Transepiphyseal extension of osteosarcoma: Incidence, mechanism, and implications

Abstract

Forty-five cases of osteosarcoma were studied for transepiphyseal spread of the lesion because of the current interest in local resection and chemotherapy as treatment of this disease. In 17 cases, the epiphyseal plate had closed and all 17 had transepiphyseal extension of the tumor. In 28 cases, the epiphyseal plate was open; 2 1 showed growth or microscopic evidence of transepiphyseal extension of the lesion. The most common method of extension was directly through tile epiphyseal plate along vascular channels, o r less commonly, about the epiphyseal plate beneath the perichondrium and into the epiphysis along the epiphyeal vascular channels. The majority of these extensions were not detectable by either conventional radiography or radioisotope scanning. Local resection with preservation of the epiphysis will, in all likelihood, leave residual disease despite the oft-quoted statement that an open epiphyseal plate is a biologic barrier to the extension of bone tumors.Cancer 41:1526-1537, 1978C osteosarcoma revolves around nonablative surgical resection while relying on adjunctive chemotherapy to suppress or "cure" microresidual disease. T h e justification for such seemingly inadequate surgery has included: better cosmesis, improved function and rehabilitation, ability to maintain one's previous life-style, and in general, to provide better quality of life. 5,10 In this context, preservation of the distal femoral or proximal tibia1 epiphysis is tempting, particularly in light of the commonly held belief that an intact epiphyseal plate is a barrier to sarcomatous spread (Fig. l) Instructor.Accepted for publication July 5, 1977. M A T E R I A L S AND METHODSForty-five cases of osteosarcoma of the distal femur or proximal tibia were available for study. The series was composed of 26 males and 19 females. The average age of the series was 17 (range 8 to 34). Available data included preoperative routine AP and lateral X-rays of the lesion, tomograms, '-Tc or '9Sr bone scan, and regional angiography.The pathologic studies included gross photographs of the bi-valved specimen, specimen X-rays, and celloidin embedded macrosections of the entire lesion. An orthopedic radiologist with no prior knowledge of the point in question (epiphyseal extension) was asked to review the preoperative data and form a n opinion as to involvement of the epiphysis with tumor.The macrosections were carefully studied to determine the incidence and method of transepiphyseal extension of osteosarcoma. Finally, pathologic findings were compared with the radiologists unbiased interpretation of the preoperative studies in attempt to predict transepiphyseal tumor extension. RESULTSOf the 45 cases, 17 had closed epiphyseal plates. I n each of these, direct extension of the tumor was present across the old epiphyseal scar. In 11 of these cases, the epiphyseal scar

Allograft Reconstruction of the Knee—Methods and Outcomes

“…In most patients, the tumor arises in the metaphysis and extends down to or through the physis. 35,36 For this reason, preoperative assessment of tumor extension is critically important and MR is very sensitive in detecting transphyseal extension. 37 In all cases where attempts to preserve the physis and/or epiphysis is contemplated, careful radiographic assessment is critical and a good response to chemotherapy is necessary and hopefully, as a result of an excellent tumor response to chemotherapy, negative margins can and must be achieved.…”

Articular surface sparing procedures in the treatment of bone sarcomas

“…If the anatomic knee can be preserved with a safe surgical margin of tumor excision, potentially better long-term functional results should follow. Early studies of pathologic specimens obtained at the time of surgery [56,57] have suggested that the prevalence of transepiphyseal spread of the tumor in metaphyseal osteosarcoma is 81%. Most recently, studies have described the accuracy of MRI in detecting epiphyseal extension of osteosarcoma, showing a sensitivity of 100% with no false negatives [33,34,37].…”

Vascularity of Cartilage

“…Osteosarcoma almost always arises singly in the metaphyseal ends of long bones. Generally, the tumor mass fills the marrow cavity in the metaphyseal region, replaces the cancellous bone, and extends along a broad front toward the unclosed epiphyseal growth plate, at which site it is stopped in its further extension (Enneking and Kagan, 1978;. Tumor spread through the uncalcified epiphyseal cartilage occurs only in advanced stages of the disease, and it generally follows preexisting nutritive vascular channels, which have been shown to pen etrate the epiphyseal cartilage in préadolescent humans (Trueta and Morgan, 1960;Spira and Farin, 1967).…”

“…Tumor spread through the uncalcified epiphyseal cartilage occurs only in advanced stages of the disease, and it generally follows preexisting nutritive vascular channels, which have been shown to pen etrate the epiphyseal cartilage in préadolescent humans (Trueta and Morgan, 1960;Spira and Farin, 1967). This penetration of epiphyseal cartilage by osteo sarcoma cells may also be facilitated by microfractures, ischemic necrosis, and inflammation secondary to the loss of structural support of underlying bone (Enneking and Kagan, 1978). Once osteosarcoma cells have invaded the epi physeal bone, rapid erosion of the bone occurs.…”