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.

Effect of Alaska pollock-gelatin sheet on repair strength and regeneration of nerve.

The aim of the study was to investigate the repair strength and the biocompatibility of Alaska pollock-derived gelatin (ApGltn) sheet for nerve repair. Cadaveric digital nerves were repaired with double suture, single suture + ApGltn sheet, single suture + fibrin glue, single suture, ApGltn sheet and fibrin. Maximum failure loads were measured (20 nerves each). Rat sciatic nerves were repaired with double suture, single suture + ApGltn sheet, single suture, ApGltn sheet, fibrin glue and resection (10 nerves each). Macroscopic appearance, muscle weight and histopathological findings were examined 8 weeks postoperatively. The mean failure load of ApGltn sheet (0.39 N) was significantly higher than that of a fibrin (0.05 N), and that of single suture + ApGltn sheet (1.32 N) was significantly higher than that of a single suture alone (0.97 N). Functional and histological assessments showed similar nerve recovery among the suture, ApGltn and fibrin groups. ApGltn sheet has potential for clinical application as an alternative to fibrin.

Effect of bolus property on swallowing dynamics in patients with dysphagia.

BACKGROUND: Modification of foods or liquids is commonly administered as part of dysphagia treatment. However, no consensus exists on the parameters for defining texture-modified food for patients with dysphagia. OBJECTIVES: The aim of this study was to evaluate the effect of food/liquid material on swallowing physiology in patients with dysphagia and to discuss the optimal food choice for direct swallowing therapy. MATERIALS AND METHODS: A total of 140 patients underwent a videofluoroscopic swallowing study using three test foods/liquids: 3 mL of mildly thick liquid (Thick liquid), jelly made of agar and polysaccharide (Jelly) and jelly made of pectin (Reset gel). Outcome measures of videofluoroscopic images, bolus transit time and hyoid movements were compared. RESULTS: The frequency of chewing movements was highest for Jelly, followed by Reset gel and Thick liquid. While the probability of oral residue was the highest for Reset gel, pharyngeal residue after swallowing was high for Thick liquid as compared to Jelly and Reset gel. Oral transit time and pharyngeal transit time for Thick liquid were significantly smaller than that for Jelly and Reset gel. Pharyngeal delay time was significantly smaller for Thick liquid than that for Jelly and Reset gel. There was no difference in hyoid elevation time and hyoid movement time among the conditions. CONCLUSION: Mildly thick liquid material may be optimal for patients with primarily oral motor function impairment and jelly, such as Reset gel, may be more suitable for patients with primarily pharyngeal motor function impairment or oral and pharyngeal coordinative motor function decline.

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.

In Situ Helium Isotope Microimaging of Meteorites.

Isotope imaging is commonly used to investigate the localization of trace elements and their isotopes. In situ noble gas analysis of meteorites revealed the distribution of primordial noble gases that were trapped in the building blocks of asteroids and planets during the early stage of the solar system evolution. Solar wind noble gases are among the primordial gases present in meteorites and were trapped through exposure to solar wind. Micrometer-resolution in situ noble gas analysis has not been achieved due to the lack of sensitivity and spatial resolution. The microscale imaging technique is crucial for identifying the carrier phase of the solar wind noble gases. We have developed 4He isotope imaging utilizing secondary neutral mass spectrometry with strong field postionization. This technique achieved a lateral resolution of 2 µm and a 4He detection limit of 2 × 1017 cm-3. This development allows for the study of a solar wind gas-rich meteorite, Northwest Africa 801 carbonaceous chondrite, with micrometer resolution. The solar wind 4He carriers are fine-grained particles and are sparsely scattered in the matrix region.

Chewing Well Modulates Pharyngeal Bolus Transit During Swallowing in Healthy Participants.

Mastication is controlled by central pattern generator in the brainstem and can be modulated by volition. The aim of this study was to investigate the effect of chewing well on swallowing. Twenty-six healthy participants were instructed to eat 8, 12, and/or 16 g of steamed rice with barium sulphate under the following two conditions: chewing freely task (CF; chewing naturally in their usual manner) and chewing well task (CW; chewing the food with a request to "chew well"). We evaluated bolus transport and swallowing movement using videofluoroscopy and electromyography of the masseter, suprahyoid and thyrohyoid muscles. The chewing time and pharyngeal transit time (PTT) at the first swallow showed high reproducibility in both CF and CW. PTT for CW was significantly shorter and longer than CF in 12 and 16 g, respectively. In 12 g, CW increased the pharyngeal bolus velocity and decreased thyrohyoid EMG activity during swallowing compared with CF. In 16 g, the difference between CW and CF in the estimated swallowed bolus volume was positively correlated with that in upper esophageal sphincter transit duration. We speculate that CW modulates PTT during swallowing depending on the mouthful volume.

Alaska Pollock-derived Gelatin Sealant has Higher Sealing Strength than, and Comparable Biocompatibility with, Fibrin Sealant in Porcine and Rat Dural Injury Models.

STUDY DESIGN: Burst strength study in porcine dural models and functional and histological study in rat dural models. OBJECTIVE: This study aimed to investigate the sealing strength and biocompatibility of Alaska pollock-derived gelatin (ApGltn) and fibrin sealants in disrupted dural injuries. SUMMARY OF BACKGROUND DATA: Disruption of the dura mater occurs during spine surgery, leading to cerebrospinal fluid leakage. Fibrin sealant is usually applied to ruptured sites; however, it lacks sealing strength. A novel biocompatible sealant composed of ApGltn was recently demonstrated to have good burst strength and biocompatibility in the porcine aorta. METHODS: Ten porcine dura maters with central holes were covered with ApGltn and fibrin sealants (five samples per group). The maximum burst strength of each sealant was measured, and histological examination was performed after burst testing. Twenty-seven dura maters of male Wistar rats were used for functional and histopathological evaluations. The rats were treated with three surgical interventions: defect + ApGltn sealant; defect + fibrin sealant; defect alone (nine rats per group). Macroscopic confirmation of the sealant, hindlimb motor function analysis, and histopathological examination were performed at 2, 4, and 8 weeks after the procedure. RESULTS: The maximum burst strength of the ApGltn sealant was approximately 4.4 times higher than that of the fibrin sealant (68.1±12.1 vs. 15.6±8.7 mmHg; P<0.001). Histological examination confirmed that the ApGltn sealant showed tight adhesion to the dural surface, whereas a gap was observed between the fibrin sealant and the dura mater. In the rat model, the ApGltn sealant resulted in spinal function and dural histological findings similar to those of the fibrin sealant. CONCLUSIONS: The ApGltn sealant had a higher sealing strength than, and comparable effect on dura regeneration with, the fibrin sealant.

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome.

BACKGROUND: This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome. METHODS: We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed. RESULTS: Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %. CONCLUSIONS: Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases. LEVEL OF EVIDENCE: Diagnostic III.

Long-standing Ulnar Wrist Pain Caused by an Anatomic Variant of the Ulnar Nerve: A Case Report.

CASE: We present a 28-year-old woman with long-standing left ulnar wrist pain. Physical examination revealed severe tenderness over the pisiform; imaging findings were normal. Surgical exploration revealed compression of an aberrant branch, likely Kaplan's accessory branch, around the pisiform. Complete symptom relief was achieved after nerve decompression. CONCLUSION: Clinical symptoms associated with Kaplan's accessory branch are rare, indicating that many branches may be asymptomatic or overlooked despite the presence of symptoms. Kaplan's accessory branch should be considered as a potential differential diagnosis for refractory ulnar wrist pain.

Persistent Ulnar Nerve Palsy with Cubitus Valgus Deformity Following a Surgically Treated Flexion-type Supracondylar Humeral Fracture - A Case Report.

Introduction: Supracondylar humeral fractures (SHFs) in children are mostly extension-type. SHFs have a high risk of cubitus varus deformity, while valgus deformity is rarely described. Nerve palsy can also occur during or after the injury, with most cases recovering spontaneously. Here, we present a rare case of cubitus valgus deformity after a flexion-type SHF with ulnar nerve (UN) palsy, which was successfully treated by corrective osteotomy and anterior transposition of the UN. Case Report: A 10-year-old girl had left-sided cubitus valgus deformity with persistent UN palsy 4 months after open reduction and internal fixation (ORIF) at another hospital. Half a year after the initial operation, corrective osteotomy of the distal humerus with neurolysis and subcutaneous anterior transposition of the UN were performed. She showed excellent recovery 14-month postoperatively and reported restored motor and sensory function with symmetrical elbow appearance. Conclusion: Surgeons usually observe the elbow angle carefully to avoid cubitus varus deformity. However, when treating a case of flexion-type SHFs, ORIF should be conducted to avoid cubitus valgus deformity, which could potentially cause UN traction as well as cosmetic dissatisfaction.

Influence of Electrodiagnostic Studies on Surgery for Carpal Tunnel Syndrome: A Retrospective Analysis of Data from a Single Urban Institution.

Background: This study aimed to clarify the influence of preoperative electrodiagnostic (EDX) utilisation and its severity on surgically treated patients with carpal tunnel syndrome (CTS). Methods: This retrospective study analysed the data of patients who underwent CTS surgery at our facility from 2012 to 2022. Data regarding age, sex, affected side, diabetes mellitus, rheumatoid arthritis, haemodialysis and insurance type were collected, along with the following clinical information: utilisation of EDX, steroid injection, number of items of preoperative physical examination and history taking, intervals between symptom onset and the initial visit and between the initial visit and surgery, type of surgical procedure and surgery categorisation (primary or revision). EDX data (EDX severity, interval between EDX and surgery and concomitant nerve lesions) were also investigated. Univariate and multivariate analyses were conducted to assess the influence of EDX utilisation and severity on clinical parameters. Results: Of the 343 hands enrolled in our study, 304 (89%) underwent preoperative EDX assessment. EDX severity was classified as normal, mild, moderate or severe in 6 (2%), 18 (6%), 102 (34%) and 178 hands (58%), respectively. After the univariate and multivariable analyses, more items of preoperative physical examination and history taking were associated with non-EDX utilisation, whereas younger age, female sex and steroid injection were associated with milder EDX. Conclusions: Increased number of items of preoperative physical examination and history taking or steroid injection were independently associated with non-EDX utilisation or milder EDX, respectively, suggesting that when thorough clinical evaluation is conducted, hand surgeons may be less likely to request for EDX before surgery. Moreover, their treatment recommendation may be influenced by EDX severity. Level of Evidence: Level III (Diagnostic).

Press-Fit Hemihamate Arthroplasty for the Proximal Interphalangeal Joint.

Background Chronic proximal interphalangeal joint fracture-dislocations with articular malunion are complex injuries. Hemihamate arthroplasty is an established technique for the management of both acute and chronic cases but is associated with several complications. We present the clinical experience of modified press-fit hemihamate arthroplasty. Description of Technique The base of the middle phalanx was exposed from the volar side, and the cartilage defect of the proximal interphalangeal joint (PIPJ) was evaluated in the hyperextended position. A bone hole was created slightly toward the volar side to recreate the curvature of the PIPJ. The hemihamate osteochondral graft was harvested and fixed into the bone hole in a press-fit manner without using a screw. The volar plate and flexor tendon sheath were then reattached. Patients and Methods The study included three patients with chronic dorsal fracture-dislocations of the PIPJ. All patients were treated for >6 weeks after the injury (average 11 weeks). Results The average total arc of motion of the affected joint improved from 38 degrees before surgery to 80 degrees after surgery. Radiographically, bone union and congruity of the joint surface were achieved in all the patients. None of the treated patients complained of resting pain and reported minimal pain during activity (average visual analog scale 0.5; range 0-1.4). Conclusions Press-fit hemihamate arthroplasty is a safe and effective procedure for treating chronic PIPJ fracture-dislocations without the risk of screw protrusion.

Surgical Approaches for Thoracic Outlet Syndrome: A Review of the Literature.

Thoracic outlet syndrome (TOS) is caused by entrapment of the neurovascular bundle in the interscalene, costoclavicular, or subpectoral minor space. Compression in the interscalene or costoclavicular space with the first rib and scalene muscle leads to vascular and neurogenic TOS, whereas compression in the subpectoral minor space leads to pectoralis minor syndrome. Various surgical approaches exist for the treatment of TOS. The introduction and development of surgical approaches have minimized surgical invasiveness and complications. The reported approaches include transaxillary, supraclavicular, infraclavicular, posterior, combined transaxillary and supraclavicular, combined supraclavicular and infraclavicular (paraclavicular), endoscopic-assisted transaxillary, and video-assisted thoracoscopic approaches. In this review, we summarize the reported surgical approaches for TOS treatment, in terms of the history of the approach, surgical procedure, advantages and disadvantages, clinical outcomes, and complications. An adequate excision of compression structures, including the first rib and scalene muscles, provides satisfactory outcomes regardless of the approach selected, whereas an inadequate release of compression structures leads to failed or recurrent outcomes. Reducing the risk of complications is the most important aspect of TOS management. Surgery should be performed safely, with sufficient resection of compression structures. Additionally, the approach should be selected based on the surgeon's skill, surgeon's preferences, surgical invasiveness, cosmetic appearance, and the presence of special equipment, as well as other advantages and disadvantages of each approach.

Modulation of reflex responses of the anterior and posterior bellies of the digastric muscle in freely moving rats.

BACKGROUND: Chewing and licking are primarily activated by central pattern generator (CPG) neuronal circuits in the brainstem and when activated trigger repetitive rhythmic orofacial movements such as chewing, licking and swallowing. These CPGs are reported to modulate orofacial reflex responses in functions such as chewing. OBJECTIVE: This study explored the modulation of reflex responses in the anterior and posterior bellies (ant-Dig and post-Dig, respectively) of the digastric muscle evoked by low-intensity trigeminal stimulation in conscious rats. METHODS: The ant-Dig and post-Dig reflexes were evoked by using low-intensity electrical stimulation applied to either the right or left inferior alveolar nerve. Peak-to-peak amplitudes and onset latencies were measured. RESULTS: No difference was observed between threshold and onset latency for evoking ant-Dig and post-Dig reflexes, suggesting that the latter was also evoked disynaptically. The peak-to-peak amplitude of both reflexes was significantly reduced during chewing, licking and swallowing as compared to resting period and was lowest during the jaw-closing phase of chewing and licking. Onset latency was significantly largest during the jaw-closing phase. Inhibitory level was similar between the ant-Dig and post-Dig reflex responses and between the ipsilateral and contralateral sides. CONCLUSION: These results suggest that both the ant-Dig and post-Dig reflex responses were significantly inhibited, probably due to CPG activation during feeding behaviours to maintain coordination of jaw and hyoid movements and hence ensure smooth feeding mechanics.

Artificial Lunate Arthroplasty for Kienböck Disease With Multiple Extensor Tendon Ruptures: A Case Report.

CASE: A 73-year-old woman presented with wrist pain and loss of extension in the middle and ring fingers. Radiography revealed a dorsally displaced lunate fragment, resulting in a diagnosis of Kienböck disease with extensor tendon rupture. Artificial lunate replacement and tendon transfer were performed as treatment. Two years postoperatively, the pain was relieved, and the extension lag was 0°. The wrist motion and carpal height had also improved. CONCLUSION: Lunate excision, partial wrist arthrodesis, or proximal row carpectomy are known treatments for Kienböck disease with extensor tendon rupture. Lunate arthroplasty is a novel, useful treatment option for this condition.

Distal Radioulnar Joint Locking with Bipolar Injury.

Background Locking of the distal radioulnar joint (DRUJ) induces restriction of the active and passive motion of pronation or supination of the forearm. Diagnosis of DRUJ locking due to a triangular fibrocartilage complex (TFCC) tear is sometimes difficult. Case Description A 15-year-old female suffered from restriction of forearm supination after cast immobilization for the treatment of an elbow injury. The active and passive range of motion (ROM) of supination was 30 degrees, while the active ROM of pronation was normal. Radiographs of the elbow showed a fracture of the medial epicondyle and a fracture around the radial head. Radiographs of the wrist showed a subluxation of the ulnar head. Accurate diagnosis of supination restriction was difficult before surgery, so an operation was performed for the diagnosis and treatment. DRUJ locking was reduced manually and arthroscopic findings showed central perforation of the TFCC. Forearm supination improved to 90 degrees postoperatively. Literature Review DRUJ locking due to a TFCC injury is rare and this condition with bipolar injury has not been reported. Clinical Relevance DRUJ locking due to an injured TFCC should be considered as one of the differential diagnoses of supination contracture.