Explore the vast range of titles available.

Objective To evaluate the efficacy of the double‐row and double‐pulley technique in treating anterior shoulder glenoid fracture (Ideberg type Ia) using shoulder arthroscopy. Methods Thirty‐six patients with Ideberg type Ia admitted from March 1, 2017, to March 1, 2020, were retrospectively reviewed. Data of the patients' history included age, sex, side of the affected arm, the mean time from injury to surgery, the surgical duration, the average blood loss, and the average total duration of hospital stay. The double‐row and double‐pulley technique was used to repair the scapular glenoid fracture under arthroscopy. Computed tomography (CT) was used to evaluate fracture healing after surgery. The American Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder joint scoring system, and the Constant–Murley shoulder function score were used to assess the function of the affected shoulder. Results The surgical duration was 90–150 min, with a mean of 127 min. The average blood loss was 90 mL (range, 60–120 mL), and the average total duration of hospital stay was 9.2 days (range, 3 to 14 days). At 9 months after surgery, the CT results showed that all fractures healed, and all patients returned to their previous levels of activity and regained an excellent range of motion. The visual analog scale (VAS) score was 7.55 ± 1.32 before surgery, and the VAS score significantly decreased to 1.24 ± 0.72 at 12 months after the operation (p < 0.05). The Constant, ASES, and UCLA shoulder function scores were 44.38 ± 2.16, 43.47 ± 12.76, and 21.80 ± 1.16 before the surgery, respectively, which improved to 93.52 ± 2.82, 91.34 ± 8.28, and 33.24 ± 1.64, respectively, in the following 12 months. One patient experienced fat liquefaction. However, no cases of deep venous thrombosis, iatrogenic neurovascular compromise, wound infection, or neurovascular injury were identified. Conclusion The double‐row and double‐pulley technique for treating Ideberg type Ia under shoulder arthroscopy has minor surgical trauma, reliable fracture reduction and fixation, less postoperative pain, and fewer postoperative complications and significantly improves the patient's shoulder joint function. Schematic diagram of double‐row and double‐pulley reduction transverse position of scapula fracture. Scapular glenoid Ideberg type Ia fracture, after the use of arthroscopy to reduce the fracture, two anchors are screwed into the upper and lower fracture of the fracture, and the cross section is fixed with double rows and double pulleys.

There is substantial evidence indicating that double-row (DR) repair restores more of the anatomic rotator cuff footprint and is biomechanically superior to single-row (SR) repair. Transosseous-equivalent (TOE) techniques have shown biomechanical advantages when compared with traditional DR, including increased contact at the rotator cuff footprint, higher pressure at the tendon-bone interface, and increased failure strength. Several meta-analyses of evidence level 1 and 2 studies have shown a lower rate of failed/incomplete healing when DR repair was compared with SR repair types. There is some limited evidence that TOE techniques improve healing rates in large and massive tears as compared with SR and DR. Overall, most level 1 and 2 studies have failed to prove a significant difference between SR and DR repairs in terms of clinical outcomes. However, most studies include only short-term follow-up, minimizing the impact that the higher rate of retears/failed healing seen with SR repairs can have in the long term. There are no high-quality clinical studies comparing different DR configurations, and there are currently not enough clinical data to determine the functional advantages of various DR technique modifications over one another. Although numerous biomechanical and clinical studies comparing different rotator cuff repair techniques have been published in the past decade, none has achieved universal acceptance. It is essential for the orthopaedic surgeon to know in detail the available literature to be able to apply the most appropriate and cost-effective technique in terms of healing and functional outcomes. This review provides a critical analysis of the comparative biomechanical and clinical studies among SR, DR, and TOE techniques reported in the literature in the past decade.

Objectives Bankart lesion is one of the most common lesions of the glenohumeral joint. Several double‐row suture methods were reported for Bankart repair, which could provide more stability, yet more motion limitation and complications. Therefore, we introduced a new double‐row Bankart repair technique, key point double‐row suture which used one anchor in the medial line. The purpose of this article is to investigate the clinical outcomes of this new method and to compare it with single‐row suture. Methods Seventy‐eight patients receiving key point double‐row suture or single‐row suture from October 2010 to June 2014 were collected retrospectively. The basic information including gender, age, dominant arm, and number of episodes of instability was collected. Before surgery, the glenoid bone loss was measured from the CT scan. The visual analogue scale, American shoulder and elbow surgeons, the University of California at Los Angeles shoulder scale, and subjective shoulder value were valued before surgery and at the last follow‐up. Results Forty‐four patients (24 patients receiving single‐row suture and 20 patients receiving key point double‐row suture) were followed up successfully. The follow‐up period was 9.2 ± 1.1 years (range, 7.8–11.4 years). At the last follow‐up, no significant differences were detected for any of the clinical scores. The recurrence rate was 12.5% for the single‐row group and 10% for the double‐row group, respectively (p = 0.795) 14 patients (31.8%) in the single‐row group and nine patients (26.5%) in the double‐row group were tested for active range of motion. A statistically significant difference was found only for the internal rotation at 90° abduction (48.9° for single‐row and 76.7° for key point double‐row, p = 0.033). Conclusion The key point double‐row sutures for Bankart lesions could achieve similar long‐term outcomes compared with single‐row suture, and one medial anchor did not result in a limited range of motion. The low recurrence rate and previous biomechanical results also indicate the key point double‐row suture is a reliable method. The key point double‐row suture technique, as compared to the single‐row suture technique, provides an additional medial anchor without any significant reduction in the range of motion. The biomechanical results and low recurrence rate of the key point double‐row suture technique further support its reliability and effectiveness in Bankart repair.

Objective To evaluate the postoperative efficacy and the clinical outcomes of arthroscopic modified double‐row biceps tenodesis versus labral repair. Methods A retrospective study was conducted in 56 patients with isolated type II superior labrum anterior and posterior (SLAP) lesions from March 2015 to November 2018. Thirty patients (male:female = 17:13) were treated with labral repair, and 26 patients (male:female = 15:11) were treated with modified double‐row biceps tenodesis. The average age of the labral repair group and the modified double‐row biceps tenodesis group were 42.8 ± 10.6 and 40.9 ± 10.2 years, respectively. Pre‐ and postoperative assessments with the visual analog scale (VAS), University of California Los Angeles (UCLA), and American Shoulder and Elbow Surgeons (ASES) scores were compared between the two treatment groups. Additional outcome measures included patient satisfaction, the time to return to previous activities, workers' compensation status, and postoperative complications. Results At a 2‐year follow‐up, the tenodesis group showed significant differences in postoperative VAS (1.5 to 1.8, respectively; p = 0.008), patient satisfaction (92.3% vs. 46.7%, p < 0.001), and recovery time to return to their previous activities (6.8 ± 1.8 vs. 8.1 ± 1.5, p = 0.007) compared to the labral repair group; however, there was no significant difference in postoperative ASES and UCLA scores between the two groups. Additionally, one patient in the tenodesis group developed persistent postoperative stiffness, which was resolved by conservative treatment. In the labral repair group, two patients presented with persistent postoperative night pain, three developed persistent postoperative stiffness, and two required a subsequent capsular release. Conclusions Compared with the labral repair group, the arthroscopic modified double‐row biceps tenodesis showed more encouraging postoperative pain reduction, earlier recovery to previous activities, and higher patient satisfaction. Schematic diagram of the arthroscopic modified double‐row biceps tenodesis: (A) The superiorly double‐loaded suture anchor was implanted; (B) A penetrator grasper device was used to penetrate the long head of the biceps tendon (LHBT); (C, D) One of the limbs was used to go through the tendon and to make a suture loop, while the other limb was used to pull through the suture loop; (E) The second suture anchor was then implanted; (F) The suture strands from the superiorly and inferiorly implanted anchors were tightened using standard suture techniques and cut off.

Purpose The purpose of our study was to evaluate the initial fixation strength of bridging techniques compared to other suture techniques for rotator cuff repair using a biomechanical animal model, which incorporated pretesting of intact tendons. Methods Seventy-six fresh bovine shoulders were used for testing seven suture configurations including simple suture (SS), mattress suture (MS), Mason-Allen (MA), modified double row (mDR), SpeedBridge (SpB), SpeedBridge with medial fixation (mSpB), and double-mattress SutureBridge (dmSuB) techniques. Cyclic loading was performed with all intact bone-tendon complex before (pretest) and after repair of the tendon (main test) at the level of 10 and 180 N at 100 Hz with displacement-controlled ramps of ±33 mm/s. The pretest was stopped after 200 cycles. For the main test, the loading scheme was continued for a maximum of 500 cycles or until failure. Results The mean elongation of all 76 intact tendons measured at the pretest was 3.8 ± 0.6 mm (2.4–5.4 mm). No differences of gap formations at the 1st cycle were detected between SS, MS, MA, and mDR. SpB showed significant higher gap formations compared to all other suture techniques ( p  = 0.001). No significant differences were detected between mSpB and dmSuB, whereas both techniques were significant different when compared to the other groups ( p  < 0.05). Conclusions In this study, results showed that bridging techniques with medial fixations have superior initial repair strength compared to other suture techniques. Knowledge of initial fixation strength of rotator cuff repair techniques may be of informative value to the surgeon.

A PEEK button is developed to improve the tendon-to-bone compression area. In total, 18 goats were divided into 12-week, 4-week, and 0-week groups. All underwent bilateral detachment of the infraspinatus tendon. In the 12-week group, 6 were fixed with a 0.8–1 mm-thick PEEK augment (A-12, Augmented), and 6 were fixed with the double-row technique (DR-12). Overall, 6 infraspinatus were fixed with PEEK augment (A-4) and without PEEK augment (DR-4) in the 4-week group. The same condition was performed in the 0-week groups (A-0 and DR-0). Mechanical testing, immunohistochemistry assessment, cell responses, tissue alternation, surgical impact, remodeling, and the expression of type I, II, and III collagen of the native tendon-to-bone insertion and new footprint areas were evaluated. The average maximum load in the A-12 group (393.75 (84.40) N) was significantly larger than in the TOE-12 group (229.17 (43.94) N) (p < 0.001). Cell responses and tissue alternations in the 4-week group were slight. The new footprint area of the A-4 group had better fibrocartilage maturation and more type III collagen expression than in DR-4 group. This result proved the novel device is safe and provides superior load-displacement to the double-row technique. There is a trend toward better fibrocartilage maturation and more collagen III secretions in the PEEK augmentation group.

Defects in the bearings greatly affect vibrations and performances of rotating transmission systems. Moreover, most previous works estimated the defect shape as a regular shape. However, the actual defect shape is not actually regular. To obtain more accurate vibration characteristics of a defective double row cylindrical roller bearing, an irregular-shaped defect modeling method and a dynamic model of double row cylindrical roller bearing with irregular-shaped defects are proposed in this paper. The dynamic model includes all components and their interactions. A test verification is proposed to validate the established model. The effects of the bearing load, rotating speed, and different independent shape defect sizes on the double row cylindrical roller bearing vibrations are investigated. The comparisons of vibrations between the irregular defect shape and simplified defect shape are studied. The results show that the simplified defect shape model will cause the vibrations to be overestimated. The established dynamic model with the actual defect is more reasonable than the simplified defect model. Moreover, this paper can provide a comprehensive analytical method for double row cylindrical roller bearing vibrations.

Background: Comparative studies and randomized controlled trials (RCTs) often use the P (probability) value to convey the statistical significance of their findings. P values are an imperfect measure, however, and are vulnerable to a small number of outcome reversals to alter statistical significance. The inclusion of a fragility index (FI) and fragility quotient (FQ) may aid in the interpretation of a study’s statistical strength. Purpose/Hypothesis: The purpose of this study was to examine the statistical stability of studies comparing single-row to double-row rotator cuff repair. It was hypothesized that the findings of these studies would be vulnerable to a small number of outcome event reversals, often fewer than the number of patients lost to follow-up. Study Design: Systematic review; Level of evidence, 3. Methods: We analyzed comparative studies and RCTs on primary single-row versus double-row rotator cuff repair that were published between 2000 and 2021 in 10 leading orthopaedic journals. Statistical significance was defined as a P < .05. The FI for each outcome was determined by the number of event reversals necessary to alter significance. The FQ was calculated by dividing the FI by the respective sample size. Results: Of 4896 studies screened, 22 comparative studies, 10 of which were RCTs, were ultimately included for analysis. A total of 74 outcomes were examined. Overall, the median FI was 2 (interquartile range [IQR], 1-3), and the median FQ was 0.035 (IQR, 0.020-0.057). The mean FI was 2.55 ± 1.29, and the mean FQ was 0.043 ± 0.027. In 64% of outcomes, the FI was less than the number of patients lost to follow-up.) Additionally, 81% of significant outcomes needed just a single outcome reversal to lose their significance. Conclusion: Over half of the studies currently used to guide clinical practice have a number of patients lost to follow-up greater than their FI. The results of these studies should be interpreted within the context of these limitations. Future analyses may benefit from the inclusion of the FI and the FQ in their statistical analyses.

Double-row tapered roller bearings have been widely used in various equipment recently due to their compact structure and ability to withstand large loads. The dynamic stiffness is composed of contact stiffness, oil film stiffness and support stiffness, and the contact stiffness has the most significant influence on the dynamic performance of the bearing. There are few studies on the contact stiffness of double-row tapered roller bearings. Firstly, the contact mechanics calculation model of double-row tapered roller bearing under composite loads has been established. On this basis, the influence of load distribution of double-row tapered roller bearing is analyzed, and the calculation model of contact stiffness of double-row tapered roller bearing is obtained according to the relationship between overall stiffness and local stiffness of bearing. Based on the established stiffness model, the influence of different working conditions on the contact stiffness of the bearing is simulated and analyzed, and the effects of radial load, axial load, bending moment load, speed, preload, and deflection angle on the contact stiffness of double row tapered roller bearings have been revealed. Finally, by comparing the results with Adams simulation results, the error is within 8%, which verifies the validity and accuracy of the proposed model and method. The research content of this paper provides theoretical support for the design of double-row tapered roller bearings and the identification of bearing performance parameters under complex loads.

The present article summarizes current trends in arthroscopic rotator cuff repairs focusing on the used repair technique, potential influencing factors on the results, and long-term outcome after reconstruction of the rotator cuff. Moreover, different treatment options for the treatment for irreparable rotator cuff ruptures were described, and the results of additional augmentation of the repairs with platelet-rich plasma were critically analyzed. Based on the current literature, double-row repairs did not achieve superior clinical results compared to single-row repairs neither in the clinical results nor in the re-rupture rate. Multiple factors such as age, fatty infiltration, and initial rupture size might influence the results. If the rupture is not repairable, various options were described including cuff debridement, partial repair, tuberoplasty, or tendon transfers. The additional augmentation with platelet-rich plasma did not reveal any significant differences in the healing rate compared to conventional rotator cuff repairs. Level of evidence IV.