Quantitative evaluation of natural progression of fatty infiltration and muscle atrophy in chronic rotator cuff tears without tear extension using magnetic resonance imaging.

Background: The pathology of and mechanisms underlying muscle degeneration remain unclear. We aimed to quantitatively evaluate the natural changes in fatty infiltration and muscle atrophy in patients with chronic rotator cuff tears using 3-dimensional 2-point Dixon magnetic resonance imaging. Methods: Thirty patients with nonoperatively observed rotator cuff tears without tear extension were evaluated using multiple magnetic resonance imaging examinations with a minimum interval of 2 years. The fatty infiltration ratio (%fat) and muscle volume of the rotator cuff muscles were compared between the 2 examinations in those with supraspinatus (SSP) tear <2 cm (<2 cm SSP group), SSP tear ≥2 cm (≥2 cm SSP group), and massive tear (massive group). The SSP) infraspinatus, and teres minor (ISP + TM), and subscapularis muscles were evaluated. Results: The massive group showed a significantly greater %fat than the <2 and ≥2 cm SSP groups in the SSP (P = .002) and ISP + TM muscles (P < .001). The total muscle volume did not differ among the 3 groups for all rotator cuff muscle components. The %fat values did not change in any rotator cuff components during the follow-up period in all groups. The total muscle volume in the massive group significantly decreased in the SSP (P = .018) and ISP + TM muscles (P = .013). Conclusion: The present results indicate that fatty infiltration of the torn muscle occurs in the early phase after a rotator cuff tear, whereas muscle atrophy appears to progress gradually in chronic rotator cuff tears. Early intervention before muscle degeneration should be considered if the tear involves the infraspinatus tendon.

Recent advances in unlinked total elbow arthroplasty in Japan.

Background: Total elbow arthroplasty (TEA) is a valuable therapeutic approach for improving function and relieving pain in severely deformed elbow joints. However, TEA is associated with a high incidence of complications. In Japan, the use of unlinked TEA has a long history, with the development of the Kudo prosthesis marking a significant milestone. Subsequently, various unlinked implant designs have been developed. Although favorable long-term clinical results have been reported, complications remain a concern. To further improve the outcome of unlinked TEA, attempts have been made in recent years to develop various surgical approaches and intraoperative support devices. This review focuses on the clinical outcomes and recent advances in unlinked TEA in Japan. Methods: A comprehensive review of clinical results and advancements in unlinked TEA in Japan was conducted. The analysis included trends in the number of TEA, medium-term and long-term results for unlinked TEA, surgical approaches, or preoperative planning techniques. Results: Several implant designs have been developed in Japan. Clinical studies have reported satisfactory long-term outcomes with these implants, but complications, such as infection, fractures, and dislocation, have been observed. In order to enhance the outcomes of unlinked TEA, various triceps-on approaches have been developed as alternatives to the triceps-detaching approach, which compromises the continuity between the triceps tendon and ulna, leading to inevitable complications related to the triceps tendon. Preservation or repair of the surrounding soft tissues is considered critical for preventing postoperative instability due to the absence of a radial head in the current unlinked TEA design. Computed tomography-based 3-dimensional preoperative planning has been pioneered in Japan, demonstrating its effectiveness in predicting implant size and achieving appropriate implant placement. Additionally, augmented reality-assisted surgery is being explored to accurately translate preoperative planning into the surgical procedure. Conclusion: Unlinked TEA for inflammatory arthritis has exhibited promising long-term results in Japan, with ongoing efforts to improve surgical techniques and preoperative planning. Further advancements are anticipated to prevent complications such as dislocation and peri-implant fractures.

Webplasty using an external fixator for complex syndactyly caused by Apert syndrome.

BACKGROUND: Webplasty can be conducted for complex syndactyly caused by Apert syndrome (also referred to as Apert hand) by extending the soft tissue in the lateral direction using an external fixator. This study aimed to verify the usefulness of webplasty without skin grafting. METHODS: Webplasty with lateral extension was conducted at a single institution from 2015 to 2023. The patients were four children with Apert hand aged 1-3 years. A custom-made small external fixator was used for all of the soft tissue extension. RESULTS: Webplasty without skin grafting was completed by the time all five patients were 5-6 years of age. CONCLUSION: Webplasty without skin grafting was possible with lateral extension of the soft tissue using a simple external fixator.

Extra-Articular Stabilization for the Treatment of Recurrent Sternoclavicular Joint Instability: A Report of Two Cases.

CASE: A 22-year-old man and a 14-year-old adolescent boy, who exhibited moderate general joint laxity, experienced recurrent sternoclavicular joint instability without traumatic events. The patients were successfully treated with extra-articular stabilization using autologous tendon grafts without surgical exposure of the sternoclavicular joint. CONCLUSION: Atraumatic instability of the sternoclavicular joint is rare but often results in recurrent instability accompanied by discomfort, pain, and limitations in activities. Extra-articular stabilization, which reinforces the anterior capsule of the sternoclavicular joint and prevents anterior displacement of the proximal clavicle at the elevated arm position, could be a viable surgical option for this pathological condition.

Severe Shoulder Pain Caused by Lipoma Arborescens in the Subdeltoid Bursa: A Case Report.

Introduction: Lipoma arborescens is a tumor-like lesion that occurs inside joints and synovial bursae, especially in knee joints. It rarely occurs in the shoulder joints and this disease usually causes severe shoulder pain. This study aims to report a rare case of lipoma arborescens occurring in the subdeltoid bursa with severe shoulder pain. Case Report: A 59-year-old woman with severe pain and restriction of range of motion (ROM) for her right shoulder consisting for 2 months was referred to our hospital. Magnetic resonance imaging (MRI) findings revealed that a tumor-like lesion exists in the subdeltoid bursa in her right shoulder and blood examinations revealed no abnormal findings. Surgical resection of the tumor-like lesion was performed and the rotator cuff was repaired because this tumor-like lesion invaded the rotator cuff partially. Pathology examination of the resected tissues was consistent with lipoma arborescens. One year after surgery, the patient's shoulder pain was diminished and its ROM recovered. There was no significant difficulty in activities of daily living. Conclusion: Lipoma arborescens should be considered when patients present with complaints of severe shoulder pain. Even if their physical findings do not suggest rotator cuff injuries, MRI should be performed to rule out lipoma arborescens.

Influence of Timing on Surgical Outcomes for Acute Humeral Shaft Fractures.

Surgical treatment for humeral shaft fractures has been reported to yield satisfactory results; however, there may be complications, such as delayed bone union, nonunion, iatrogenic radial nerve injury, and infection. The risk factors for postoperative complications remain largely unknown. This study aimed to investigate the influence of timing of surgery on the incidence of postoperative complications of acute humeral shaft fractures. We retrospectively reviewed 43 patients who underwent osteosynthesis for acute humeral shaft fractures between 2006 and 2020. The patients were divided into early (21 patients) and delayed (22 patients) treatment groups based on the timing of the surgical intervention (within or after four days). Outcomes were the incidences of complications (delayed union, nonunion, iatrogenic radial nerve injury, and infection) and postoperative fracture gaps. We evaluated the outcomes using plain radiographs and clinical notes. In addition, we performed subgroup analyses on outcomes in a subgroup of patients who underwent intramedullary nailing and one who underwent plate fixation. The frequency of delayed union was significantly higher in the delayed group (P=0.046), and the postoperative fracture gap size was also significantly greater in the delayed group (P=0.007). The subgroup analyses demonstrated a significant association between the increased incidence of delayed union and delayed surgical interventions only in the intramedullary nailing subgroup (P=0.017). This study suggests that performing surgery within four days after acute humeral shaft fracture is recommended to reduce the occurrence of delayed union, particularly in cases requiring intramedullary nailing fixation.

A Prospective Randomized Comparison of Variable-Angle and Fixed-Angle Volar Locking Plating for Intra-Articular Distal Radius Fractures.

PURPOSE: To compare clinical and radiographic outcomes of using a variable-angle volar locking plate (VAVLP) with those of using a fixed-angle volar locking plate (FAVLP) for treating unstable intra-articular fractures of the distal radius. METHODS: One hundred twenty patients with unstable intra-articular fractures of the distal radius were randomized to open reduction and internal fixation with a VAVLP (n = 60) or an FAVLP (n = 60). Supplementary methods (eg., Kirschner wire fixation) were required in 4 patients with a VAVLP and 9 with an FAVLP. Clinical outcomes were evaluated at 6 weeks, 3 months, 6 months, and 1 year after surgery. Posteroanterior and lateral radiographs were used to measure standard radiographic parameters before surgery, in the immediate postoperative period, and at 1 year. Plate prominence and articular congruity were quantified using computed tomography at 6 months. RESULTS: There were no significant differences in any clinical outcome between the groups at any follow-up time. Volar tilt was significantly greater in patients treated with a FAVLP in the immediate postoperative period (8° vs 6°) and at 1 year (8° vs 5°). Although significant differences were not found in articular gap or stepoff between the 2 plates, the distal and volar prominence of the VAVLP was significantly greater than that of the FAVLP at 6 months. Significantly more patients treated with a VAVLP had a complication (38% vs 19%). However, most secondary surgeries were performed for hardware removal, and no patients from either group had complex regional pain syndrome or tendon rupture. CONCLUSIONS: Patients with intra-articular distal radius fractures can expect good functional and radiographic outcomes with VAVLP or FAVLP fixation. The VAVLP may be more prone to technical errors, leading to complications, whereas the FAVLP is more likely to require supplementary fixation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Normal values and ranges of the lateral capitello-humeral angle in healthy children.

The lateral capitello-humeral angle (LCHA), which is an index of sagittal alignment of the elbow, has gradually been adopted for the postoperative assessment of radiographic results. However, the normal values and ranges of the LCHA remain unclear. A retrospective cohort study was performed to evaluate the normal values and ranges of the LCHA in a sample of healthy children with even distributions of age, sex and laterality. A total of 168 radiographs of the elbows of healthy children (age range, 0-11 years) with even distributions of age, sex and laterality were reviewed. The primary aim was to analyze the normal values and ranges of the LCHA categorized by age, sex and laterality. The secondary aim was to assess the association of the LCHA with increasing age. The LCHA between sex or laterality in each age category was also compared. The mean LCHA of the 168 patients was 47.1° (range, 27°-63°). There was a weak association between the LCHA and increasing age (r = 0.41). The mean LCHA in females (49.1°) was significantly larger than that in males (45.1°). Significant sex-related differences were observed in age categories between 2 and 7 years. Results of this study will be useful in the postoperative radiographic assessment of sagittal alignment of the elbow in children.

Smoking cessation increases levels of osteocalcin and uncarboxylated osteocalcin in human sera.

Smoking is thought to be a risk factor for osteoporosis development; however, the consequences of stopping smoking for bone homeostasis remain unknown. Here we conducted two separate human studies and show that bone mineral density was significantly lower in smokers than in non-smokers. The first was an observational study of pre- and post-menopausal healthy female smokers and non-smokers; the second included 139 current smokers determined to stop smoking. In the second study, levels of bone formation markers such as osteocalcin and uncarboxylated osteocalcin significantly increased after successful smoking cessation, as verified by significantly reduced levels of serum cotinine, a nicotine metabolite. Moreover, nicotine administration to mice reduced bone mineral density and significantly increased the number of osteoclasts in bone. Reduced bone mass phenotypes seen in nicotine-treated mice were significantly increased following nicotine withdrawal, an outcome accompanied by significantly reduced serum levels of tartrate-resistant acid phosphatase, a bone resorption marker. Taken together, our findings suggest that bone homeostasis is perturbed but can be rescued by smoking cessation.

Acute progressive bilateral carpal tunnel syndrome associated with remitting seronegative symmetrical synovitis with pitting edema syndrome: A case report.

The association between carpal tunnel syndrome (CTS) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome, an elderly onset rheumatic disease, is not fully understood. Here, we describe a case of acute CTS caused by RS3PE syndrome. An 84-year-old man visited the hospital with sudden onset of severe neuralgia in the median nerve and pitting edema in both hands. Computed tomography showed low-density areas around the flexor tendons and median nerve compression in the carpal tunnel. Rapidly progressing intolerable neuralgia and paralysis required urgent carpal tunnel release in the left hand. After surgery, we considered the possibility of RS3PE syndrome and started the administration of prednisolone. The pitting edema and neuralgia improved. In this case, imaging and intraoperative findings suggest that the effusion generated from flexor tenosynovitis associated with RS3PE syndrome increased the internal pressure in the carpal tunnel rapidly, which led to acute CTS and urgent surgery.

Electronic engineering of a tetrathiafulvalene charge-transfer salt via reduced symmetry induced by combined substituents.

A 1 : 1 metallic charge-transfer salt is obtained by cosublimation of (Z,E)-(SMe)2Me2TTF and TCNQ. X-ray diffraction studies confirm the formation of segregated stacks comprising donor and acceptor molecules in [(E)-(SMe)2Me2TTF](TCNQ). The crystal packing features lateral SS interactions between TTF stacks, which is in sharp contrast to that in (TTF)(TCNQ). Structural analysis and theoretical studies afford a partial charge-transfer (ρ ≈ 0.52), leading to a system with the electronic structure close to quarter-filled. Resistivity measurements reveal that this material behaves as a metal down to 56 K and 22 K at 1 bar and 14.9 kbar, respectively. The thermopower is negative in the metallic regime, indicating the dominant role of the acceptor stacks for the observed conducting behavior. Analysis of single-crystal EPR spectra shows the remaining spin susceptibility at 4.3 K, suggesting the importance of the Hubbard U correction. These results highlight the judicious engineering of electronic and geometrical effects on the TTF core; the combined use of methyl and thiomethyl groups has decreased the TCNQ bandwidth while maintaining the segregated stacks, converting the metal to insulator (M-I) transition to more 4kF like. In addition, the enhanced SS contacts between the TTF stacks lead to more rapidly decreasing M-I transition temperature under various pressures.

Dorsal subscapularis approach for the surgical drainage of subscapularis intramuscular abscess: a case report.

BACKGROUND: Abscess formation in the subscapularis muscle is a rare clinical condition. Few reports are available regarding the treatment methods and surgical approaches for subscapularis intramuscular abscesses. Here, we describe a case of subscapularis intramuscular abscess that was treated successfully via surgical drainage using a new approach, the "dorsal subscapularis approach". CASE PRESENTATION: A 67-year-old woman presented to our hospital with complaints of fever and disturbance of consciousness. Two days prior to visiting our hospital, right shoulder pain and limited range of motion in the shoulder were noted. Cerebrospinal fluid examination and contrast-enhanced computed tomography (CT) imaging on admission revealed a right subscapularis intramuscular abscess with concomitant bacterial meningitis. The patient's clinical symptoms improved after antibiotic administration for 3 weeks, but the right shoulder pain persisted. Contrast-enhanced CT imaging performed after antibiotic administration revealed an abscess in the right shoulder joint space, in addition to a capsule of the abscess in the right subscapularis muscle. We performed open surgical drainage for the abscess, which had spread from the subscapularis muscle to the glenohumeral joint. Using the deltoid-pectoral approach, we detected exudate and infected granulation tissue in the joint cavity. Furthermore, we separated the dorsal side of the subscapularis muscle from the scapula using a raspatory and detected infected granulation tissue in the subscapularis muscle belly. We performed curettage and washed as much as possible. After surgery, antibiotic administration continued for 2 weeks. The patient's right shoulder pain subsided and CT performed 2 months after surgery revealed no recurrence of infection. CONCLUSIONS: The present case indicated that a subscapularis intramuscular abscess could lead to severe concomitant infections of other organs via the hematogenous route. Thus, early detection and treatment are necessary. Moreover, in this case, surgical drainage using a dorsal subscapularis approach was beneficial to treating the abscess, which had spread from the subscapularis muscle to the glenohumeral joint.

Clavicle fracture at the suture hole after acromioclavicular joint reconstruction using a suture-button: a case report.

BACKGROUND: Intraosseous suture-button devices have been used for acromioclavicular joint reconstruction due to its relative simplicity compared with other procedures. However, the complications of acromioclavicular joint reconstruction using a suture-button are not fully understood. Here, we describe a case of a clavicle fracture at the suture hole following acromioclavicular joint reconstruction using a suture-button and hook plate. CASE PRESENTATION: A 28-year-old man presented at our hospital after a fall from his bicycle. The patient had a history of acromioclavicular joint reconstruction with a suture-button and a hook plate for right acromioclavicular joint dislocation, seven months ago at another hospital. The hook plate had been removed four months ago, while X-ray radiography before removal had shown the widening of a suture hole. In the current fall from the bicycle, X-ray radiography revealed a clavicle fracture through the previous drill hole for suture-button. We removed the suture-button and performed an open reduction and internal fixation for the clavicle fracture. CONCLUSION: The present case indicated that a clavicle fracture at the suture hole, although rare, is one of the complications after an acromioclavicular joint reconstruction using a suture-button. This case suggested that drilling to the necessary minimum when making suture holes and paying attention to the widening of suture holes are important to prevent a postoperative clavicle fracture.

Posterosuperior shoulder dislocation due to the rupture of deltoid posterior fibers: a case report.

BACKGROUND: Superior shoulder dislocation is a rare type of shoulder dislocation. Its occurrence is thought to be associated with rupture of the deltoid; however, few reports are available on the mechanism of onset and the treatment of a superior shoulder dislocation. Here we describe a case of dislocation in the direction of the posterior acromion, referred to as posterosuperior shoulder dislocation, caused by the traumatic rupture of deltoid posterior fibers. CASE PRESENTATION: An 83-year-old woman who fell on her right elbow in the hospital presented to our department with complaints of right shoulder pain. She had been undergoing conservative treatment for a massive rotator cuff tear and a rupture of the long head of biceps tendon 5 years previously. X-ray radiography images at the time of the trauma revealed that the right humeral head was dislocated upwards and in the direction of the posterior acromion. Magnetic resonance imaging (MRI) revealed newly ruptured deltoid posterior fibers, in addition to the massive rotator cuff tear. Closed reduction was performed and the shoulder joint was held in external rotation at 30 degrees for 6 weeks. However, re-dislocation was observed at an early stage after the removal of the orthosis and marked instability remained. CONCLUSIONS: This is the first case of posterosuperior shoulder dislocation. It suggests that rupture of the deltoid posterior fibers contributes to the onset of posterosuperior shoulder dislocation in patients with a massive rotator cuff tear. Moreover, in superior shoulder dislocation, conservative treatment may result in continuing instability which requires surgical treatment.

Suppressed Triplet Exciton Diffusion Due to Small Orbital Overlap as a Key Design Factor for Ultralong-Lived Room-Temperature Phosphorescence in Molecular Crystals.

Persistent room-temperature phosphorescence (RTP) under ambient conditions is attracting attention due to its strong potential for applications in bioimaging, sensing, or optical recording. Molecular packing leading to a rigid crystalline structure that minimizes nonradiative pathways from triplet state is often investigated for efficient RTP. However, for complex conjugated systems a key strategy to suppress the nonradiative deactivation is not found yet. Here, the origin of small rates of a nonradiative decay process from triplet states of conjugated molecular crystals showing RTP is reported. Optical microscopy analysis showed that, despite a favorable molecular stacking, an aromatic crystal with strong RTP is characterized by small diffusion length and small values of the diffusion coefficient of triplet excitons. Quantum chemical calculations reveal a large overlap between the lowest unoccupied molecular orbitals but very small overlap between the highest occupied molecular orbitals (HOMOs). Inefficient electron exchange caused by the small overlap of HOMOs prevents triplet excitons from diffusing over long distances and consequently from quenching at defect sites inside the crystal or at the crystal surface. These results will allow design of comprehensive molecular structures to obtain molecular solids with more efficient RTP.

Benzothienobenzothiophene-Based Molecular Conductors: High Conductivity, Large Thermoelectric Power Factor, and One-Dimensional Instability.

On the basis of an excellent transistor material, [1]benzothieno[3,2-b][1]benzothiophene (BTBT), a series of highly conductive organic metals with the composition of (BTBT)2XF6 (X = P, As, Sb, and Ta) are prepared and the structural and physical properties are investigated. The room-temperature conductivity amounts to 4100 S cm(-1) in the AsF6 salt, corresponding to the drift mobility of 16 cm(2) V(-1) s(-1). Owing to the high conductivity, this salt shows a thermoelectric power factor of 55-88 µW K(-2) m(-1), which is a large value when this compound is regarded as an organic thermoelectric material. The thermoelectric power and the reflectance spectrum indicate a large bandwidth of 1.4 eV. These salts exhibit an abrupt resistivity jump under 200 K, which turns to an insulating state below 60 K. The paramagnetic spin susceptibility, and the Raman and the IR spectra suggest 4kF charge-density waves as an origin of the low-temperature insulating state.

Adaptation process for standing postural control in individuals with hemiparesis.

PURPOSE: To study the adaptation process for standing postural control in patients with hemiparesis after stroke. METHODS: The changes of a standing posture developed in nine hemiparetic patients who had never maintained an upright stance alone (aged 48-62 years; 6-19 days after stroke) was evaluated by recording ground reaction forces and surface electromyographic (EMG) from lower limbs. A 60-s standing trial without any instruction about body alignment was repeated five times, and the experience-related changes of centre of pressure (COP) and integrated EMG data were estimated. RESULTS: In the early standing trials, patients balanced themselves by managing the average COP position around the midline of both feet, accompanied by increased muscular activity of the non-paretic leg. COP displacement gradually decreased in the later standing trials (P < 0.05). Postural adaptations were achieved by shifting the centre of body sway to the side of the non-paretic foot (P < 0.05) while reducing biceps femoris muscular activity (P < 0.01) in the non-paretic leg. CONCLUSIONS: This study revealed that weight-bearing asymmetry might contribute to improving increased body sway and muscular over-activity of the non-paretic leg. When planning rehabilitative treatment for hemiparetic patients, we should consider that weight-bearing asymmetry may be a result of systematic postural control.