Posterior Horn Of Medial Meniscus Research Articles

“Push and Park” Microdrilling Technique for Chondral Lesions of the Patella: A Technical Note

Abstract Background: The most used treatment modality for chondral lesions of the patella, particularly when the lesion is <2 cm2, is microdrilling. However, reduced working space and mobility of the patella make this procedure technically difficult. To bypass this technical difficulty, we describe a simple technique of “Push and park” for microdrilling of the chondral lesions of the patella. Materials and Methods: Patients operated on by this technique in 2021 were followed for 1 year. Patients operated for magnetic resonance imaging-proven International Cartilage Repair Society grade III and IV patellofemoral chondral lesions (PFCLs) that are localized and <2 cm2 with or without other concomitant knee pathologies were included. The functional outcomes were evaluated using the Tegner Lysholm score and Kujala score. Results: Twenty-one patients were included in the study. Of these, 7 cases had isolated PFCL, 8 cases had associated medial meniscal posterior horn root tears, and the remaining 6 cases had anterior cruciate ligament injuries. The mean follow-up period was 14 (±2) months. The average age was 41 (±7) years. We had 12 female and 9 male patients. The Tegner Lysholm and Kujala scores improved significantly in all the patients at 1-year postsurgery (P = 0.035 and P = 0.026, respectively). Conclusion: We have described a simple and reproducible technique for microdrilling of difficult-to-access patellar lesions. When used appropriately, the technique can be a cost-effective method of managing the chondral lesions of the patella.

Pattern in Simultaneous Rupture of the Medial Collateral Ligament and Anterior Cruciate Ligament Assessed by Magnetic Resonance Imaging

Background: Determining the exact details of complex traumatic injuries such as knee ligament rupture will be a crucial point in planning the surgical approach, which is determined through accurate imaging techniques such as magnetic resonance imaging (MRI). We aimed to evaluate the pattern of medial collateral ligament (MCL) rupture in patients who presented with simultaneous rupture of the anterior cruciate ligament (ACL) and MCL.
 Methods: We evaluated knee MRI in 44 patients (25 women and 19 men, mean age: 38.6 ± 5.4 years) who suffered from clinically acute simultaneous ACL and MCL injuries. Meniscus status, MCL rupture patterns, and pivot bone bruise were analyzed.
 Results: Concerning ACL rupture, 38.6% had a partial ACL rupture, and 61.4% had a complete rupture. The meniscus ruptured in 61.4%. The most common site of the meniscus rupture was related to the medial posterior horn (37.0%). The vertical type rupture was the most common (37.0%), followed by the horizontal rupture (29.6%). MCL rupture was present in all patients with grade 2 rupture revealed in 52.3%. Regarding the location of MCL ligament rupture, the highest ratio was found in the femoral site (65.9%). Semimembranosus rupture was observed in 2.3%. Pivot bone bruise was positive in 34.1%. Medial patellofemoral ligament (MPFL) rupture was also revealed in 68.2%. There was a significant relationship between the grade of rupture in the MCL and the presence of pivot bone bruise (P < 0.001).
 Conclusion: Femoral detachment of MCL and posterior horn of medial meniscus (PHMM) are the most common sites of MCL injury and meniscus rupture in the context of ACL rupture. Besides, our results show a relevant influence of the extent of bone bruise on the grade of MCL rupture.

The Effect of Lateral Extra-articular Tenodesis in an ACL-Reconstructed Knee With Partial Medial Meniscectomy: A Biomechanical Study

Background: Knee laxity increases with medial meniscectomy in anterior cruciate ligament (ACL)–reconstructed knees; however, the biomechanical effect of an additional lateral extra-articular tenodesis (LET) is unknown. Purpose/Hypothesis: The purpose of this study was to determine the kinematic effect of a LET in knees that underwent combined ACL reconstruction (ACL-R) and partial medial meniscus posterior horn (MMPH) meniscectomy. It was hypothesized that the addition of LET would reduce laxity in the ACL-reconstructed knee. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen human cadaveric knees (mean age, 41.5 years) were tested using a robotic system under 3 loads: (1) 89.0 N of anterior tibial (AT) load, (2) 5 N·m of internal rotation (IR) tibial torque, and (3) a simulated pivot shift—a combined valgus of 7 N·m and IR torque of 5 N·m—at 0°, 15°, 30°, 45°, 60°, and 90° of knee flexion. Kinematic data were acquired in 4 states: (1) intact, (2) ACL-R, (3) ACL-R + partial MMPH meniscectomy (MMPH), and (4) ACL-R + partial MMPH meniscectomy + LET (MMPH+LET). Results: In response to AT loading, there was a significant increase seen in AT translation (ATT) in the MMPH state at all knee flexion angles compared with the ACL-R state, with the highest increase at 90° of knee flexion (mean difference, 3.1 mm) (P < .001). Although there was a significant decrease in ATT at 15° of knee flexion with MMPH+LET (P = .022), no significant differences were found at other knee flexion angles (P > .05). In MMPH with IR torque, a significant increase was observed in IR at all knee flexion angles except 90° compared with the ACL-R state (range, 2.8°-4.9°), and this increase was significantly decreased at all flexion angles with the addition of LET (range, 0.7°-1.6°) (P < .05). Conclusion: Performing a partial MMPH meniscectomy increased ATT and IR in response to AT and IR loads compared with the isolated ACL-R state in a cadaveric model. However, when the LET procedure was performed after partial MMPH meniscectomy, a significant decrease was seen at all knee flexion angles except 90° in response to IR and torque, and a significant decrease was seen at 15° of knee flexion in response to AT load. Clinical Relevance: LET may be a useful adjunct procedure after ACL-R with partial MMPH meniscectomy to reduce knee laxity.

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.

Poster 256: Pediatric Meniscus Repair: Safety Profile based on &gt; 2000 Arthroscopic Meniscus Repairs

Objectives: Pediatric meniscus tear prevalence is increasing, and meniscus preservation methods are essential for long term knee function in this at risk group. In this patient population meniscus anatomy and vascularity may support higher rates of healing after repair, but safety of meniscus repair has not been studied in a large prospective cohort group. The purpose of this study is to establish the incidence of complications associated with pediatric meniscus repairs in a multi-center prospective quality improvement registry, and to identify the characteristics of meniscus repair that are associated with complications. Methods: A prospective multi-center quality improvement registry (16 institutions, 26 surgeons) monitoring the safety of meniscus repairs was reviewed. Audit processes using CPT codes were designed to ensure that all consecutive cases were prospectively entered on patients &lt;19 years old into a HIPAA- compliant electronic platform. Each meniscus repair case with a complication form was secondarily reviewed to ensure consistency of identification and grading according to the modified Clavien Dindo classification. Demographics, tear type, repair technique, and implant type, when applicable, were included, and a common cause analysis was performed to evaluate risk factors for early repair failures. Results: 2375 meniscus repair cases were identified, with a mean age of 15.1 years (2-19) and 44.1% females. These consisted of (25%) isolated repair, (5.4%) discoid meniscus repair, and (66.9%) concomitant ACL and meniscus repair. Overall complication rate was 12.64%, with 5.67% grade III complications. The most common complications were motion loss/stiffness (3.96%), failed repair (2.3%) and continued pain/mechanical symptoms (2.09%). Failed repair was identified in all repair groups but had the highest prevalence in isolated meniscus repair (6.38%), in which grade III complications were more common overall. Stiffness was more common when a meniscus repair was performed during an ACL reconstruction (2.1% Grade II and 1.27% Grade III). There was no statistical difference in complications associated with age, gender, or technique, medial or lateral meniscus, displacement, or zone of repair. However, posterior horn and posterior horn + body repairs of the medial meniscus sustained more complications (p=0.003) as did longitudinal/complex tears of the lateral meniscus (p=0.02). Conclusions: Pediatric meniscus repairs performed arthroscopically have a complication rate of 12.64%, with 1 and 20 meniscus repairs leading to a grade III complication. Although there is no difference in complications based on technique, posterior horn medial meniscus and longitudinal tears of lateral meniscus may be at higher risk of complications.

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.

“A 2 YEAR PROSPECTIVE STUDY EVALUATING DIAGNOSTIC ACCURACY OF MAGNETIC RESONANCE IMAGING (MRI) IN DETECTION OF RAMP LESIONS OF MEDIAL MENISCUS”

The purpose of this study is to Correlate the characteristic pattern of lesions affecting posterior horn of medial meniscus in MRI with Arthroscopic findings and calculate sensitivity, specificity and accuracy in diagnosis of ramp lesions. Methodology:It is a 2-year prospective study conducted in department of orthopedics, Rajarajeswari Medical college and Hospital, Banglore. Patients who were diagnosed with meniscal injuries were posted for arthroscopy surgery after obtaining the informed consent. In this study we compared MRI findings with arthroscopic findings of medial meniscal ramp lesions of knee. The data is prepared and sensitivity, specificity, accuracy of MRI were calculated. Results:A total of 112 patients of knee injuries were evaluated in which the Medial meniscus was injured in 64.96% of cases. The MM tear with ramp lesion was present in 26(65%) cases, of which 5 (12.5%) cases had grade I tear, 8 (20%) cases had grade II tear and 13 (32.5%) cases had grade III tear. The sensitivity, specificity, PPV and NPV were calculated and we found Sensitivity 88.89%, Specificity 84.62%, Positive predictive value 92.31%, Negative predictive value 78.57%, Accuracy 87.50%. Conclusions:The Meniscal Ramp lesions need to evaluation of the knee injuries accurately is very crucial for the proper management and outcome. MRI shows moderate sensitivity, specificity and accuracy in the diagnosis of ramp lesions in posterior horn of medial meniscus with more false positives and false negative values. Common causes of false positive findings in MRI is due to misinterpretation of intra meniscal signal changes (grade II signal changes) or normal anatomy as tears. The arthroscopic evaluation of ramp lesions was done using a postero-medial and trans-notch view and other accessory portals.

Concomitant Medial and Lateral Meniscus Posterior Horn Root Repair With ACL Reconstruction Using Trans-Tibial Tunnel Technique

Concomitant medial meniscus posterior horn root tears and lateral meniscus posterior horn root tears are rare in occurrence. There is limited literature on the simultaneous repair of medial and lateral meniscus root tears, with ACL reconstruction. We discuss management of concomitant medial meniscus posterior horn root tear (MMPHRT), lateral meniscus posterior horn root tear (LMPHRT), and anterior cruciate ligament (ACL) tear. We highlight the surgical technique in which we perform a repair of both medial and lateral meniscus posterior horn root repairs with ACL reconstruction. We explain the sequence of such a repair to avoid tunnel coalescence.

MR evaluation of the posteromedial corner of the knee: association of posterior horn medial meniscus tear with posterior oblique ligament and distal semi-membranosus tendon tear.

To assess if posterior oblique ligament and distal semi-membranosus tendon tears are associated with posterior horn medial meniscus tears on MRI. From January 1, 2018 to December 31, 2019, 56 patients who met the inclusion criteria were enrolled in this study. Of the 56 patients, 43 patients who had a posterior horn of medial meniscus tear were included in the study group. A control group of 13 individuals was formed for comparison. Two radiologists reviewed the MR images and recorded the presence and grades of posterior oblique ligament and distal semi-membranosus tendon tears. We used the independent t-test and one-way ANOVA to compare the tear grades. Interobserver agreement was analyzed using a Cohen's κ coefficient (κ value) for categorical variables. The mean grades for the posterior oblique ligament and distal semi-membranosus tendon tears were significantly higher in the study group (all, p < 0.001). Interobserver agreement between the two readers was substantial in assessing the grade of posterior oblique ligament tear (κ = 0.653±0.087) and almost perfect in assessing the grade of distal semi-membranosus tendon tear (κ = 0.876±0.060). Posterior oblique ligament and distal semi-membranosus tendon tears are significantly associated with posterior horn of medial meniscus tear and medial meniscus posterior root tears, and the peel-back mechanism could be related to this association. Presenting this paper could adjust radiologist search patterns and potentially help orthopedists with management and pre-surgical planning for the posteromedial corner injury of the knee.

The Wave Sign Correlates with the Posterior Horn Medial Meniscus (PHMM) Tear in the Anterior Cruciate Ligament (ACL) Deficient Knee.

A posterior horn medial meniscus (PHMM) tear subjects the knee to pathological stresses, especially in the setting of a deficient anterior cruciate ligament (ACL). These PHMM tears have to be surgically addressed, however they remain a diagnostic challenge. Hence, this study aims to evaluate the wave sign as an arthroscopic diagnostic aid for the PHMM tear which may be occult. This is a retrospective study of 61 consecutive patients (62 ACL-deficient knees) who underwent arthroscopic primary ACL reconstruction between September 2017 and August 2018. We defined PHMM tears as tears located in the posterior one-third of the medial meniscus. Root tears and ramp lesions were included in our analysis. The arthroscopic findings were recorded after a comprehensive arthroscopic survey. In the sample of ACL-deficient knees, 44 (71.0%) had a concomitant medial meniscus tear. The most common location for the tear was in the posterior horn (81.8%). There were seven occult PHMM tears, not described by the radiologist or identified by the operating surgeon on the pre-operative magnetic resonance imaging. The wave sign was identified in 10 (16.1%) knees, all confirming the presence of the PHMM tear. A positive correlation was found between the presence of the wave sign and the PHMM tear. The wave sign has a statistically significant but weak positive correlation with the presence of the PHMM. We view the wave sign as a valuable arthroscopic cue to rule-in the presence of the PHMM tear in the ACL-deficient knee.

Effect of Blood Flow Restriction Training in Rehabilitation of Posterolateral Corner Reconstruction of Knee: A Case Study

The aim of this case report was to evaluate the outcome of blood flow resistance training in the rehabilitation of posterolateral corner reconstruction in a 26-year-old male who met with a road traffic accident eight months ago. He was diagnosed with grade 3 anterior cruciate ligament ACL and posterior horn of medial meniscus along with proximal tibia posterolateral corner injury with posterior cruciate ligament PCL tear over right knee joint following which he underwent arthroscopy surgery for the same. Though he underwent early postoperative rehabilitation as prescribed he continued to experience difficulty in climbing down the stairs swelling over right knee crepitus in the right knee joint associated with movements. He visited outpatient department of Alvarsquos College of Physiotherapy and Research Centre at Moodbidri for evaluation and further management. Residual muscle weakness and associated impairments were identified in the examination and hence was suggested to continue rehabilitation for the same. To strengthen the muscles blood flow restriction training protocol was incorporated in the routine rehabilitation of posterolateral corner reconstruction. The literature on effect of blood flow restriction training following posterolateral corner injuries is scarce and the present study outcomes could provide some insight into the same. Lower Extremity Function Scale was used to evaluate the outcomes of blood flow restriction training before and after the intervention. A total of 15 sessions of blood flow restriction training was given for quadriceps and hamstrings and the outcomes were assessed. Significant changes were observed in lower extremity functional scale from a pre-intervention score of 42.580 to post-intervention score of 6080. The increase in the scores above nine scales indicate an improvement in the functional performances of lower extremity. It can be thus be concluded that blood flow restriction training could be effective in improving residual lower extremity deficits following arthroscopic posterolateral corner injuries.

The Efficacy of High Tibial Osteotomy with or without Post-root Medial Meniscus Repair: A Systematic Review

Background: High tibial osteotomy (HTO) is a knee joint treatment modality for medial compartment arthritis, aiming to improve articular cartilage healing by shifting the lower limb’s axis. It is commonly used in younger patients with pain and active lifestyles, preventing advanced cartilage deterioration. Varus malalignment may often be accompanied with medial meniscus root tears. In recent years, meniscus root tears are often been repaired. However, the efficacy of medial meniscus repairs with high tibial in varus malalignment with medial meniscal tears remains a controversy. Purpose: The purpose is to study the functional outcomes of concurrent medial meniscus root repair with HTO versus HTO alone. Study design: Systematic review. Methods: According to Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of medial meniscus posterior root tear (MMPRT) repair with HTO versus HTO alone and extracted data about characteristics of patients, clinical functional scores, and radiologic outcomes. One reviewer extracted data and 1 reviewer assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the functional outcome of HTO alone or HTO and MMPRT repair in patients of varus malalignment and medial meniscus root tears. Results: 6 studies with 264 patients were identified. Data from these studies were segregated in HTO only and HTO with medial meniscus repair group. The findings of this systematic review suggest that the outcomes of HTO with MMPHRR and of only HTO are not statistically significant, meaning that doing valgus osteotomy only in patients with varus knee and MMPHRT can give good results regardless of not repairing the meniscus. Conclusion: HTO with medial meniscus posterior horn root repair seems to have no significant improvement in the functional outcomes of the patient. However, long-term studies need to be performed. Keywords: High tibial osteotomy, medial meniscus, root repair, arthroscopy, varus malalignment, meniscus, root tear

Case report: unusual posteromedial capsular lesion with posterior lateral meniscus root tear in two patients with constitutional genu recurvatum presenting after an acute ACL injury

Ramp lesions of the medial meniscus and posterior lateral meniscus root tears (LMPRT) can be present simultaneously in up to 8% of patients undergoing anterior cruciate ligament (ACL) reconstruction. The prevalence of these complex and highly unstable meniscal tears increases exponentially with the severity of the injury. The posteromedial capsule (PMC) has often been disregarded in the past when discussing ligamentous and meniscal injuries, but the recent interest in ramp lesions has drawn surgeons’ attention to the posteromedial structures of the ACL injured knee. While the meniscocapsular junction is commonly repaired in unstable ramp lesions, in the current literature there is no report regarding proximal PMC lesions, be they in isolation or associated with complex meniscal injuries.We report here two cases of proximal posteromedial capsular lesions associated with medial meniscus instability and posterior lateral root tears after ACL injury. The first case involves a meniscus ramp lesion associated with a proximal PMC tear and a posteromedial fluid collection in the muscle plane on magnetic resonance in a 22-year-old male soccer player. The second case involves a 21-year-old female soccer player who presented with a PMC lesion after hyperextension/valgus knee injury. The capsular lesions were repaired to restore capsular tension and improve medial meniscus posterior horn stability.

Medial meniscus posterior root tears and partial meniscectomy significantly increase stress in the knee joint during dynamic gait.

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. 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 1000N 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. 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%. 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.

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.

Novel Posterior Anchoring Method Associated With Medial Meniscus Posterior Root Repair

Introduction: Transtibial pullout repair is the gold standard surgical treatment for medial meniscus (MM) posterior root tear. However, posteromedial extrusion of the MM during knee flexion may remain a problem postoperatively. Materials and Methods: We used a novel posterior anchoring technique to help reduce posteromedial extrusion, applying two cinch sutures (TCSs) to the MM posterior horn and creating a bone tunnel at the center of the posterior root attachment to pullout the suture. Another bone tunnel was created at the posterior corner of the medial tibial plateau in the externally rotated knee flexion. The first anchor of an all-inside meniscal repair device was inserted through the inferior surface of the MM posterior horn with tensioning TCS and the second anchor into the bone tunnel. Tibial fixation of pullout sutures was performed using a bioabsorbable screw in 30 degrees knee flexion. Conclusions: Our posterior anchoring method, combined with conventional pullout repair with TCS, helped reduce posteromedial extrusion in patients with a MM posterior root tear.

A new indirect magnetic resonance imaging finding in anterior cruciate ligament injuries: Medial and lateral meniscus posterior base angle.

Objectives This study aimed to define the medial meniscus posterior base angle (MMPBA) and the lateral meniscus posterior base angle (LMPBA) measured in the medial and lateral meniscus posterior horns and examine the biomechanical and morphological relationship between anterior cruciate ligament (ACL) injuries and posterior meniscus horns using these parameters.Patients and methods The retrospective study was conducted with 32 patients with ACL rupture and 40 control patients, for a total of 72 patients (40 males, 32 females; mean age: 36.3±9.9 years; range, 18 to 57 years), between January 2016 and January 2018. The posterior tibial slope (PTS) was measured in standard radiographs, and MMPBA and LMPBA values were assessed by standard knee magnetic resonance imaging. The MMPBA was defined as the angle between the line passing through the medial meniscus’ tibial side border and the line passing through the capsular side border in the sagittal section's medial meniscus posterior horn. The LMPBA was defined as the angle between the line passing through the lateral meniscus' tibial side border and the line passing through the capsular side border on the sagittal section's lateral meniscus posterior horn. Groups were compared for PTS, MMPBA, and LMPBA.Results When both groups were compared in terms of MMPBA and LMPBA, patients with ACL rupture had significantly higher base angles (p<0.001 and p=0.031, respectively). The mean MMPBA was 84.27º±12.59º (range, 62º to 106.1º) in patients with ACL rupture, while it was 70.75º±7.85º (range, 55.1º to 88.6º) in the control group. The mean LMPBA was 83.62º±11.4º (range, 62.3º to 105.9º) in patients with ACL rupture, while it was 76.94º±11.46º (range, 30.8º to 96.5º) in the control group. In the receiver operating characteristics curve analysis, the cut-off value of MMPBA was 84.5, and values above this showed a 58.5% sensitivity and a 97.6% specificity for ACL rupture, whereas for LMPBA, the cut-off value was 93.15, and values above this showed a 27.3% sensitivity and a 95.1% specificity for ACL rupture. The PTS and MMPBA were significantly correlated with each other (p=0.047). The MMPBA and LMPBA were also significantly correlated with each other (p=0.011). However, there was no significant correlation between PTS and LMPBA (p=0.56).Conclusion Medial meniscus posterior base angle and LMPBA values above 84.5º and 93.15º, respectively, are new indirect magnetic resonance imaging findings of ACL injury.

Retrospective Cross Sectional MRI Study of Morphometry of Menisci of Knee Joint

Introduction: Meniscal tears are commonly encountered in clinical practice and cause significant musculoskeletal morbidity. Most of the data available on Morphometry of menisci in Indian population are through cadaveric studies and very few MRI studies are available to substantiate the available data. Aim of the study: To gather data on the Morphometry of menisci in South Indian population and compare it with the existing literature. Material and Method: 100 MRI images collected retrospectively were used to study menisci. Height and width of MM and LM were measured both in sagittal and coronal planes. Results: It was observed that in both sexes the height of the Anterior horn of Medial meniscus was significantly higher than that of Lateral meniscus. Width of the Anterior horn and body showed significantly higher values in Lateral meniscus whereas width of Posterior horn of Medial meniscus showed significantly higher values in both sexes. Height of Medial meniscus in all the segments was higher in males though the difference was significant only in anterior horn and Posterior horn segments. Height of Lateral meniscus was significantly higher in males in all the segments. Conclusion: Results of this study will add to the existing literature on the Morphometry of menisci and will serve as a database for patients undergoing meniscal allografts. KEY WORDS: Medial meniscus, Lateral meniscus, Meniscal tears, musculoskeletal morbidity.

Can MRI knee joint measurements predict the population at risk of ACL injury?

BackgroundAnterior cruciate ligament (ACL) injuries have been increasing significantly over time. The relationship between the ACL injury and the knee joint structures is poorly understood. The purpose of this study is to examine whether the measurements of different structures in the knee joint are linked with ACL injury in affected patients.MethodsThis retrospective case–control study included patients who suffered from ACL tears and underwent magnetic resonance imaging (MRI). A control group of patients with no knee pathologies on MRI was included. Fourteen knee variables, including lateral meniscus (LM) posterior horn height, length, depth, and volume; medial meniscus (MM) posterior horn height, length, depth, and volume; lateral and medial (MFC) femoral condyle sphere diameter; lateral and medial tibial plateau length; and patella tendon horizontal and vertical diameter, were collected. A multivariate logistic regression including LM posterior horn depth, MM posterior horn length, MM volume, MFC sphere diameter, and patella tendon horizontal diameter and receiver operating characteristic curve, was used to compare the two groups.ResultsA total of 85 patients were included in our study; 54 suffered from ACL injuries and 31 as a control group with normal knee MRI. Logistic regression revealed that increased LM posterior horn depth (OR = 1.27; 95% CI = 1.03–1.56; p = 0.028), decreased MM posterior horn length (OR = 0.71; 95% CI = 0.55–0.93; p = 0.013), and MFC sphere diameter (OR = 1.20; 95% CI = 1.01–1.43; p = 0.035) were independent risk factors for ACL rupture. The MFC sphere diameter yielded the highest area under the curve: 0.747 (95% CI, 0.632–0.862). No difference was found in the other measurements between the two groups.ConclusionsConcerning the difference in anatomical variations, the lateral meniscus posterior horn depth and medial femoral condyle sphere diameter were higher, while medial meniscus posterior horn length was lower in patients with an ACL injury. These structural knee measurements could have a possible increase in the likelihood of sustaining an ACL injury and can be used by clinicians to predict ACL injury.

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.