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Purpose To define the bony attachments of the medial ligaments relative to anatomical and radiographic bony landmarks, providing information for medial collateral ligament (MCL) surgery. Method The femoral and tibial attachments of the superficial MCL (sMCL), deep MCL (dMCL) and posterior oblique ligament (POL), plus the medial epicondyle (ME) were defined by radiopaque staples in 22 knees. These were measured radiographically and optically; the precision was calculated and data normalised to the sizes of the condyles. Femoral locations were referenced to the ME and to Blumensaat’s line and the posterior cortex. Results The femoral sMCL attachment enveloped the ME, centred 1 mm proximal to it, at 37 ± 2 mm (normalised at 53 ± 2%) posterior to the most-anterior condyle border. The femoral dMCL attachment was 6 mm (8%) distal and 5 mm (7%) posterior to the ME. The femoral POL attachment was 4 mm (5%) proximal and 11 mm (15%) posterior to the ME. The tibial sMCL attachment spread from 42 to 71 mm (81–137% of A-P plateau width) below the tibial plateau. The dMCL fanned out anterodistally to a wide tibial attachment 8 mm below the plateau and between 17 and 39 mm (33–76%) A-P. The POL attached 5 mm below the plateau, posterior to the dMCL. The 95% CI intra-observer was ± 0.6 mm, inter-observer ± 1.3 mm for digitisation. The inter-observer ICC for radiographs was 0.922. Conclusion The bone attachments of the medial knee ligaments are located in relation to knee dimensions and osseous landmarks. These data facilitate repairs and reconstructions that can restore physiological laxity and stability patterns across the arc of knee flexion.

Purpose Simple elbow dislocations are accompanied with lateral ulnar collateral ligament ruptures. For persisting instability, surgery is indicated to prevent chronic posterolateral rotatory instability. After lateral collateral ligament (LCL) complex repair the repair is protected by temporary immobilization, limited range of motion and hinged bracing. Internal bracing is an operative alternative augmenting the LCL repair using non-absorbable suture tapes. However, the stability of LCL repair with and without additional augmentation remains unclear. The hypothesis was that LCL repair with additional suture tape augmentation would improve load to failure. Secondary goal of this study was to evaluate different humeral fixation techniques. A humeral fixation using separate anchors for the LCL repair and the augmentation was not expected to provide superior stability compared to using only one single anchor. Methods Twenty-one elbows were tested. A cyclic varus rotational torque of 0.5–3.5 Nm was applied in 90°, 60°, 30°, and 120° elbow flexion to the intact, torn, and repaired LCLs. The specimens were randomized into three groups: repair alone (group I), repair with additional internal bracing using two anchors (group II), repair using one humeral anchor (group III). A load-to-failure protocol was conducted. Results Load to failure was significantly higher in groups II (26.6 Nm; P  = 0.017) and III (23.18 Nm; P  = 0.038) than in group I (12.13 Nm). No significant difference was observed between group II and III. All specimens lost reduction after LCL dissection by a mean of 4.48° ± 4.99° (range 0.66–15.82). The mean reduction gain after repair was 7.21° ± 4.97° (2.70–21.23; mean over reduction, 2.73°). The laxity was comparable between the intact and repaired LCLs ( n.s .), except for varus movements at 30° in group II ( P  = 0.035) and 30° ( P  = 0.001) and 120° in group III ( P  = 0.008) with significantly less laxity. Inserting the ulnar suture anchor showed failure in the thread in 10 cases. Conclusion LCL repair with additional internal bracing yielded higher load to failure than repair alone. Repair with additional internal bracing for the humeral side using one anchor was sufficient. A higher primary stability would facilitate postoperative management and allow immediate functional treatment. Reducing the number of humeral anchors would save costs.

Changes in collateral blood flow, which sustains brain viability distal to arterial occlusion, may impact infarct evolution but have not previously been demonstrated in humans. We correlated leptomeningeal collateral flow, assessed using novel perfusion magnetic resonance imaging (MRI) processing at baseline and 3 to 5 days, with simultaneous assessment of perfusion parameters. Perfusion raw data were averaged across three consecutive slices to increase leptomeningeal collateral vessel continuity after subtraction of baseline signal analogous to digital subtraction angiography. Changes in collateral quality, Tmax hypoperfusion severity, and infarct growth were assessed between baseline and days 3 to 5 perfusion-diffusion MRI. Acute MRI was analysed for 88 patients imaged 3 to 6 hours after ischemic stroke onset. Better collateral flow at baseline was associated with larger perfusion-diffusion mismatch (Spearman's Rho 0.51, P < 0.001) and smaller baseline diffusion lesion volume (Rho − 0.70, P < 0.001). In 30 patients without reperfusion at day 3 to 5, deterioration in collateral quality between baseline and subacute imaging was strongly associated with absolute (P = 0.02) and relative (P < 0.001) infarct growth. The deterioration in collateral grade correlated with increased mean Tmax hypoperfusion severity (Rho − 0.68, P < 0.001). Deterioration in Tmax hypoperfusion severity was also significantly associated with absolute (P = 0.003) and relative (P = 0.002) infarct growth. Collateral flow is dynamic and failure is associated with infarct growth.

Background. Upper partial fibulectomy has been preliminarily proved to have the efficacy for pain alleviation and improvement of function in patients with mild to moderate medial compartment knee osteoarthritis (KOA). However, the previous studies lack the control group with other treatments. The aim of this prospective, randomized controlled study is to compare the clinical and biomechanical effects between upper partial fibulectomy and drug conservative treatment on improvement of clinical pain, function, and gait for patients with mild to moderate medial knee osteoarthritis (KOA) and further discuss its biomechanical mechanism. Methods. From August 2016 to February 2017, 49 and 48 patients with mild to moderate medial KOA were allocated to fibulectomy and drug groups. We assessed the patients’ visual analog scale (VAS) pain score, Hospital for Special Surgery (HSS) knee score, limb alignment, passive flexion/extension range of motion (ROM) of the knee, and 3D gait kinematics and kinetics parameters before and after intervention. Repeated-measures ANOVA with Dunnett’s post hoc assessment and multivariate analysis of variance were applied for intragroup and intergroup comparisons, respectively. Results. The improvement in the fibulectomy group on the VAS pain score, HSS knee score, walking speed, and walking knee range of motion (ROM) was statistically better than that in the drug group. The decreased overall peak knee adduction moment (KAM) (decreased by 16.1%) and hip-knee-ankle (HKA) angle (decreased by 0.99° from a more varus alignment to a more neutral alignment) of the affected and operated side 1 year after surgery were observed in the fibulectomy group. Conclusion. This research demonstrated that as a biomechanical intervention, upper partial fibulectomy can be a better choice in pain relief and function and gait improvement than drug conservative treatment for patients with early-stage knee OA. The long-term clinical outcomes, indication, and rationale for the improvement in clinical symptoms should be investigated further.

Purpose In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically ‘isolated’ ACL ruptures. Methods Patients who underwent ACL reconstruction for complete ‘presumed isolated’ ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient’s characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. Results Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus ‘ramp’ lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site ( p  < 0.01). Logistic regression analysis identified younger age (OR 1.2, p  < 0.05), simultaneous sMCL injury (OR 6.75, p  < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p  < 0.01) as predictive factors for a dMCL injury. Conclusion The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. Level of evidence III.

Purpose To define the length-change patterns of the superficial medial collateral ligament (sMCL), deep MCL (dMCL), and posterior oblique ligament (POL) across knee flexion and with applied anterior and rotational loads, and to relate these findings to their functions in knee stability and to surgical repair or reconstruction. Methods Ten cadaveric knees were mounted in a kinematics rig with loaded quadriceps, ITB, and hamstrings. Length changes of the anterior and posterior fibres of the sMCL, dMCL, and POL were recorded from 0° to 100° flexion by use of a linear displacement transducer and normalised to lengths at 0° flexion. Measurements were repeated with no external load, 90 N anterior draw force, and 5 Nm internal and 5 Nm external rotation torque applied. Results The anterior sMCL lengthened with flexion ( p  < 0.01) and further lengthened by external rotation ( p  < 0.001). The posterior sMCL slackened with flexion ( p  < 0.001), but was lengthened by internal rotation ( p  < 0.05). External rotation lengthened the anterior dMCL fibres by 10% throughout flexion ( p  < 0.001). sMCL release allowed the dMCL to become taut with valgus rotation ( p  < 0.001). The anterior and posterior POL fibres slackened with flexion ( p  < 0.001), but were elongated by internal rotation ( p  < 0.001). Conclusion The structures of the medial ligament complex react differently to knee flexion and applied loads. Structures attaching posterior to the medial epicondyle are taut in extension, whereas the anterior sMCL, attaching anterior to the epicondyle, is tensioned during flexion. The anterior dMCL is elongated by external rotation. These data offer the basis for MCL repair and reconstruction techniques regarding graft positioning and tensioning.

Cardiovascular disease remains the leading global cause of death, and the number of patients with coronary artery disease (CAD) and exhausted therapeutic options (i.e., percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical treatment) is on the rise. Therefore, the evaluation of new therapeutic approaches to offer an alternative treatment strategy for these patients is necessary. A promising research field is the promotion of the coronary collateral circulation, an arterio-arterial network able to prevent or reduce myocardial ischemia in CAD. This review summarizes the basic principles of the human coronary collateral circulation, its extracardiac anastomoses as well as the different therapeutic approaches, especially that of stimulating the extracardiac collateral circulation via permanent occlusion of the internal mammary arteries.

We show that collateral plays an important role in the design of debt contracts, the provision of credit, and the incentives of lenders to monitor borrowers. Using a unique data set from a large bank containing timely assessments of collateral values, we find that the bank responded to a legal reform that exogenously reduced collateral values by increasing interest rates, tightening credit limits, and reducing the intensity of its monitoring of borrowers and collateral, spurring borrower delinquency on outstanding claims. We thus explain why banks are senior lenders and quantify the value of claimant priority.

Purpose The purpose of the present study was to determine how the medial structures and ACL contribute to restraining anteromedial instability of the knee. Methods Twenty-eight paired, fresh-frozen human cadaveric knees were tested in a six-degree of freedom robotic setup. After sequentially cutting the dMCL, sMCL, POL and ACL in four different cutting orders, the following simulated clinical laxity tests were applied at 0°, 30°, 60° and 90° of knee flexion: 4 Nm external tibial rotation (ER), 4 Nm internal tibial rotation (IR), 8 Nm valgus rotation (VR) and anteromedial rotation (AMR)—combined 89 N anterior tibial translation and 4 Nm ER. Knee kinematics were recorded in the intact state and after each cut using an optical tracking system. Differences in medial compartment translation (AMT) and tibial rotation (AMR, ER, IR, VR) from the intact state were then analyzed. Results The sMCL was the most important restraint to AMR, ER and VR at all flexion angles. Release of the proximal tibial attachment of the sMCL caused no significant increase in laxity if the distal sMCL attachment remained intact. The dMCL was a minor restraint to AMT and ER. The POL controlled IR and was a minor restraint to AMT and ER near extension. The ACL contributed with the sMCL in restraining AMT and was a secondary restraint to ER and VR in the MCL deficient knee. Conclusion The sMCL appears to be the most important restraint to anteromedial instability; the dMCL and POL play more minor roles. Based on the present data a new classification of anteromedial instability is proposed, which may support clinical examination and treatment decision. In higher grades of anteromedial instability an injury to the sMCL should be suspected and addressed if treated surgically.

Background and purposeCollateral blood flow to the affected cerebral territory in acute ischemic stroke may modify the effect of intravenous alteplase treatment (IVT) prior to endovascular treatment (EVT). We assessed whether an interaction effect between arterial collateral status, assessed by both a visual and quantitative collateral score (CS), and administration of IVT plus EVT was present in the MR CLEAN-NO IV trial.MethodsBaseline CT or MR angiography (CTA and MRA) from patients included in MR CLEAN-NO IV was assessed using both a visual and automated quantitative score for arterial collateral status. We included 526 patients with visual CS and 401 with quantitative CS in this prespecified analysis. The primary outcome was functional outcome measured as the modified Rankin Scale score at 90 days. Interaction terms of treatment allocation (IVT plus EVT vs EVT alone) and collateral scores were included in regression models to assess whether the treatment effect of IVT differed by arterial collateral status.ResultsIVT plus EVT was not statistically significantly associated with better functional outcome compared with EVT alone (adjusted common odds ratio 1.14; 95% CI 0.84 to 1.55). There was no statistically significant modification of IVT treatment effect on functional outcome by either visual or quantitative CS (adjusted p-interaction=0.34; adjusted p-interaction=0.57, respectively).ConclusionIn the MR CLEAN-NO IV trial, we did not find evidence that arterial collateral status measured with a visual score or quantitative score can inform treatment decisions regarding IVT plus EVT for patients with acute ischemic stroke due to large vessel occlusion in the anterior circulation within 4.5 hours.