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 two, four, and eight weeks after the procedure.

RESULTS

The maximum burst strength of the ApGltn sealant was ~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.

CONCLUSION

The ApGltn sealant had a higher sealing strength than, and comparable effect on dura regeneration with, the fibrin sealant.

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.

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.

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.

Identifying prognostic biomarkers for palbociclib add-on therapy in fulvestrant-resistant breast cancer using cell-free DNA sequencing

BACKGROUND

The FUTURE trial (UMIN000029294) demonstrated the safety and efficacy of adding palbociclib after fulvestrant resistance in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced and metastatic breast cancer (ABC/MBC). In this planned sub-study, cancer panel sequencing of cell-free DNA (cfDNA) was utilized to explore prognostic and predictive biomarkers for further palbociclib treatment following fulvestrant resistance.

MATERIALS AND METHODS

Herein, 149 cfDNA samples from 65 patients with fulvestrant-resistant disease were analysed at the time of palbociclib addition after fulvestrant resistance (baseline), on day 15 of cycle 1, and at the end of treatment using the assay for identifying diverse mutations in 34 cancer-related genes.

RESULTS

During the course of treatment, mutations in ESR1, PIK3CA, FOXA1, RUNX1, TBX3, and TP53 were the most common genomic alterations observed. Analysis of genomic mutations revealed that before fulvestrant introduction, baseline PIK3CA mutations were marginally lower in metastatic aromatase inhibitor (AI)-treated patients compared to adjuvant AI-treated patients (P = 0.063). Baseline PIK3CA mutations were associated with poorer progression-free survival [hazard ratio: 1.62, P = 0.04]. Comparative analysis between baseline and early-changing gene mutations identified poor prognostic factors including early-changing MAP3K1 mutations (hazard ratio: 4.66, P = 0.04), baseline AR mutations (hazard ratio: 3.53, P = 0.04), and baseline PIK3CA mutations (hazard ratio: 3.41, P = 0.02). Notably, the relationship between ESR1 mutations and mutations in PIK3CA, MAP3K1, and TP53 weakened as treatment progressed. Instead, PIK3CA mutations became correlated with TP53 and FOXA1 mutations.

CONCLUSIONS

Cancer panel testing for cfDNA identified prognostic and predictive biomarkers for palbociclib add-on therapy after acquiring fulvestrant resistance in patients with HR+/HER2- ABC/MBC.

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.

Volar Transfer of the Lateral Band With Transverse Retinacular Ligament for the Correction of Swan Neck Deformity

BACKGROUND

This retrospective study was designed to evaluate a surgical treatment for swan neck deformity of the fingers involving the volar transfer of the lateral band using the transverse retinacular ligament.

METHODS

Ten patients who underwent this surgical procedure for swan neck deformity treatment and were followed up for a mean of 26 months (range: 12-65 months) were included in the study. The dorsally located lateral bands were transferred toward the volar aspect of the finger, and their position was maintained using the transverse retinacular ligament. Improvement of the snapping and swan neck deformity was confirmed by intraoperative active motion of the finger. The active range of motion of the affected finger was evaluated pre- and postoperatively.

RESULTS

Extension of the proximal interphalangeal (PIP) joint averaged 30° (range: 20°-40°) preoperatively and improved to -2° (range: -5°-0°) postoperatively. Extension of the distal interphalangeal (DIP) joint averaged -30° (range: -15° to -70°) preoperatively and improved to -15° (range: 0° to -55°) postoperatively. The mean improvement in range of motion of the DIP joint was 15° (range: 10°-25°). The flexion of both the PIP and DIP joint did not significantly change in any of the patients postoperatively.

CONCLUSIONS

Surgical transfer of the lateral band using the transverse retinacular ligament is effective in correcting mild swan neck deformity. Hyperextension of the PIP joint is corrected well, but the severe extension lag of the DIP joint remains uncorrected postoperatively.

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.

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.

In-vivo kinematics of the trapeziometacarpal joint in dynamic pinch motion using four-dimensional computed tomography imaging

OBJECTIVE

CT imaging precisely and quantitatively analyzes the kinematics of the carpal bones to evaluate the etiology of related osteoarthritis. Previous studies have investigated the kinematics of the trapeziometacarpal joint using static CT scans of various postures including the pinch position. This study analyzed the in-vivo kinematics of the trapeziometacarpal joint during dynamic pinch motion in young healthy volunteers using four-dimensional CT.

MATERIALS AND METHODS

Twelve healthy young volunteers participated in this study. Each participant held the pinch meter between their thumb and index finger and pinched it with maximum force for a period of 6 s. This series of movement was recorded using a four-dimensional CT. The surface data of the trapezium and first metacarpal of all frames were reconstructed, and bone movement at the trapeziometacarpal joint was calculated using sequential three-dimensional registration. The instantaneous pinch force of each frame was measured using a pointer on a pinch meter that was reconstructed from the CT data.

RESULTS

The first metacarpal was abducted (15.9 ± 8.3°) and flexed (12.2 ± 7.1°) relative to the trapezium, and significantly translated to the volar　(0.8 ± 0.6 mm) and ulnar directions (0.9 ± 0.8 mm) with maximum pinch force. This movement consistently increased with the pinch force.

CONCLUSION

This study successfully employed 4D-CT to precisely demonstrate changes in rotation and translation at the trapeziometacarpal joint during pinch motion for various instantaneous forces.

Painful snapping of the middle finger caused by hyperplasia of the ulnar lateral band: A case report

Snapping of fingers can be caused by pathologies such as stenosing flexor tenosynovitis. However, snapping symptoms in the metacarpophalangeal (MP) joint caused by hypertension and hyperplasia of the lateral band are rare. We present a 26-year-old female with symptoms of painful snapping of the middle finger. When the finger was actively flexed from the hyperextension of the MP joint, the ulnar lateral band was prominent, and a snapping phenomenon occurred. The cause of the snapping finger was considered to be tightness of the ulnar lateral band, and surgery was planned. Intraoperatively, the ulnar lateral band was tense and hyperplastic. The snapping phenomenon disappeared immediately after the resection of the lateral band. It is important to consider this condition as one of the differential diagnoses of snapping finger when the patient complains of an atypical snapping phenomenon.

Rupture of the Flexor Pollicis Longus Tendon Involved between the Radial Shaft and the Volar Locking Plate

We report the case of a 61-year-old woman with right-sided flexor pollicis longus (FPL) tendon ruptured a month after volar locking plate fixation. Five months after the initial operation, hardware removal and reconstruction of the FPL tendon with the ipsilateral palmaris longus were performed. The proximal stump of the ruptured FPL tendon was found in the space between the distal radius and plate.

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.

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.

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.

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).

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.

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.