painful popping is a highly predictive clinical sign of medial meniscal posterior root tears (MMPRTs) in middle-aged to older patients. There are lacks of studies about the prevalence of a painful popping event and the condition of the medial compartment at the time of popping event in MMPRTs. HypothesisWe hypothesized that most of MMPRTs with a single painful popping event would show pre-existed pathologic medial meniscal extrusion (MME) and articular cartilage degeneration, and larger contact area of medial femoral condyle to medial tibial plateau could affect the MME. In addition, MME would be correlated with knee osteoarthritis. Patients and methodsThirty-eight patients (mean age 58.5±10.5) who had painful popping within 3 weeks were included. On MRIs, absolute MME, relative percentage of extrusion (RPE), MME-medial femoral condyle (MFC)/medial tibial condyle (MTC) at 0° ratio, and medial compartments’ Modified Outerbridge Scale (MOS) were evaluated. Kellgren-Lawrence (K-L) grade was also assessed. ResultsThe MME parameters including absolute MME, RPE, and the ratio between MME and MFC/MTC at 0° were 2.9±1.2mm, 22.0±10.3%, and 3.2±1.3. Patients who with MOS and K-L grade≥2 were 33 (86.8%) and 32 (84.2%). Patients were divided into MME≥3mm (group G, n=20) and MME<3mm (groupL, n=18). The MME parameters were significantly greater in group G than group L (all, p<0.001). The group G had worse osteoarthritis progression in terms of MOS and K-L grade than the group L (p=0.035 and 0.077, respectively) MME≥3mm showed significantly association with MOS≥3 (p=0.045). DiscussionMore than 80% of MMPRT patients with an event of painful popping within 3 weeks showed that medial compartment degeneration preceded the event of popping. Therefore, identification of MME and articular cartilage degeneration at the time of painful popping in MMPRTs could be helpful when the surgeon determines the most appropriate treatment. Level of evidenceIV, Case-series.