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en: Cumulative Incidence of Osteochondritis Dissecans of the Capitellum in Preadolescent Baseball Players.

en: Level III, local nonrandom sample cohort.

ja: The risk of OCD of the capitellum developing within a 1-year period in preadolescent baseball players was 1.8%. Players aged 10 to 11 years had a significantly greater risk of capitellar OCD development than those aged 6 to 9 years.

en: Arthroscopy : the Journal of Arthroscopic & Related Surgery


en: Platelet-rich plasma does not reduce skeletal muscle fibrosis after distraction osteogenesis.

en: From this study, our results suggest that PRP did not significantly reduce skeletal muscle fibrosis due to distraction osteogenesis.

ja: The amount and area of collagenous tissue increased in both the PRP and control groups following distraction osteogenesis, but the changes were not significantly different between both groups at all time points (p = 0.89, 0.45, 0.33 and 0.52 at 4, 6, 8 and 10 weeks).

en: Journal of Experimental Orthopaedics

ja: Journal of Experimental Orthopaedics


en: Clinical Outcome of Arthroscopic Treatment for Posteromedial Elbow Impingement in Adolescent Baseball Players.

en: Level IV, therapeutic case series.

ja: This retrospective study evaluated the clinical outcome of arthroscopic treatment for posteromedial elbow impingement in adolescent baseball players. Patients were eligible for participation if they had undergone surgery at least 2 years earlier and excluded if they had arthritis, loose bodies, osteochondritis dissecans, ulnar collateral ligament tear, flexor/pronator injuries or medial epicondylitis, or nerve problems. Patients were also excluded if they had undergone prior elbow surgery, were younger than 13 years, or were older than 19 years. Arthroscopic treatment included debridement of posteromedial synovitis, fragment removal, and olecranon spur excision. At a mean follow-up of 26.7 (range 24-42) months, patients were evaluated based on a questionnaire, examination, and the previously reported elbow outcome score.

ja: Arthroscopy : the Journal of Arthroscopic & Related Surgery


en: Bilateral osteochondritis dissecans of the capitellum in fraternal twins: A case report

en: We report the cases of 15-year-old male fraternal twins with bilateral osteochondritis dissecans (OCD) of the capitellum in the absence of syndromic features. At the time of presentation, they had been actively engaged in competitive rhythmic gymnastics for 3 years. Both patients had chronic symptoms in the right elbow, and both underwent arthroscopic evaluation and management. The cases of these 2 patients provide evidence to support the theory that the etiology of OCD may have a genetic background.

en: JBJS Case Connector

ja: JBJS Case Connector


en: 成長期野球肘の診断と治療

ja: 成長期野球肘の診断と治療

en: Monthly Book Orthopaedics

ja: Monthly Book Orthopaedics


en: Outcome of an elbow check-up system for child and adolescent baseball players.

en: About 30% of youth baseball players had episodes of elbow pain, and 64.1% of players with elbow pain had abnormal findings on physical examination. Furthermore, 85.2% of subjects who underwent radiographic examination exhibited radiographic abnormalities. About 4% of young baseball players had an abnormal finding on initial ultrasonography screening, and nearly 50% of them had OCD of the capitellum on radiographs. J. Med. Invest. 63: 171-174, August, 2016.

en: The Journal of Medical Investigation : JMI


en: Efficacy of Achilles Suture Bridge Technique for Insertional Achilles Tendinosis in an Obese and Athletic Patient.

en: Here, we report the efficacy of the suture bridge technique for treating insertional Achilles tendinosis in an obese and athletic patient. A 48-year-old man presented to our department with a 6-month history of left posterior heel pain. The patient was an athlete (triathlon) and appeared obese (height: 197 cm, body weight: 120 kg, body mass index: 30.9). A diagnosis of insertional Achilles tendinosis was made. Because 6 months of conservative treatments had failed, we performed open resection of the calcaneal exostosis and Haglund's deformity along with debridement of the degenerative tissue of the tendon. Wide detachment of the insertion of the Achilles tendon was necessary, and reattachment of the tendon was performed using the Arthrex SpeedBridge(TM) system (Arthrex, Inc., Naples, FL). Six weeks postoperatively, this patient was allowed to walk with full weight bearing. Twelve weeks after surgery, this patient started jogging with neither pain nor evidence of Achilles tendon rupture. The suture bridge technique was effective for the reconstruction of the Achilles tendon in an obese and athletic patient. J. Med. Invest. 63: 310-314, August, 2016.

ja: The Journal of Medical Investigation : JMI


en: An Unusual Cause of Posterior Elbow Impingement: Detachment of a Hypertrophied Posterior Fat Pad.

en: We report a case of a 47-year-old woman who developed posterior impingement of the elbow due to detachment of a hypertrophied posterior fat pad. She reported acute left elbow pain after leaning back onto a hard object with her hand and subsequently experienced a "catching" sensation. Comparison with the magnetic resonance images of a normal elbow revealed a hypertrophied posterior fat pad interposed between the olecranon and olecranon fossa in both elbows, with the fat pad in the left elbow located more inferiorly than that in the right elbow. Elbow arthroscopy showed the olecranon fossa covered by the fat pad, a portion of which was detached from the rest of the pad. Debridement of the detached portion was performed until no impingement was evident. Postoperatively, full extension of the elbow did not elicit pain. Clinicians should include this pathology among the differential diagnoses for posterior elbow pain.

en: Case Reports in Orthopedics

ja: Case Reports in Orthopedics


en: Fracture of a persistent olecranon physis in an adult

en: Trauma Case Reports

ja: Trauma Case Reports


en: Epidemiology of shoulder injuries in young baseball players and grading of radiologic findings of Little Leaguer's shoulder.

en: Relatively few epidemiological studies have examined shoulder injuries. This study aimed to investigate the epidemiology of such injuries in young baseball players. A total of 2,055 players aged 9-12 years who participated in a regional championship between 1983 and 1985 were the subjects of this investigation. They were assessed by questionnaire and radiographic examination. Prevalence of shoulder pain was determined according to position, years of baseball playing experience, and training hours per week. Radiographic examination was recommended to all players who complained of shoulder pain. Of the 2,055 subjects, 275 (13.4%) reported episodes of pain in the throwing shoulder. Years of baseball experience, but not player position or training hours per week, was significantly associated with shoulder pain. Forty-one of the 275 subjects reporting shoulder pain agreed to undergo radiography and 15 exhibited findings of Little Leaguer's shoulder. Their lesions could be classified into three distinct grades based on radiographic findings: grade I, widening of the epiphyseal plate in the lateral area (n=9); grade II, widening at all areas of the epiphyseal plate and demineralization of the metaphysis (n=5); and grade III, a slipped epiphysis (n=1). J. Med. Invest. 62: 123-125, August, 2015.


en: Forearm lengthening by distraction osteogenesis: A report on 5 limbs in 3 cases.

en: Radioulnar length discrepancy causes pain and decreases function of the wrist, forearm, and elbow. Limb lengthening, which has been used in the treatment of various deformities of the forearm, is necessary to restore balance between the ulna and radius. We treated 5 limbs in 3 patients (2 boys, 1 girl; mean age 9.3 years old) with radioulnar length discrepancy by distraction osteogenesis of either the ulna or radius using external fixators. We dissected the interosseous membrane between the ulna and radius in 3 limbs in 2 cases and did not do so in 2 limbs of 1 case. These cases include 2 cases with hereditary multiple exostoses, and 1 case with multiple epiphyseal dysplasia. The results were investigated and evaluated in this study, using appropriate clinical and radiographic parameters, noting the state of the interosseous membrane, which has an important role in forearm stability. The mean fixation period was 113 days. The mean distraction distance was 22.8 mm. The mean follow-up period was 637.7 days. The mean ulnar shortening and radial articular angle respectively improved from 7.4 mm and 30.2° preoperatively to -0.1 mm and 34.8° postoperatively. Balance between the ulna and radius was restored, and the results showed significant improvements in range of motion of the joints. However, 2 unintended radial head subluxations occurred in 2 limbs without dissection of the interosseous membrane. In addition, a keloid remained in 1 limb due to pin site infection. Forearm lengthening by distraction osteogenesis was useful in our cases. It is important to recognize the function of the interosseous membrane when lengthening is performed by osteotomy of the proximal ulna by gradual distraction with an external fixator. J. Med. Invest. 62: 219-222, August, 2015.


en: Ganglion cyst arising from the infrapatellar fat pad in a child.

en: A ganglion cyst is a cystic lesion containing myxoid matrix and lined by a pseudomembrane. A ganglion cyst arising from the infrapatellar fat pad is very rare, with only a few reports appearing in the literature, and the present case is the first report of this lesion in a child. A 10-year-old boy presented with right knee pain that showed no improvement despite resting from sports activity for 1 month. Magnetic resonance imaging revealed a multilobular mass between the infrapatellar fat pad and anterior cruciate ligament. Arthroscopic excision of the mass was performed. The mass was noted to arise from the infrapatellar fat pad and was filled with myxoid matrix. The histological diagnosis was a ganglion cyst. In active pediatric patients with pain or limited range of motion in the knee, physicians should consider the possibility of a ganglion cyst from the infrapatellar fat pad, despite its rarity. J. Med. Invest. 62: 245-247, August, 2015.


en: Cartilage degeneration at symptomatic persistent olecranon physis in adolescent baseball players.

en: Background. Elbow overuse injuries are common in adolescent baseball players, but symptomatic persistent olecranon physis is rare, and its pathogenesis remains unclear. Purpose. To examine the histopathological and imaging findings of advanced persistent olecranon physis. Methods. The olecranon physes of 2 baseball pitchers, aged 14 and 15 years, were examined by preoperative magnetic resonance imaging (MRI), and surgical specimens were examined histologically. Results. T2-weighted MRI revealed alterations in the intrachondral signal intensity possibly related to collagen degeneration and increased free water content. Histological findings of specimens stained with hematoxylin-eosin showed complete disorganization of the cartilage structure, hypocellularity, chondrocyte cluster formation, and moderately reduced staining. All these findings are hallmarks of osteoarthritis and are suggestive of cartilage degeneration. Conclusion. Growth plate degeneration was evident in advanced cases of symptomatic persistent olecranon physis. These findings contribute to understanding the pathogenesis of this disease.

en: Advances in Orthopedics

ja: Advances in Orthopedics


en: Retrograde intramedullary nailing with a blocking pin technique for reduction of periprosthetic supracondylar femoral fracture after total knee arthroplasty: technical note with a compatibility chart of the nail to femoral component.

en: Periprosthetic fractures after total knee arthroplasty (TKA) present a clear management challenge, and retrograde intramedullary nails have recently gained widespread acceptance in treatment of these fractures. In two cases, we found a blocking screw technique, first reported by Krettek et al., was useful in the reduction of the fractures. Both patients attained preinjury mobility after intramedullary nailing. Moreover, we present a chart summarizing the notch designs of various femoral components because some prosthetic knee designs are not amenable to retrograde nailing. We hope this will be helpful in determining indications for retrograde nailing in periprosthetic fractures after TKA.


en: Prevalence of Osteochondritis Dissecans of the Capitellum in Young Baseball Players: Results Based on Ultrasonographic Findings.

en: The prevalence of OCD of the capitellum was 2.1% in 1000 baseball players aged 10 to 12 years, with no differences in prevalence according to age or player position.

en: Orthopaedic Journal of Sports Medicine

ja: Orthopaedic Journal of Sports Medicine


en: State of the art: elbow arthroscopy: review of the literature and application for osteochondritis dissecans of the capitellum.

en: Elbow arthroscopy has become a safe and effective treatment option for a number of elbow disorders. The most rewarding and successful indication is the removal of loose bodies. Loose bodies are often a result of osteochondritis dissecans (OCD) of the capitellum, and arthroscopy in this case is useful for performing debridement, thereby eliminating the need for a more extensive open procedure associated with complications. In this review, we describe our arthroscopic technique for OCD of the capitellum. We usually conduct arthroscopy in the supine position, and use 2.9-mm arthroscopes of 30° and 70°. The 70° arthroscope provides a greater operative field than the 30° arthroscope. Arthroscopic treatment for OCD may require 2 anterior and 2 posterior portals. Loose bodies are commonly found in the radial fossa, coronoid fossa, and in the olecranon fossa. Once the loose bodies are removed, all unstable cartilage of the capitellum lesion is removed to create a stable bed. If any sclerotic changes to the lesion bed are observed, we create microfractures in the lesion bed. The most significant complication in arthroplasty is neurovascular injury. However, we have never experienced this devastating complication, which can be avoided by paying careful attention to detail. J. Med. Invest. 61: 233-240, August, 2014.

en: The Journal of Medical Investigation : JMI


en: Elbow Injuries in Youth Baseball Players without Prior Elbow Pain : a One-year Prospective Study


en: Early changes in muscle atrophy and muscle fiber type conversion after spinal cord transection and peripheral nerve transection in rats.

en: BACKGROUND: Spinal cord transection and peripheral nerve transection cause muscle atrophy and muscle fiber type conversion. It is still unknown how spinal cord transection and peripheral nerve transection each affect the differentiation of muscle fiber type conversion mechanism and muscle atrophy. The aim of our study was to evaluate the difference of muscle weight change, muscle fiber type conversion, and Peroxisome proliferator-activated receptor-gamma coactivatior-1alpha (PGC-1alpha) expression brought about by spinal cord transection and by peripheral nerve transection. METHODS: Twenty-four Wistar rats underwent surgery, the control rats underwent a laminectomy; the spinal cord injury group underwent a spinal cord transection; the denervation group underwent a sciatic nerve transection. The rats were harvested of the soleus muscle and the TA muscle at 0 week, 1 week and 2 weeks after surgery. Histological examination was assessed using hematoxylin and eosin (H&E) staining and immunofluorescent staing. Western blot was performed with 3 groups. RESULTS: Both sciatic nerve transection and spinal cord transection caused muscle atrophy with the effect being more severe after sciatic nerve transection. Spinal cord transection caused a reduction in the expression of both sMHC protein and PGC-1alpha protein in the soleus muscle. On the other hand, sciatic nerve transection produced an increase in expression of sMHC protein and PGC-1alpha protein in the soleus muscle. The results of the expression of PGC-1alpha were expected in other words muscle atrophy after sciatic nerve transection is less than after spinal cord transection, however muscle atrophy after sciatic nerve transection was more severe than after spinal cord transection. CONCLUSION: In the conclusion, spinal cord transection diminished the expression of sMHC protein and PGC-1alpha protein in the soleus muscle. On the other hand, sciatic nerve transection enhanced the expression of sMHC protein and PGC-1alpha protein in the soleus muscle.

en: Journal of Neuroengineering and Rehabilitation


en: The Most Effective Exercise for Strengthening the Supraspinatus Muscle --- Evaluation by Magnetic Resonance Imaging

en: Electromyography has been used to determine the best exercise for strengthening the supraspinatus muscle, but conflicting results have been reported. Magnetic resonance imaging T2 relaxation time appears to be more accurate in determining muscle activation. To determine the best exercises for strengthening the supraspinatus muscle. Criterion standard. Six male volunteers performed three exercises: the empty can, the full can, and horizontal abduction. Immediately before and after each exercise, magnetic resonance imaging examinations were performed and changes in relaxation time for the subscapularis, supraspinatus, infraspinatus, teres minor, and deltoid muscles were recorded. The supraspinatus muscle had the greatest change among the studied muscles in relaxation time for the empty can (10.5 ms) and full can (10.5 ms) exercises. After the horizontal abduction exercise the change in relaxation time for the supraspinatus muscle (3.6 ms) was significantly smaller than that for the posterior deltoid muscle (11.5 ms) and not significantly different from that of the other muscles studied. The empty can and full can exercises were most effective in activating the supraspinatus muscle.

en: The American Journal of Sports Medicine

ja: The American Journal of Sports Medicine


en: Effect of weight bearing on recovery from nerve injury in skeletal muscle

en: Journal of Applied Physiology

ja: Journal of Applied Physiology