Rotational Instability Research Articles

Transtibial Lateral Meniscal Root Repair Technique to Appose Remnant Root With Torn Body: The Double Compression Knot

Anterior cruciate ligament reconstructions are often performed with associated procedures, most commonly for associated meniscal tears. The lateral meniscal root tear is a commonly associated injury, which increases rotational instability and results in altered tibiofemoral biomechanics. Lateral meniscectomy results in poorer functional and long-term outcomes, making repair vital. The position of the lateral root tear makes its repair technique complicated. Because of the proximity to vessels posteriorly, the all-inside technique is considered potentially unsafe, and current transtibial repair techniques fail to appose the body with the root remnant. In the lineage of Laprade, who proclaimed the use of a transtibial suture for radial tears elsewhere in the knee in order to reduce the shear force, we describe a transtibial technique that optimizes meniscal apposition, theoretically improving the repair biomechanics and is technically easier to perform in comparison to suture hook techniques with one tunnel and one suture.

Influence of the magnetic field and the mean flow configuration on spatial structure and growth rate of normal modes

The first part of the work presents the results of numerical experiments with the magnetohydrodynamic model of “shallow water” to assess the degree of influence of the magnetic field on the development of instabilities conditioned by a combination of inhomogeneities in the mean flow and the mean magnetic field. Normal mode calculations have confirmed the earlier obtained result on the different influence of weak and strong magnetic fields on the instability of differential rotation. Calculations have shown that a weak magnetic field stabilizes the development of instabilities, whereas a strong magnetic field, on the contrary, enhances the instability. Azimuthal inhomogeneities of differential rotation in all cases contribute to the development of instabilities. In the second part of the work, we examine the spatial structure of normal modes and make an attempt to interpret the torsional oscillations observed in the atmospheres of Earth and the Sun. Calculations have shown that regular axisymmetric disturbances can be caused by the formation of a cyclonic vortex above the pole, which is characteristic of Earth's atmosphere and, possibly, of the Sun's atmosphere. The least damped normal mode of a stable polar cyclone has a structure of torsional oscillations. Flow anomalies and the development of an anticyclonic eddy in winter at midlatitudes destroy torsional oscillations and lead to a rapid amplification of normal modes, which are more complex in structure.

Влияние магнитного поля и конфигурации среднего течения на пространственную структуру и скорость роста нормальных мод

The first part of the work presents the results of numerical experiments with the magnetohydrodynamic model of “shallow water” to assess the degree of influence of the magnetic field on the development of instabilities conditioned by a combination of inhomogeneities in the mean flow and the mean magnetic field. Numerical simulation of normal modes has confirmed the earlier obtained result on the different influence of weak and strong magnetic fields on the instability of differential rotation. Calculations have shown that a weak magnetic field stabilizes the development of instabilities, whereas a strong magnetic field, on the contrary, enhances the instability. Azimuthal inhomogeneities of differential rotation in all cases contribute to the development of instabilities. In the second part of the work, we examine the spatial structure of normal modes and make an attempt to interpret the torsional oscillations observed in the atmospheres of Earth and the Sun. Calculations have shown that regular axisymmetric disturbances (torsional oscillations) can be caused by the formation of a cyclonic vortex above the pole, which is characteristic of Earth’s atmosphere and, possibly, of the Sun’s atmosphere. The least damped normal mode of a stable polar cyclone has a structure of torsional oscillations. Flow anomalies and the development of an anticyclonic eddy in winter at midlatitudes destroy torsional oscillations and lead to a rapid amplification of normal modes, which are more complex in structure.

Surgical Treatment of Posterolateral Rotational Instability of the Elbow: a Systematic Review

Posterolateral rotational instability (PLRI) of the elbow joint can occur acutely as a result of dislocation of the bones of the forearm, and also be chronic, for example, after inadequate healing of a previous rupture of the lateral ligamentous complex, in particular the lateral ulnar collateral ligament (LUCL). It is necessary to take into account that, as a result of repeated microtraumas, persistent pain syndrome and recurrence of dislocation develop, which can lead to disability. We conducted a systematic review of the literature according to the protocol outlined in the PRISMA guidelines. From 1,903 publications, 11 studies were selected that met our criteria and assessed the results of treatment of 181 patients. The main reason for the development of PLRI was simple traumatic dislocation of the forearm bones (37.5%). Of the studies that assessed the elbow joint using the MEPS, 86.5% of patients had excellent or good results, with a mean MEBS score of 91 points. Before surgery, pain syndrome was present in 131 patients (87.3%) out of 150, and in the postoperative period it was observed in 55 (36.6%) out of 150 (p=0.01). The incidence of recurrent instability after surgery was observed in 6.6% of patients. A review of the literature on the problem of the elbow joint shows that this problem has not been fully studied, treatment strategies differ and should be performed based on the surgeon’s experience and available data, however, it has been proven that the key to the stability of the elbow joint is the LUCL, which requires its restoration through its refixation or plastic surgery.

Is antero-lateral complex of knee joint of critical importance in restoring rotational instability in patients with anterior cruciate ligament tear?

Antero-lateral ligament complex (ALC) is a vital structure for maintaining rotational stability of the knee. Evaluation of ALC radiologically (MRI) is still unpopular in setting of anterior cruciate ligament injury. A dire necessity exists for the orthopedic surgeons in outdoor patient department settings to rule out involvement of ALC. So, that it can be addressed during operating for Anterior Cruciate Ligament injury. The authors have formulated an algorithm on a personal level and have implemented this screening program and initiated screening of young to middle aged patients reporting with rotational knee instability for ALC involvement before recommending final operative plan. This screening program which uses specifically devised physical tests have significantly reduced the number of underdiagnosed Antero Lateral Ligament tear.

Tibial-Sling Triangular Medial Collateral Ligament Reconstruction With Posterior Oblique Ligament Limb

Background: While most medial-sided knee injuries can be managed conservatively, high-grade injuries of the posteromedial corner have been reported to have less than optimal outcomes with conservative approaches, resulting in residual valgus and rotational instability. Consensus among experts postulates that treatment should be based on reconstructing both the superficial medial collateral ligament (sMCL) and the posterior oblique ligament (POL). We present a modified technique of a tibial-sling anatomic MCL reconstruction with a POL limb. Indications: High-grade injuries of the posteromedial corner, specifically injuries with medial joint gapping in extension or grade 3 medial-sided tears. Technique Description: The MCL is reconstructed with a semitendinosus autograft in a tibial sling, created by converging perpendicular bone tunnels at its anatomic tibial insertion, and fixed to a femoral tunnel in the isometric point just posterior and proximal to the medial epicondyle with the knee at 30° of flexion. That same single femoral tunnel will be shared by the two strands of the semitendinosus graft and a limb of gracilis autograft to reproduce the POL, passed through a tibial tunnel in the posteromedial margin of medial tibial condyle, and fixed in extension. Discussion/Conclusion: As recent evidence suggests that medial reconstruction should be preferred over repair, due to favorable complication and failure rates, we describe a technique that is both anatomic-based, reproducing the 2 main medial knee structures (sMCL, POL), and also cost-saving, with decreased need of fixation devices. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Outcomes and complications after treatment for anteromedial facet fracture of the coronoid process: A systematic review

BackgroundFracture of the anteromedial facet (AMF) of the coronoid process is associated with varus posteromedial rotatory instability (VPMRI). However, there is still controversy regarding the optimal treatment for AMF fracture. The purpose of this study is to report on a systematic review of the outcomes and complications after treatment for AMF fracture. MethodsThis study was conducted using electronic databases, PubMed, EMBASE and Scopus. Studies reporting outcome scores and complications were included. Studies that did not utilize O'Driscoll classification for AMF fractures were excluded. Through conduct of a thorough review of included studies, definite VPMRI were identified and cases involving other injury mechanisms were excluded. ResultsFifteen articles reporting on 246 patients were included. According to O'Driscoll classification, 6.2% of cases were anteromedial subtype I, 73.7% were subtype II, and 20.1% were subtype III. Two-hundred sixteen patients (87.8%) were treated surgically and 30 patients (12.2%) were treated conservatively. Lateral collateral ligament (LCL) injuries were 76.2% (157/206) and medial collateral ligament injuries were 16.9% (33/195). Among 216 cases who underwent surgical treatment, depending on the fragment size, displacement, and instability, coronoid fixation was performed in 189 cases and LCL repair alone was performed in 27 cases. The mean final Mayo Elbow Performance Score was 92.1 and the Broberg & Morrey score was 89.5. The overall complication and reoperation rates were 17.7% (41/232) and 12.9% (26/202). ConclusionsBoth surgical and conservative treatment for AMF fractures resulted in satisfactory final clinical outcomes. However, high complication and reoperation rates were observed.

Predicting the need for collateral ligament repair in transolecranon fractures of the elbow: a traffic light model.

Biomechanical studies have shown that translation of the proximal radius relative to the capitellum in the sagittal plane can predict integrity of the collateral ligaments in a transolecranon fracture model; no studies have examined this in clinical practice. Nineteen consecutive transolecranon fracture dislocations were retrospectively reviewed. Data collection included patient demographics, fracture classifications, surgical management, and failure with instability. Distance between the center of the radial head and the center of the capitellum was measured on initial radiographs by 2 independent raters on 3 separate occasions. Statistical analysis was used to compare the median displacement between patients who required collateral ligament repair for stability and those who did not. Sixteen cases with a mean age of 57 years (range 32-85) were analyzed with an inter-rater Pearson coefficient of 0.89 for displacement measurement. Median displacement where collateral ligament repair was needed and performed was 17.13 mm (interquartile range [IQR]=10.43-23.88) compared with 4.63 mm (IQR=2.68-6.58) where collateral ligament repair was not performed and not required (P=.002). In 4 cases, ligament repair was not performed initially but deemed necessary based on clinical outcome and postoperative and intraoperative images. Of these, the median displacement was 15.59 mm (IQR=10.09-21.20), and 2 of these required revision fixation. Where displacement on initial radiographs exceeded 10 mm, lateral ulnar collateral ligament (LUCL) repair was required in all cases (red group). If less than 5 mm, ligament repair was not required in any case (green group). Between 5 and 10 mm, following fracture fixation, the elbow must be screened carefully to assess for any instability and a low threshold set for LUCL repair to prevent posterolateral rotatory instability (amber group). Using these findings, we propose a traffic light model to predict the need for collateral ligament repair in transolecranon fractures and dislocation.

Mechanical evaluation of revision surgery for femoral shaft nonunion initially treated with intramedullary nailing: Exchange nailing versus augmentation plating

IntroductionExchange nailing (EN) or augmentation plating (AP) has been employed to treat nonunions after intramedullary nailing for femoral shaft fractures. Although instability is a factor in hypertrophic nonunion, mechanical evaluations have been limited because the contribution of the callus to fracture site stability varies with healing. Our previous study illustrated the potential for evaluation using a finite element analysis (FEA) that incorporates callus material properties. This study aimed to mechanically evaluate revision surgery for nonunions using FEA. Materials and methodsA quantitative computed tomography-based FEA was performed on virtual revision models of a patient with suspected nonunion after intramedullary nailing. In addition to the initial nailing model (IN) with an 11-mm diameter (D) and 360-mm length (L), four EN models with D12mm (EN1), D13mm (EN2), D12mm-L400mm (EN3), and D13mm-L400mm (EN4) nails and three AP models with 5- (AP1), 6- (AP2), and 7-hole (AP3) plates were created. As with bone, callus was assigned inhomogeneous material properties derived from density based on an empirical formula. The hip joint reaction force and muscle forces at maximum load during the gait cycle were applied. The volume ratio of the callus at the fracture site with a tensile failure risk of ≥1 (tensile failure ratio) and bone fragment movement were evaluated. ResultsThe tensile failure ratio was 11.6 % (IN), 10.1 % (EN1), 6.3 % (EN2), 10.9 % (EN3), 6.2 % (EN4), 6.4 % (AP1), 7.2 % (AP2), and 7.7 % (AP3), respectively. The bone fragment movement showed an opening on the lateral side with the initial intramedullary nailing. However, both revision surgeries reduced the opening, leading to compression except in the EN1 model. The proximal bone fragments were internally rotated relative to the distal fragments, and the rotational instability was more suppressed in models with lower tensile failure ratio. ConclusionsFor EN, the increase in diameter, not length, is important to suppress instability. AP reduces instability, comparable to a 2 mm increase in nail diameter, and screw fixation closer to the fracture site reduces instability. This study suggest that AP is mechanically equivalent to EN and could be an option for revision surgery for femoral shaft nonunions.

How to avoid knee tunnel convergence when performing a combined anterior cruciate ligament reconstruction and lateral extraarticular tenodesis utilizing the antero medial window

The anterolateral structures of the knee have been demonstrated to have a significant impact on reducing rotational instability and the forces applied to the anterior cruciate ligament reconstruction (ACL) graft after surgical reconstruction. Combined ACL reconstruction and lateral extraarticular tenodesis are being performed at an increasing number due to its promising outcome in properly indicated patients. However, tunnel convergence in combined ACLR and lateral extraarticular tenodesis can lead to graft damage and possible failure defeating the purpose of this very effective technique. This technical note describes how to avoid knee tunnel convergence when performing a combined ACL reconstruction with lateral extraarticular tenodesis utilizing the “Antero medial window”.

Evolution of MHD torus and mass outflow around spinning AGNs

ABSTRACT We perform axisymmetric, 2D magnetohydrodynamic simulations to investigate accretion flows around spinning active galactic nuclei. To mimic the space–time geometry of spinning black holes, we consider effective Kerr potential, and the mass of the black holes is 108 M⊙. We initialize the accretion disc with a magnetized torus by adopting the toroidal component of the magnetic vector potential. The initial magnetic field strength is set by using the plasma beta parameter (β0). We observe self-consistent turbulence generated by magneto rotational instability (MRI) in the disc. The MRI turbulence transports angular momentum in the disc, resulting in an angular momentum distribution that approaches a Keplerian distribution. We investigate the effect of the magnetic field on the dynamics of the torus and associated mass outflow from the disc around a maximally spinning black hole (ak = 0.99). For the purpose of our analysis, we investigate the magnetic state of our simulation model. The model β0 = 10 indicates the behaviour similar to the ‘magnetically arrested disc’ state, and all the other low magnetic model remains in the SANE state. We observe that mass outflow rates are significantly enhanced with the increased magnetic field in the disc. We find a positive correlation between the magnetic field and mass outflow rates. We also investigate the effect of black hole spin on the magnetized torus evolution. However, we have not found any significant effect of black hole spin on mass outflows in our model. Finally, we discuss the possible astrophysical applications of our simulation results.

A Disturbed Voussoir Beam Structure Mechanical Model and Its Application in Feasibility Determination of Upward Mining

China is endowed with a large quantity of residual coal resources that require upward mining. The stability of interburden strata structures and accurate determination are crucial for safe mining. Therefore, we established a mechanical model of disturbed voussoir beam structures of interburden strata in upward mining. The model was solved, and stability analysis and instability mechanism analysis were conducted. Based on this model, a new method for determining the feasibility of upward mining was proposed and applied to the upward mining of coal seam No. 7 in Baijiazhuang Coal Mine. A physical simulation experiment and numerical simulation were conducted to validate the method. Through research, it was found that the model had two instability mechanisms: rotation instability and sliding instability. When the disturbance load crossed the critical block of the structures, the model was most likely to experience sliding instability. When the disturbance load acted entirely on the critical block, rotation instability was more likely to occur. The result of the determination, performed using the new method, showed that there was no rotation instability or sliding instability in the interburden strata structures of coal seam No. 7, indicating that the coal seam could be mined upward. This result was consistent with the determinations using the statistical method, “three-zone” method, and balanced surrounding rock method. Physical and numerical simulations revealed that the upward mining of coal seam No. 7 caused the subsidence, rotation, and separation compaction of the interburden strata structures but that the structures remained stable. The results indicate that the proposed model and method have accuracy and applicability, being able to guide the practical feasibility determination of upward mining.

Injuries of the medial side of the knee : When and how should they be treated?

Different medial structures are responsible for restraining valgus rotation, external rotation, and anteromedial rotation. When injured this can result in various degrees of isolated and combined instabilities. In contrast to earlier speculation, the posterior oblique ligament (POL) is no longer considered to be the main stabilizer of anteromedial rotatory instability (AMRI). Acute proximal medial ruptures are typically managed conservatively with very good clinical results. Conversely, acute distal ruptures usually require a surgical intervention. Chronic instabilities mostly occur in combination with instabilities of the anterior cruciate ligament (ACL). The clinical examination is a particularly important component in these cases to determine the indications for surgery for an additional medial reconstruction. In cases of severe medial and anteromedial instabilities, surgical treatment should be considered. Biomechanically, a combined medial and anteromedial reconstruction appears to be superior to other reconstruction methods; however, there is currently alack of clinical studies to confirm this biomechanical advantage.

Physical Properties of the Young Asteroid Pair 2010 UM26 and 2010 RN221

The main belt asteroids 458271 (2010 UM26) and 2010 RN221 share almost identical orbital elements, and currently appear as comoving objects ∼30″ apart in the plane of the sky. They are products of the breakup of a parent object, or the splitting of a binary, with a separation age measured in decades rather than thousands or millions of years as for most other asteroid pairs. The nature of the precursor body and the details of the breakup and separation of the components are unknown. We obtained deep, high-resolution imaging using the Hubble Space Telescope to characterize the pair and to search for material in addition to the main components that might have been released upon breakup. The primary and secondary have absolute magnitudes H = 17.98 and 19.69, respectively, and effective diameters 760 and 350 m (assuming geometric albedo 0.20). The secondary/primary mass ratio is 0.1, assuming equal densities. Time-series photometry shows that the primary rotates with period ∼5.9 hr and has a small photometric range (0.15 mag), while the period of the secondary is undetermined (but ≳20 hr) and its lightcurve range is at least 1 mag. The primary rotation period and component mass ratio are consistent with a simple model for the breakup of a rotationally unstable precursor. However, unlike other observationally supported instances of asteroid breakup, neither macroscopic fragments nor unresolved material are found remaining in the vicinity of this asteroid pair. We suggest that the pair is a recently dissociated binary, itself formed earlier by rotational instability of 2010 UM26.

Introducing Skeletally-Mature Anterior Cruciate Ligament Reconstruction Technique Using Reinforcement (SATURN) With Iliotibial Band Autograft

Anterior cruciate ligament (ACL) injuries are increasingly common in the adolescent age group. Recent literature has endorsed combining ACL reconstruction with lateral extra-articular procedures to minimize residual rotatory knee instability and reduce the risk of reinjury in this age group. This technique describes a single-bundle combined anatomical ACL reconstruction and lateral extra-articular reinforcement performed with a single iliotibial band autograft. Also this technique allows for the ACL reconstruction and lateral extra-articular stabilization to be performed through a single surgical incision while obtaining autograft tissue without disruption of the extensor or hamstring mechanisms.

Relationship between shoulder rotation deficit and elbow instability in healthy baseball players.

Elbow valgus instability is a risk factor for elbow medial collateral ligament injury. This study aimed to investigate the relationship between shoulder range of motion and elbow valgus instability using an ultrasound imaging system. A questionnaire and ultrasound examination were used for the study. Thirty-seven high school baseball players (15-18 years) with no history of shoulder or elbow disorders were included. Shoulder range of motion was measured at 90° of adduction, 10° of horizontal adduction, and 90° of elbow flexion in the supine resting position. To evaluate elbow valgus instability, an ultrasound imaging system was used to measure the shortest distance from the apex of the ulnar capitulum to the humeral glenoid with 2.5 kg of valgus stress applied to the ulnohumeral joint. The presence of elbow valgus instability was determined by the value obtained by subtracting the joint space distance on the non-throwing side from that on the throwing side. Student's t-test was applied for the range of shoulder rotation between the two groups, and Pearson's correlation coefficient was used for the relationship between the range of shoulder rotation and elbow instability. Statistical significance was set at 5%. The range of internal and total shoulder rotation was significantly lower in participants with elbow valgus instability than those without elbow valgus instability (P<0.001). In addition, a significant moderate correlation was found in the range of internal (r=0.608, P<0.001) and total shoulder (r=0.479, P<0.001) rotations. Decreased shoulder range of motion may affect elbow valgus instability.

Biomechanical Evaluation of Different Fixation Methods for a First Metatarsal Transverse Neck Osteotomy in a Hallux Valgus Sawbone Model

Category: Bunion Introduction/Purpose: There are no studies available that provide information about fixation methods for minimally invasive Hallux Valgus osteotomies. Our objective was to evaluate different fixation methods' strength for a first metatarsal transverse neck osteotomy in a sawbone model. Methods: 30 sawbone foot models were used. Transverse neck first metatasal osteotomies were performed and fixed in a standardized fashion in 6 different configurations. Group 1 used one 4.0 screw; Group 2 used two (one 4.0 and one 3.0) parallel screws; Group 3 used two (one 4.0 and one 3.0) divergent screws; Group 4 used two divergent screws, one 4.0 with lateral metatarsal head cortex purchase, and one 3.0 screw; Group 5 was like Group 4, but with two 4.0 screws. Group 6 was like Group 4 and 5, but with two 3.5 screws. Cyclic and load to failure testing were performed, measuring stiffness and force needed to create deformity, using a Zwick Roell Universal Testing Machine. Results: Group 1 failed due to rotational instability. Group 2 showed increased stiffness (p &lt; 0.05) against group 1. Group 3 did not achieve difference to group 2. Group 4 was stronger (p &lt; 0.05) in all variables than groups 1-3. Group 5 did not show differences against Group 4. Group 6 was only stronger than Group 1-2. Conclusion: In this study, better biomechanical behavior is seen using divergent screws with lateral head cortex purchase. This is the first study that provides biomechanical information on first metatarsal transverse neck osteotomy fixation methods. Clinical studies are needed to evaluate the clinical impact of these findings.

Diagnostic Accuracy of Conventional Ankle CT Scan With External Rotation and Dorsiflexion in Patients With Acute Isolated Syndesmotic Instability

Category: Ankle; Sports Introduction/Purpose: Syndesmotic injury in an athletic population is associated with a prolonged ankle disability after an ankle sprain and often requires a longer recovery than a lateral collateral ligament injury. Although several imaging tests are available, diagnosing syndesmotic instability remains challenging. The main objective was to determine the diagnostic accuracy of conventional ankle computed tomography (CT) scans with the joint in external rotation and dorsiflexion and compare it with that of conventional ankle CT scans in a neutral position. Methods: Between September 2018 and April 2021, this prospective study consecutively included adults visiting the foot and ankle outpatient clinic with a positive orthopedic examination for acute syndesmotic injury. Participants underwent 3 CT scan tests. First, ankles were scanned in a neutral position. Second, ankles were scanned with 45° of external rotation, dorsiflexion, and extended knees. Third, ankles were scanned with 45° of external rotation, dorsiflexion, and flexed knees. Three measurements, comprising rotation (measurement a), lateral translation (measurement c), and anteroposterior translation (measurement f) of the fibula concerning the tibia, were used to diagnose syndesmotic instability in the 3 CT scans. Magnetic resonance imaging was used as a reference standard. The area under the curve (AUC) was used to compare the diagnostic accuracy, and Youden’s J index was calculated to determine the ideal cutoff point. Results: Images obtained in 68 participants (mean age, 36.5 years; range, 18-69 years) were analyzed, comprising 36 syndesmotic injuries and 32 lateral collateral ligament injuries. The best diagnostic accuracy occurred with the rotational measurement a, in which the second and third CT scans with stress maneuvers presented greater AUCs (0.97 and 0.99) than the first CT scan in a neutral position (0.62). The ideal cutoff point for the stress maneuvers was 1.0 mm in the rotational measurement and reached a sensitivity and specificity of 83% and 97% for the second CT scan with extended knees and 86% and 100% for the third CT scan with flexed knees, respectively. Conclusion: Conventional ankle CT with stress maneuvers has excellent performance for diagnosing subtle syndesmotic rotational instability, as it shows a greater AUC and enhanced sensitivity at the ideal cutoff point compared with ankle CT in the neutral position.

Current development in surgical techniques, graft selection and additional procedures for anterior cruciate ligament injury: a path towards anatomic restoration and improved clinical outcomes-a narrative review.

Anterior cruciate ligament (ACL) reconstruction has been widely used for ACL injury for a long time. However, residual rotational instability and osteoarthritic changes after ACL reconstruction have been identified as problems. Thus, anatomic reconstruction techniques, various types of grafts and additional procedures have been desired to improve the clinical outcomes and knee instability. Although clinical outcomes and knee stability are better than in the past, ipsilateral graft failures still occur in 4-17% and osteoarthritic changes are seen in about 20% of patients after ACL reconstruction. To remedy these problems, it is necessary to improve the understanding of various surgical techniques and grafts and to pursue further improvement of surgical techniques. Therefore, the objective of this review is to summarize the advantages and disadvantages of various surgical techniques and graft selection, and additional procedures for ACL injury. A literature review was conducted on the surgical procedures for ACL injury. Recent trends in surgical techniques, graft selection, and additional procedures for ACL injury were described. We performed a literature search in PubMed for studies published from origin to May 8, 2023. Studies were required to be English-language articles. Although many reports indicate that double-bundle ACL reconstruction is comparable to anatomic single-bundle (SB) reconstruction, intraoperative complications such as tunnel coalition exist in double-bundle reconstruction, and the technique needs to be improved. ACL repair has shown good short-term results, but long-term results need to be examined in the future. Quadriceps tendon autograft is being used more frequently, but hamstrings tendon autograft and bone-patellar tendon-bone autograft also have good results. In addition, in higher-risk cases, lateral extra-articular tenodesis (LET) and anterolateral ligament (ALL) reconstruction can be performed with good results. To further improve clinical outcomes, more anatomical reconstructions should be pursued. Autografts are better than allografts and synthetic grafts, but further study is needed to determine which graft is better. Additional procedures should be performed in highly unstable cases and in revision cases.

Conservative versus surgical management of isolated O'Driscoll II coronoid fracture: A systematic review

PurposeThe purpose of this systematic review is to summarize the current literature on conservative and surgical management of isolated O'Driscoll II coronoid fracture. Study DesignSystematic review. MethodsWe systematically searched Medline, Embase, Google Scholar, and Web of Science databases for published studies by complying with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and using the keywords “isolated coronoid fracture,” “O'Driscoll type 2 coronoid fracture,” “anteromedial coronoid fracture,” “anteromedial facet coronoid fracture,” “posteromedial rotatory instability,” and “varus posteromedial rotatory instability.” Patients were divided into conservative treatment and surgical treatment groups. Oxford Centre for Evidence-Based Medicine and Methodological Index for Non-Randomized Studies were assessed to determine each article’s quality. The primary outcomes of the present reviews were the Mayo elbow performance score (MEPS) and the disabilities of the arm, shoulder, and hand (DASH) score, and the secondary outcomes were associated with complications and reoperations. Eligible trials were independently chosen by two review authors, and a third reviewer resolved all disagreements. ResultsThe search yielded 458 records, among which 446 articles were of relevance, and 12 were included. In the final review, 138 patients were evaluated—98 (71%) who received surgical treatment and 40 (29%) who received conservative treatment. The mean MEPS score and the DASH score of surgical treatment were 91 and 8, respectively; 69.8% of patients had excellent scores, and 27.0% had good scores. The mean MEPS score and the DASH score of conservative treatment were 92 and 12, respectively; 70.6% of patients had excellent scores, and 23.5% had good scores. ConclusionsIn select cases, conservative treatment can achieve good results in the treatment of isolated O'Driscoll II coronoid fracture when a stricter indication is followed. However, there is insufficient evidence to recommend the appropriate treatment for a particular fracture subtype, and there is a need for more high-quality randomized controlled trials to determine which treatment is superior.