Rotational Stability Research Articles

Biomechanical Stability of Femoral Neck System for Pauwels Type III Femoral Neck Fractures Based on Different Reduction Quality.

To further investigate the biomechanics of a femoral neck system (FNS) for Pauwels type III femoral fractures based on three different reductions.We constructed three different reduction (anatomical reduction, negative buttress reduction, and positive buttress reduction) models of Pauwels type III femoral neck fractures. Then, three cannulated screws (3CS), dynamic hip screws (DHS), dynamic hip screws combined with an anti-rotation screw (DHS + ARS), one-hole femoral neck system (1HFNS), and two-hole femoral neck system (2HFNS) were assembled with the reduction models, respectively, to simulate the internal fixation surgical procedure. All models had a load of 2100N in line with the femoral mechanical axis applied. The implant stress, the head and implant displacements, and the rotational angles of all models were recorded and analyzed.Compared to 3CS and 2HFNS, 1HFNS had higher implant stress (higher than 92.5MPa and 46.3MPa, respectively) and displacement (higher than 0.9mm and 0.8mm, respectively) in the anatomical reduction. 2HFNS exhibited the highest stress values (225.5MPa) in the anatomical reduction but the lowest values (159.8MPa) in the positive buttress reduction when compared to the other implants. 2HFNS showed the best rotational stability in the negative and positive buttress reduction (rotational angels of 0.8° and 0.6°, respectively).Based on the outcome of this computational study, it might be concluded that 2HFNS was an alternative fixation for the treatment of Pauwels type III femoral neck fracture, especially when anatomical reduction cannot be perfectly attained. More relevant clinical and biomechanical studies are needed in the future.

The Iliopsoas: Anatomy, Clinical Evaluation, and Its Role in Hip Pain in the Athlete: A Scoping Review.

Disability due to iliopsoas (IP) pain and dysfunction is underdiagnosed in the athletic population. The IP unit consists of the psoas major and iliacus muscles converging to form the IP tendon and is responsible primarily for hip flexion strength but has a number of secondary contributions such as femoral movement, trunk rotation, core stabilization, and dynamic anterior stability to the hip joint. As the IP passes in front of the anterior acetabulum and labrum, the diagnosis of IP pain may be confused with labral tearing seen on magnetic resonance imaging. This is in addition to the low sensitivity of magnetic resonance imaging to detect IP tendinitis and bursitis. Resisted seated hip flexion as well as direct palpation of the IP tendon and muscle belly are useful to assess function and help determine whether the IP may be the source of pain, which is common in athletes. Both biomechanical and clinical investigations have demonstrated the role of IP as an anterior hip stabilizer. Patients with signs of hip microinstability, developmental dysplasia of the hip, and increased femoral anteversion are at risk of IP pain and poor outcomes after IP lengthening, highlighting the importance of the IP in providing dynamic anterior hip stability.

Intraoperative repair of functional subscapularis during RSA by deltopectoral approach could improve internal rotation but does not prevent anterior dislocation

IntroductionThe role of the subscapularis following reverse shoulder arthroplasty (RSA) remains controversial as repair could restore adequate internal rotation and shoulder stability, but might compromise external rotation. The purpose of this multi-centre study, on a large cohort of RSAs performed using the deltopectoral approach, was to determine the effect of subscapularis preoperative status and intraoperative repair on range of motion, clinical scores and rates of complications at a minimum follow-up of 2 years. HypothesisRepair of a functional subscapularis grants better internal rotation and stability without compromising external rotation. Materials and methodsWe retrospectively reviewed records of all RSAs (n=916) performed by 14 surgeons that participated in a large national society symposium, and excluded 234 operated by the anterosuperior approach, 42 operated for rheumatoid arthritis, fractures, instability or post traumatic sequalae, and eight that had adjuvant latissimus dorsi tendon transfer (LDTT). This left 632 RSAs, in which the subscapularis was detached in 594, and repaired after detachment in 495. Patients completed pre- and postoperative Constant Score and postoperative Subjective Shoulder Value (SSV). Active forward elevation, active external rotation (ER), and active internal rotation (IR) were recorded pre- and postoperatively. Complications following RSA that required conservative treatment, reoperation without implant removal, as well as reoperation with implant removal were recorded. ResultsOf the initial cohort of 632 shoulders, 120 (19%) were lost to follow-up, 12 (2%) died due to causes unrelated to RSA, and 26 (4%) were revised with implant removal. Of the remaining 474 shoulders, 259 (55%) had a functional repaired subscapularis (Group FR), 59 (12%) had a non-functional repaired subscapularis (Group nFR), whereas 68 (14%) had a not repaired subscapularis (Group nR). Comparison of patient demographics revealed no significant differences among the three groups. Postoperative Constant Score (p=0.031) and SSV (p=0.016) were significantly different among the three groups, but effect sizes were small and not clinically relevant. Differences in postoperative ER as well as postoperative IR were not significant among the three groups: 91 (35%) gained functional IR in Group FR, 11 (19%) in Group nFR, and 13 (19%) in Group nR. Three shoulders (1.2%) reported subjective instability and 1 (0.4%) dislocated in Group FR, but none in either Groups nFR or nR. DiscussionDespite statistically significant differences in Constant Score and SSV among the three groups, the clinical relevance of these differences is negligible, so repair of functional subscapularis has little or no influence on functional outcomes. During RSA by deltopectoral approach, repair of a functional subscapularis could slightly improve internal rotation in some patients but does not compromise external rotation, forward elevation or clinical scores, while repair of a non-functional subscapularis, compared to non-repair, did not improve range of motion or clinical scores. Level of evidenceIII; retrospective comparative.

THE RETROSPECTIVE ANALYSIS OF TRIGEN INTERTAN NAIL IN THE TREATMENT OF UNSTABLE INTERTROCHANTERIC FEMORAL FRACTURES AT HOSPITAL FOR TRAUMATOLOGY AND ORTHOPAEDICS.

Intertrochanteric fractures are highly prevalent among the elderly population, with approximately 90% occurring in individuals aged over 65. These geriatric fractures are associated with elevated mortality rates and significant functional impairment. Common treatment modalities for unstable intertrochanteric fractures include proximal femoral nail antirotation (PFNA) and the InterTan nail (IT). PFNA and IT are frequently employed due to their lower failure rates and favorable biomechanical properties, resulting in positive clinical outcomes for the management of unstable intertrochanteric fractures. The unique design of the IT nail, featuring two cephalocervical screws within an integrated mechanism, permits linear intraoperative compression and rotational stability of the neck and head fragment. In this study, we assess the clinical outcomes of IT nail utilization in the treatment of intertrochanteric fractures at the Hospital for Traumatology and Orthopedics. This study comprises a retrospective analysis and case series report. Between February 2021 and August 2021, we retrospectively evaluated 35 patients who underwent treatment with the IT nail for unstable intertrochanteric fractures. Epidemiological data, operative duration, intraoperative blood loss, intraoperative blood transfusion requirements, length of hospital stay, bone healing rates, and IT nail-related complications were recorded. The mean age of the patients was 70.97 ± 16.97 years, with a mean operative time of 60 minutes, mean intraoperative blood loss of 160.86 ± 72.8 ml, mean intraoperative blood transfusion volume of 203.43 ± 189.29 ml, and a mean hospital stay of 7 days. Bone healing was observed in 97.14% of cases. The treatment of unstable intertrochanteric fractures using the IT nail in elderly patients was successful. Our findings indicate favorable clinical outcomes in terms of surgical duration, intraoperative blood loss, hospitalization duration, and union rates for elderly patients. Further investigations are warranted to validate these early results.

Comparison of Short-Arm Immobilization and Long-Arm Immobilization in Conservatively Managed Distal Radius Fractures: A Meta-Analysis and Systematic Review.

Distal radius fractures are often treated conservatively with immobilization. Immobilizing above the elbow limits forearm rotation, though recent literature has suggested the effects on radiographic or functional outcomes may be negligible. This systematic review and meta-analysis aimed to analyze the radiographic and functional outcome scores of distal radius fractures managed with short-arm (SA) immobilization and long-arm (LA) immobilization. An electronic systematic search was performed of the PubMed and EMBASE databases from inception to October 5, 2022. All randomized controlled trials (RCTs) involving patients with acute distal radius fractures undergoing nonoperative treatment (involving application/maintenance of immobilization) comparing above-elbow versus below-elbow constructs were included. The outcomes of interest were changes in radiographic parameters (loss of volar tilt [VT], radial height [RH], and radial inclination [RI]), loss of reduction, requirement for surgery, and patient-reported functional outcomes (Disabilities of the Arm, Shoulder, or Hand [DASH] or Quick DASH survey). The Cochrane Risk of Bias Tool 2.0 was used for study quality assessment. The effect size of the interventions was assessed using random effect models to calculate mean differences (MDs) for continuous variables and odds ratios (ORs) for categorical variables. Standardized mean difference (SMD) was calculated for patient-reported functional outcome scores. Nine studies involving 983 cases were included, including 497 SA and 486 LA. No statistically significant differences were observed with regards to VT (P= 0.83), RH (P= 0.81), RI (P= 0.35), loss of reduction (P= 0.33), requirement for surgery (P= 0.33), or patient-reported functional outcomes (P= 0.10). There was no difference in radiographic outcomes, need for surgery, or functional scores among patients treated with SA and LA immobilization. Utilizing SA immobilization is a safe option for conservative management of distal radius fractures and the benefits of mitigating complications associated with LA immobilization may supersede the theoretical limited forearm rotational stability observed with SA immobilization. Further study is required to determine the optimal method of SA immobilization.

Comparison of the effect of capsular bend on the rotational stability between 2 toric intraocular lenses.

To compare the effect of capsular bend on the rotational stability between 2 toric intraocular lenses (IOLs). Eye Hospital of Wenzhou Medical University, Hangzhou, Zhejiang Province, China. Prospective study. Patients with preexisting astigmatism received AcrySof IQ (SN6AT) or TECNIS (ZCT/ZMT) toric IOL during cataract surgery. CASIA2 was used to record the toric IOL axial orientation and capsular bend index (CBI) at the 1-day, 1-week, 1-month, and 3-month interval postoperatively. The postoperative rotational stability and CBI of both models were compared. A total of 58 eyes from 58 patients were enrolled in this study. The total misalignment of the TECNIS (ZCT/ZMT) group (6.96 ± 5.10 degrees, 7.41 ± 5.19 degrees, 6.93 ± 5.29 degrees, and 6.86 ± 5. 27 degrees) was significantly higher than that of the AcrySof IQ (SN6AT) group (3.55 ± 2.21 degrees, 4.00 ± 2.74 degrees, 3.72 ± 2.72 degrees, and 3.52 ± 2.50 degrees) at all follow-up intervals ( P < .05). The mean rotation of the TECNIS (ZCT/ZMT) group (2.66 ± 2.18 degrees) was significantly greater than that of the AcrySof IQ (SN6AT) group (1.65 ± 1.47 degrees) from 1 day to 1 week postoperatively ( P < .05). The capsular bend formation in the TECNIS (ZCT/ZMT) group was delayed compared with the AcrySof IQ (SN6AT) group ( P < .05, at the 1-week, 1-month, and 3-month interval). The TECNIS (ZCT/ZMT) group showed fibrosis in the peripheral anterior capsule, leading to its stretching away from the IOL surface, while the AcrySof IQ (SN6AT) group exhibited gentle adherence of the anterior capsule to the IOL surface. The AcrySof IQ toric IOL (SN6AT) exhibited greater rotational stability than the TECNIS toric IOL (ZCT/ZMT), which may partially result from the delay in capsular bend formation of TECNIS at the 1-day to 1-week follow-up postoperatively.

Rotational stability of a new hydrophobic acrylic intraocular lens platform.

To evaluate rotational stability for ease of rotation of a new intraocular lens (IOL) platform with 4 haptics in an ex vivo model and compare it with a control single-piece lens with 2 open loops. Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. Experimental study. 10 human cadaver eyes were prepared as per the Miyake-Apple technique. After injection of the test or control lens, clockwise and counterclockwise rotations were attempted with a hook, with and without an ophthalmic viscosurgical device in place. Ease of rotation was scored as (1) very easy, (2) easy, (3) difficult, and (4) very difficult. Rotation of the entire eye containing test or control IOL was also performed with a multipurpose rotator (2 minutes; 220 revolutions per minute) to evaluate its effect on IOL alignment. There were statistically significant differences regarding ease of rotation between test and control lenses in all 4 scenarios, with rotation being more difficult with the test lens ( P < .05, Wilcoxon signed-rank test). No change in the alignment of test or control lenses was observed after eye rotation with the multipurpose rotator. The new IOL platform showed greater rotational stability than the control lens in this model, owing to design features such as 4 small arcs of contact between the haptics and the bag equator, a bulge at the distal end of each haptic, and arcuate haptics with curvatures oriented toward each other.

A COMSOL novel micromirror matrix model for digital image display

Digital micromirror devices (DMD) have gained significant attention in various scientific and industrial domains due to their potential for spatial light and laser modulation. However existing micromirrors designs often face limitations in terms of rotation angles, voltage consumption, and stability time for some type of applications. In this paper, we address these issues by exploring micromirror structure materials, more precisely, the materials for the torsion bar. To achieve this, we have used COMSOL Multiphysics knowing to provide accurate predictive simulation results, to design a micromirror model incorporating three inclination modes: unidirectional, bidirectional, and a user-defined free mode. Through extensive simulations, we have compared different materials for the torsion bar of the micromirror and have evaluated their performance in terms of voltage consumption, stability time, rotation angles and electric energy consumption. Aluminum 3008-H18 emerged as the optimal choice, exhibiting a stability time of 40 μs and achieving a maximum tilt of 12.75 degrees. The micromirror system has demonstrated stable position within the voltage range (from 0 volts to 27 volts) and maximum electric energy consumption of 7.72 × 10−8 μJ. Our micromirror design features a 10 × 10 μm reflective element capable of achieving a maximum inclination of ±12.75 degrees. To enhance the capabilities of the micromirror, an 8 × 8 micromirror matrix has been developed, enabling collective and coordinated movements of individual micromirrors. Also, a process for translating digital images into micromirror states has been devised, enabling accurate image display on the matrix. Simulation results demonstrate the effectiveness of the micromirror matrix design and the image processing script, images displayed on the micromirror matrix exhibit high accuracy, faithfully reproducing desired patterns in the primary images. Overall, our proposed micromirror model and micromirror matrix model offer enhanced performance, versatility, and accuracy, enabling a diverse array of simulations across scientific research and industrial domains.

Contributions of the Abductor Muscles to Rotational and Distractive Stability of the Hip in a Biomechanical Cadaveric Model.

The gluteus minimus (GMin) and gluteus medius (GMed) are important dynamic stabilizers of the hip, but quantitative data on their biomechanical roles in stabilizing the hip are currently lacking. To (1) establish a reproducible biomechanical cadaveric model of the hip abductor complex and (2) characterize the effects of loading the GMin and GMed on extraneous femoral rotation and distraction. Controlled laboratory study. A total of 10 hemipelvises were tested in 4 muscle loading states: (1) unloaded, (2) the GMin loaded, (3) the GMed loaded, and (4) both the GMin and GMed loaded. Muscle loads were applied via cables, pulleys, and weights attached to the tendons to replicate the anatomic lines of action. Specimens were tested under internal rotation; external rotation; and axial traction forces at 0°, 15°, 30°, 60°, and 90° of hip flexion. When loaded together, the GMin and GMed reduced internal rotation motion at all hip flexion angles (P < .05) except 60° and reduced external rotation motion at all hip flexion angles (P < .05) except 0°. Likewise, when both the GMin and GMed were loaded, femoral distraction was decreased at all angles of hip flexion (P < .05). The results of this study demonstrated that the GMin and GMed provide stability against rotational torques and distractive forces and that the amount of contribution depends on the degree of hip flexion. Improved understanding of the roles of the GMin and GMed in preventing rotational and distractive instability of the hip will better guide treatment of hip pathologies and optimize nonoperative and operative therapies.

Why Your Patient May Need an ACL Reconstruction Plus Lateral Extra-Articular Tenodesis Procedure.

Anterior cruciate ligament (ACL) tears are one of the most common knee injuries experienced by active individuals engaging in cutting sports. Despite improved surgical techniques and rehabilitation, the return to sport rate and re-tear rates remain unsatisfactory. Lateral extra-articular tenodesis (LET) is a procedure that has been growing in interest when performed in conjunction with ACL reconstruction. The benefits of adding an LET procedure to an ACL surgery may include greater rotational stability, decreased re-tear rates, and improved return to play. Level of evidence: V.

Can lateral tenodesis improve the rotational stability of the ACL reconstruction? A finite element analysis.

One of the most common knee injuries is the Anterior Cruciate Ligament (ACL) rupture with severe implications on knee stability. The usual treatment is the ACL Reconstruction (ACLR) surgery where the surgeon replaces the torn ligament with a graft in an effort to restore knee kinematics. In case of excessive rotatory instability, Lateral Extra-Articular Tenodesis (LET) can be performed in combination with ACLR. Additionally, LET appears to reduce ACLR graft forces minimizing graft failure chances. However, there are concerns about overconstraining physiological rotation. To gain insight in this controversial topic, we developed an automatic, open-source tool to create a series of Finite Element (FE) models attempting to investigate the interactions of ACLR and LET through simulation. We started by creating a validated model of the healthy knee joint that served as reference for subsequent FE simulations. Then, we created FE models of standalone ACLR and combined ACLR-LET. Each model was assessed by applying a loading profile that resembles the reduction phase of the Pivot-Shift clinical exam. We measured the External Tibia Rotation (ETR), the Posterior Tibia Translation (PTT) of the lateral tibial compartment, and the ACLR graft stress developed around the femoral tunnel insertion site. We observed the following: a) LET reduces ETR and PTT compared to isolated ACLR, b) combined ACLR-LET is more sensitive to LET graft pretension with lower values showcasing performance closer to the healthy joint, c) LET reduces ACLR graft forces for the same pretension values, d) LET exhibits significant overconstraint for higher pretension values. In general, these findings are in agreement with relevant clinical studies and accentuate the potential of the developed framework as a tool that can assist orthopaedists during surgery planning. We provide open access for the FE models of this study to enhance research transparency, reproducibility and extensibility.

Study of the stress-strain state in models of various options for osteosynthesis of tibial bones with diaphyseal fractures in the middle third in children with osteogenesis imperfecta and incomplete growth Part 1. Compression

Background. Osteogenesis imperfecta is accompanied by multiple fractures of skeletal bones, the development of progressive deformations of the long bones of the limbs and, as a result, the inability to stand and walk. At present, the most promising means for stabilizing bone fragments are intramedullary fixators of various designs. Installation of internal fixators without the possibility of their lengthening during the skeletal growth leads to an increase in the frequency of repeated surgical interventions due to the need for their replacement. The purpose was to investigate the stress-strain state of the lower leg models under the influence of compressive load in conditions of fracture of both bones in the middle third and their osteosynthesis using intramedullary rods of various designs in children with osteogenesis imperfecta and incomplete growth. Materials and methods. A mathematical modeling of osteosynthesis of tibial bones with a fracture in the middle third in children with osteogenesis imperfecta was performed in two options: 1 — using a rod without rotational stability; 2 — a rod with rotational stability of the structure. During the research, the stress-strain state of the model was studied under the influence of vertical compressive load. Results. Under compressive loads, the use of a rod with rotational stability does not lead to any significant changes in the stress-strain state of the model compared to tibial osteosynthesis with a rotationally unstable rod. This can be explained by the fact that before resisting the loads acting along the longitudinal axis of the rods, both rods are unstable, so all loads are carried by the bone structures. This is a “fee” for the opportunity to “grow”. The presence of rotational stability of an intramedullary rod does not have a significant effect on the stress distribution in the models under compressive loading. But it should be noted that when using a rotationally stable rod, the stresses in the distal tibia are slightly reduced, and what is especially important, in the fracture zone too. Thus, a growing rod with a locked rotational movement creates more favorable conditions for the fusion of tibial fractures in the middle third, which is of great importance in the treatment of children with osteogenesis imperfecta. Conclusions. Under the influence of compressive loads, the presence of rotational stability of an intramedullary rod does not provide significant advantages from the point of view of stress distribution in the model of a tibial fracture in the middle third. However, due to the presence of a movable support at the distal end of the tibia, even with a vertical compressive load, a small torque can occur between the bone fragments, which should block the rod with a locked rotational movement. This is the cause for a decrease in the stress in the distal fragment of the tibia.

Rotational stability and capsular bag performance of a hydrophobic acrylic open-loop single-piece intraocular lens.

To evaluate the rotational stability and capsular bag performance of a blue light-absorbing hydrophobic acrylic open-loop single-piece intraocular lens (IOL) with a blast-finished anchor wing haptic design during the first 6 postoperative months. In this prospective clinical study, patients with age-related cataract and potential postoperative corrected distance visual acuity (CDVA) of 0.2 logMAR or better were included. The patients received a non-toric hydrophobic acrylic single-piece IOL with an axis mark (YST0.00; Nidek Co. Ltd, Japan). Surgeries were video-taped. Retroillumination images were acquired 1 h, 1 week and 6 months postoperatively. Rotational stability was assessed by precise image overlay. At 6 months, Purkinje meter measurements were performed to evaluate tilt and decentration. In total, 100 eyes of 77 patients were included in the analysis. Mean absolute rotation was 2.1 ± 1.7° (median 1.7, range: 0-7.9) at 6 months (1 h - 6 months postoperatively). IOL rotation was ≤3° and ≤6° in 74 (74%) and 98 (98%) eyes, respectively. Mean absolute IOL rotation from the end of surgery to 6 months was 2.5 ± 2.2° (median 2.3, range: 0-15.6; n = 78). Mean tilt (pupillary axis) and decentration were 4.1 ± 1.9° (median 4.0, range: 0.5-8.2) and 0.35 ± 0.17 mm (median 0.32, range: 0.06-0.91) respectively (n = 84). Postoperatively, 98 (98%) eyes achieved a CDVA of 0.2 logMAR or better, 95 (95%) of ≤0.1 and 81 (81%) of ≤0.0. This hydrophobic acrylic single-piece IOL showed an excellent rotational stability and capsular bag position with low tilt and decentration values.

Rotational stability of monofocal and diffractive multifocal toric intraocular lens with identical design and material: a propensity score based prospective comparative study

PurposeTo compare the rotational stability of a monofocal and a diffractive multifocal toric intraocular lens(IOLs) with identical design and material.MethodsThis prospective study enrolled patients who underwent plate-haptic toric IOL (AT TORBI 709 M and AT LISA 909 M) implantation. Propensity score matching (PSM) was performed to balance baseline factors. Follow-up examinations were conducted at 1 h, 1 day, 3 days, 1 week, 2 weeks, 1 month, and 3 months postoperatively. A linear mixed model of repeated measures was used to investigate the changes in IOL rotation over time. A 2-week timeframe was utilized to assess differences in IOL rotation between the two groups.ResultAfter PSM, a total of 126 eyes were selected from each group for further analysis. Postoperatively, the time course of IOL rotation change in the two groups remained consistent, with the greatest rotation occurring between 1 h and 1 day postoperatively. At the 2-week postoperative mark, the monofocal toric IOL exhibited a higher degree of rotation compared to the multifocal toric IOL (5.40 ± 7.77° vs. 3.53 ± 3.54°, P = 0.015). In lens thickness(LT) ≥ 4.5 mm and white-to-white distance(WTW) ≥ 11.6 mm subgroups, the monofocal toric IOL rotated greater than the multifocal toric IOL (P = 0.026 and P = 0.011, respectively).ConclusionThe diffractive multifocal toric IOL exhibits superior rotational stability compared to the monofocal toric IOL, especially in subgroups LT ≥ 4.5 mm and WTW ≥ 11.6 mm. Moreover, the time course of IOL rotation change is consistent for both, with the maximum rotation occurring between 1 h and 1 day postoperatively.

Clinical outcomes and rotational stability after implantation of a monofocal toric intraocular lens with textured haptics in normal vs high axial lengths.

To compare the clinical outcomes and rotational stability after implantation of a toric intraocular lens (IOL) with textured haptics in eyes with normal vs high axial lengths (ALs). Nethradhama Superspeciality Eye Hospital, Bangalore, India. 2-arm, retrospective comparative study. This retrospective study included 114 eyes of 114 patients who underwent femtolaser cataract surgery followed by implantation of the HOYA Vivinex Toric monofocal IOL (Model XY1A-SP), of which 62 and 52 eyes belonged to normal (≤23.9 mm) and high (≥24 mm) AL groups, respectively. 1 week and 3 months postoperatively, clinical outcomes and rotational stability of the toric IOL was evaluated. 3 months postoperatively, % eyes achieving refractive astigmatism accuracy within ≤0.50 diopter, was 100% (n = 62) in the normal vs 94% (n = 49) in the high AL group. All eyes that is, 100% (n = 62) in the normal and 96.15% (n = 50) eyes in the high myopia group were <5 degrees of the intended axis. The mean change in postoperative rotation from 1 week to 3 months was 0.28 ± 0.09 degrees in the normal, and 0.30 ± 1.11 degrees in the high AL group ( P = .80). No significant correlation was observed between AL and white-to-white diameter with 1-week postoperative rotation values. No eye required repositioning of toric IOL for significant misalignment. No significant differences were observed for clinical outcomes and postoperative rotational stability between eyes with normal and high ALs, suggesting excellent rotational stability of the Vivinex Toric IOL with textured haptics in all eyes, irrespective of the preoperative AL measurements.

Combining an Anterolateral Complex Procedure With Anterior Cruciate Ligament Reconstruction Reduces the Graft Reinjury Rate and Improves Clinical Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-established surgical procedure, but it may not always restore complete rotational knee stability. Interest is increasing in anterolateral complex (ALC) procedures, lateral extra-articular tenodesis (LET) and anterolateral ligament reconstruction (ALLR), in association with ACLR to overcome this problem. The better ALC procedure, LET or ALLR, remains controversial to date. Purpose: To analyze the patient-reported outcome measures and ACL reinjury rate after ACLR with an ALC procedure compared with after isolated ACLR, as well as to analyze the clinical results and graft failure rate of the LET group versus the ALLR group. Study Design: Systematic review and meta-analysis; Level of evidence, 2. Methods: A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart was used to conduct a comprehensive search of 5 databases: Scopus, MEDLINE, Embase, PubMed, and the Cochrane Database of Systematic Reviews. Only randomized controlled trials were included. Eligible articles were classified according to the levels of evidence of the Oxford Centre for Evidence-Based Medicine. A methodological quality assessment of randomized controlled trials was performed using the Risk of Bias 2 tool. The present systematic review and meta-analysis was registered on PROSPERO. Results: A total of 14 clinical trials were included in the final analysis, with 1830 patients. Isolated ACLR or a combined procedure with LET or ALLR was performed, with several characteristics described, including the surgical technique, additional torn knee structures and their management, graft failure, complications, clinical outcomes, clinical and instrumental examinations to assess knee stability, and postoperative protocols. Regarding clinical outcomes, pivot-shift tests and reduced graft failure, a significant difference was found in the superiority of the combined ACLR associated with the ALC procedure compared with an isolated ACLR (P < .05). No statistically significant difference was found between the 2 ALC procedures. Conclusion: This systematic review and meta-analysis reported on the importance of combined ACLR and ALC procedures in patients with a high-grade rotational laxity, as both procedures, LET or ALLR, without superiority of one over the other, are associated with improved pivot-shift tests, patient-reported outcome measures, and reduced graft failure rates.

ВЛИЯНИЕ ЭРИТРОПОЭТИНА НА ПЕРВИЧНУЮ СТАБИЛЬНОСТЬ ИМПЛАНТАТА У ПАЦИЕНТОВ С ХРОНИЧЕСКОЙ БОЛЕЗНЬЮ ПОЧЕК

Study Subject. The study of factors that improve bone repair-one of the current clinical areas of surgical dentistry. In our study, we hypothesized that the addition of EPO to the material in reconstructive surgeries prior to dental implant placement may also have similar effects, increasing osseointegration in the bone of patients with chronic kidney disease (CKD). Erythropoietins (EPO) have been experimentally demonstrated to be involved in bone remodeling, induction of angiogenesis and secretion of a large number of trophic factors in animals.&#x0D; Objective to study the primary implant stability in CBD patients of both sexes with different bone categories and types, and the effect on EPO stability during delayed dental implantation (DDI).&#x0D; Methodology. Patients between 45 and 59 years of age who were indicated for implant dentures were included in the study. Implants were placed in the lateral and distal portions of the maxilla (LF) and mandible (LF).&#x0D; Results and their discussion. Depending on the gender, clubular filtration rate (CBF), 12 groups of examined patients were distinguished, each of which corresponded to a certain stage of CKD. Two more gender groups were made up of patients on ambulatory hemodialysis and corresponding to stage G5 of CKD – stage G5g. 728 implantations were performed, of which 368 (50.69%) in native bone, 112 (15.38%) in partially regenerated bone, and 248 (33.07%) in fully regenerated bone. The rotational stability index (IT) was determined using a calibrated manual torque wrench. The axial stability index – Implant Stability Quotient (ISQ) was calculated using the RchA system – Osstell ISQ – by screwing the SmartPeg Type to the implant. Each index was studied immediately after implant insertion or 6 months after reconstructive surgery, in situations where CI was not previously performed. In a prospective cohort study of a select group (those taking EPO and those without), the use of erythropoietin during dental implant surgery had a significant effect on implant stability when DI was performed according to a delayed protocol.

Insights into the rotational stability of toric intraocular lens implantation: diagnostic approaches, influencing factors and intervention strategies.

Toric intraocular lenses (IOLs) have been developed to enhance visual acuity impaired by cataracts and correct corneal astigmatism. However, residual astigmatism caused by postoperative rotation of the toric IOL is an important factor affecting visual quality after implantation. To decrease the rotation of the toric IOL, significant advancements have been made in understanding the characteristics of toric IOL rotation, the factors influencing its postoperative rotation, as well as the development of various measurement techniques and interventions to address this issue. It has been established that factors such as the patient's preoperative refractive status, biological parameters, surgical techniques, postoperative care, and long-term management significantly impact the rotational stability of the toric IOL. Clinicians should adopt a personalized approach that considers these factors to minimize the risk of toric IOL rotation and ensure optimal outcomes for each patient. This article reviews the influence of various factors on toric IOL rotational stability. It discusses new challenges that may be encountered to reduce and intervene with rotation after toric IOL implantation in the foreseeable future.

Evaluation of Clinical Results of Implantation of Toric Intraocular Lenses Including their Rotational Stability.

The aim of the study was to evaluate the clinical results of the implantation of the toric intraocular lens Acrysof IQ Toric SN6AT3_8(Alcon Laboratories, Inc., Fort Worth, TX, USA), including an evaluation of its rotational stability. 30 eyes of 16 patients (4 males, 12 females; mean age 68 years) with regular corneal astigmatism ranging from -1.5 to -4.0 Dcyl were included in this retrospective study. All the patients underwent uncomplicated cataract surgery with the implantation of a toric intraocular lens (TIOL) at the Department of Ophthalmology of the Faculty of Medicine and Dentistry of Palacký University in Olomouc and University Hospital Olomouc during the course of 2020. Follow-up examinations were performed 3-6 months after cataract surgery. We monitored the resulting uncorrected distance visual acuity (UDVA), postoperative refraction, rotational stability of the implanted lens and subjective patient satisfaction. mean preoperative corneal astigmatism was -2.41 ±0.67 Dcyl. UDVA improved from a mean value of 0.45 ±0.25 (expressed in decimal Snellen optotype values) to 0.91 ±0.16. The spherical equivalent value of 0.41 ±2.92 improved to -0.11 ±0.27 postoperatively. The mean deviation from the planned axis was 4.87 ±4.75. Subjective satisfaction was rated by patients on a scale of 1-5, with a mean score of 1.5. TIOL implantation is a safe and effective solution for patients with corneal astigmatism and cataract. Our results demonstrate improved UDVA, rotational stability of the TIOL and subjective patient satisfaction with the outcome of the surgery.

Single-Strand “Short Isometric Construct” Medial Collateral Ligament Reconstruction Restores Valgus and Rotational Stability While Isolated Deep MCL and Superficial MCL Reconstruction Do Not

Background: Historical MCL (medial collateral ligament) reconstruction (MCLR) techniques have focused on the superficial MCL (sMCL) to restore valgus stability while frequently ignoring the importance of the deep MCL (dMCL) in controlling tibial external rotation. The recent recognition of the medial ligament complex importance has multiple studies revisiting medial anatomy and questioning contemporary MCLR techniques. Purpose: To assess whether (1) an isolated sMCL reconstruction (sMCLR), (2) an isolated dMCL reconstruction (dMCLR), or (3) a novel single-strand short isometric construct (SIC) would restore translational and rotational stability to a knee with a dMCL and sMCL injury. Study Design: Controlled laboratory study. Methods: Biomechanical testing was performed on 14 fresh-frozen cadaveric knee specimens using a custom multiaxial knee activity simulator. The specimens were divided into 2 groups. The first group was tested in 4 states: intact, after sectioning the sMCL and dMCL, isolated sMCLR, and isolated dMCLR. The second group was tested in 3 states: intact, after sectioning the sMCL and dMCL, and after single-strand SIC reconstruction (SICR). In each state, 4 loading conditions were applied at 0°, 20°, 40°, 60°, and 90° of knee flexion: 8-N·m valgus torque, 5-N·m external rotation torque, 90-N anterior drawer, and combined 90-N anterior drawer plus 5-N·m tibial external rotation torque. Anterior translation, valgus rotation, and external rotation of the knee were measured for each state and loading condition using an optical motion capture system. Results: sMCL and dMCL transection resulted in increased laxity for all loading conditions at all flexion angles. Isolated dMCLR restored external rotation stability to intact levels throughout all degrees of flexion, yet valgus stability was restored only at 0° of flexion. Isolated sMCLR restored valgus and external rotation stability at 0°, 20°, and 40° of flexion but not at 60° or 90° of flexion. Single-strand SICR restored valgus and external rotation stability at all flexion angles. In the combined anterior drawer plus external rotation test, isolated dMCL and single-strand SICR restored stability to the intact level at all flexion angles, while the isolated sMCL restored stability at 20° and 40° of flexion but not at 60° or 90° of flexion. Conclusion: In the cadaveric model, single-strand SICR restored valgus and rotational stability throughout the range of motion. dMCLR restored rotational stability to the knee throughout the range of motion but did not restore valgus stability. Isolated sMCLR restored external rotation and valgus stability in early flexion. Clinical Relevance: In patients with anteromedial rotatory instability in the knee, neither an sMCLR nor a dMCLR is sufficient to restore stability.