{'fraction_non_alphanumeric': 0.04236373448461954, 'fraction_numerical': 0.021046950890447922, 'mean_word_length': 5.293718166383702, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 1, 'substrings_counts': 1, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
CORR Insights®: Can Navigation Improve the Ability to Achieve Tumor-free Margins in Pelvic and Sacral Primary Bone Sarcoma Resections? A Historically Controlled Study.

Auniversal goal in oncologic surgery is achieving tumorfree margins when treating primary sarcomas of bone, soft tissue, or both [3, 8, 12]. With the advent of high-resolution preoperative imaging and improved radiation techniques, tumor-free resections are becoming more feasible at anatomic sites where in the past this has beenmore difficult, such as the pelvis and the sacrum [1]. Two technological solutions—intraoperative navigation and custom-made threedimensional-printed resection guides— seek to improve real-time accuracy at the moment of tumor resection, as a way to achieve tumor-free margins while preserving healthy tissues to every extent possible [1, 4, 9]. As both of these technologies are new, there is insufficient evidence to support their routine use, or favor one over the other. But, in my view, there is a clear theoretical benefit for both navigation and custom-made cutting guides, because the use of these technologies requires judicious preoperative planning that forces the surgeon to go over the surgical plan more than once. Additionally, reduction in surgical time, more anatomic reconstructions, and increased accuracy are goals more reliably attained with the assistance of technology. In fact, I have personally experienced these advantages in my practice. Still, there are advocates and detractors for each of these technologies [4, 5, 9]. As for navigation in pelvic and sacral resections, data originate from non in-vivo (cadaver and saw-bones modes) experimental studies [10] and small patient series with historic controls [1, 5, 10]. While recognizing the shortcomings of those designs, it nonetheless is exciting that the preliminary findings from those reports include greater accuracy in osteotomies, lower risk of intralesional resection, decreased blood loss, reduced operative time, and fewer complications. Critics of navigation point to increased costs, longer setup times in the operating room, and intraoperative software issues [9], and, of course, the lack of randomized or well-controlled study designs. Others express concern with infection risk [4, 6], surgical learning curves [7], and the detrimental effects in the training of future orthopaedic oncologists (lack of ability to perform complex resections without either of these technologies) [7, 11]. In the current study, Bosma and colleagues [2] present a large comparative and well-controlled case series. They found a 30% increase in adequate bone margin after resection, with navigation increasing the probability of a good osseous margin (OR = 4.14 [95% CI, 1.43-12.01]; p = 0.007) [2]. This CORR Insights is a commentary on the article “Can Navigation Improve the Ability to Achieve Tumor-free Margins in Pelvic and Sacral Primary Bone Sarcoma Resections? A Historically Controlled Study” by Bosma and colleagues available at: DOI: 10. 1097/CORR.0000000000000766. The author certifies that neither he, nor any members of his immediate family, have any commercial associations (such as consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. The opinions expressed are those of the writer, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. S. A. Lozano-Calderón MD, PhD (✉), Massachusetts General Hospital, Harvard Medical School, Department of Orthopaedic Surgery, 55 Fruit Street, YAW 3B Suite 3700, Boston, MA 02114 USA, Email: slozanocalderon@mgh.harvard.edu