Reconstruction Following Tumor Resections in Skeletally Immature Patients

To the Editor: We read with interest the article by Levin et al.1 We were surprised to see a previously published image by our group2 as Figure 1 in the Levin article. After exchanging a few e-mails with Dr. Levin, he apologized for the inappropriate appearance of this image in his article. The apologies were accepted. But for the sake of the scientific clinical evidence, we would like to make few clarifications.Figure 1: MRI (A) and histologic images (B and C) of a metaphyseal osteosarcoma in a 15-year-old boy. This MRI showed a false-positive result. The tumor did not cross the physis at any point. (Panel A reproduced with permission from San-Julián M, Cañadell J: Imaging-based indications for resection with epiphyseal preservation, in San-Julián M, ed: Cañadell´s Pediatric Bone Sarcomas: Epiphysiolysis Before Excision, ed 2. Switzerland, Springer International Publishing, 2016, pp 147-159. The patient’s name has been removed for reasons of privacy. Panels B and C copyright Mikel San-Julián, MD, PhD, Jesús Dámaso Aquerreta, MD, PhD, Blanca Vazquez-García, MD, and Miguel Angel Idoate MD, PhD, Universidad de Navarra, Pamplona, Spain.)The image in question is an MRI of a young patient who underwent surgery at our institution, the Clínica Universidad de Navarra, Pamplona, Spain, in 1997 (Figure 1, A). We have all his records and we still have his MRI, which we enclosed to the editors. However, our main concern is the misinterpretation of the image. The Levin et al1 article indicated a “subtle involvement of the epiphysis from a metaphyseal osteosarcoma (arrow) in a skeletally immature patient.” However, this particular tumor did not cross the physis. This image illustrates that there are false-positive findings in MRI regarding the crossing of the physis by metaphyseal sarcomas (Figure 1, A). We have never seen such a subtle involvement of the epiphysis in tumors such as this, partially touching the physis, and we have never seen a false-negative MRI regarding the crossing of the physis by a tumor.3 The authors indicate that “>80% of high-grade metaphyseal osteosarcomas show some degree of transphyseal spread.”1 Based on our experience, that percentage is approximately 50% to 60%.3 Breach of the physis by a metaphyseal pediatric osteosarcoma is a matter of time.4 The fact that the growth plate is in many cases a barrier against metaphyseal sarcomas and the ability of MRI to detect it comprise the bedrock foundation of the Cañadell technique. This technique does not represent a lengthening procedure, as the authors also wrongly indicate in the article; rather, the technique is an epiphysiolysis to obtain a safe margin of resection. A safe margin is not a matter of quantity (centimeters) but of quality (the small layer of growth plate covering the metaphysis after epiphysiolysis is achieved in Cañadell’s technique). This technique was first used in 1984 and first published in a series in 1994,5 and after 33 years of experience, we can assure the reader that the procedure is safe and successfully used in many countries. 6 The Authors Reply: We greatly appreciate the feedback regarding the recently published review, “Reconstruction Following Tumor Resections in Skeletally Immature Patients.”1 We recognize that we inadvertently submitted the incorrect image for Figure 1, and we apologize that this was not appreciated during our proofing process. It appears as though the image included in the published manuscript may be that of a patient from Clínica Universidad de Navarra, Pamplona, Spain, and is similar to one previously published, as referenced in our manuscript.6 The published figure was part of an old teaching file, and we simply made an honest mistake. We have apologized to Dr. San-Julián for unintentionally including an image of one of his patients without permission. Interestingly, although the included MRIs appeared to demonstrate physeal involvement, histologic analysis failed to demonstrate any epiphyseal extension on that patient. Although MRI remains the best discriminatory test for evaluation of transphyseal extension, Dr. San-Julián’s patient demonstrates the limitation of imaging studies compared with the standard of histopathologic evaluation. Dr. Cañadell has done pioneering work on the use of physeal distraction in this clinical setting, as referenced in our review. Although our published article did not elucidate the technical details of the procedure for its use in metaphyseal tumors that are unacceptably close to the physis, Dr. Cañadell’s published technique is that of physeal distraction using a monolateral external fixator to provide 2 cm of lengthening during preoperative chemotherapy.5 This technique is used to provide an adequate margin for resection while preserving the epiphysis, rather than for the purposes of limb lengthening. It should be clarified that after wide resection, Dr. Cañadell’s described technique is to use either allograft or autograft to fill the post-resection bone defect.5 However, some authors have attempted to use bone transport for this purpose instead. Our article briefly reviews the current understanding of distraction osteogenesis for filling bone defects in patients undergoing chemotherapy for bone sarcomas, and we feel that we have provided a fair evaluation of the present literature on the topic. The results and complications of Cañadell’s technique are not reviewed in our article, although there is a reported infection rate of 9%, and only a 2% to 3% rate of distraction through unintended sites, such as through the tumor. Despite these excellent results, we maintain that the proximity of the tumor to the growth plate in the figure published from Dr. San-Julián’s manuscript would have obviated the use of this technique in our hands. Adam S. Levin, MD Alexandre Arkader, MD Carol D.