Sho Kohyama

A giant plexiform schwannoma of the brachial plexus: case report.

We report the case of a patient who noticed muscle weakness in his left arm 5 years earlier. On examination, a biloculate mass was observed in the left supraclavicular area, and Tinels sign caused paresthesia in his left arm. Magnetic resonance imaging showed a continuous, multinodular, plexiform tumor from the left C5 to C7 nerve root along the course of the brachial plexus to the left brachia. Tumor excision was attempted. The median and musculocutaneous nerves were extremely enlarged by the tumor, which was approximately 40 cm in length, and showed no response to electric stimulation. We resected a part of the musculocutaneous nerve for biopsy and performed latissimus dorsi muscle transposition in order to repair elbow flexion. Morphologically, the tumor consisted of typical Antoni A areas, and immunohistochemistry revealed a Schwann cell origin of the tumor cells moreover, there was no sign of axon differentiation in the tumor. Therefore, the final diagnosis of plexiform Schwannoma was confirmed.

Stress fracture of the scaphoid in an elite junior tennis player: a case report and review of the literature

BackgroundThe carpal scaphoid is the most commonly fractured carpal bone in young adults after a fall on an outstretched arm that results in acute dorsal flexion of the wrist. However, stress fractures of the scaphoid are relatively rare. To the best of our knowledge, we describe the first case in the literature of carpal scaphoid stress fracture in a tennis player.Case presentationAn 18-year-old Japanese man who was an elite junior tennis player was referred to our hospital after radiography and computed tomography revealed a carpal scaphoid fracture. The patient presented with pain in the wrist joint and tenderness over the anatomical snuff-box with diffuse swelling and reduced active dorsal flexion and flexion of the right wrist. The patient was treated conservatively and resumed participation in competitive events 5 months after his initial presentation.ConclusionsIn this case, the scaphoid stress fracture had resulted from repetitive practicing of the attacking backhand high volley, which involved excessive dorsal flexion of the wrist. Although rare, scaphoid stress fractures must be considered in tennis players with chronic wrist pain.

Subacute volar dislocation of the distal radioulnar joint without fracture: A case report and literature review

This is the first report describing subacute volar dislocation of the distal radioulnar joint treated by open reduction and stabilization of the distal radioulnar joint by means of a suture anchor. Acute volar dislocation of the distal radioulnar joint successfully treated by closed or open reduction has previously been reported. In our case, surgery was performed five weeks after the initial injury. Good stabilization was obtained by reattaching the triangular fibrocartilage complex to the ulnar fovea with a suture anchor. It is important not to misdiagnose distal radioulnar joint dislocation, and the suture anchor technique is an effective treatment option.

A Magnetic Resonance Imaging–Based Staging System for Osteochondritis Dissecans of the Elbow: A Validation Study Against the International Cartilage Repair Society Classification

Background: Evaluations of the stability of osteochondritis dissecans (OCD) lesions of the elbow using magnetic resonance imaging (MRI) have resulted in reports with variable accuracy. Therefore, the International Cartilage Repair Society (ICRS) classification remains the gold standard to determine OCD lesion stability. Because OCD commonly occurs in pediatric patients, a noninvasive method comparable with the ICRS classification is desired. Hypothesis/Purpose: Based on the previous literature, the capitellum of unstable OCD lesions has an irregular outline on MRI because of displacement or dislocation of the lesion via synovial fluid inflow. Therefore, we defined a 4-stage classification, similar to the ICRS classification, which focused on the outline of the capitellum and articular cartilage status on MRI without subchondral bone information. The purpose of this study was to validate this MRI-based staging system against the ICRS classification and to verify its accuracy in diagnosing unstable OCD lesions of the elbow. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 81 patients with OCD of the elbow who were surgically treated were evaluated. The MRI-based stages were as follows: stage 1, normal-shaped capitellum and articular cartilage without signal intensity change; stage 2, normal-shaped capitellum and articular cartilage with signal intensity change; stage 3, irregular-shaped capitellum and discontinuity of the articular cartilage; and stage 4, dislocated lesion with an articular cartilage defect. Agreement between the MRI and ICRS classifications was evaluated, and the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for lesion instability were determined. The intraclass correlation coefficient (ICC) for intrarater and interrater reliability of the MRI-based staging system was calculated. Results: Agreement between the MRI-based staging system and the ICRS classification was 88.9%, with a sensitivity of 98.4%, specificity of 84.2%, PPV of 95.3%, and NPV of 94.1% for diagnosing an unstable lesion. The ICC was high for both intrarater (0.925) and interrater (0.915-0.939) reliability. Conclusion: The MRI-based staging system corresponded well with the ICRS classification, providing an accurate preoperative assessment of OCD lesions of the elbow, even with minimal subchondral bone information.

Intraoperative Local Administration of Platelet-Rich Plasma (PRP) during Neurolysis Surgery for the Treatment of Digital Nerve Crush Injury

The digital nerves are important for normal hand function. In addition to conventional therapies such as neurolysis, direct repair, and auto/allografts, new treatments administering growth factors and cells for promoting nerve regeneration exist. Platelet-rich plasma (PRP), an autologous product with proven therapeutic effects for musculoskeletal disorders, is a new treatment option for peripheral nerve injury. We hypothesized that PRP could stimulate healing of digital nerve injuries. In the current case report, intraoperative local administration of PRP was performed during neurolysis surgery for a healthy 28-year-old woman with digital nerve crush injury. Five weeks postinjury, surgery was performed due to severe uncontrollable neuropathic pain and no sensory nerve action potential derivation of the index finger. Therapeutic effects were assessed by physical examination, visual analog scale for pain, and nerve conduction study. Postoperatively, early neuropathic pain relief and good functional recovery were obtained with no PRP-related adverse events. This case report demonstrates the therapeutic potential of intraoperative PRP to enhance the healing process of nerve crush injury in the acute phase and to decrease the neuropathic pain, thus enhancing healing of peripheral nerve crush injury.

Trapezium Fracture Associated with Thumb Carpometacarpal Joint Dislocation: A Report of Three Cases and Literature Review

Isolated trapezium fracture in combination with thumb carpometacarpal (CMC) joint dislocation is extremely rare, and no treatment consensus exists. Herein, we report 3 successfully treated cases of isolated trapezium fracture with thumb CMC joint dislocation. While good short-term results have been reported in the literature, the possibility of substantial ligament injuries that can lead to future instability of the thumb CMC joint must be noted. In order to obtain an excellent long-term clinical result, we propose the consideration of the anatomical repair of the CMC joint in terms of both bony and ligamentous structures in cases where instability remains after fracture fixation.

Disruption of Flexor Tendon after Intrasheath Triamcinolone Acetonide Injection for Trigger Digits: Two Case Reports

We experienced two cases of flexor tendons rupture after triamcinolone acetate (TA) injection for trigger finger. A 45-year-old man underwent injection of 40 mg of TA and 1 mL of 1% lidocaine solution into his little finger. While playing golf 3 months after the injection, he heard a popping sound, and was unable to flex it. A 57-year-old female nurse had undergone injection of 40 mg of TA and 1 mL of 1% lidocaine solution into her thumb twice at a 2-month interval. Two months after the second injection, she was unable to flex it. Both cases had high concentrated TA injection at trigger digits. The present and previous cases illustrate that when TA is injected into trigger digits, the dose should be low, the safety interval should be long, and refuse injection into the tendon proper.

Anatomical Variations of the Extensor Carpi Ulnaris Groove: A New Computed Tomography-based Evaluation

BACKGROUND This study aimed to develop a classification that precisely describes the extensor carpi ulnaris (ECU) groove morphology. METHODS Reconstructed axial plane computed tomography scans of the wrists of 200 patients were reviewed. Three groups of groove shape were created based on the position of the deepest point: deviated to the ulnar side (Type U), in the middle of the groove (Type M), and deviated to the radial side (Type R). Groove depth, width, carrying angle, and radius of the curvature were measured using the Picture Archiving and Communication System in a slice in which the ulnar head was the largest. RESULTS Type U was present in 88 patients (44%), Type M in 74 patients (37%), and Type R in 38 patients (19%). The average depth, width, carrying angle, and radius of curvature were 2.2 mm, 9.2 mm, 135.8° and 7.0 mm, respectively. Depth, width, and carrying angle were normally distributed. Both depth and width were statistically correlated with the carrying angle; groove depth and width were not correlated. ECU groove shape and depth showed excellent intra- and inter-observer reliabilities; the reliabilities for the width were poor. Therefore, depth subgroups were defined using cutoffs of ±2 standard deviations (SD): d1 (≤-2 SD), ≤1.0 mm; d2 (±SD), 1.1-3.3 mm; and d3 (≥+2 SD), ≥3.4 mm. The 200 wrists were classified as follows: 0.5% Ud1, 40.2% Ud2, 1.3% Ud3, 0.8% Md1, 38.3% Md2, 0.8% Md3, 1.5% Rd1, 16.4% Rd2, and 0.2% Rd3. CONCLUSIONS The detailed morphology of the ECU groove was classified using three major types and depth subgroups. The Type R ECU groove, which lacks a medial bony buttress, might be more prone to ECU-related injuries. This classification helps to understand the ECU tendon-related injury pathologies and may provide valuable information for treatment decisions; however, further research is necessary.

Lipofibromatous Hamartoma of the Median and Ulnar Nerves at the Ipsilateral Wrist

Lipofibromatous hamartoma (LFH) is a rare condition of the peripheral nerves that typically affects the median nerve. To the best of our knowledge, this is the first report of LFH of both, the median and ulnar nerves, at the wrist of a 63-year-old female patient. The patient presented to our hospital with a 40-year history of pain, numbness, and dysesthesia affecting all fingers of her left hand. Atrophy of the thenar muscles and the first dorsal interosseous was observed upon physical examination. Imaging studies and a surgery revealed that the patients median and ulnar nerves were significantly enlarged, confirming the LFH diagnosis. The patients dysesthesia and numbness improved after Carpal tunnel and Guyon canal release, and her pinch ability improved after opponensplasty. LFH has been known to be solitary, typically affecting median nerve, but it must be noted that the tumor may affect multiple nerves like in our case.

Multiple Finger Extensor Tendon Dislocations in Systemic Lupus Erythematosus with Unique Trigger Phenomena

Dislocation of extensor tendons is the most frequently seen complaint for suffers of rheumatoid arthritis. Here, we present a rare clinical case of multiple finger extensor tendon dislocations in systemic lupus erythematosus (SLE). Upon physical examination, active extension of middle, ring and little fingers were impossible at the MP joint. A trigger phenomenon was generated when these extensors were reduced in passive extension. The procedure was performed under local anesthesia. A satisfactory clinical outcome was achieved with sagittal band reconstruction and reinforcement for the site using juncturae tendinum. Surgical intervention under the local anesthesia allowed for extensive gathering of information about repair site strength and dynamic stability.