Medial Meniscal Posterior Horn Tears Research Articles

Clinical and MRI Outcomes of Repaired Peripheral Longitudinal Tears of the Posterior Horn of the Medial Meniscus With ACL Reconstruction: Results According to Tear Size.

Arthroscopic repair of longitudinal tears in the medial meniscal posterior horn (MMPH) has been reported to result in high rates of meniscal healing when performed alongside anterior cruciate ligament reconstruction (ACLR). However, studies that have focused on longitudinal tears and their impact on clinical outcomes after arthroscopic repair are insufficient. To investigate the clinical outcome and healing status after concomitant arthroscopic ACLR and repair of MMPH peripheral longitudinal tears, with respect to the tear length. Cohort study; Level of evidence, 3. A total of 263 patients who underwent concurrent arthroscopic suture repair of longitudinal tears of the MMPH and ACLR were enrolled. All patients had 2-year postoperative magnetic resonance imaging (MRI) evaluations, and 61% of patients underwent a second-look arthroscopy. The exclusion criteria were partial meniscectomies and multiligament injuries. Patients were assessed pre- and postoperatively for clinical scores, amount of anterior translation, grade of pivot shift, and presence of meniscal tear extension. According to the length of longitudinal tears, patients were classified into 2 groups: (1) patients with tears that were located in the posterior compartment and (2) patients with tears that extended to the midbody of the meniscus. Binary stepwise logistic regression analysis was used to evaluate the risk factors for unhealed menisci as identified by MRI. A total of 83 patients were included in this study-52 patients (group 1) had MMPH tears without tear extension and 31 patients (group 2) had MMPH tears with tear extension. There were no differences in outcomes between the groups, including the healing rate after meniscal repair (P > .05). Based on postoperative MRI scans, 67 patients (80.7%) were categorized as completely healed and 16 patients (19.3%) as unhealed. There were no significant differences between the completely healed and unhealed groups in outcomes or the rate of preoperative midbody tear extension. Higher body mass index and lower preoperative Lysholm scores were identified as risk factors for unhealed menisci. Overall, the rate of complete healing of MMPH tears repaired concomitantly with ACLR was 80.7% (67/83), and midbody tear extension did not affect the healing rate of the repaired meniscus. Results indicate that suture repair for unstable MMPH tears should be considered regardless of tear size.

Association Between Anterior Tibial Subluxation of Lateral Compartment and High-Grade Knee Laxity in Patients With Anterior Cruciate Ligament Deficiency

Background: High-grade knee laxity and excessive anterior tibial subluxation (ATS) are correlated with poor clinical outcomes in patients with anterior cruciate ligament (ACL) deficiency and share similar risk factors; however, the association between excessive ATS and high-grade knee laxity remains unclear. Purpose: To identify the association between excessive ATS and high-grade knee laxity in patients with ACL deficiency and determine the possibility that ATS can predict high-grade knee laxity. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 226 patients who underwent ACL reconstruction between May 2018 and March 2022 were analyzed in the present study; the high-grade group consisted of 113 patients who had a grade 3 result on the preoperative anterior drawer test, Lachman test, or pivot-shift test while under anesthesia, and the low-grade group consisted of 113 matched patients. The ATS values for medial and lateral compartments (ATSMC and ATSLC) were measured on magnetic resonance imaging while patients relaxed the quadriceps in the supine position under no anesthesia. The optimal cutoff values of ATSMC and ATSLC for high-grade knee laxity were determined using receiver operating characteristic curves. Univariate and multivariate logistic regression analyses with stratification were performed to identify the association between excessive ATS and high-grade knee laxity. Results: Compared with the low-grade group, the high-grade group had a longer time from injury to surgery; higher rates of medial meniscus posterior horn tear (MMPHT), lateral meniscus posterior horn tear (LMPHT), and anterolateral ligament (ALL) abnormality; and larger lateral tibial slope, ATSMC, and ATSLC. The optimal cutoff value was 2.6 mm (sensitivity, 52.2%; specificity, 76.1%) for ATSMC and 4.5 mm (sensitivity, 67.3%; specificity, 64.6%) for ATSLC in predicting high-grade knee laxity. After adjustment for covariates, ATSLC ≥4.5 mm (odds ratio [OR], 2.94; 95% CI, 1.56-5.55; P = .001), MMPHT (OR, 2.62; 95% CI, 1.35-5.08; P = .004), LMPHT (OR, 2.39; 95% CI, 1.20-4.78; P = .014), and ALL abnormality (OR, 2.09; 95% CI, 1.13-3.89; P = .019) were associated with high-grade knee laxity. The association between excessive ATSLC and high-grade knee laxity was validated in patients with acute ACL injury as well as those with chronic ACL injury. Conclusion: Excessive ATSLC was associated with high-grade knee laxity in patients who had ACL deficiency, with a predictive cutoff value of 4.5 mm. This study may help surgeons estimate the degree of knee instability more accurately before anesthesia and may facilitate preliminary surgical decision-making, such as appropriate graft choices and consideration of extra-articular augmentation.

Internal tibial torsion is associated with medial meniscus posterior horn tears.

Risk factors for meniscal tears play a decisive role in deciding on treatment and rehabilitation. The purpose of this study was to investigate the effect of tibial rotation on medial meniscus posterior horn tears (MMPHTs). This study is a retrospective case-control study. Fifty patients with meniscal tears and 57 knees with intact meniscus were compared. Tibial rotation, femoral version, tibial slope and knee varus were measured in each participant. Knee osteoarthritis was classified according to the Kellgren-Lawrence classification. Demographic characteristics were noted. There were significant differences in the mean tibial torsion angles and mean mechanical axes between the groups. The mean tibial rotation and mean mechanical axis were 26.3° ± 6.7 and 3.7° ± 2.7 in the MMPHT group and 30.3° ± 8.4 and 2.05° ± 2.7 in the control group, respectively (p = 0.008, p = 0.002). The current retrospective study has shown that tibial rotation is markedly reduced in patients with MMPHTs. Although the actual mechanism is not clear, the internal torsion of the tibia causes a decrease in the foot progression angle and increases the knee adduction moment, which in turn increases the medial tibial contact pressure. Internal torsion of the tibia, such as knee varus, may play a role in the aetiology of MMPHTs by this way. Whilst there was a significant difference in the mean varus and tibial torsion between the groups, there was no significant difference in the mean femoral version or tibial slope. III.

High-grade pivot-shift phenomenon after anterior cruciate ligament injury is associated with asymmetry of lateral and medial compartment anterior tibial translation and lateral meniscus posterior horn tears.

To investigate whether the high-grade pivot-shift phenomenon is associated with asymmetry of the lateral and medial compartment anterior tibial translation (L-ATT and M-ATT) and lateral meniscus posterior horn (LMPH) tears in anterior cruciate ligament (ACL) injuries. A retrospective analysis was performed on 192 consecutive patients who had complete ACL injuries between January 2019 and December 2020. Among these, 156 met the inclusion criteria. L-ATT and M-ATT were measured using preoperative weight-bearing magnetic resonance imaging (MRI), and the differences between L-ATT and M-ATT were calculated. Thirty-five patients who demonstrated excessive differences in L-ATT and M-ATT (> 6.0mm) were regarded as asymmetric (study group), and 36 patients with minimal or no differences in L-ATT and M-ATT (< 3.0mm) were allocated to the control group. Demographic data, grade of the pivot-shift test, integrality of LMPH, and medial meniscus posterior horn (MMPH) were compared between the groups. Moreover, predictors of high-grade pivot-shift phenomenon, including asymmetry of L-ATT and M-ATT, integrity of LMPH and MMPH, time from injury to surgery, sex, age, and body mass index (BMI) were assessed using multivariable logistic regression analysis. The difference between L-ATT and M-ATT in the study group was significantly higher than that in the control group (mean ± SD: 8.4 ± 2.1mm vs. 1.5 ± 1.0mm, P < 0.001). A higher proportion of patients with high-grade pivot-shift phenomenon (2 + and 3 +) and LMPH tears were identified in the study group (high-grade pivot-shift phenomenon: 25/35 vs. 13/36, P = 0.003; LMPH tears: 18/35 vs. 5/36, P = 0.001). Additionally, asymmetry of L-ATT, M-ATT (odds ratio 5.8; 95% CI 1.7-19.8; P = 0.005), and LMPH tears (odds ratio 3.8; 95% CI 1.3-11.6; P = 0.018) were found to be good predictors of the high-grade pivot-shift phenomenon after ACL injury, whereas MMPH tears, time from injury to surgery, sex, age, and BMI were not. In patients with ACL injury, the high-grade pivot-shift phenomenon is associated with asymmetry between L-ATT and M-ATT, and LMPH tears. III.

Clinical oberservation on rotator cuff suture threader and strapping suture in meniscus tear under arthroscopy

To explore clinical effect of arthroscopic meniscus tear strapping suture by rotator cuff suture threader. Forty patients with meniscus tear injury admitted from July 2015 to May 2019, including 27 males and 13 females, aged from 20 to 55 years old with an average of (36.0±1.4) years old. Menisci laceration was sutured with rotator cuff suture thread under arthroscopy. Postoperative complication was observed, Lysholm knee joint score before and after operation at 12 months were used to evaluate clinical effects, visual analogue scale (VAS) and range of knee flexion and extension were applied to evaluate recovery of pain and function. All patients were followed up from 12 to 15 months with an average of (12.6±0.7) months.No complication such as joint effusion, suture failure occurred. Two patients occurred mild pain after activity without clinical physical abnormality, and 1 patient manifested moderate pain with joint space tenderness, the other rest without abnormal. Lysholm knee joint score was increased from (49.55±1.21) preoperatively to (98.95±0.42) at 12 months after operation, VAS score decreased from (5.18±0.78)preoperatively to (1.03±0.77) at 12 months after operation, and range of knee joint flexion and extension activity increased from (50.63±9.20)°preoperatively to (130.38±4.99)°after operation, and there were statistical differences in Lysholm knee joint score, VAS and range of knee joint flexion and extension activity (P< 0.05). Arthroscopic strapping suture by rotator cuff suture threading device applies to most meniscus injuries, including medial meniscus posterior horn tears, lateral meniscus body tears and lateral meniscus posterior horn tears. This technique meets the need of full-internal meniscus suture without specialmeniscus suture, and has advantages of convenient operation, less complications and good postoperative function.

Pullout Repair Associated With a Bridging Suture Using FiberLink for the Medial Meniscus Posterior Horn/Root Tear

Transtibial pullout repair for the medial meniscus (MM) posterior root tear has become the gold standard. However, an optimal repair technique has not yet been established for MM posterior horn (MMPH) tear with a sufficient root remnant. We describe a pullout repair technique associated with a bridging suture using FiberLink (Arthrex, Naples, FL) for the MMPH tear. In this bridging suture technique, the simple cinch stitch is applied to the root remnant and MMPH. The loop end of the FiberLink is inserted into the MMPH, and its free-end is inserted into the root remnant. Next, the suture is tensioned and tied on the superior surface of the MMPH. The bridging suture and the additional simple stitch applied to the MMPH are pulled out through the tibial tunnel and fixed to the tibia on an expected tension. This technique might lead to better meniscal healing of the tear site, because it involves bridging of the MMPH and root remnant, and lower risk of suture cut-out owing to the biomechanical strength.

Effects of medial meniscal slope and medial posterior tibial slope on the locations of meniscal tears: A retrospective observational study.

The aim of this study was to analyze the relationship between medial posterior tibial slope (MPTS) and medial meniscus slope (MMS) with the location of meniscal lesions. We hypothesize that meniscuses with greater MPTS and MMS are more likely to have lesions in posterior horn.A total of 292 patients underwent arthroscopic surgery between January 2014 to September 2019 due to knee osteoarthritis (OA) and meniscal lesions were reviewed. Based upon the location of meniscal tears, patients were categorized as group B (tears in posterior horn) and group A (other sites). MPTS and MMS were measured from magnetic resonance imaging (MRI) slices. Osteoarthritis grade was evaluated in anteroposterior radiographs by the criteria defined by Kellgeren and Lawrence. Demographic data, OA grade, MPTS, and MMS for the 2 groups were compared and analyzed.The group A had 29 (39%) male and 45 (61%) female subjects with a mean age of 57.07 ± 6.79 years. Group B consists of 74 (34%) male and 144 (66%) female subjects with a mean age of 58.90 ± 7.594 years. (P = .067 and P = .458 for age and sex, respectively). In group A, 31 knees (42%) were determined to be Kellgren–Lawrence grade one, 32 knees (43%) grade two, and 11 knees (15%) grade three. In group B, 86 knees (39%) were categorized in grade one, 85 knees (39%) in grade two, and 47 knees (26%) in grade three (P = .085). The mean MPTS was 5.06 ± 2.11 degree for group A and 6.15 ± 2.37 degree for group B (P = .001). The mean MMS for group A was lower than group B (1.38 ± 2.12 degree vs 3.14 ± 2.92 degree; P < .000)This study demonstrated that increased MPTS and MMS may be considered as the risk factors for medial meniscal posterior horn tears.

Clinical observation of arthroscopic all-inside combined with outside-in "suture loop" repair for meniscus bucket-handle tear

To investigate the effectiveness of arthroscopic all-inside combined with outside-in "suture loop" repair for meniscus bucket-handle tear (BHT). Between August 2016 and May 2019, 44 case of meniscus BHT were treated with arthroscopic all-inside combined outside-in "suture loop". There were 29 males and 15 females with an average age of 26.6 years (range, 18-42 years). The causes of injury included sports injury in 31 cases, falling injury in 7 cases, and sprain in 6 cases. There were 32 cases of medial meniscus posterior horn tears and 12 cases of lateral meniscus posterior horn tears. The disease duration ranged from 6 weeks to 3 months. Thirty-three cases were complicated with anterior cruciate ligament rupture. All patients had normal lower limb alignment. The preoperative Lysholm score was 42.1±9.1. According to the evaluation criteria of MRI and Barrett et al., the healing of meniscus was evaluated, and the effectiveness was evaluated by Lysholm score. All the 44 patients were followed up 8-36 months with an average of 16.8 months. At last follow-up, according to the evaluation criteria of Barrett et al., 39 cases were clinically healed, 5 cases were not healed, the clinical healing rate was 88.6%; according to MRI evaluation, 32 cases were completely healed, 7 cases were partially healed, and 5 cases were not healed, the total healing rate was 88.6%, and the complete healing rate was 72.7%. Lysholm score was 87.8±4.8, which was significantly different from that before operation ( t=31.060, P=0.000). Arthroscopic all-inside combined with outside-in "suture loop" repair is a reliable and effective method for the meniscus BHT, which can obtain good joint function.

Effect of medial meniscal posterior horn tears on tibial translation in ACL-intact knees: a case control study based on MRI

Background: This aim of this study was to determine the relationship between medial meniscal tear and tibial translation in the anterior cruciate ligament (ACL)-intact knees. Methods: MRI of 278 patients, ages 18 to 50 yr, with medial meniscus posterior horn tears were evaluated. Two reviewers independently measured lateral and medial anterior tibial translation (ATT). Intraclass correlation coefficient (ICC) analysis was used to compare the results. Results: The ICC values of measurements of lateral ATT and medial ATT were 0.995 and 0.998, respectively; these values demonstrated almost perfect agreements. Age showed no significant difference between the control and patient groups (P&gt;0.05). Lateral ATT values were lower in the patient group than those in the control group; however, there were no statistically significant differences between the groups (P=0.81). Medial ATT values were significantly lower in the patient groups than in the controls (P&lt;0.05). Conclusions: Our results demonstrated significantly lower medial ATT values in patients with medial meniscus posterior horn tear in ACL-intact knees. However, most studies are dynamic and performed with ACL-ruptured knees or after meniscectomies in either ACL-intact or ACL-ruptured knees. Level of Evidence: Level III.

Medial Meniscal Posterior Horn Tears Are Associated With Increased Posterior Tibial Slope: A Case-Control Study

Background: While the medial meniscal posterior horn (MMPH) is reported to bear a considerable portion of overall load on the knee joint, including compressive and shear forces, no study has yet investigated the relationship between the MMPH and posterior tibial slope (PTS), which is a geometric factor associated with the shear force component in the presence of a compressive load in the knee joint. Hypothesis/Purpose: The purpose was to investigate the relationship between the PTS and MMPH tears in patients without ligamentous injury. It was hypothesized that the PTS is greater in patients with MMPH tears as compared with those without. Study Design: Cohort study; Level of evidence, 3. Methods: From March 2015 to December 2018, 159 patients with isolated MMPH tears and 60 patients without any pathologic findings on magnetic resonance imaging (control group) were included in this study. The PTS in the affected and contralateral knees was compared between the groups, which were statistically matched according to baseline characteristics (ie, age, sex, body mass index, radiographic osteoarthritis grade according to the Kellgren-Lawrence scale, and hip-knee-ankle angle) via the inverse probability of treatment weighting method. Furthermore, the MMPH tear group was subdivided according to meniscal tear patterns; these subgroups were then compared with the control group. Results: The mean PTS was significantly greater in the MMPH tear group than in the control group (affected knee: MMPH tear group, 7.0°± 3.4° [mean ± SD]; control group, 5.2°± 2.1°, P < .001; contralateral knee: MMPH tear group, 6.7°± 3.3°; control group, 4.7°± 2.2°, P < .001). The mean PTS in each subgroup also tended to be greater than that in the control group. In the receiver operating characteristic curve analysis, the cutoff point of the PTS discriminating between the MMPH tear and control groups was 6.6° for the affected knee (sensitivity, 55.3%; specificity, 75.0%) and 5.5° for the contralateral knee (sensitivity, 61.0%; specificity, 76.7%). Conclusion: An increased PTS is strongly associated with an increased incidence of MMPH tears and less affected by the meniscal tear patterns.

Dynamic Between-Leg Differences While Walking in Anterior Cruciate Ligament-Deficient Patients With and Without Medial Meniscal Posterior Horn Tears.

Background:Patients with anterior cruciate ligament–deficient (ACLD) knees with medial meniscal posterior horn tears (MMPHTs) have been reported to demonstrate a combined stiffening and pivot-shift gait pattern compared with healthy controls. Movement asymmetries are implicated in the development and progression of osteoarthritis.Purpose:To investigate the knee kinematics and kinetic asymmetries in ACLD patients with (ACLD + MMPHT group) and without (ACLD group) MMPHTs while walking on level ground.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 15 patients with isolated unilateral ACL ruptures, 10 with unilateral ACL ruptures and MMPHTs, and 22 healthy controls underwent gait testing between January 2014 and December 2016. Between-leg differences (BLDs) in knee kinematics and kinetics were compared among participants in all groups.Results:The ACLD + MMPHT group demonstrated significantly greater BLDs in knee moments in the sagittal plane during the loading response phase than the ACLD and control groups. Compared with the control group, the ACLD and ACLD + MMPHT groups demonstrated significantly greater BLDs in knee angles in the sagittal plane during the midstance and terminal stance phases. Compared with the control group, significantly greater BLDs in knee rotation moments were found throughout the stance phase in both the ACLD and the ACLD + MMPHT groups. BLDs in lateral ground-reaction forces (GRFs) in the ACLD + MMPHT and ACLD groups were both significantly greater than the control group during the loading response phase. BLDs in anterior GRFs in the ACLD + MMPHT and ACLD groups were both significantly greater than the control group during the loading response phase. Only the ACLD + MMPHT group demonstrated greater BLDs in vertical GRFs than the control group during the loading response phase, while no significant differences were observed between the ACLD and control groups.Conclusion:The ACLD + MMPHT group demonstrated significantly more knee flexion moment asymmetries than the ACLD and control groups during the loading response phase. Both the ACLD + MMPHT and the ACLD groups demonstrated significant knee angle and moment asymmetries in the sagittal plane during the terminal stance phase than the control group. Both the ACLD + MMPHT and the ACLD groups demonstrated knee rotation moment asymmetries during the midstance and terminal stance phases compared with the control group. A rehabilitation program for ACLD patients both with and without MMPHTs should take into consideration these asymmetric gait patterns.

Three dimensional knee kinematics and kinetics in ACL-deficient patients with and without medial meniscus posterior horn tear during level walking

BackgroundThe location of the meniscus tear has been reported to influence kinematics in anterior cruciate ligament deficient (ACLD) knees. Medial meniscus posterior horn tear (MMPHT) often occurred after ACL rupture. Whether MMPHT influences the kinematics and kinetics in ACLD knees has not been reported yet. Research questionThe purpose of this study was to investigate three-dimensional (3D) kinematics and kinetics in ACLD knees with and without MMPHT (ACLD + MMPHT, ACLDs) during level walking. MethodsFifteen patients with isolated unilateral ACLD, ten with unilateral ACLD + MMPHT, and twenty-two healthy controls underwent gait testing between January 2014 and December 2016. Participant characteristics, as well as gait parameters, were compared among control, ACLDs and ACLD + MMPHT knees. ResultsCompared to the healthy controls, the ACLD knees with and without MMPHT showed significant extension deficiency at maximum extension (flexion: ACLDs: 7.83 ± 4.3°, ACLD + MMPHT: 11.09 ± 7.8°, control: 3.12 ± 4.6°, p = 0.005) and lower extension moments during terminal stance phase of gait. Compared with the healthy controls, significantly increased external tibial rotation during pre-swing phase and lower rotation moments at terminal stance phase were observed in the ACLD + MMPHT knees, but not in the ACLDs knees. No significant differences in gait parameters were observed between ACLDs and ACLD + MMPHT knees during stance phase of walking. SignificanceThe ACLD knees with medial meniscus posterior horn tear exhibited extension deficiency, increased external tibial rotation, lower extension and internal rotation moments during the terminal stance phase compared to healthy control knees, presenting a combination of “stiffening gait” and “pivot shift gait” pattern. The ACLDs knees only presented extension deficiency and lower extension moments compared with healthy control knees, presenting a “stiffening gait”. Medial meniscus posterior horn tear did not significantly affect gait patterns during stance of walking in ACLD knees.

Meniscal Extrusion in the Knee: Should only 3 mm Extrusion be Considered Significant? An Assessment by MRI and Arthroscopy.

Aim. The aim of this study was to assess whether significant meniscal extrusion of more than 3 mm or of even lesser degrees of extrusion could be considered significant. We also aimed to determine the morphology of tears that are most likely to be associated with significant extrusion.Study design and material. The study was done retrospectively on a group of 202 patients (157 males and 45 females) who had been seen in our hospital between 2007 and 2011 with meniscal tears (in one knee only) diagnosed by MRI and confirmed on arthroscopy. Extrusion of 3 mm or more (usually considered significant) was seen in 102 cases and less than 3 mm in 100. Extrusion was measured on the coronal MR images rather than on saggital images because of ease and reproducibility. The tears were confirmed by arthroscopy and correlated with the extent of extrusion on MRI.Results: Out of the total of 202 cases, 102 cases (50.5%) had extrusion of 3 mm or more on MRI. Of these, the medial meniscal posterior horn tears accounted for 63 cases (64.26%), 21 cases were medial meniscal body tears (21.42%), five medial meniscal root tears (5.1%), nine lateral meniscal body tears (9.18%) and four lateral meniscal posterior horn tears(4.08%). Forty-four cases had extrusion of 3-4 mm, 26 had extrusion of 4-5mm, 17 cases had extrusion of 5-6mm, ten had extrusion of 6-7mm and five had extrusion of 7 mm or more. One hundred cases fell in the < 3mm extrusion category, of which 80 (39.6%) were in the 2-3 mm extrusion group and 20 (9.9%) in the 1-2 mm extrusion group. They comprised of 61 cases of medial meniscal posterior horn tears, 23 cases of medial meniscal body tears, six medial meniscal root tears, eight lateral meniscal body tears and two lateral meniscal posterior horn tears. The highest proportion of meniscal tears was seen in the 2-3 mm category comprising nearly 40% of the entire study group. The majority of tears were medial meniscal posterior horn tears.Conclusion: Menisci that extruded 2-3 mm from the tibial margin formed a major proportion of menisci treated for tears by repair or menisectomy. We should consider extrusion of more than 2mm as significant. Most tears had extrusion of 2-4 mm.

Meniscal Extrusion and Spontaneous Osteonecrosis With Root Tear of Medial Meniscus: Comparison With Horizontal Tear

The incidence of root tears in patients with spontaneous osteonecrosis of the knee has been studied, but the incidence of spontaneous osteonecrosis of the knee in patients with medial meniscus root tears has not. We assessed the latter incidence and evaluated the characteristics of medial meniscus root tears by comparing clinical status, the degree of osteonecrosis, and meniscal extrusion in patients with horizontal tears. Sixty-three patients who were diagnosed with medial meniscus posterior horn tear and treated by arthroscopic surgery between March 2005 and March 2009 were evaluated retrospectively. Patients were divided into 2 groups, the root tear group (R group) and the horizontal tear group (H group). Functional scores and radiography, simple radiography, and magnetic resonance imaging were investigated. No significant differences in age, body mass index, and symptom duration were observed between the 2groups. The incidence of osteonecrosis was 12 of 36 knees (33.3%) in the R group and 4 of 27 (14.8%) in the H group. The mean absolute extrusion was 4.1 ± 0.7 mm and 3.5 ± 1.4 mm in the R and H groups, respectively (P= not significant). The mean relative percentage of extrusion in the R group (46.1% ± 9.0%) was greater than that in the H group (35.3% ± 13.2%) (P= .01). The degree of osteonecrosis (ellipsoidal volume) was also greater in the R group (423.1 ± 236.7 mm(3)) than that in the H group (175.8 ± 43.6 mm(3)) (P= .03). Though not significant, the visual analog pain score had a tendency to be more severe and knee scores had a tendency to be lower in the R group than in the H group. Medial meniscus root tears had a greater degree of meniscal extrusion and wider osteonecrosis than horizontal tears of the posterior horn related to loss of the main function of the meniscus. Level III, retrospective comparative study.

Longitudinal Tear of the Medial Meniscus Posterior Horn in the Anterior Cruciate Ligament–Deficient Knee Significantly Influences Anterior Stability

Background: Longitudinal tears of the medial meniscus posterior horn (MMPH) are commonly associated with a chronic anterior cruciate ligament (ACL) deficiency. Many studies have demonstrated the importance of the medial meniscus in terms of limiting the amount of anterior-posterior tibial translation in response to anterior tibial loads in ACL-deficient knees. Hypothesis: An MMPH tear in an ACL-deficient knee increases the anterior-posterior tibial translation and rotatory instability. In addition, MMPH repair will restore the tibial translation to the level before the tear. Study Design: Controlled laboratory study. Methods: Ten human cadaveric knees were tested sequentially using a custom testing system under 5 conditions: intact, ACL deficient, ACL deficient with an MMPH peripheral longitudinal tear, ACL deficient with an MMPH repair, and ACL deficient with a total medial meniscectomy. The knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 134-N anterior and 200-N axial compressive tibial load. The rotatory kinematics were also measured at 15° and 30° of flexion in a combined rotatory load of 5 N·m of internal tibial torque and 10 N·m of valgus torque. Results: Medial meniscus posterior horn longitudinal tears in ACL-deficient knees resulted in a significant increase in anterior-posterior tibial translation at all flexion angles except 90° (P < .05). An MMPH repair in an ACL-deficient knee showed a significant decrease in anterior-posterior tibial translation at all flexion angles except 60° compared with the ACL-deficient/MMPH tear state (P < .05). The total anterior-posterior translation of the ACL-deficient/MMPH repaired knee was not significantly increased compared with the ACL (only)–deficient knee but was increased compared with the ACL–intact knee (P > .05). A total medial meniscectomy in an ACL-deficient knee did not increase the anterior-posterior tibial translation significantly compared with MMPH tears in ACL-deficient knees at all flexion angles (P > .05). In a combined rotatory load, tibial rotation after MMPH tears or a total medial meniscectomy in an ACL-deficient knee were not affected significantly at all flexion angles. Conclusion: This study shows that an MMPH longitudinal tear in an ACL-deficient knee alters the knee kinematics, particularly the anterior-posterior tibial translation. MMPH repair significantly improved anterior-posterior tibial translation in ACL-deficient knees. Clinical Relevance: These findings may help improve the treatment of patients with ACL and MMPH longitudinal tear by suggesting that the medial meniscal repairs should be performed for greater longevity when combined with an ACL reconstruction.

Anterior Knee Laxity Increases Gapping of Posterior Horn Medial Meniscal Tears

Background Meniscal tears often occur in association with anterior cruciate ligament (ACL) lesions or in chronically lax knees. It is also known that meniscal repairs are less likely to heal in ACL-deficient knees. Purpose To test the effect of different knee joint motion and loading conditions on the gapping behavior of longitudinal posterior horn meniscal tears in stable and ACL-deficient knee joints. Study Design Controlled laboratory study. Methods Longitudinal tears of 3 cm were set in the posterior horn of the medial menisci in 10 human cadaveric joints. The medial plateau of the knees was replaced by a transparent replica, and an arthroscope was placed underneath to observe the gapping phenomenon of the meniscal tears. The maximum gap width occurring during flexion-extension under various motion and loading situations was registered in intact and ACL-deficient joints before and after meniscal repair with FasT-Fix suture anchors. Results Longitudinal meniscal tears gapped significantly wider after ACL transection under 30-N axial joint load (P < .05). Increasing the axial load to 200 N or applying external moments to the knee did not lead to further alterations in the gap size. Gapping was significantly reduced after meniscal repair (P < .01). However, after meniscal repair, gapping under 30-N and 200-N axial joint load was still increased significantly after ACL transection compared with the ACL-intact state (P < .05). Conclusion Anterior knee laxity increases gapping across both unrepaired and repaired vertical peripheral medial meniscal posterior horn tears. Clinical Relevance Repairing such meniscal tears without reconstructing the ACL may affect meniscus healing rates or increase the risk of retears. Moderate rehabilitation regimens can be recommended, allowing at least for partial weightbearing and knee motion from extension to 120° of flexion in a stable knee. However, caution should be recommended if meniscal repair is performed in a knee joint with persistent anterior laxity due to ACL deficiency.

Predictors of degenerative medial meniscus extrusion: radial component and knee osteoarthritis

the purpose of this study was to determine the effect of a radial tear on degenerative medial meniscus posterior horn tear extrusion and to identify predictors of medial meniscus extrusion. we reviewed the records of 102 knees with medial meniscus posterior horn tears and degeneration that underwent a partial meniscectomy. Tears were classified as root (n = 17) and non-root (n = 85) tears, or as radial (n = 46) and non-radial (n = 56) tears. Groups were compared in terms of absolute and relative meniscal extrusion, and the proportion of knees with major (> 3 mm) extrusion. Multiple regression analysis was used to identify predictors of extrusion. the radial group had greater mean absolute (4 ± 1 vs. 3 ± 1 mm, P = 0.001) and relative (31 ± 11 vs. 23 ± 12%, P = 0.031) extrusion than the non-radial group. The radial group also had a greater proportion of major extrusions than the non-radial group (74% vs. 26%; P = 0.016). In contrast, the root tear and non-root tear groups were similar in terms of mean absolute (3 ± 1 vs. 3 ± 1 mm, P = n.s.) and relative (30 ± 7 vs. 26 ± 13%; P = n.s.) extrusion and in terms of proportion with major extrusions (59 vs. 55%; P = n.s.). Extrusion was found to be associated with a similar strength with both the presence of a radial component and the preoperative Kellgren-Lawrence grade. meniscal extrusion was greater and more severe in knees with a radial tear component than in knees without a radial component. The incidence and degree of major extrusion was similar in knees with root tears and non-root tears. A radial component and knee osteoarthritis severity were similarly predictive of absolute and relative extrusion. Meniscal extrusion in osteoarthritic knees was associated not only with degenerative meniscal tear but also with osteoarthritis severity. Therefore, arthroscopic meniscal procedures, especially meniscal repair, should be cautiously considered in patients with meniscal extrusion.

Clinical and Second-Look Arthroscopic Evaluation of Repaired Medial Meniscus in Anterior Cruciate Ligament—Reconstructed Knees

Background Tears of the medial meniscus posterior horn (MMPH) are frequently found in knees with deficient anterior cruciate ligaments (ACLs). There are few studies that have evaluated healing of the menisci and the factors associated with healing. Hypothesis The repaired menisci would show good healing in the knees with reconstructed ACLs, and the healing capacity of the menisci would differ according to the size, type, and location of the tear as well as the age and gender. Study Design Case series; Level of evidence, 4. Methods From August 1997 to February 2007, 311 knees underwent MMPH repair using either a modified all-inside or inside-out technique with concomitant ACL reconstruction. Among these patients, a second-look arthroscopy was performed at a mean of 37.7 months postoperatively (range, 12-128 months) in 140 patients. Clinical parameters and outcomes were evaluated. The repaired menisci were divided into complete, incomplete, and failure-to-heal groups. The factors associated with meniscal healing were statistically assessed. Results Among 140 patients, 118 (84.3%) showed complete healing, 17 (12.1%) had incomplete healing, and 5 (3.6%) failed to heal. The clinical success rate was 96.4% (135/140) because patients in the incomplete group showed no clinical symptoms associated with meniscal tears. Healing was associated with the tear location (P < .001) and type of tear (P = .0237) on the univariate analysis and the location (P = .0401) only on the multivariate analysis. Conclusion Repaired MMPH tears in knees with reconstructed ACLs healed without complications and had satisfactory clinical results. The tear location and type were factors associated with healing on the univariate analysis and location only on the multivariate analysis.

Arthroscopic all-inside suture repair of medial meniscus lesion in anterior cruciate ligament—deficient knees: Results of second-look arthroscopies in 39 cases

To evaluate by second-look arthroscopy the clinical results of arthroscopic all-inside sutures with hook using 2 posteromedial portals for medial meniscus posterior horn (MMPH) tears in patients who underwent concurrent anterior cruciate ligament (ACL) reconstruction. Case series. From May 1997 to June 2001, 78 knees underwent surgery for MMPH tears with arthroscopic all-inside sutures with hook and concurrent ACL reconstruction. Among them, 39 patients were evaluated with follow-up second-look arthroscopy. All MMPH tears were repaired by arthroscopic all-inside suture technique using 2 posteromedial portals. The second-look arthroscopy was performed, on average, 19 months (range, 6 to 40 months) after the ACL reconstruction and meniscal repair. They were divided into complete healing, incomplete healing, and failure groups. Tear size, type, and location were analyzed. We determined clinical criteria for success in meniscal status as (1) not positive for 4 clinical objective parameters--joint line pain and tenderness, locking or catching, recurrent effusions, and McMurray test; and (2) complete healing of all-inside sutured meniscus during second-look arthroscopy. Among 39 knees assessed by second-look arthroscopy, 32 (82.1%) knees showed complete healing and 6 (15.4%) showed incomplete healing without any positive findings of the clinical symptoms. Furthermore, all cases in the incompletely healed group had complete healing of the posterior horn, which was sutured by an all-inside suture; the incomplete healing was observed between the junction areas of all-inside to inside-out sutures, which was mainly at the posteromedial corner. The success rate was 97.4% (38 of 39 patients) overall for all-inside suture healing. The 1 patient (2.6%) with clinical failure had a retear of the repaired site. The average knee scores improved and all showed less than 2-mm side-to-side difference on KT-2000 testing. Arthroscopic all-inside vertical suture using a suture hook resulted in a high rate of healing even in large and complex vertical tears. This suturing can be one of the optimal treatments for MMPH tears greater than 1 cm during concurrent ACL reconstruction. Level IV, Therapeutic Study, Cases Series (no, or historical, control group).

Results of Arthroscopic All-Inside Sutures in Medial Meniscus with Concomitant Anterior Cruciate Ligament Reconstruction

Purpose: To evaluate the clinical results of arthroscopic all-inside suture using 2 posteromedial portals for medial meniscus posterior horn (MMPH) tears by second-look arthroscopy in patients received concurrent anterior cruciate ligament (ACL) reconstruction. Materials and Methods: From May 1997 to June 2001, 78 MMPH tears were treated with arthroscopic all-inside sutures with concurrent anterior cruciate ligament (ACL) reconstruction. Among these 39 patients were availablefor follow-up evaluation by second-look arthroscopy. All MMPH tears were repaired using the arthroscopic all-inside suture technique using 2 posteromedial portals. Second-look arthroscopy was performed on average 19 months (range 6 to 40 month) after the ACL reconstruction and meniscal repair. Meniscus healing status was defined and classified. According to the Henning classification, they were divided into complete healing, incomplete healing, and failure. Tear size, type and location were analyzed and compared with healing category. We determined clinical criterias for success in meniscal status as; (1) no positive among 4 clinical objective parameters: joint line pain and tenderness, locking or catching, recurrent effusions, and positive McMurry test; and (2) complete healing of all-inside sutured meniscus during second-look arthroscopy. Results: Of 39 knees assessed by second-look arthroscopy, 32 (82.1%) showed complete healing, 6 (15.4%) incomplete healing without any positive findings of clinical symptoms. Furthermore, all in the incompletely healed group showed complete healing of the posterior horn, which was sutured by allinside suture, whereas incomplete healing was observed at the junctional areas between all-inside and inside-out sutures, mainly at the posteromedial corner. So the overall success rate was 97.4% (38/39) for all-inside suture healing. The one (2.6%) patient with clinical failure revealed a retear of the repaired site, and subsequent subtotal menisectomy was performed. KT-2000 arthrometry showed that sagittal knee laxity was less than 2 mm (Average 1.5 mm, SD 0.72) in all reconstructed knees. The average knee scores, Lysholm knee score and HSS score, at final follow up were 95.5 and 96.5, respectively. As expected, small, longitudinal, and more peripheral (red-red zone) tears resulted in a higher healing outcome. Conclusion: Accurate repair with arthroscopic all-inside vertical suture using a suture hook, resulted in a high healing rate even in large and complex vertical tears. Arthroscopic all-inside meniscal suturing may be an optimal treatment for medial meniscus posterior horn tear greater than 1 cm during concurrent anterior cruciate ligament reconstruction.