Jae-Do Kim

Differential presentations, clinical courses, and survivals of osteosarcomas of the proximal humerus over other extremity locations.

BackgroundAlthough there are controversies about the prognosis of proximal humeral osteosarcoma, our previous study showed poor survival in those patients. In the present study, we undertook to determine why this site is associated with a poor outcome and to identify the clinicopathologic variables involved.MethodsThe study cohort consisted of 36 proximal humeral and 341 other extremity American Joint Committee on Cancer (AJCC) stage II osteosarcomas. We examined the clinicopathologic differences between these osteosarcomas. The prognostic significances of factors identified for a proximal humoral location were evaluated by survival analysis of all 377 patients.ResultsPatients with a proximal humeral osteosarcoma had the following characteristics: a higher incidence of pathologic fracture (Pxa0<xa00.01), an osteolytic pattern on plain radiographs (Pxa0<xa00.01), an unusual pathological subtype (Pxa0=xa00.01), poor histologic response (Pxa0<xa00.01), and an increased tumor-volume ratio (TVR) (Pxa0<xa00.01). Multivariate analysis revealed that a large tumor volume (Pxa0<xa00.01), an increase in tumor volume (Pxa0<xa00.01), and a poor histologic response to preoperative chemotherapy (Pxa0<xa00.01) independently predicted shorter metastasis-free survival.ConclusionsThe association between proximal humeral osteosarcoma and poor survival could be the result of unresponsiveness to chemotherapy, which was expressed by a tumor volume increase in our patients.

Prognosis of extremity osteosarcoma in patients aged 40–60 years: A cohort/case controlled study at a single institute

BACKGROUNDnThe outcome of older osteosarcoma patients with multi-disciplinary management has not been clearly defined.nnnMETHODSnWe conducted a cohort (n=375) and a case-control (n=78) study on 26 older age patients (40-60 years) with localized osteosarcoma of extremity. In the case-control study, controls were matched for location and initial tumor volume.nnnRESULTSnCompared to 349 younger patients, older age patients showed an osteolytic pattern on plain radiographs (P=0.05), fibroblastic subtype (P<0.01), and poor histologic response (P=0.03). Multivariate analysis revealed that a large absolute tumor volume (P<0.01), a tumor location in the proximal humerus (P=0.02), and a poor histologic response to preoperative chemotherapy (P<0.01) independently predicted poorer metastasis-free survival. However, an older age showed marginal significance (P=0.09). A case-control study showed a higher proportion of the fibroblastic subtype and poor histologic response in the case group. Five-year metastasis-free survival rates for the 26 cases and 52 controls were 40.1+/-10.1% and 61.5+/-6.8%, respectively (P=0.02).nnnCONCLUSIONSnOlder age osteosarcoma patients showed an unfavorable histologic response to chemotherapy and lower survival than younger patients. Nevertheless, a further larger-scale study is required to confirm our observations.

A 9-month-old phosphaturic mesenchymal tumor mimicking the intractable rickets.

Phosphaturic mesenchymal tumor is an extremely rare disease and is frequently associated with oncogenic osteomalacia showing paraneoplastic syndrome, which is characterized by phosphaturia, hypophosphatemia, normocalcemia, and decreased levels of 1,25-dihydroxyvitamin D3 associated with a tumor. A 2-year-old boy, who had a soft tissue tumor on his right thigh and previously diagnosed as myositis ossificans at 9-months-old, was presented with rachitic rosary and mildly enlarged tumor. Biochemical investigations showed hypophosphatemia, hyperphosphaturia, and an increased alkaline phosphatase level of 440 U/l (25-100 U/l), suggesting rickets, which was resistant to vitamin D dietary supplementation. We were certain of intractable rickets because of oncogenic hypophosphatemia and thus decided to excise the soft tissue mass. We observed laboratory improvement of rickets after 2 weeks. On the basis of surgical and histopathological examinations, the tumor was finally diagnosed as the phosphaturic mesenchymal tumor.

Pelvis and extremity osteosarcoma with similar tumor volume have an equivalent survival

The poor prognosis of pelvic osteosarcoma is well recognized, but the cause of this prognosis has not been well defined.

Distractive bridge plating in metaphyseal comminuted fractures of the distal radius through a pronator sparing approach

For distal radial fractures with metaphyseal comminution and radial shortening, the key treatment goal, aside from anatomic reduction of the articular surface, is maintenance of radial length, in order to maintain the normal biomechanics of the wrist. Our distractive bridge plating technique, applied via a pronator sparing approach, was expected to be effective in maintaining the radial length of distal radial fractures with metaphyseal comminution treated with volar plating. However, there were some disadvantages to this approach, namely exposure of the surgeon to additional radiation as compared with conventional plating, satisfactory reduction except radial length by manual manipulation, and provisional fixation is a prerequisite to plating. Our technique has important benefits, in particular, the ability to preserve vascular supply and restore radial length.