Rotational Instability Research Articles

Control the Working Process of the Rotor System with Tilting Pad Bearing

Various processes take place in rotor systems with tilting pad bearings. It is important not only to control but also to manage these processes. Due to the instability of the oil film layer in a bearing with inclined pads, oil whirl/whip can occur. Such whirl/whip destabilize the operation of the rotor system. Additional elastic elements between the tilt pads suppress oil whirl/whip and thus reduce rotor vibration excitation. By identifying the working zones of such bearings where oil whirl and whip occur, the problems of rotor rotation instability can be solved. In order to determine the effectiveness of the elastic elements between the tilting pads, research was conducted. A special stand with diagnostic equipment was used for the tests. The clearance between the rotor and the bearing was 50 μm. During the research, the rotor rotation speed was varied from 0 to 5000 rpm. After conducting the research, stable and unstable rotor working zones were determined (Zone I: 0 to 1938 rpm; Zone II: 1938–3923 rpm; Zone III: 3923–5000 rpm). Based on the obtained research results, it is possible to control the working process of the rotor system.

MRI of the Elbow - Update 2024.

Elbow pain can result in significant morbidity. MRI can help diagnosing the cause of elbow pain.Based on a systematic literature search as well as knowledge gained through frequent participation in conferences dedicated to advances in musculoskeletal imaging, this review aims to give a brief overview of normal anatomy and common pathologies of tendons and ligaments of the elbow on magnetic resonance imaging.Stabilization of the elbow joint is provided by osseous structures and passive ligamentous and active muscular support. Loss of these important stabilizers, due to trauma and overuse, can result in elbow instability. Additional MR views or intra-articular contrast media can be useful for the detection of specific pathologies.MRI is frequently used to detect posttraumatic or chronic conditions, which can lead to posterolateral or posteromedial elbow instability. Knowledge of normal anatomy, variants, pathologies, as well as appropriate imaging is crucial to make the diagnosis. · Epicondylitis occurs due to chronic degeneration with tendinosis and partial tendon tearing and is not related to an acute inflammatory reaction.. · Posterolateral or posteromedial elbow instability can be the result of trauma with loss of passive ligamentous and active muscular stabilization.. · The most common elbow instability is posterolateral rotatory instability with the LUCL being the most important stabilizer affected by injury.. · Schinnerl C, Weber M, Benninger E et al. MRI of the Elbow - Update 2024. Fortschr Röntgenstr 2024; DOI 10.1055/a-2416-1491.

Outcome of Locking Plate Fixation Adjunctive to Intramedullary Rodding in Osteogenesis Imperfecta Patients.

An intramedullary rodding is the preferred fixation method in limb stabilization of OI patients. However, the intramedullary rod may not provide adequate fixation and rotational stability, especially in adolescents and adults. The incorporation of adjunctive plate fixation alongside intramedullary rodding has been introduced to enhance this stability, although its complications remain insufficiently understood. The goal of this study was to explore the outcomes of adjunctive plating in conjunction with intramedullary rodding for limb stabilization in OI patients, emphasizing the complications related to the plates during the healing phase and following plate removal. This retrospective study examined 74 limb segments from 45 patients with OI who underwent intramedullary rodding and adjunctive plating from 2008 to 2022. Criteria for inclusion comprised surgical treatment followed by a minimum of 2 years of follow-up or complication before that time point. The need for adjunctive plating arose from inadequate fixation, rotational instability, and persistent cortical gaps with intramedullary rodding alone. Medical records and follow-up radiographs were reviewed to assess the healing of the target lesion and any complications. The study encompassed 30 males and 15 females, ranging in age from 4 to 38 years, with 51 femoral and 23 tibial segments receiving treatment. Union was successfully achieved in 63 cases (85.3%), with an average union time of 14.4 months. Plates were subsequently removed in 62 cases after an average duration of 18.0 months. Before union, 11 revision surgeries were performed in 4 peri-implant fractures, 1 screw pull-out, and 6 failure of union. One sustained peri-implant fracture after the union. Following the removal of plates, complications included 10 refractures at screw sites, 3 progressive angulations at the previously targeted lesions, and 1 osteomyelitis. Kaplan-Meier analysis revealed that half of the refractures occurred within 1.8 years postplate removal. The overall complication showed borderline significance (P=0.056) among age groups. All the plate-related complications occurred at the diaphyseal, unicortical screws. Plate fixation, when used as an adjunct to intramedullary rodding, effectively stabilizes limbs in OI patients when intramedullary rods alone are inadequate. Nevertheless, given the significant risks associated with plate-related complications, adjunctive plating should be employed selectively only in instances where the union is unlikely to be achieved with intramedullary rodding alone. Level IV-case series.

Differential rotation in neutron stars at finite temperatures

IntroductionThis paper investigates the impact of differential rotation on the bulk properties and onset of rotational instabilities in neutron stars at finite temperatures up to 50 MeV.MethodsUtilizing the relativistic Brueckner-Hartree-Fock (RBHF) formalism in full Dirac space, the study constructs equation of state (EOS) models for hot neutron star matter, including conditions relevant for high temperatures. These finite-temperature EOS models are applied to compute the bulk properties of differentially rotating neutron stars with varying structural deformations.ResultsThe findings demonstrate that the stability of these stars against bar-mode deformation, a key rotational instability, is only weakly dependent on temperature. Differential rotation significantly affects the maximum mass and radius of neutron stars, and the threshold for the onset of bar-mode instability shows minimal sensitivity to temperature changes within the examined range.DiscussionThese findings are crucial for interpreting observational data from neutron star mergers and other high-energy astrophysical events. The research underscores the necessity of incorporating differential rotation and finite temperature effects in neutron star models to predict their properties and stability accurately.

Dorsal Screw Osteosynthesis of a Scaphoid Nonunion associated with Congenital Scaphotrapezial and Lunotriquetral Coalitions: A Case Report

We present the case of a 24-year-old man who sustained a scaphoid fracture in the presence of congenital scaphotrapezial and lunotriquetral coalitions. As the fracture progressed to a nonunion, a screw osteosynthesis was performed. The altered biomechanics caused by the two coalitions necessitated a dorso-proximal surgical approach, and two screws were implanted to prevent rotational instability. The scaphoid fracture healed entirely.

Management of Multiligament Knee Injuries Using Anatomic Autograft Reconstructions: A Case Series.

While proven effective management of multiligament knee injury (MLKI) using allograft is often reported, it has shown an increased risk for graft failure compared with autograft and raises availability and cost issues. Osseous stock preservation and tunnel convergence avoidance led us to develop a compromise innovative surgical procedure using only ipsilateral autograft for anatomic reconstruction of Schenck III-L or higher MLKI. We report the description and early outcomes of our initial experience. Our strategy consisted of an anatomic single-bundle posterior cruciate ligament reconstruction with quadriceps tendon autograft and a "Versailles" reconstruction for the posterolateral corner, which we modified to reconstruct the anterolateral ligament in case of anteromedial rotatory instability, called "full lateral." A second-stage surgery was planned for anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft. Outcomes were Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores for functional status, Short Form 12 (SF-12) for quality of life, and visual analog scale (VAS) for pain. Complications, full weight-bearing, return to work, and sport were also computed. Between March 2019 and August 2020, 10 patients were included. At follow-up, light pain was found in nine patients with a mean VAS of 1.2 ± 2.16 during the day. The mean Lysholm, Tegner, and subjective IKDC scores were good, with 61.2 ± 20.6, 2.8 ± 2.1, and 52.6 ± 20.4, respectively. However, quality of life was altered with poor SF-12 scores. In our first 10 patients with Schenck III-L or higher MLKI, our procedure using only ipsilateral autograft enabled correct daily knee functional activities while preserving osseous stock.

Medial sleeve fractures in elite-athletes: A heterogeneous group, anatomical and case-based considerations.

The purpose of this study is to provide a detailed description of the anatomy and radiology of the medial sleeve and present an approach in its management among elite athletes. Five cases of elite athletes who underwent treatment for a medial sleeve injury of which the diagnosis was confirmed through physical examination and additional magnetic resonance imaging scan are described in this study. Two patients presented with isolated medial sleeve injuries, while the other three patients suffered from concomitant ankle injuries. Non-operative treatment consisted of relative rest, soft cast immobilization and mobilization in a walking boot or kinesiotape which was successful in four of the cases with regard to the medial sleeve. One patient underwent surgery due to syndesmotic instability. Another patient presented with combined medial and lateral ankle instability which was treated surgically with an open medial and lateral ligament repair. All patients were able to return to their pre-injury sports and at the time of the last follow-up were still playing in their pre-injury level of competition. Medial sleeve injuries of the ankle in elite athletes should be considered in the differential diagnosis for athletes presenting with medial ankle pain. Inherent knowledge regarding anatomy is essential when guiding the management of these injuries which can be treated successfully with a non-operative approach consisting of relative rest, immobilization, kinesiotape and physical therapy. In case of persistent medial instability or rotational instability, surgical repair is a viable treatment option. Both modalities allow athletes to return to the pre-injury level of competition. However, early diagnosis is crucial to minimize the delay of appropriate treatment and avoid potential residual symptoms. Level IV.

A Flat Reconstruction of the Medial Collateral Ligament and Anteromedial Structures Restores Native Knee Kinematics: A Biomechanical Robotic Investigation

Background: Injuries of the superficial medial collateral ligament (sMCL) and anteromedial structures of the knee result in excess valgus rotation and external tibial rotation (ER) as well as tibial translation. Purpose: To evaluate a flat reconstruction of the sMCL and anteromedial structures in restoring knee kinematics in the combined MCL- and anteromedial-deficient knee. Study Design: Controlled laboratory study. Methods: Eight cadaveric knee specimens were tested in a 6 degrees of freedom robotic test setup. Force-controlled clinical laxity tests were performed with 200 N of axial compression in 0°, 30°, 60°, and 90° of flexion: 8 N·m valgus torque, 5 N·m ER torque, 89 N anterior tibial translation (ATT) force, and an anteromedial drawer test consisting of 89 N ATT force under 5 N·m ER torque. After determining the native knee kinematics, we transected the sMCL, followed by the deep medial collateral ligament (dMCL). Subsequently, a flat reconstruction of the sMCL with anteromedial limb, mimicking the function of the anteromedial corner, was performed. Mixed linear models were used for statistical analysis (P < .05). Results: Cutting of the sMCL led to statistically significant increases in laxity regarding valgus rotation, ER, and anteromedial translation in all tested flexion angles (P < .05). ATT was significantly increased in all flexion angles but not at 60° after cutting of the sMCL. A combined instability of the sMCL and dMCL led to further increased knee laxity in all tested kinematics and flexion angles (P < .05). After reconstruction, the knee kinematics were not significantly different from those of the native state. Conclusion: Insufficiency of the sMCL and dMCL led to excess valgus rotation, ER, ATT, and anteromedial tibial translation. A combined flat reconstruction of the sMCL and the anteromedial aspect restored this excess laxity to values not significantly different from those of the native knee. Clinical Relevance: The presented reconstruction might lead to favorable results for patients with MCL and anteromedial injuries with an anteromedial rotatory knee instability.

Arthroscopic lateral collateral ligament imbrication for the treatment of posterolateral rotatory elbow instability

ObjectivesPosterolateral rotatory elbow instability (PLRI) is commonly treated with open lateral collateral ligament (LCL) reconstruction techniques. This cohort study evaluates the efficacy of a less invasive arthroscopic LCL imbrication technique for reducing grade I or II PLRI. MethodsForty-three patients with stage I or II PLRI, unresponsive to conservative therapy, were included. Diagnoses were based on chronic post-traumatic pain (11 patients), chronic atraumatic lateral elbow pain (20), and previous open tennis elbow surgery (12). Following clinical and arthroscopic diagnosis confirmation, the LCL imbrication technique was performed. The Mayo Elbow Performance Score (MEPS) and range of motion (ROM) were assessed preoperatively and postoperatively using the Shapiro-Wilk test and Wilcoxon signed rank test, respectively, with a minimum 12-month follow-up (range 12-48 months). ResultsMEPS increased significantly from a median of 45 points preoperatively to 90 (range 80–100) at three months and 95 (range 80-100) at 12 months follow-up (p < 0.001). Postoperative median flexion reached 140°, and extension was 0°. At 12 months, two patients experienced a 10° extension deficit; 95.3% (41/43) achieved full ROM. Knot irritation occurred in four patients (out of the first ten of this cohort, 9.3%), three of them requiring knot removal. Switching to a PDS 1 suture eliminated this complication. One patient underwent arthroscopic arthrolysis for adhesions after 14 months. ConclusionArthroscopic LCL imbrication offers favorable outcomes for grade I or II PLRI from the third postoperative month, with minimal complications. A slight restriction in ROM and transient knot discomfort were the main issues, the latter resolved by switching to a thinner PDS suture.

Residual Rotatory Instability after ACL Reconstruction Surgery

Residual Rotatory Instability after ACL Reconstruction Surgery

Arthroscopically Assisted Reconstruction of Lateral Metatarsosesamoid Suspensory and Lateral Metatarsophalangeal Collateral Ligaments in the Management of Iatrogenic Hallux Varus Deformity

The medial and lateral metatarsosesamoid suspensory ligaments together with the sesamoid apparatus are the main contributors to the rotational stability of the first metatarsophalangeal joint (MTPJ). Rotational instability of first MTPJ is a major factor in the development of hallux valgus and varus deformities. As the great toe starts to rotate, the muscle pulls across the first MTPJ, causing it to become imbalanced and lead to progressive medial or lateral deviation of the great toe. The gold standard and most reliable option for hallux varus deformity is first MTPJ fusion. However, it results in stiffness and loss of joint function and is reserved for arthritic and stiff first MTPJ. Flexible iatrogenic hallux varus is corrected by optimally anatomic ligament reconstruction. The purpose of this Technical Note is to describe the details of arthroscopically assisted reconstruction of lateral metatarsosesamoid suspensory and lateral metatarsophalangeal collateral ligaments in management of iatrogenic hallux varus deformity. We reconstruct the lateral metatarsosesamoid suspensory ligament to restore the rotational stability of the first MTPJ in hallux varus deformity. This together with reconstruction of the lateral metatarsophalangeal collateral ligament anatomically corrects both the medial deviation and rotation deformity of the great toe.

Mini-LET: A Technique Note.

Lateral extra-articular tenodesis (LET) has shown an upswing in popularity since the role of antero-lateral rotatory instability (ALRI) in ACL tears has become better understood. Its primary aim is to restore antero-lateral rotatory stability and hence reduce stresses placed on the ACL graft in high-risk individuals which should reduce graft failure rates. Many techniques have been described for LET using a variety of fixation methods (screws, anchors, etc.). Most of these techniques rely on a large incision laterally. We describe a novel technique ('mini-LET') which uses a 3-4cm incision, to improve cosmesis.

Anconeus Exertional Compartment Syndrome and Posterolateral Rotatory Elbow Instability: A Clinical Association and Rare Cause of Elbow Pain

Background: Anconeus compartment syndrome is a rarely reported compartment syndrome in the anconeus muscle compartment of the forearm. It has anatomic and pathophysiological associations with posterolateral rotatory instability (PLRI) of the elbow. Purpose: To present the history, management, and outcomes of 4 patients with anconeus compartment syndrome. Secondary aims were to (1) establish normative anconeus pressures and (2) measure the volume of this compartment with and without PLRI in cadavers. Study Design: Case series; Level of evidence, 4. Methods: Four patients with clinical signs of anconeus compartment syndrome (2 gymnasts, 1 swimmer, and 1 footballer/weightlifter) were identified over a 3-year period (2015-2017 inclusive). Patient history, sporting activity, physical examination, anconeus compartment pressures, and treatment outcomes were recorded. Manometry of the anconeus compartment in 2 healthy male controls was performed to establish normative compartment pressures. Anconeus volumetric anatomy and the effect of creating PLRI on compartment volume was investigated in 4 cadaveric elbows. Results: All 4 patients had microtraumatic PLRI, and 2 patients had anconeus hypertrophy. Anconeus compartment pressures at rest and at 2-minutes postexercise were median 28.0 and 67.5 mm Hg, respectively, in the patients and mean 16.5 and 18 mm Hg, respectively, in the controls. Simultaneous fasciotomy and PLRI reconstructive procedures were performed in 2 patients, with outcomes showing full return to competition. Fasciotomy alone was performed in 2 patients to allow return to competition, with both requiring later reconstruction to address PLRI. Cadaver dissection revealed that the anconeus compartment was extremely small and that creation of PLRI reduced the direct volume of the compartment and increased the distance between the anconeus origin and insertion. Conclusion: Our case series demonstrated that anconeus compartment syndrome can occur in upper limb-dominant athletes in the presence of PLRI and anconeus hypertrophy. Pain is relieved by fasciotomy, but definitive treatment of the underlying instability prevents further symptomatology.

The Incidence of Injuries to Ramp Semimembranosus Complex Lesions After ACL Injury: An MRI Study

Background: Medial meniscal ramp lesions have recently been an area of interest because of their recognized prevalence in association with anterior cruciate ligament (ACL) ruptures. Anatomically, the medial meniscal ramp is composed of the meniscocapsular ligament in continuity with the semimembranosus muscle and the meniscotibial ligament. Diagnosis of ramp semimembranosus complex (RSC) injuries remains challenging, and their prevalence is likely to be underestimated in comparison with ramp lesions. Purpose: To determine the prevalence of RSC lesions after a complete ACL rupture. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A retrospective database analysis was performed. The cohort consisted of the first 100 patients with complete ACL rupture confirmed by magnetic resonance imaging (MRI) who underwent knee arthroscopy for ACL reconstruction in 2019. The semimembranosus lesions were identified using MRI by 2 independent radiologists specializing in musculoskeletal imaging. The ramp lesions were initially diagnosed using MRI and then confirmed during arthroscopy by an experienced knee surgeon. The magnitude of rotatory instability was recorded using the pivot-shift test. A multivariate analysis was used to determine the lesions associated with the semimembranosus complex. Results: Of 100 patients, 53 showed lesions of the RSC; among them, 30 ramp lesions were confirmed after arthroscopic evaluation, and 40 semimembranosus lesions (23 without ramp lesion and 17 with ramp lesion) were found using MRI. A positive pivot shift was present in 57% of patients with combined RSC injury ( P = .04) compared with 36% in patients without an RSC lesion. Conclusion: Lesions of the RSC were found in more than half of ACL ruptures in this retrospective cohort. Rotational instability could be associated with combined ACL and RSC injury.

Functional Outcomes and Return to Sport of Combined ACL Reconstruction and Lateral Extra-Articular Tenodesis in High-Pivot Kabbadi Players: A Prospective Cohort Study of 93 Elite Players.

Our understanding of antero-lateral rotatory instability (ALRI) has evolved considerably, with a shift towards a combined procedure of ACL reconstruction and lateral extra-articular procedure (LEAP) to reduce ALRI and decrease graft re-rupture rates. Despite mounting evidence for the same in high-pivot and high-contact athletes in the West, there is a paucity of data for regional sports such as kabbadi. To the authors best knowledge, this is the first such study to track the outcomes of the combined procedure (ACLR and LEAP) in kabbadi players. Ethics approval was obtained from the institutional ethics review committee. A total of 93 consecutive kabbadi players with ALRI were recruited for undergoing the combined procedure of ACLR with lateral extra-articular tenodesis. Demographical variables (age and gender) and functional outcome scores (IKDC, Lysholm, VAS, AOFAS, and FADI) were recorded pre-operatively and followed up at 6week, 3month, 6month and 1 year post-surgery. In addition, complications (pain, stiffness, residual laxity, re-rupture, and infection) and return to sport were recorded. All 93 patients completed the prospective cohort study with no drop-outs. The mean age of the study population was 22.4 ± 2.7years and 84% were males. VAS, IKDC and Lysholm scores showed significant improvement at each time frame during the study period and significant improvement at end of the study period versus baseline. AOFAS and FADI scores showed no significant difference between baseline and end of study period. There was no significant difference with respect to age and gender for knee (IKDC and Lysholm) or ankle (AOFAS and FADI) scores. Return to sport was achieved in 99% of study participants with return to pre-injury level was 86%. Re-rupture rate was low (n = 2 patients) and the majority of complications related to the LET (either a complaint of swelling or shape change phenomenon). The present study shows that ACLR with LET provides a safe and effective option for treating kabbadi players engaged in an inherently high-pivot and high-contact sport. Knee outcomes (VAS, IKDC and Lysholm scores) showed substantial improvement versus baseline with a high degree of return to sport at pre-injury level and low re-rupture rate.

Single-bundle ACL combined with ALL reconstruction yields comparable outcomes in patients with varied anatomical risk factors for ACL graft failure

BackgroundAnterior cruciate ligament (ACL) graft failure is influenced by factors such as meniscal tears and tibial plateau slope. Combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has reduced failure rates; however, its efficacy in high-risk patients remains unclear. This study hypothesized that combined ACL and ALL reconstruction would yield similar clinical outcomes in patients with varying risks of ACL failure.Patients and methodsA total of 76 patients who underwent primary single-bundle ACL reconstruction combined with ALL reconstruction between June 2018 and June 2021 were included. The medial tibial slope (MTS), lateral tibial slope (LTS), and anterior tibial translation (ATT) were measured using magnetic resonance imaging and plain radiography of the knee joint. The meniscal lesions were assessed during surgery. Preoperative clinical assessments and final follow-up were conducted using patient-reported outcome measurements (PROMs), including the International Knee Documentation Committee (IKDC) evaluation, Lysholm knee scoring scale, and Tegner Activity scale. PROMs were collected at least two years postoperatively.ResultsThe average follow-up was 32.5 ± 7.4 months. There were no significant differences in postoperative IKDC score, Lysholm score, or Tegner activity score between patients with or without medial meniscus injury (p = 0.155, 0.914, and 0.042, respectively), with or without lateral meniscus injury (p = 0.737, 0.569, and 0.942, respectively), medial tibial slope > 12° or ≤ 12° (p = 0.290, 0.496, and 0.988, respectively), or lateral tibial slope > 7.4° or ≤ 7.4° (p = 0.213, 0.625, and 0.922, respectively). No significant correlations were found between anterior tibial translation and postoperative IKDC (R = -0.058, p = 0.365), Lysholm (R = -0.017, p = 0.459), or Tegner activity scores (R = -0.147, p = 0.189).ConclusionOur study demonstrates that single-bundle ACL reconstruction combined with ALL reconstruction provides reliable and comparable clinical outcomes in patients with high-risk factors for ACL graft failure, such as increased tibial slope or meniscal injury. Our results suggest that the indications for ALL reconstruction may be expanded to include patients with a high tibial slope or meniscal injury, because these factors have been shown to contribute to increased rotational instability and high rates of ACL graft failure. Future prospective randomized controlled trials with large patient cohorts and long follow-up periods are needed to validate these findings and establish clear guidelines for patient selection and surgical decision-making.Level of evidenceLevel 3.

Medial Ligament Complex Reconstruction With Allograft Using Less Invasive Onlay Fixation and Suture Tape Augmentation

Injury to the medial complex of the knee may result in persisting valgus and rotatory instability. In combination with concomitant meniscotibial ligament disruption, maldistributed contact forces are placed on the medial compartment, which may result in the progression of osteoarthritis. When facing chronic valgus and/or posteromedial instability, definitive treatment with medial ligament complex reconstruction in combination with additional repair of the meniscotibial ligament when necessary should be done to anatomically restore proper knee biomechanics and kinematics. This technique describes reconstruction of both the superficial medial collateral ligament (sMCL) and posterior oblique ligament with a single allograft, with additional suture tape augmentation used to reinforce the sMCL. Additionally, less invasive onlay fixation is used via a knotless loop mechanism to secure the posterior oblique ligament to its tibial insertion and the sMCL at 2 points along its distal tibial insertion.

Anatomic double-bundle transtibial anterior cruciate ligament reconstruction restores graft length changes but leads to larger graft bending angles.

The purpose of this study was to evaluate the femoral tunnel position using a modified anatomic transtibial (TT) double-bundle anterior cruciate ligament reconstruction (DBACLR) and to investigate the knee kinematics, graft length and graft bending angle following DBACLR. Ten patients who underwent DBACLR using the modified TT technique were included in the study. All patients performed a single-legged lunge under a dual fluoroscopic imaging system to assess the 6 degrees of freedom tibiofemoral kinematics. Femoral tunnel position was evaluated via postoperative three-dimensional (3D) computed tomography. The area centroids of anteromedial (AM) and posterolateral (PL) bundles were determined on 3D knee models. The lengths of AM and PL bundles, as well as graft bending angle at the femoral tunnel aperture, were measured by created virtual fibres. The reconstructed knee rotated more externally compared with the contralateral knee between 0° and 60° (p ≤ 0.049). There is no significant difference in the length change of AM bundle (n.s.) and PL bundle (n.s.) between the two sides from 0° to 120° during the lunge motion. The maximum graft bending angle at the femoral tunnel aperture occurred at 0° of knee flexion, with the AM graft bending angle was 72.6° ± 9.0° and the PL graft bending angle was 90.3° ± 9.7°. The modified TT technique used in this study could achieve anatomical ACL reconstruction, restoring graft length change patterns compared to contralateral knees. However, residual rotational instability of the reconstructed knee was observed after DBACLR, despite achieving anatomic tunnel placement. Therefore, double-bundle reconstruction may not sufficiently address the persistent rotational instability of the knee. Additionally, larger graft bending angles at the femoral tunnel aperture were found with the modified TT technique. Therefore, further improvement to the TT technique should focus on reducing the graft's curvature while maintaining the anatomical properties of the knee joint. The findings of this study highlight the need for improved surgical techniques to address residual rotational instability and optimise graft curvature. These improvements are crucial for enhancing patient outcomes and long-term joint function following ACL reconstruction. Level II.

Highly extensile approach for comminuted ulna coronoid process fractures with mini-plate fixation: a case series of 31 patients

BackgroundFor the treatment of coronoid process fractures, medial, lateral, anterior, anteromedial, and posterior approaches have been increasingly reported; however, there is no general consensus on the method of fixation of coronal fractures. Here, we present a highly-extensile minimally invasive approach to treat coronoid process fractures using a mini-plate that can achieve anatomic reduction, stable fixation, and anterior capsular repair. Further, the study aimed to determine the complication rate of the anterior minimally invasive approach and to evaluate functional and clinical patient-reported outcomes during follow-up.MethodsThirty-one patients diagnosed with coronoid fractures accompanied with a “terrible triad” or posteromedial rotational instability between April 2012 and October 2018 were included in the analysis. Anatomical reduction and mini-plate fixation of coronoid fractures were performed using an anterior minimally invasive approach. Patient-reported outcomes were evaluated using the Mayo Elbow Performance Index (MEPI) score, range of motion (ROM), and the visual analog score (VAS). The time of fracture healing and complications were recorded.ResultsThe mean follow-up time was 26.7 months (range, 14–60 months). The average time to radiological union was 3.6 ± 1.3 months. During the follow-up period, the average elbow extension was 6.8 ± 2.9° while the average flexion was 129.6 ± 4.6°. According to Morrey’s criteria, 26 (81%) elbows achieved a normal desired ROM. At the last follow-up, the mean MEPI score was 98 ± 3.3 points. There were no instances of elbow instability, elbow joint stiffness, subluxation or dislocation, infection, blood vessel complications, or nerve palsy. Overall, 10 elbows (31%) experienced heterotopic ossification.ConclusionAn anterior minimally invasive approach allows satisfactory fixation of coronoid fractures while reducing incision complications due to over-dissection of soft tissue injuries. In addition, this incision does not compromise the soft tissue stability of the elbow joint and allows the patient a more rapid return to rehabilitation exercises.

MRI in Postero-Lateral Corner Injuries of the Knee Joint: Clinical-Radiological Correlation

Abstract Background The posterolateral corner (PLC) was once regarded as the “dark side of the knee” owing to the complex and variable anatomy superimposed on the inconsistent terminology used in the literature to describe the structures in this region. Aim of the Work To describe the role of MRI in assessment of posteriolateral corner injury of knee joint. Patients and Methods This cross sectional study was conducted in department of Radiology in Ain Shams University, the data collected from database to reach sample size number and enrolled data of 20 patients in period was 18-24 months. Results We were able to show that the MRI procedure we gave accurately visualises the majority of the complex individual components of the posterolateral knee, as well as damage to these structures, in this investigation. When the diagnosis of grade III injuries to the posterolateral knee is in doubt, we believe that MRI of the posterolateral knee is a useful complement to the surgeon. In our capacity to correctly diagnose damaged structures on MRI, there were no clear differences between acute and chronic knee injuries. On MRI, avulsions or tears of the direct arm or anterior arm insertion off the fibular styloid show focal discontinuity, nonvisualization, increased signal intensity, or proximal retraction, often with a contemporaneous bone avulsion. The damage pattern can also be seen in axial and sagittal views. Conclusion When posterolateral rotatory instability is suspected, the MRI approaches that described for visualizing particular injuries to the posterolateral knee will almost always reveal the bulk of the affected structures. When a posterolateral knee injury is assessed on MRI, using a special MRI protocol that covers the full fibular head and styloid on all imaging sequences will help in identifying these structures.