Evaluation of the reliability and accuracy of MRI for the diagnosis of meniscal ramp lesions.

BACKGROUND: Meniscal ramp lesions are a special type of meniscal injury that affects the periphery of the posterior horn of the medial meniscus and/or its meniscocapsular attachments, strongly associated with anterior cruciate ligament (ACL) tears. Due to their location, these lesions can be missed arthroscopically so it is essential to diagnose them on preoperative magnetic resonance imaging (MRI). PURPOSE: To evaluate the accuracy of MRI in detecting meniscal ramp lesions in patients with ACL tears using arthroscopy as the reference standard. MATERIAL AND METHODS: Two musculoskeletal radiologists, blinded to the surgical findings, retrospectively and independently evaluated 106 knee MRI scans for the presence of meniscal ramp lesions in non-consecutive patients who underwent arthroscopic ACL reconstruction between January 2019 and July 2022 by a single surgeon at one institution. Having arthroscopy as reference, the diagnostic sensitivity and specificity as well as the positive and negative predictive values (PPV/NPV) of the MRI scans were calculated. Cohen's kappa coefficient was used to test inter-observer reliability. A P value <0.05 was considered statistically significant. RESULTS: In the study group of 106 patients (72 men, 34 women; mean age = 33.84 ±13.12 years), 76 had an arthroscopy-confirmed meniscal ramp lesion, while 30 did not. The sensitivity and specificity of MRI for the detection of meniscal ramp lesion were 88% and 87%, respectively. The PPV and NPV were 94% and 74%, respectively. Inter-rater reliability was excellent (k = 0915). CONCLUSION: This study demonstrates that MRI can accurately detect meniscal ramp lesions.

Association of intraoperative medial joint gap laxity in the flexion position with subjective knee instability after fixed-bearing posterior-stabilised total knee arthroplasty.

BACKGROUND: Postoperative subjective knee instability is an important clinical outcome after total knee arthroplasty (TKA), however the association with intraoperative soft tissue balance remains unclear. This study aimed to assess the association between intraoperative soft tissue balance and postoperative subjective knee instability in fixed-bearing posterior-stabilised (PS) TKA. METHODS: This retrospective case-control study included 457 patients who underwent fixed-bearing PS TKA. Intra-articular distraction force was quantitatively applied to measure the gap parameters (length and angle) during surgery. The intraoperative joint gap parameters and postoperative clinical outcomes between the patients with (n = 90) and without (n = 367) subjective knee instability were compared. The risk factors for subjective postoperative knee instability were analysed using multivariate logistic regression analysis. RESULTS: The patients with subjective knee instability demonstrated a medially wider intra-articular gap angle and worse Knee Society Score 2011 symptoms (18 vs. 21; p < 0.01), satisfaction (27 vs. 30; p < 0.01), functional activity (55 vs. 65; p < 0.01), and Forgotten Joint Score 12 items (51 vs. 65; p < 0.01) than those in the patients without subjective knee instability. The use of measured resection technique (odds ratio, 2.3; 95% CI, 1.1-4.8; p = 0.02) and the medial laxity of joint gap balance in the flexion position (odds ratio, 1.2; 95% CI, 1.0-1.4; p = 0.04) were detected as risk factors for postoperative subjective knee instability. CONCLUSION: In fixed-bearing PS TKA, intraoperative medial joint laxity in the flexion position was associated with postoperative subjective knee instability, and surgical techniques to achieve sufficient soft tissue balance contributed to improve postoperative subjective clinical outcomes. LEVEL OF EVIDENCE: Ⅲ (case-control study).

Drilling the tibial tunnel in an arthroscopic popliteus bypass from the anteromedial tibial cortex decreases risk of popliteal vascular injury.

Purpose: Drilling the tibial tunnel in tibiofibular-based posterolateral corner (PLC) reconstructions is usually performed with a starting point from Gerdy's tubercle. Drilling the tunnel starting from the anteromedial tibial cortex could reduce the risk of popliteal neurovascular (PNV) injury. The purpose of this study is to assess the distance on Magnetic Resonance Imaging Scans (MRI) of the PNV bundle and peroneal nerve (PN) to these two different tunnel trajectories. Methods: A total of 87 MRI scans were assessed. The ideal exit point of the tibial tunnel in PLC reconstructions was marked. We added 10 mm from this point in a straight posterior and in an oblique trajectory, mimicking the two different tunnel trajectories and measured the distance to the PNV bundle and PN from these two points. Results: The mean distance of the tip of the guide wire drilled with a trajectory from Gerdy's tubercle to the PNV bundle and the peroneal nerve was respectively 13.2 mm (SD = 3.96) and 17.7 mm (SD = 4.39). The mean distance of the tip of the guide wire drilled with a trajectory from the anteromedial tibial cortex to the PNV bundle and the PN was respectively 19.6 mm (SD = 4.19) and 12.2 mm (SD = 3.96).). Drilling in a trajectory from the anteromedial tibial cortex significantly increases the distance to the PNV bundle (p < 0.001). Conclusion: Tibial tunnel drilling in a tibiofibular based PLC reconstruction from the anteromedial tibial cortex significantly increases the distance to the popliteal artery but with a decreased distance to the peroneal nerve. Level of evidence: level IV.

Wearable sensor systems measure differences in knee laxity between healthy and affected knees during dynamic exercise activities: A systematic review.

Purpose: Knee laxity can be experienced as knee instability which may lead to a limitation in the activity of patients. Current methods to determine knee instability are performed in a static setting, which does not always correlate with dynamic knee laxity during activities. Wearables might be able to measure knee laxity in a dynamic setting and could be of added value in the diagnosis and treatment of excessive knee laxity. Therefore, the aim of this systematic review is to provide an overview of the wearables that have been developed and their ability to measure knee laxity during dynamic activities. Methods: The PRISMA guidelines for systematic reviews were followed. A literature search was conducted in EMBASE, PubMed and Cochrane databases. Included studies assessed patients with knee instability using a non-invasive wearable sensor system during dynamic activity, with comparison to a reference system or healthy knees. Data extraction was performed by two authors via a predefined format. The risk of bias was assessed by The Dutch checklist for diagnostic tests. Results: A total of 4734 articles were identified. Thirteen studies were included in the review. The studies showed a great variety of patients, sensor systems, reference tests, outcome measures and performed activities. Nine of the included studies were able to measure differences in patients with knee instability, all including a tri-axial accelerometer. Differences were not measurable in all parameters and activities in these studies. Conclusions: Wearables, including at least a tri-axial accelerometer, seem promising for measuring dynamic knee laxity in the anterior-posterior and mediolateral direction. At this stage, it remains unclear if the measured outcomes completely reflect the knee instability that patients experience in daily life. Level of Evidence: Level III.

Diagnosing popliteofibular ligament injuries in anterior cruciate ligament-injured knees: A prospective magnetic resonance imaging study investigating the inter- and intraobserver reliability of identification of the popliteofibular ligament.

Purpose: The aim of our study was to investigate the intra- and interobserver reliability for the identification of the popliteofibular ligament (PFL) in magnetic resonance imaging (MRI) scans in patients with an anterior cruciate ligament (ACL) injury and ascertain the prevalence of PFL tears in ACL-injured knees without clinically high-grade posterolateral corner injury. Methods: MRI readings were performed retrospectively by two surgeons on 84 patients who underwent ACL reconstruction in our department. The presence of the PFL on both sagittal and coronal images as well as the presence of PFL tears was noted. Readings were repeated 6 weeks later for one observer. The κ value was calculated to determine the intra- and interobserver reliability for identification of the PFL and the prevalence of PFL tears was ascertained. Results: The PFL was visualized in 90.5%-91.7% of MRI scans. The intra- and interobserver reliability of visualizing the PFL on MRI had an κ value of 0.63 and 0.66 (substantially reliable), respectively. The intraobserver reliability for identification of PFL tears had an κ value of 0.26 (fair reliability). We found a 4.8% prevalence of PFL tears in ACL-injured knees. Conclusions: There is substantially reliable intra- and interobserver reliability for the identification of the PFL on MRI scans but only fair reliability for the identification of PFL tears. A 4.8% prevalence of PFL tears in ACL-injured knees without clinically confirmed high-grade posterolateral corner injury can be observed in our series. Level of Evidence: Level IV.

Estimating the Reliability and Validity of the Quadrant Hop Test in the Assessment of the Functional Stability of the Knee.

Background Many sporting activities demand multidirectional skills and movements, emphasizing the importance of various fitness components such as functional stability, strength, power, endurance, and range of motion. These aspects must be thoroughly assessed before athletes can return to sports safely following an injury. Although the single-leg hop test (SHT) is widely used as the gold standard for evaluating joint stability, it has limitations in assessing multidirectional movements. Therefore, further research is necessary to explore whether increasing the dynamicity of the hop test in different directions enhances its sensitivity in assessing knee joint stability across all four directions. The objective of this study was to investigate the applicability of a new functional assessment tool, the quadrant hop test (QHT), for evaluating lower limb functional stability. Methodology One hundred nineteen amateur sportsmen who are in the age group of 18-25 years with a limb symmetry index of the lower limb calculated through SHT of >80% were included. All the participants performed the SHT, a triple hop test (THT), a crossover hop test (CHT), and the QHT on two different days, with two investigators assessing the QHT on different days and then recording the measurements of Hop distance. Results The mean difference between SHT, THT, and CHT with QHT was 4.59%, with a moderate correlation between all the hop tests. The Cronbach's alpha revealed good intra-rater (0.917) and inter-rater reliability (0.912) of the QHT. Conclusion The QHT proves to be a reliable and valid measure for assessing the functional stability of the lower limb and is 4.59% more sensitive than SHT, THT, and CHT in assessing knee stability and in return to sports criteria.

Pediatric ACL Reconstruction in Children-An Evaluation of the Transphyseal Technique's Efficacy and Safety.

INTRODUCTION: Injuries of the anterior cruciate ligament (ACL) are commonly found in the general population, both among adult and pediatric patients, and their incidence has been increasing in recent years. Most of the late literature agrees that surgical reconstruction of the ACL is effective in improving long-term outcomes in pediatric patients, while others in the past have pleaded for non-surgical management. PURPOSE/HYPOTHESIS: Our study aims to verify if ACL reconstruction (ACLR) using transphyseal technique in skeletally immature patients will provide angular deviations or growth restrictions. STUDY DESIGN: Retrospective cohort study; Level of evidence 4. METHODS: We perfomed a retrospective study to verify if transphyseal ACLR in children with less than or equal to 2 years of remaining growth leads to either limb length discrepancies or axis deviations. RESULTS: Most patients who were treated using transphyseal technique showed significant improvements in their functional scores. There were statistically significant differences in lateral distal femoral angles (LDFA) and medial proximal tibial angles (MPTA), with no clinical impact. There was no significant limb length discrepancy (LLD) during the 2-year follow-up. CONCLUSIONS: Transphyseal ACLR is safe among children who have less than or equal to 2 years of remaining growth and brings no risk of axis deviations or limb length discrepancy.

Evaluating the Distribution, Quality, and Educational Value of Videos Related to Knee Instability Exercises on the Social Media Platform TikTok.

Introduction TikTok, a globally popular short-form video platform, offers a unique space for healthcare professionals to share advice, particularly under common conditions such as knee pain or instability. Despite its popularity, doubts persist regarding the reliability of medical information disseminated on TikTok. This study aimed to evaluate the quality of TikTok videos as a source of patient information on knee instability, recognizing the need for a comprehensive assessment of potential misinformation on this influential social media platform. Methods A search for "knee stability exercises" on TikTok yielded 448 videos, of which 187 met the inclusion criteria. These videos were categorized by source and evaluated using the Knee Exercise Education Scoring Tool (KEEST) and an information analysis questionnaire, DISCERN. Results General user videos (69.84%) had notably lower DISCERN scores than healthcare professional videos (29.1%) across all categories (P < 0.001, P = 0.282, P = 0.131, and P = 0.010). The DISCERN scores were inversely linked to video metrics (views, likes, comments, favorites, and shares). General user videos were largely of poor quality (66.4%), whereas healthcare professional videos spanned poor (61.8%), fair (28.2%), good (9.1%), and excellent (1.8%) categories. Both general users (12.31/25) and healthcare professionals (12.18/25) exhibited average quality according to KEEST standards (P = 0.809), with an intriguing inverse correlation between video popularity and DISCERN score. Conclusion Healthcare professionals demonstrated superior evidence-based content (DISCERN), whereas both groups were comparatively educated on treatment plans and effects (KEEST). TikTok's prevalent knee instability videos lack quality, proper sourcing, treatment risk information, and explanation. Moreover, popularity is inversely correlated with quality, and healthcare professionals appear to offer better evidence-based content. TikTok's role in healthcare highlights the importance of ensuring accurate information and implementing content quality regulations.

[Imaging of the anterior cruciate ligament and anterolateral rotational instability of the knee joint]. / Bildgebung des vorderen Kreuzbands und der anterolateralen Rotationsinstabilität des Kniegelenks.

The anterior cruciate ligament (ACL) is essential for the stability of the knee joint and ACL tears are one of the most common sports injuries with a high incidence, especially in sports that require rotational movements and abrupt changes in direction. Injuries of the ACL are rarely isolated and are often accompanied by meniscal and other internal knee injuries, which increase the risk of osteoarthritis. The spectrum of ACL injuries includes strains, partial tears and complete tears. Magnetic resonance imaging (MRI) plays a pivotal role in the diagnostics as it can accurately depict not only the ACL but also accompanying injuries. Proton density and T2-weighted sequences are particularly suitable for evaluating the ACL, which is usually well visible and assessable in all planes. In addition to depicting fiber disruption as a direct sign and central diagnostic indicator of an ACL tear, there are numerous other direct and indirect signs of an ACL injury in MRI. These include abnormal fiber orientations, signal increases and an anterior subluxation of the tibia relative to the femur. The bone marrow edema patterns often associated with ACL tears are indicative of the underlying injury mechanism. The treatment of ACL tears can be conservative or surgical depending on various factors, such as the patient's activity level and the presence of accompanying injuries. The precise and comprehensive description of ACL injuries by radiology is crucial for optimal treatment planning. Anterolateral rotational instability (ALRI) of the knee joint characterizes a condition of excessive lateral and rotational mobility of the tibia in relation to the femur in the anterolateral knee region. This instability is primarily caused by a rupture of the ACL, with the anterolateral ligament (ALL) that was rediscovered about 10 years ago, also being attributed a role in stabilizing the knee. Although ALRI is primarily diagnosed through clinical examinations, MRI is indispensable for detecting injuries to the ACL, ALL, and other internal knee structures, which is essential for developing an optimal treatment strategy.

Knee instability caused by altered graft mechanical properties after anterior cruciate ligament reconstruction: the early onset of osteoarthritis?

Anterior cruciate ligament (ACL) rupture is a very common knee joint injury. Torn ACLs are currently reconstructed using tendon autografts. However, half of the patients develop osteoarthritis (OA) within 10 to 14 years postoperatively. Proposedly, this is caused by altered knee kine(ma)tics originating from changes in graft mechanical properties during the in vivo remodeling response. Therefore, the main aim was to use subject-specific finite element knee models and investigate the influence of decreasing graft stiffness and/or increasing graft laxity on knee kine(ma)tics and cartilage loading. In this research, 4 subject-specific knee geometries were used, and the material properties of the ACL were altered to either match currently used grafts or mimic in vivo graft remodeling, i.e., decreasing graft stiffness and/or increasing graft laxity. The results confirm that the in vivo graft remodeling process increases the knee range of motion, up to >300 percent, and relocates the cartilage contact pressures, up to 4.3 mm. The effect of remodeling-induced graft mechanical properties on knee stability exceeded that of graft mechanical properties at the time of surgery. This indicates that altered mechanical properties of ACL grafts, caused by in vivo remodeling, can initiate the early onset of osteoarthritis, as observed in many patients clinically.

Complex Primary Total Knee Arthroplasty in a Young Patient With Neurofibromatosis Type One and Multidirectional Knee Instability: Technical Tips and Outcome.

Neurofibromatosis is an inherited disorder that causes skin discoloration and tumors. The musculoskeletal symptoms are specific, including bone deformities, dysplasia, joint instability, and osteoporosis. We present a rare case of a young patient with neurofibromatosis and multidirectional knee instability who underwent a successful complex primary knee replacement surgery. Stress right knee radiographs showed global joint instability with permanent anterior knee dislocation, excessively hypoplastic femoral condyles and patella, joint surfaces incongruency, and hypoplastic varus tibia, with intraluminal midshaft bone bridge causing severe stenosis. The patient could not walk, had an unstable recurvatum right knee, and used a wheelchair for her professional activities. The surgery involved a fully cemented rotating-hinged total knee arthroplasty with tibial and femoral stems. After three years of follow-up, the patient remains pain-free, fully ambulatory with no walking aids, a stable knee, a full range of motion, and no signs of aseptic loosening. This case highlights the decision-making difficulties and the significant surgical challenges faced during the operation.

Clinical Reproducibility and Reliability of Lever Sign (Lelli's) Test for Acute ACL Tear Performed by Medical Students.

Background: Injuries to the anterior cruciate ligament (ACL) in sports are frequent in children and young adults participating in sporting activities involving rotational and pivoting movements. Magnetic resonance imaging is the most accurate diagnostic tool to detect an ACL tear. There are, however, a number of specialized tests available to assess ACL competency. Hypothesis: A novel test was described with extremely high clinical accuracy. The purpose of this study was to assess its clinical accuracy when performed by non-orthopedic providers, such as medical students. Methods: A cross-sectional study design was adopted, and two patients with an MRI-proven complete ACL tear were selected. One patient was thin, and the other was overweight, and both were examined by 100 medical students for both the injured and uninjured knee. The results for these exams were recorded, and a statistical analysis of the screening test was done to evaluate the new special test. Results: Our results were different from the ones found in the literature: we found the test to have a significantly lower performance in terms of sensitivity, specificity, and positive and negative likelihood ratios compared to the literature numbers. Conclusion: The Lever sign (Lelli's) test loses clinical credibility and significance when performed by non-orthopedic providers or doctors, such as medical students in our study.

The Role of Lateral Extra-articular Tenodesis in Anterior Cruciate Ligament Reconstruction and Treatment of Rotatory Knee Instability: a Scoping Review.

PURPOSE OF REVIEW: The addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction (ACLR) has become increasingly popular to address residual rotatory knee instability. The purpose of this article is to review the anatomy and biomechanics of the anterolateral complex (ALC) of the knee, outline different LET techniques, and provide biomechanical and clinical evidence for its use as an augmentation procedure with ACLR. RECENT FINDINGS: Rotatory knee instability has been identified as a common contributor to ACL rupture in both the primary and revision settings. Several biomechanical studies have shown that LET reduces strain on the ACL by decreasing excess tibial translation and rotation. Additionally, in vivo studies have demonstrated restoration of side-to-side differences in anterior-posterior knee translation, higher rates of return to play, and overall increased patient satisfaction following combined ACLR and LET. As a result, various LET techniques have been developed to help offload the ACL graft and lateral compartment of the knee. However, conclusions are limited by a lack of concrete indications and contraindications for use of LET in the clinical setting. Recent studies have shown that rotatory knee instability contributes to native ACL and ACL graft rupture and LET may provide further stability to reduce rates of failure. Further investigation is needed to establish concrete indications and contraindications to determine which patients would most benefit from added stability of the ALC.

A Novel Classification of Coronal Plane Knee Joint Instability Using Nine-Axis Inertial Measurement Units in Patients with Medial Knee Osteoarthritis.

The purpose of this study was to propose a novel classification of varus thrust based on gait analysis with inertial motion sensor units (IMUs) in patients with medial knee osteoarthritis (MKOA). We investigated thigh and shank acceleration using a nine-axis IMU in 69 knees with MKOA and 24 (control) knees. We classified varus thrust into four phenotypes according to the relative medial-lateral acceleration vector patterns of the thigh and shank segments: pattern A (thigh medial, shank medial), pattern B (medial, lateral), pattern C (lateral, medial), and pattern D (lateral, lateral). Quantitative varus thrust was calculated using an extended Kalman filter-based algorithm. We compared the differences between our proposed IMU classification and the Kellgren-Lawrence (KL) grades for quantitative varus thrust and visible varus thrust. Most of the varus thrust was not visually perceptible in early-stage OA. In advanced MKOA, increased proportions of patterns C and D with lateral thigh acceleration were observed. Quantitative varus thrust was significantly increased stepwise from patterns A to D. This novel IMU classification has better clinical utility due to its ability to detect subtle kinematic changes that cannot be captured with conventional motion analysis even in the early stage of MKOA.

Review of Cha et al. (2005) on "Arthroscopic Double Bundle Anterior Cruciate Ligament Reconstruction: An Anatomical Approach".

This classic discusses the original publication 'Arthroscopic double-bundle anterior cruciate ligament reconstruction (ACL): An anatomical approach', the first detailed description of the surgical technique popularised by Dr Freddie Fu. The technique, in which the anteromedial and posterolateral bundles of the ACL are reconstructed individually using two grafts with independent bone tunnels, was designed to more closely recreate the function of the native ACL by more closely reproducing the functional anatomy. This reconstruction was biomechanically superior to single-bundle reconstruction, particularly with regards to rotational control, leading to great interest from ACL surgeons around the world. Clinical superiority was more difficult to demonstrate; however, and the technical difficulty of the procedure has limited its use. Nevertheless, the pursuit of improved patient outcomes through attention to functional anatomical detail continues. 'Recreating the functional anatomy of the intact ACL remains the cornerstone of ACL reconstruction'.

Long-term results after anterior cruciate ligament reconstruction using patellar tendon versus hamstring tendon autograft with a minimum follow-up of 10 years-a systematic review.

INTRODUCTION: A lot of research addresses superiority of the two commonly used autografts bone-patellar tendon-bone (BPTB) and hamstring tendon for anterior cruciate ligament (ACL) reconstruction, without getting to consensus. While there are numerous studies and reviews on short- to mid-term follow-up, not much literature is available on long-term follow-up. As patients suffering ACL injuries are often of young age and high athletic activity, it is crucial to have the best evidence possible for graft choice to minimize consequences, like osteoarthritis later on. MATERIALS AND METHODS: A search of the online databases, PubMed and Embase, was carried out last on 31st March 2022 for studies comparing BPTB and hamstring tendon (HT) autografts for ACL reconstruction in human patients with a minimum follow-up of 10 years. The methodological quality of each study has been evaluated using the modified Coleman Methodology Score. Results on the three variables patient-oriented outcomes, clinical testing and measurements and radiographic outcomes were gathered and are presented in this review. RESULTS: Of 1299 records found, nine studies with a total of 1833 patients were identified and included in this systematic review. The methodological quality of the studies ranged from a Coleman Score of 63-88. Many studies reported no or only few statistically significant differences. Significant results in favour of BPTB were found for activity levels and for instrumented laxity testing with the KT-1000 arthrometer. Better outcomes for HT were found in IKDC-SKF, the KOOS, donor site morbidity, pivot shift test, radiographic osteoarthritis (IKDC C or D) and contralateral ACL rupture. No studies presented significant differences in terms of Lysholm Score or Tegner Activity Score, Lachman test, single-legged hop test, deficits in range of motion, osteoarthritis using the Kellgren and Lawrence classification or graft rupture. CONCLUSION: We cannot recommend one graft to be superior, since both grafts show disadvantages in the long-term follow-up. Considering the limitation of our systematic review of no quantitative analysis, we cannot draw further conclusions from the many insignificant results presented by individual studies. LEVEL OF EVIDENCE: IV.

Function and strain of the anterolateral ligament part II: reconstruction.

PURPOSE: Anterolateral rotatory instability (ALRI) may result from isolated ruptures of the anterior cruciate ligament (ACL) or combined lesions with the anterolateral ligament (ALL). Biomechanical studies have demonstrated that the ALL contributes to the overall rotational stability of the knee. The purpose of this study was to investigate the biomechanical function of anatomic ALL reconstruction (ALLrec) in the setting of a combined ACL and ALL injury and reconstruction. The hypothesis was that combined ACL reconstruction (ACLrec) and ALLrec (ACL/ALLrec) significantly reduces internal rotation and shows load sharing between both reconstructions compared with isolated ACLrec. METHODS: Eight fresh-frozen cadaveric knees were evaluated using a six degrees of freedom knee simulator. Continuous passive motion and external loads were tested. Kinematic differences between ACLrec and combined ACL/ALLrec were compared. Additionally, ACL graft tension and ALL graft strain were measured continuously throughout the testing protocol. RESULTS: Combined anatomic ACL/ALLrec significantly improved the internal rotatory stability compared with isolated ACLrec at 30°-90° under an internal rotation moment. During a static pivot-shift test, additional ALLrec showed no significant reduction of ap-translation. ALLrec resulted in an increase in ACL graft tension during continuous passive motion and with additional internal rotation moment. CONCLUSION: In the case of a combined ACL and ALL deficiency, concurrent ACLrec and ALLrec significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL at flexion angles ≥ 30°. Nevertheless, additional ALLrec with fixation at 60° and with low tension could not restore extension-near rotatory stability. For that reason, ALLrec with fixation at 60° flexion cannot be recommended in clinical application.

Positional MR imaging of normal and injured knees.

OBJECTIVES: This study uses a practical positional MRI protocol to evaluate tibiofemoral translation and rotation in normal and injured knees. METHODS: Following ethics approval, positional knee MRI of both knees was performed at 35° flexion, extension, and hyperextension in 34 normal subjects (mean age 31.1 ± 10 years) and 51 knee injury patients (mean age 36.4 ± 11.5 years, ACL tear n = 23, non-ACL injury n = 28). At each position, tibiofemoral translation and rotation were measured. RESULTS: Normal knees showed 8.1 ± 3.3° external tibial rotation (i.e., compatible with physiological screw home mechanism) in hyperextension. The unaffected knee of ACL tear patients showed increased tibial anterior translation laterally (p = 0.005) and decreased external rotation (p = 0.002) in hyperextension compared to normal knees. ACL-tear knees had increased tibial anterior translation laterally (p < 0.001) and decreased external rotation (p < 0.001) compared to normal knees. Applying normal thresholds, fifteen (65%) of 23 ACL knees had excessive tibial anterior translation laterally while 17 (74%) had limited external rotation. None (0%) of 28 non-ACL-injured knees had excessive tibial anterior translation laterally while 13 (46%) had limited external rotation. Multidirectional malalignment was much more common in ACL-tear knees. CONCLUSIONS: Positional MRI shows (a) physiological tibiofemoral movement in normal knees, (b) aberrant tibiofemoral alignment in the unaffected knee of ACL tear patients, and (c) a high frequency of abnormal tibiofemoral malalignment in injured knees which was more frequent, more pronounced, more multidirectional, and of a different pattern in ACL-tear knees than non-ACL-injured knees. KEY POINTS: • Positional MRI shows physiological tibiofemoral translation and rotation in normal knees. • Positional MRI shows a different pattern of tibiofemoral alignment in the unaffected knee of ACL tear patients compared to normal control knees. • Positional MRI shows a high prevalence of abnormal tibiofemoral alignment in injured knees, which is more frequent and pronounced in ACL-tear knees than in ACL-intact injured knees.

Reproducibility of MRI in the diagnosis of meniscal ramp lesions: an inter-observer study.

BACKGROUND: Meniscal ramp lesions have gained much prominence in recent years due to a significant increase in their diagnosis and their important biomechanical involvement in the knee. A new proposed classification of these lesions has recently been published. PURPOSE: To evaluate the reproducibility of the new classification of meniscal ramp lesions recently published using magnetic resonance imaging (MRI). MATERIAL AND METHODS: A total of 249 post-traumatic knee MRI studies were evaluated by three musculoskeletal radiologists independently. Patients with an anterior cruciate ligament (ACL) tear on MRI in addition to a recent history of trauma to the knee for <12 months were included in the study, for a total of 95. We carried out an inter-observer concordance study to analyze whether the new classification is reproducible to detect meniscal ramp lesions and to classify them into their different types. RESULTS: Among our study cohort of 95 patients, we found 47 (49.5%) ramp lesions. In the inter-observer study, we obtained a good concordance (k = 0.733) in the detection of these lesions and an excellent one (k = 0.843) when the type of lesion is described. CONCLUSION: This study demonstrates that the new classification of meniscal ramp lesions has good reproducibility on MRI.

Anterior Cruciate Ligament Reconstruction Procedures Using the Iliotibial Band Autograft.

The Micheli anterior cruciate ligament (ACL) procedure is a combined intra-articular and extra-articular knee stabilization technique that combines lateral augmentation with ACL reconstruction using the iliotibial band as an autograft for both aspects of the technique. Its primary indication is for ACL reconstruction in skeletally immature patients with more than 2 years of growth remaining. Studies have shown it to be effective at restoring knee biomechanics to have minimal risk of complications, including those associated with growth disturbances and a relatively low ACL graft rupture rate. Additional studies are needed to better understand the potential utilization of this technique and related modifications in the marginally skeletally immature patient, skeletally mature adolescent, adult, and revision ACL reconstruction settings.