Biomechanical comparison between low profile 2.7 mm distal locking hook plate and 3.5 mm distal locking hook plate for acromioclavicular joint injury: A finite element analysis.

PURPOSE: Although hook plate fixation is popularly used, concerns exist regarding periprosthetic fractures and the necessity to remove the plate to prevent subacromial erosion and subsequent acromion fracture, due to its non-anatomical design. We hypothesized that a low profile 2.7 mm distal locking hook plate would provide comparable stability to a properly used 3.5 mm distal locking hook plate MATERIALS AND METHODS: A 3.5 mm distal locking plate (type 1) and a low profile 2.7 mm plate (type 2) were assessed by finite element analysis. Peak von Mises stress (PVMS) was calculated on the acromion's undersurface, clavicle shaft, and hook, focusing on how these stresses varied with the number and placement of distal locking screws. RESULTS: Increased distal screws in both types led to lower PVMS on the acromion's undersurface and the hook, with the lowest acromion PVMS observed in type 2 with three distal screws, and on the hook in type 1 with two distal screws. Increasing the number of distal screws similarly reduced PVMS on the clavicle shaft, with the lowest in type 1 with two distal screws. In both plate types, the most posterior distal locking screw played a crucial role in distributing stress across the acromion and the hook. CONCLUSION: The low profile 2.7 mm distal locking hook plate showed comparable biomechanical results to the 3.5 mm distal locking hook plate. Increasing the number of distal locking screws showed less stress concentration on the bone and hook in both models. The most posterior distal locking screw showed an essential role in stress distribution.

Conformity of Three Pre-Contoured Clavicular Plates Compared Using Personalized 3D-Printed Models of Clavicles from Patients.

The human clavicle's unique S-shaped, three-dimensional structure complicates fracture management. This study evaluated the anatomical conformity of pre-contoured anatomical plates using 3D-printed clavicle models. CT scans from 30 patients (15 males and 15 females) were used to create these models. Three brands of distal clavicle plate systems (Acumed, Synthes, and Arthrex) were tested for fit. Measurements included the distance from the distal end of the clavicle to the plate's lateral end, the gap between the clavicle and the plate, and the overhang distance. Results showed significant differences in clavicle length between sexes, with men having a mean length of 156.1 ± 7.6 mm and women 138.4 ± 4.3 mm, both with normal distribution (p > 0.05). The mean lateral distance was 7.9 ± 1.7 mm, and the mean medial gap was 3.6 ± 3.0 mm, showing no significant differences between products or sexes. The mean overhang distance was 5.8 ± 4.6 mm, with larger values in women for the Acumed (p = 0.037) and Arthrex (p = 0.000) plates. Overall, pre-contoured plates exhibited notable discrepancies, especially in shorter clavicles.

Arthroscopic evaluation of the rotator cuff vasculature: inferences into the pathogenesis of cuff tear and re-tear.

BACKGROUND: Little is known about alterations of the rotator cuff (RC) macroscopic vasculature associated with medical conditions and/or habits that predispose a person to diseases of the peripheral microcirculation. The high frequency of cuff tear and re-tear in patients with diabetes, hypercholesterolemia, uncontrolled arterial hypertension, or metabolic syndrome may be due to tissue hypovascularity. METHODS: The macroscopic vasculature of both the articular and bursal sides of the posterosuperior RC was evaluated arthroscopically in 107 patients (mean age, 58.2 years) with no RC tear. Patients were divided into three groups according to medical comorbidities and lifestyle factors (group I, none; group II, smokers and/or drinkers and one comorbidity; and group III, two or more comorbidities). Pulsating vessels originating from both the myotendinous and osteotendinous junctions were assessed as "clearly evident," "poorly evident," or "not evident." RESULTS: Groups I, II, and III comprised 36, 45, and 26 patients, respectively. Within the myotendinous junction, vessels were visualized in 22 group I patients (61%), 25 group II patients (55%), and 6 group III patients (23%) (P=0.007). Pulsating arterial vessels originating from the osteotendinous junction were seen in 42%, 36%, and 0% of patients, respectively (P<0.001). Within the bursal side of the RC, a dense anastomotic network was visualized (either clearly or poorly) in 94% (34), 80% (36), and 35% (9) of patients, respectively (P<0.001). CONCLUSIONS: The macroscopic vasculature of the RC is influenced by pre-existing diseases and lifestyle factors, which may impair peripheral microcirculation. Level of evidence: III.

Effect of Porcine-Derived Absorbable Patch-Type Atelocollagen for Arthroscopic Rotator Cuff Repair: A Prospective Randomized Controlled Trial.

BACKGROUND: Even though arthroscopic rotator cuff repair is recognized as a standard treatment option, the risk of postoperative retear is a major concern. PURPOSE: To evaluate the effect of porcine-derived absorbable patch-type atelocollagen during arthroscopic rotator cuff repair. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 64 patients with rotator cuff tears diagnosed on magnetic resonance imaging (MRI) were enrolled prospectively from November 2020 to December 2021. Both groups had repairs using the suture bridge technique. For the atelocollagen group, before securing the lateral anchors, we inserted porcine-derived absorbable patch-type atelocollagen between the footprint and the tendon. On postoperative day 2, the patients underwent MRI to confirm containment of the patch-type atelocollagen. At 6 months and 1 year postoperatively, the signal intensity of the repaired tendon was assessed using MRI. Patients were evaluated using the Constant score as the primary outcome, along with the visual analog scale for pain; range of motion; American Shoulder and Elbow Surgeons score; University of California, Los Angeles, score; and Korean Shoulder Score preoperatively and at 2, 3, 6, and 12 months postoperatively. RESULTS: No significant changes in the Constant score as primary outcome, pain or other functional scores, and range of motion were observed between the groups at 1 year postoperatively. The patch-type atelocollagen was confirmed to be contained by the time-zero MRI scan taken 2 days postoperatively. Among the 55 patients included in final analysis, 12 retear cases were recorded (21.8% retear rate). A significantly lower retear rate was found in the atelocollagen group, as 3 cases were observed in this group (10.3%) and 9 cases were observed in the conventional repair group (34.6%) (P = .048). CONCLUSION: The Constant score was not different between the groups. The retear rate after rotator cuff repair was significantly lower in the group that received porcine-derived absorbable patch-type atelocollagen compared with in the conventional group. REGISTRATION: KCT0005184 (Clinical Research Information Service [CRIS]; https://cris.nih.go.kr).

Synchronous Diagnosis of Respiratory Viruses Variants via Receptonics Based on Modeling Receptor-Ligand Dynamics.

The transmission and pathogenesis of highly contagious fatal respiratory viruses are increasing, and the need for an on-site diagnostic platform has arisen as an issue worldwide. Furthermore, as the spread of respiratory viruses continues, different variants have become the dominant circulating strains. To prevent virus transmission, the development of highly sensitive and accurate on-site diagnostic assays is urgently needed. Herein, a facile diagnostic device is presented for multi-detection based on the results of detailed receptor-ligand dynamics simulations for the screening of various viral strains. The novel bioreceptor-treated electronics (receptonics) device consists of a multichannel graphene transistor and cell-entry receptors conjugated to N-heterocyclic carbene (NHC). An ultrasensitive multi-detection performance is achieved without the need for sample pretreatment, which will enable rapid diagnosis and prevent the spread of pathogens. This platform can be applied for the diagnosis of variants of concern in clinical respiratory virus samples and primate models. This multi-screening platform can be used to enhance surveillance and discriminate emerging virus variants before they become a severe threat to public health.

Plate prebending using a three-dimensional-printed model affords effective anatomical reduction in clavicular shaft fractures.

BACKGROUND: A precontoured plate rarely fits properly within the patient's clavicle and must be bent intraoperatively. This study aimed to determine whether anatomical reduction could be achieved using a plate bent before surgery. METHODS: This study included 87 consecutive patients with displaced mid-shaft clavicle fractures who underwent plate fixation and were followed-up for a minimum of 1 year. After exclusions, 39 consecutive patients underwent fixation with a precontoured plate bent intraoperatively (intraoperative bending group), and 28 underwent fixation with the plate bent preoperatively (preoperative bending group). Using free software and a three-dimensional (3D) printer, ipsilateral clavicle 3D-printed models were constructed. Using plain radiographs, the distance between the edge of the lateral inferior cortex and the medial inferior cortex was measured. The angle between the line connecting the inferior cortex edge and the line passing through the flat portion of the superior cortex of the distal clavicle was measured. RESULTS: Mean length differences between the ipsilateral and contralateral clavicle were smaller on both anteroposterior (AP; P=0.032) and axial images (P=0.029) in the preoperative bending group. The mean angular differences on both AP (P=0.045) and axial images (P=0.008) were smaller in the preoperative bending group. No significant differences were observed between the two groups in functional scores at the last follow-up. CONCLUSIONS: Smaller differences in length and angle between the ipsilateral and contralateral clavicle, indicative of reduction, were observed in the preoperative bending group. Using the precontoured technique with low expense, the operation was performed more effectively as reflected by a shorter operation time. Level of evidence: III.

Rotator cuff degeneration and healing after rotator cuff repair.

Rotator cuff tear is a common shoulder injury that compromises both function and quality of life. Despite the prevalence of the injury and advancements in repair techniques, a significant percentage of these repairs fail. This review aims to explore the multifactorial reasons behind this failure, including the degenerative nature of the rotator cuff tendon, inherent and extrinsic factors, and the role of hypoxia in tissue degeneration. Additionally, it elucidates potential strategies for improving healing outcomes.

Eye-Mimicked Neural Network Composed of Photosensitive Neural Spheroids with Human Opsin Proteins.

An in vitro model, composed of the short-wavelength human opsins and rhodopsins, is created. Two types of photosensitive neural spheroids are transfected for selective reaction under bluish-purple and green lights. These are employed to two devices with intact neuron and neural-spheroid to study the interaction. By photostimulation, the photosensitive spheroid initiated photoactivation, and the signal generated from its body is transmitted to adjacent neural networks. Specifically, the signal traveled through the axon bundle in narrow gap from photosensitive spheroid to intact spheroid as an eye-to-brain model including optic nerve. The whole process with photosensitive spheroid is monitored by calcium ion detecting fluorescence images. The results of this study can be applied to examine vision restoration and novel photosensitive biological systems with spectral sensitivity.

Ultrasensitive Gas Detection Based on Electrically Enhanced Nanoplasmonic Sensor with Graphene-Encased Gold Nanorod.

Nanoplasmonic sensors are a widely known concept and have been studied with various applications. Among them, gas detection is engaging attention in many fields. However, the analysis performance of nanoplasmonic sensors based on refractive index confined to the metal nanostructure characteristics causes challenges in gas detection. In this study, we develop a graphene-encased gold nanorod (AuNR)-based nanoplasmonic sensor to detect cadaverine gas. The graphene-encased AuNR (Gr@AuNR) presents an ultrasensitive peak wavelength shift even with tiny molecules. In addition, the external potential transmitted through graphene induces an additional shift. A chemical receptor is immobilized on Gr@AuNR (CR@Gr@AuNR) for selectively capturing cadaverine. The CR@Gr@AuNR achieves ultrasensitive detection of cadaverine gas, and the detection limit is increased to 15.99 ppb by applying a voltage to graphene. Furthermore, the experimental results of measuring cadaverine generated from spoiled pork show the practicality of CR@Gr@AuNR. The strategy of external-boosted nanoplasmonics provides new insight into plasmonic sensing and applications.

Simulation-Based Cybersecurity Testing and Evaluation Method for Connected Car V2X Application Using Virtual Machine.

In a connected car, the vehicle's internal network is connected to the outside through communication technology. However, this can cause new security vulnerabilities. In particular, V2X communication, to provide the safety of connected cars, can directly threaten the lives of passengers if a security attack occurs. For V2X communication security, standards such as IEEE 1609.2 define the technical functions that digital signature and encryption to provide security of V2X messages. However, it is difficult to verify the security technology by applying it to the environment with real roads because it can be made up of other safety accidents. In addition, vehicle simulation R&D is steadily being carried out, but there is no simulation that evaluates security for the V2X application level. Therefore, in this paper, a virtual machine was used to implement a V2X communication simulation environment that satisfies the requirements for the security evaluation of connected cars. Then, we proposed scenarios for cybersecurity testing and evaluation, implemented and verified through CANoe Option.Car2X. Through this, it is possible to perform sufficient preliminary verification to minimize the variables before verifying security technology in a real road environment.

Low Transcondylar Fractures of the Distal Humerus: A Multicenter Cohort Study.

OBJECTIVES: To determine the demographic characteristics and clinical and radiologic results of low transcondylar fractures and compare them with those of other types of distal humerus fractures using multicenter data and to suggest an optimal method for their treatment. DESIGN: Retrospective cohort study. SETTING: Tertiary-care university hospital. PATIENTS: Between 2009 and 2019, 581 patients who underwent surgery for distal humerus fractures (OTA/AO classification A1 to C3) were enrolled at 7 university-affiliated hospitals. INTERVENTION: Internal fixation of low transcondylar fractures. MAIN OUTCOME MEASURES: Demographic characteristics, including sex, age, mechanism of injury, fixation methods, and complications, were compared between low transcondylar (group A) and other distal humerus (group B) fractures. Clinical outcomes assessed included pain, stability, and range of motion. Radiographs obtained at the latest follow-up were assessed for union, delayed union, nonunion, and implant failure. RESULTS: Mean age was 62.1 ± 19.1 (range, 20-95) years, and it was higher in group A (n = 100) than in group B (n = 376). Patients in group A were predominantly women. Low-energy trauma, such as that from a simple fall, was the most common cause of fracture in group A. Both column fixation, including parallel and orthogonal double plating, was performed more commonly in group A than in group B (87.4% vs. 66.4%, P < 0.001). The nonunion rate was higher in group A, but the difference was not significant. The incidence of ulnar nerve-related symptoms was higher in group A after surgery (6.3% vs. 2.0%, P = 0.003). No significant difference in clinical outcomes was found between the groups. CONCLUSIONS: Low transcondylar fractures occurred more frequently than other distal humerus fractures in older female patients and accounted for 21% of distal humerus fractures. The incidence of ulnar nerve-related symptoms was higher in patients with low transcondylar fractures after surgery. Clinical outcomes were not inferior in patients with low transcondylar fractures. The nonunion rate in patients with low transcondylar fractures treated with double plating was 3.6%. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Photosensitive Nanodiscs Composed of Human Photoreceptors for Refractive Index Modulation at Selective Wavelengths.

A photoreceptor on the retina acts as an optical waveguide to transfer an individual photonic signal to the cell inside, which is determined by the refractive index of internal materials. Under the photoactivation of photoreceptors making conformational and chemical variation in a visual cell, the optical signal modulation is demonstrated using an artificial photoreceptor-based waveguide with a controlling beam refraction. Two types of nanodiscs are made of human photoreceptor proteins, short-wavelength-sensitive opsin and rhodopsin, with spectral sensitivity. The refractive index and nonlinear features of those two photosensitive nanodiscs are investigated as fundamental properties. The photonanodiscs are photoactivated in such a way that allow refractive index tuning over 0.18 according to the biological function of the respective proteins with color-dependent response.

Wireless portable bioelectronic nose device for multiplex monitoring toward food freshness/spoilage.

Monitoring food freshness/spoilage is important to ensure food quality and safety. Current methods of food quality monitoring are mostly time-consuming and labor intensive processes that require massive analytical equipment. In this study, we developed a portable bioelectronic nose (BE-nose) integrated with trace amine-associated receptor (TAAR) nanodiscs (NDs), allowing food quality monitoring via the detection of food spoilage indicators, including the biogenic amines cadaverine (CV) and putrescine (PT). The olfactory receptors TAAR13c and TAAR13d, which have specific affinities for CV and PT, were produced and successfully reconstituted in ND structures. TAAR13 NDs BE-nose-based side-gated field-effect transistor (SG-FET) system was constructed by utilizing a graphene micropattern (GM) into which two types of olfactory NDs (TAAR13c ND and TAAR13d ND) were introduced, and this system showed ultrahigh sensitivity for a limit of detection (LOD) of 1 fM for CV and PT. Moreover, the binding affinities between the TAAR13 NDs and the indicators were confirmed by a tryptophan fluorescence quenching assay and biosimulations, in which the specific binding site was confirmed. Gas-phase indicators were detected by the TAAR13 NDs BE-nose platform, and the LODs for CV and PT were confirmed to be 26.48 and 7.29 ppb, respectively. In addition, TAAR13 NDs BE-nose was fabricated with commercial gas sensors as a portable platform for the measurement of NH3 and H2S, multiplexed monitoring was achieved with similar performance, and the change ratio of the indicators was observed in a real sample. The integration of commercial gas sensors on a BE-nose enhanced the accuracy and reliability for the quality monitoring of real food samples. These results indicate that the portable TAAR13 NDs BE-nose can be used to monitor CV and PT over a wide range of concentrations, therefore, the electronic nose platform can be utilized for monitoring the freshness/spoilage step in various foods.

A Propensity Score-Matched Comparison Between Knotless Layer-by-Layer and En Masse Suture Bridge Techniques for Delaminated Rotator Cuff Tears.

BACKGROUND: Because the articular layer is more prone to retraction than the bursal layer of the supraspinatus tendon, it is important to restore each layer anatomically while repairing delaminated rotator cuff tears (RCTs). PURPOSE: To compare clinical outcomes and tendon integrity between knotless layer-by-layer and conventional en masse repair techniques for delaminated RCTs. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We retrospectively reviewed data from 174 consecutive patients with delaminated RCTs treated by arthroscopic suture bridge repair. Only 115 patients with medium to large supraspinatus tears with delamination were included. The 33 patients treated using the knotless layer-by-layer technique (group 2) were matched 1:1 with patients treated using en masse repair with the suture bridge technique (group 1) based on propensity scores. Tendon thickness was measured on magnetic resonance imaging (MRI). Signal changes in the bursal, articular, and intratendinous layers were assessed using T2-weighted MRI. RESULTS: Postoperatively, statistically significant improvements were seen in both groups compared with preoperatively functional scores. At the final follow-up, there was a statistically significant difference in the Constant score, which was higher in group 2 than in group 1 (91.4 ± 6.0 and 84.3 ± 16.4, respectively; P = .005). There was 1 case of a retear in each group, representing a 3% retear rate. Group 2 had thicker tendons than group 1 (6.9 ± 1.1 and 6.0 ± 1.2 mm, respectively; P = .017). On T2-weighted MRI, a low signal intensity in the articular layer was more common in group 2 (P = .046). CONCLUSION: En masse repair using the suture bridge technique and the knotless layer-by-layer technique were both effective. Regarding tendon healing, no significant differences were seen in retear rates. However, superior results in terms of the Constant score, tendon thickness, and signal intensity in the articular layer were observed using the knotless layer-by-layer technique.

In situ, real-time, colorimetric detection of γ-hydroxybutyric acid (GHB) using self-protection products coated with chemical receptor-embedded hydrogel.

Due to the increase in drug-facilitated sexual assault (DFSA) enabled by the illegal use of drugs, there have been constant demands for simple methods that can be used to protect oneself against crime in real life. γ-Hydroxybutyric acid (GHB), a central nervous system depressant, is one of the most dangerous drugs for use in DFSA because it is colorless and has slow physiological effects, which pose challenges for developing in situ, real-time GHB monitoring techniques. In this study, we developed a method for in situ colorimetric GHB detection using various self-protection products (SPPs) coated with 2-(3-bromo-4-hydroxystyryl)-3-ethylbenzothiazol-3-ium iodide (BHEI) as a chemical receptor embedded in hydrogels. Additionally, smartphone-based detection offers enhanced colorimetric sensitivity compared to that of the naked eye. The developed SPPs will help address drug-facilitated social problems.

Detection and discrimination of SARS-CoV-2 spike protein-derived peptides using THz metamaterials.

The development of effective assay techniques for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently received research attention due to its rapid worldwide spread and considerable risk to human health. The receptor-binding domain (RBD) of the spike (S) protein in SARS-CoV-2, a key component for viral entry that has a unique sequence compared to other structural proteins, has been considered an important diagnostic target. In this respect, low-frequency vibrational modes have the advantage of providing information about compositional and structural dependencies at the peptide level. In this study, the sensitive and selective detection of peptides derived from the RBD in SARS-CoV-2 and SARS-CoV was investigated using metamaterial-based sensing chips with a terahertz time-domain spectroscopy (THz-TDS) system. Based on their RBD sequences, two pairs of peptides with 20 residues each were prepared. The sensitivity, specificity, and reproducibility of the proposed system were examined via quantitative analysis using THz metamaterials at three resonance frequencies, and it was found that the species could be discriminated based on their sequences. The THz signals were analyzed with regard to the major amino acid components of the peptides, and the molecular distributions were also investigated based on the hydropathy and net charge of the peptides.

In-situ food spoilage monitoring using a wireless chemical receptor-conjugated graphene electronic nose.

Monitoring food spoilage is one of the most effective methods for preventing food poisoning caused by biogenic amines or microbes. Therefore, various analytical techniques have been introduced to detect low concentrations of cadaverine (CV) and putrescine (PT), which are representative biogenic polyamines involved in food spoilage (5-8 ppm at the stage of initial decomposition after storage for 5 days at 5 °C and 17-186 ppm at the stage of advanced decomposition after storage for 7 days at 5 °C). Although previous methods showed selective CV and PT detection even at low concentrations, the use of these methods remains challenging in research areas that require in-situ, real-time, on-site monitoring. In this study, we demonstrated for the first time an in-situ high-performance chemical receptor-conjugated graphene electronic nose (CRGE-nose) whose limits of detection (LODs), 27.04 and 7.29 ppb, for CV and PT are up to 102 times more sensitive than those of conventional biogenic amine sensors. Specifically, the novel chemical receptors 2,7-bis(3-morpholinopropyl)benzo[lmn][3,8] phenanthroline-1,3,6,8(2H,7H)-tetraone (NaPhdiMor (NPM)) and 2,7-bis(2-((3-morpholinopropyl)amino)ethyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (NaPhdiEtAmMor (NPEAM)) were designed on the basis of density functional theory (DFT) calculations, and their interaction mechanism was characterized by a DFT 3D simulation. Interestingly, the CRGE-nose was connected on a micro sim chip substrate via wire bonding and then integrated into wireless portable devices, resulting in a cost-effective, high-performance prototype CRGE-nose device capable of on-site detection. The portable CRGE-nose can be used for in-situ monitoring of CV and PT concentration changes as low as 27.04 and 7.29 ppb in real meats such as pork, beef, lamb and chicken.

Why locking plates for the proximal humerus do not fit well.

INTRODUCTION: We compared the angle of the humerus and plate and to assess compatibility of a plate to the proximal humerus using three-dimensional (3D) printed models. MATERIALS AND METHODS: A total of 120 cases were included, who underwent anteroposterior shoulder radiographs. From these, 30 cases with 3D shoulder computed tomography scans were randomly selected to print 3D model. The lateral angle between the lateral cortex of the humeral shaft and lateral border of the greater tuberosity (GT), neck-shaft angle, and height from the most proximal point of the GT to the angular point were measured. When the plates were applied on the 3D models, the gap from the most proximal point of the GT to the proximal rim of the plate was measured. RESULTS: The mean lateral angle in plain radiographs was 12.9 ± 2.2° and height from the most proximal point of the GT to the angular point was 44.4 ± 4.7 mm. The bending angles of the three plates were 8° and 10°. Height from the proximal rim of the plate to the bending point was 42.4, 42.0 and 43.8 mm. In 98% of cases, the lateral angle of the humerus was larger than all three plates. In 43% of cases, height of the GT was smaller than height of plates. When plates were applied to the 3D model, the mean gap from GT to plate was 4.8 ± 2.8 mm. CONCLUSIONS: There was large variation in the lateral angle of the proximal humerus, which was not correlated with the neck-shaft angle. The lateral angle of the humerus was larger than the plates and prone to varus reduction and medial collapse. LEVEL OF EVIDENCE OR CLINICAL RELEVANCE: Basic science study.

Current concepts in the treatment of midshaft clavicle fractures in adults.

Midshaft clavicle fractures are the most common fracture of the clavicle accounting for 80% of all clavicle fractures. Traditionally, midshaft clavicle fractures are treated with conservative treatment even when prominent displacement is observed; however, recent studies revealed that nonunion or malunion rate may be higher with conservative treatment. Moreover, recent studies have shown better functional results and patient satisfaction with surgical treatment. This review article provides a review of clavicle anatomy, describes the current clavicle fracture classification system, and outlines various treatment options including current surgical options for clavicle fracture in adults.

Suture Slippage After Arthroscopic Cuff Repair: Medial Displacement of Suture Knots on Follow-up Ultrasonography.

BACKGROUND: Compared with the single-row technique, the double-row rotator cuff repair technique is known to have a higher load to failure and a lower frequency of gap formation, leading to a lower retear rate. There are some patients with poor clinical outcomes or poor muscle strength without radiologic retear. PURPOSE/HYPOTHESIS: To assess the postoperative position of suture knots via serial ultrasonography in patients who had undergone arthroscopic rotator cuff repair with the suture-bridge technique. Our hypothesis was that the suture would pull out of the lateral anchor (suture slippage), changing the positions of the medial suture knots during healing. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study included 53 patients (55 shoulders) who underwent arthroscopic suture-bridge repair and were evaluated for a minimum of 24 months. On serial ultrasonography, a straight line was drawn between the top of the greater tuberosity and the medial cortex of the anchor hole. The distances between the knots of the medial rows and the perpendicular line through the center of the anchor hole were measured in longitudinal plane images of the supraspinatus. Follow-up ultrasonography was performed at 2, 3, and 6 months postoperatively as well as at the final visit. The visual analog scale, the American Shoulder and Elbow Surgeons score, the Constant score, and the University of California, Los Angeles shoulder score were recorded preoperatively and on the final follow-up. RESULTS: Of the 55 shoulders, 6 developed retears at repaired sites. The mean follow-up duration was 37.5 months (range, 24-65 months). Slippage distance increased significantly over time (P < .001). The slippage at the final visit did not differ between patients with retear and no retear (13.4 mm for retear group; 10.6 mm for no retear group [P = .096]). CONCLUSION: Suture knots of the medial row migrated medially via a suture pullout from the lateral row anchor of suture-bridge technique. Suture slippage distance did not differ significantly between retear and no retear groups.