Activities of medical centers for athletes and spectators at cycling track events in the Tokyo 2020 Olympic and Paralympic Games.

AIM: We focused on the preparation and activities of clinics for spectators and athletes in the Izu Velodrome in Shizuoka Prefecture, which was managed by the Tokyo Organizing Committee of the Olympic and Paralympic Games (TOC). METHODS: Two medical clinics were established for the track cycling competition: one for Olympians and their associates, and one for spectators, TOC-related individuals, and volunteers. Each medical clinic had two separate buildings. One was for individuals with suspected coronavirus disease (COVID-19); the other was for individuals who were deemed unlikely to have COVID-19. RESULTS: During the Olympics, five Olympians and one umpire were transported to a designated hospital. All of them had fall-related injuries. Nine patients visited the clinic for spectators, and six of the nine were volunteers. Two volunteers showed side-effects in association with COVID-19 vaccination. Five of the nine patients had outdoor-related disease. During the Paralympics Games, no Olympians visited the clinic, and three volunteers were treated at the clinic for spectators. All had outdoor-related diseases and returned to work after treatment. There were no confirmed cases of COVID-19 among individuals who attended the Olympic cycling track during the Tokyo 2020 Olympics and Paralympics. CONCLUSIONS: The present study showed the results of activities of the two clinics for the Olympics and Paralympics. Both medical clinics were necessary for the safe operation of the Olympics and Paralympics.

Evaluation of the effect of glucosamine administration on biomarkers of cartilage and bone metabolism in bicycle racers.

In the present study, the effect of glucosamine administration (1.5 or 3 g/day) on cartilage and bone metabolism was investigated in bicycle racers, using cartilage­ and bone­specific biomarkers, including C­terminal cross­linked telopeptides of type II collagen (CTX­II), C­terminal propeptides of type II procollagen (CPII), N­terminal telopeptides of bone­specific type I collagen (NTx) and bone alkaline phosphatase (BAP). The results indicate that CPII (a marker of type II collagen synthesis) was not substantially changed, however, CTX­II (a marker of type II degradation) was reduced by glucosamine administration, particularly at a dose of 3 g/day. Consistent with these observations, the ratio of CTX­II/CPII was reduced by glucosamine administration and the effect of glucosamine was dose­dependent. By contrast, the levels of NTx (a bone resorption marker) and BAP (a bone formation marker) were not altered by glucosamine administration. A previous study by this group reported that glucosamine exerts a chondroprotective action in soccer players by preventing type II collagen degradation but maintaining type II collagen synthesis. Together these observations indicate that glucosamine may exert a chondroprotective action by preventing type II collagen degradation in athletes of various sports, including soccer players and bicycle racers.

Pedicle freezing with liquid nitrogen for malignant bone tumour in the radius: a new technique of osteotomy of the ulna.

We describe a new technique of pedicle freezing of the distal radius with malignant bone tumour and osteotomy of the normal ulna. The distal radius was sufficiently elevated to enable freezing without damaging adjacent tissues by releasing the distal radio-ulnar and radio-carpal joint and cutting the middle third of the ulna. The distal radius (including the tumour) was soaked in liquid nitrogen and the defect filled with iliac grafts. The ulna was repaired with plate and screws and was united at month 2. There was no local recurrence and the postoperative function score was 93%. This technique decreases the risk of non-union of the osteotomy site of the tumorous bone.

Bone versus soft-tissue sarcomas in the elderly.

PURPOSE: To compare survival rates in the elderly with bone versus soft-tissue sarcomas. METHODS: Records of 12 men and 8 women aged 70 to 91 (mean, 77) years with bone or soft-tissue sarcomas were retrospectively reviewed. The grade, size, location, and stage of the sarcomas, as well as their surgical margins, treatment modalities, local recurrence, metastasis, and prognosis were recorded. The mean follow-up period was 37 (range, 2-137) months. Their 5-year survival rates were estimated using the Kaplan-Meier method, and compared with 110 younger controls aged 9 to 69 (mean, 45) years during the same period. There was no significant difference between the older patients and younger controls regarding tumour grading (p=0.068, Chi squared test), stage, and pathological diagnosis. RESULTS: Six patients had bone and 14 had soft-tissue sarcomas. Of the 6 bone sarcomas, 3 were malignant fibrous histiocytomas, 2 were osteosarcomas, and one was a chordoma; all were high grade, except for the chordoma. Of the 14 soft-tissue sarcomas, 9 were malignant fibrous histiocytomas, 3 were myxofibrosarcomas, one was a liposarcoma and one an extraskeletal osteosarcoma; all were high grade except for 2 of the myxofibrosarcomas and the liposarcoma. Of the 110 younger controls, 30 had bone and 80 had soft-tissue sarcomas; 44 were low grade and 66 were high grade. The 5-year survival rate was significantly lower in older patients than in younger controls (35% vs 65%, p=0.048). Regarding bone versus soft-tissue sarcomas, the 5-year survival rate was not significantly different among older patients (0% vs 52%, p=0.068) or younger controls 61% vs 66%, p=0.863). The difference was also not significant for older patients versus younger controls with bone sarcomas (0% vs 61%, p=0.284) or soft-tissue sarcomas (52% vs 66%, p=0.368), for older patients with high- versus low-grade sarcomas 17% vs 100%, p=0.314), for older patients with sarcomas located in the limbs versus the trunk (39% vs 38%, p=0.233), as well as for older patients versus younger controls with low-grade sarcomas (100% vs 92%, p=0.512) or high-grade sarcomas (17% vs 46%, p=0.269). CONCLUSION: Survival rates tend to be lower in older patients with sarcomas, especially when the sarcoma is of bone and high grade.

Xanthoma of bone associated with lipoprotein lipase deficiency.

Lipoprotein lipase (LPL) deficiency is an extremely rare congenital metabolic disorder with an accumulation of chylomicrons in the blood. We encountered a patient with an LPL deficiency leading to multiple bone xanthomas associated with hyperlipidemia. Radiographs and MRI of the humerus and femur revealed symmetrical bone lesions, and there is a possibility that these symmetrical lesions may therefore be a characteristic feature for this disorder.

Extraskeletal osteosarcoma in Japan: multiinstitutional study of 20 patients from the Japanese Musculoskeletal Oncology Group.

BACKGROUND: The clinical features of extraskeletal osteosarcoma are not well known. Unlike osteosarcoma of the bone, the efficacy of chemotherapy for extraskeletal osteosarcoma has not been established yet. METHODS: A multiinstitutional study of extraskeletal osteosarcoma was conducted. RESULTS: A total of 20 patients were enrolled in the study from the Japanese Musculoskeletal Oncology Group institutions. Their ages ranged from 15 to 88 years (mean 50 years). Six lesions were located in the thigh, four in the chest, four in the buttocks, three in the upper arm, and others. UICC surgical stages were II in 5 patients, III in 13, and IV in 2. Surgical resection was performed in 19 patients, and the consequent surgical margin was wide in 15 patients, marginal in 3, and intralesional in 1. The overall 5-year survival rate was 66%. Three patients demonstrated tumor recurrence postoperatively, and the 5-year local control survival rate was 75%. Altogether, 15 patients received chemotherapy, of whom 11 had evaluable responses as follows: complete response in none, partial response in 5 patients, and no change or progressive disease in 6 patients, with a response rate of 45%. CONCLUSIONS: Among the patients with extraskeletal osteosarcoma, both the 5-year survival rate and the chemotherapy response rate tended to improve in this study in comparison to the findings published in previous reports. As a result, we believe that treatment regimens that include systemic chemotherapy may be able to improve the prognosis in patients with extraskeletal osteosarcoma.

Primary pleomorphic liposarcoma of bone: MRI findings and review of the literature.

Primary liposarcoma of bone is exceedingly rare. We report a case of primary pleomorphic liposarcoma in the humerus of a 38-year-old female. Radiographs demonstrated an expansile and osteolytic lesion extending from the head to the proximal part of the shaft in the right humerus. MR study showed a defined lesion in the humerus. The lesion had an iso-signal intensity and partial high-intensity lesion on T1-weighted images and a heterogeneous high signal intensity on T2-weighted images. Wide resection and proximal humeral endoprosthesis replacement were performed. Final pathological diagnosis of the lesion was pleomorphic liposarcoma. This is the second reported case of pleomorphic liposarcoma of the bone, and the first case presenting MRI findings for liposarcoma of bone.

Clear cell sarcoma arising from the chest wall: a case report.

Clear cell sarcoma is a rare malignant soft tissue neoplasm that usually arises adjacent to tendons or aponeuroses. The clinical course is rather slow, with repeated local recurrences followed by late metastases and eventual death. The principal sites of this neoplasm are the extremities, but tumors do occur in the trunk on rare occasions. We report a case of clear cell sarcoma arising from the chest wall. The patient, a 20-year-old woman, had noticed a chest wall mass and pain for 2 years. Biopsy of the mass showed abundant nests of round cells with clear cytoplasm. On immunohistochemical examination, tumor cells were strongly immunoreactive for S-100 and HMB-45. A diagnosis of clear cell sarcoma was confirmed. There was no other lesion found in the patient through routine imaging studies. She was treated with two courses of chemotherapy using ifosfamide, carboplatin, and etoposide. Subsequently, the tumor, including adjacent tissue, the chest wall, and sternum, was resected with a wide margin; and the defect of the chest wall was covered with Marlex mesh fabric, regin, and a musculocutaneous flap. She has shown no symptoms or signs of recurrence during 2 years of follow-up.