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.

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.

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.

Novel artificial nerve transplantation of human iPSC-derived neurite bundles enhanced nerve regeneration after peripheral nerve injury.

BACKGROUND: Severe peripheral nerve damage always requires surgical treatment. Autologous nerve transplantation is a standard treatment, but it is not sufficient due to length limitations and extended surgical time. Even with the available artificial nerves, there is still large room for improvement in their therapeutic effects. Novel treatments for peripheral nerve injury are greatly expected. METHODS: Using a specialized microfluidic device, we generated artificial neurite bundles from human iPSC-derived motor and sensory nerve organoids. We developed a new technology to isolate cell-free neurite bundles from spheroids. Transplantation therapy was carried out for large nerve defects in rat sciatic nerve with novel artificial nerve conduit filled with lineally assembled sets of human neurite bundles. Quantitative comparisons were performed over time to search for the artificial nerve with the therapeutic effect, evaluating the recovery of motor and sensory functions and histological regeneration. In addition, a multidimensional unbiased gene expression profiling was carried out by using next-generation sequencing. RESULT: After transplantation, the neurite bundle-derived artificial nerves exerted significant therapeutic effects, both functionally and histologically. Remarkably, therapeutic efficacy was achieved without immunosuppression, even in xenotransplantation. Transplanted neurite bundles fully dissolved after several weeks, with no tumor formation or cell proliferation, confirming their biosafety. Posttransplant gene expression analysis highlighted the immune system's role in recovery. CONCLUSION: The combination of newly developed microfluidic devices and iPSC technology enables the preparation of artificial nerves from organoid-derived neurite bundles in advance for future treatment of peripheral nerve injury patients. A promising, safe, and effective peripheral nerve treatment is now ready for clinical application.

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.

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).

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.

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.

Schwann cell-encapsulated chitosan-collagen hydrogel nerve conduit promotes peripheral nerve regeneration in rodent sciatic nerve defect models.

Chitosan has various tissue regeneration effects. This study was designed to investigate the nerve regeneration effect of Schwann cell (SC)-encapsulated chitosan-collagen hydrogel nerve conduit (CCN) transplanted into a rat model of sciatic nerve defect. We prepared a CCN consisting of an outer layer of chitosan hydrogel and an inner layer of collagen hydrogel to encapsulate the intended cells. Rats with a 10-mm sciatic nerve defect were treated with SCs encapsulated in CCN (CCN+), CCN without SCs (CCN-), SC-encapsulated silicone tube (silicone+), and autologous nerve transplanting (auto). Behavioral and histological analyses indicated that motor functional recovery, axonal regrowth, and myelination of the CCN+ group were superior to those of the CCN- and silicone+ groups. Meanwhile, the CCN- and silicone+ groups showed no significant differences in the recovery of motor function and nerve histological restoration. In conclusion, SC-encapsulated CCN has a synergistic effect on peripheral nerve regeneration, especially axonal regrowth and remyelination of host SCs. In the early phase after transplantation, SC-encapsulated CCNs have a positive effect on recovery. Therefore, using SC-encapsulated CCNs may be a promising approach for massive peripheral nerve defects.

TNFα-dependent mTOR activity is required for tenotomy-induced ectopic ossification in mice.

INTRODUCTION: Ectopic ossifications often occur in skeletal muscles or tendons following local trauma or internal hemorrhage, and occasionally cause severe pain that limits activities of daily living. However, mechanisms underlying their development remain unknown. MATERIALS AND METHODS: The right Achilles tendon in 8-week-old female or male mice was dissected. Some mice were injected intraperitoneally either with phosphate-buffered saline, dimethyl sulfoxide, cimetidine, rapamycin, celecoxib or loxoprofen for 10 weeks. One week after surgery, immunohistochemical analysis was performed for mTOR, TNFα or F4/80. Ten weeks after surgery, ectopic ossification at the tenotomy site was detected by 3D micro-CT. RESULTS: Ectopic ossification was seen at dissection sites in all wild-type mice by dissection of the Achilles tendon. mTOR activation was detected at dissection sites, and development of ectopic ossification was significantly inhibited by administration of rapamycin, an mTOR inhibitor, to wild-type mice. Moreover, administration of the histamine 2 blocker cimetidine, which reportedly inhibits ectopic ossification in tendons, was not effective in inhibiting ectopic ossification in our models. TNFα-expressing F4/80-positive macrophages accumulate at dissection sites and that ectopic ossification of the Achilles tendon dissection was significantly inhibited in TNFα-deficient mice in vivo. Ectopic ossification is significantly inhibited by administration of either celecoxib or loxoprofen, both anti-inflammatory agents, in wild-type mice. mTOR activation by Achilles tendon tenotomy is inhibited in TNFα-deficient mice. CONCLUSION: The TNFα-mTOR axis could be targeted therapeutically to prevent trauma-induced ectopic ossification in tendons.

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.

Factors Associated with Change in Diagnosis of Carpal Tunnel Syndrome after Electrodiagnostic Studies.

Background: Hand surgeons sometimes place more weight on clinical findings and may not always consider the results of electrodiagnostic studies (EDX) in the diagnosis of carpal tunnel syndrome (CTS). The aim of this study is to determine factors associated with a change in diagnosis of CTS after EDX. Methods: This is a retrospective study of all patients with an initial clinical diagnosis of CTS who underwent EDX at our hospital. We identified patients whose diagnosis changed from CTS to non-CTS after EDX and used univariate and multivariate analysis to determine if age, sex, hand dominance, unilateral symptoms, history of diabetes mellitus, rheumatoid arthritis, haemodialysis, cerebral lesion, cervical lesion, mental disorder, initial diagnosis by a non-hand surgeon, the number of examined items in CTS-6 and a CTS-negative EDX result were associated with a change in diagnosis after EDX. Results: A total of 479 hands with a clinical diagnosis of CTS underwent EDX. The diagnosis was changed to non-CTS in 61 hands (13%) after EDX. Univariate analysis demonstrated that unilateral symptoms, cervical lesion, mental disorder, initial diagnosis by a non-hand surgeon, the number of examined items and a CTS-negative EDX result were significantly associated with a change in diagnosis. In the multivariate analysis, only the number of examined items was significantly associated with a change in diagnosis. Conclusions: EDX results were particularly valued in hands where the initial diagnosis was uncertain for CTS. In hands with an initial diagnosis of CTS, the performance of sufficient history-taking and physical examination was more valued at the final diagnosis than EDX results or other aspects of the patient's background. The process of confirming a clear initial clinical diagnosis of CTS using EDX may be of little value for decision-making at the final diagnosis. Level of Evidence: Level III (Therapeutic).

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.