Use of an implant is one of the risk factors for surgical site infection (SSI) after malignant bone tumor resection. We developed a new technique of coating titanium implant surfaces with iodine to prevent infection. In this retrospective study, we investigated the risk factors for SSI after malignant bone tumor resection and to evaluate the efficacy of iodine-coated implants for preventing SSI. Data from 302 patients with malignant bone tumors who underwent malignant bone tumor resection and reconstruction were reviewed. Univariate analyses were performed, followed by multivariate analysis to identify risk factors for SSI based on the treatment and clinical characteristics. The frequency of SSI was 10.9% (33/302 tumors). Pelvic bone tumor (OR: 4.8, 95% CI: 1.8–13.4) and an operative time ≥ 5 h (OR: 3.4, 95% CI: 1.2–9.6) were independent risk factors for SSI. An iodine-coated implant significantly decreased the risk of SSI (OR: 0.3, 95% CI: 0.1–0.9). The present data indicate that pelvic bone tumor and long operative time are risk factors for SSI after malignant bone tumor resection and reconstruction, and that iodine coating may be a promising technique for preventing SSI.

Although aneurysmal bone cysts (ABCs) are benign tumours, they have the potential to be locally aggressive. Various treatment approaches, such as en bloc resection, open curettage, radiotherapy, sclerotherapy, and embolization have been proposed, but the most appropriate treatment should be selected after considering the risk of tumour recurrence and treatment complications. Endoscopic curettage (ESC) may be a less invasive alternative to open curettage for ABC treatment. We aimed to describe the use of ESC for the treatment of ABCs and to report our clinical outcomes, including the incidence rate of recurrence, radiological appearance at final follow-up, time to solid union, complications, and postoperative function. Between 1998 and 2015, 30 patients (18 men and 12 women; mean age, 17.4 years) underwent ESC for the treatment of primary ABCs at our hospital (mean postoperative follow-up, 55 months). ESC was performed under arthroscopic guidance for direct visualization, and curettage extended until normal bone was observed in the medullary cavity. To investigate bone healing after ESC, we evaluated the consolidation of cysts at the final evaluation (based on the modified Neer classification) and time to solid union after surgery, which was defined as sufficient cortical bone thickness to prevent fracture and allow physical activities. Recurrence was identified in 3 cases (10%). Curative outcomes were obtained after repeated ESC or open curettage. A log-rank analysis indicated that age < 10 years (p = 0.004) and contact of the tumour with the physis (p = 0.01) increased the risk of tumour recurrence. Residual tumours were identified in 9 cases (30%); these lesions remained inactive over the extended follow-up period. The average time to solid union after endoscopic curettage was 3.2 months. Transient radial nerve palsy was identified in 1 case. Good postoperative functional recovery occurred in all cases. ESC is a minimally invasive technique for the treatment of ABCs, and the tumour recurrence rate is comparable to that of other standard procedures. However, the application of this method should be carefully considered, especially for patients < 10 years and when the tumour comes in contact with the physis.

Endoscopic curettage is considered applicable for the treatment of simple bone cysts with the expectation that it might be less invasive than open curettage. In this study, we investigated the efficacy of endoscopic curettage for the treatment of simple bone cysts. The goal was to investigate the incidence of cyst recurrence and bone healing after endoscopic curettage. Moreover, complications and functionality at the final follow-up were evaluated. From 2003 to 2014, 37 patients with simple bone cysts underwent endoscopic curettage. Twenty-four were male and 13 were female, with a mean age of 14.7 years. Endoscopic curettage was performed with the support of an arthroscope via 7–8 mm holes penetrated by cannulated drills with a small incision. The cysts underwent curettage using angled curettes, rongeurs, and an electrical shaver until the normal bone was observed in the medullary cavity. To investigate the bone healing after endoscopic curettage, we evaluated the consolidation of the cyst at the final evaluation (Modified Neer Classification) and the time to solid union after operation, which was defined as the sufficient thickness of the cortical bone to prevent fracture and allow physical activities. Recurrence occurred in seven patients (18.9%). A log-rank analysis revealed that contact with the physis was associated with recurrence (p = 0.006). Among 31 patients (83.7%), the consolidation of cyst was considered healed at the final X-ray follow-up period, and in these patients, the mean time taken for solid union of cortical bone thinning was 4.0 months (standard deviation, 2.4). With regard to major complications of endoscopic curettage, a transient radial nerve palsy and two postoperative fractures occurred. The former problem was managed conservatively and the latter problems by transient internal fixation; these problems were managed without any further complications. All patients had a good postoperative function. Endoscopic curettage might be a useful alternative as it is a minimally invasive procedure for the treatment of simple bone cysts. Considering the relatively smaller size of this study, further investigation should be necessary for deducing the reliable conclusion.

Orthopedic oncology has begun to use three-dimensional-printing technology, which is expected to improve the accuracy of osteotomies, ensure a safe margin, and facilitate precise surgery. However, several difficulties should be considered. Cadaver and clinical studies have reported more accurate osteotomies for bone-tumor resection using patient-specific cutting guides, especially in challenging areas such as the sacrum and pelvis, compared to manual osteotomies. Patient-specific cutting guides can help surgeons achieve resection with negative margins and reduce blood loss and operating time. Furthermore, this patient-specific cutting guide could be combined with more precise reconstruction using patient-specific implants or massive bone allografts. This review provides an overview of the basic technologies used in the production of patient-specific cutting guides and discusses their current status, advantages, and limitations. Moreover, we summarize cadaveric and clinical studies on the use of these guides in orthopedic oncology.

Aims: Low-grade central osteosarcoma (LGCOS), a rare type of osteosarcoma, often has misleading radiological and pathological features that overlap with those of other bone tumours, thereby complicating diagnosis and treatment. We aimed to analyze the clinical, radiological, and pathological features of patients with LGCOS, with a focus on diagnosis, treatment, and outcomes.Methods: We retrospectively analyzed the medical records of 49 patients with LGCOS (Broder’s grade 1 to 2) treated between January 1985 and December 2017 in a single institute. We examined the presence of malignant features on imaging (periosteal reaction, cortical destruction, soft-tissue invasion), the diagnostic accuracy of biopsy, surgical treatment, and oncological outcome.Results: Based on imaging, 35 of 49 patients (71.4%) exhibited malignant features. Overall, 40 of 49 patients (81.6%) had undergone a biopsy before en-bloc resection: 27 of 40 patients (67.5%) were diagnosed on the first biopsy, which was more accurate when carried out by open rather than needle biopsy (91.3% vs 35.3% diagnostic accuracy, respectively; p < 0.001). Of the 40 patients treated by en-bloc resection, surgical margins were wide in 38 (95.0%) and marginal in two (5.0%). Furthermore, nine of 49 patients (18.4%) underwent curettage (intralesional margin) without previous biopsy. All patients with a positive margin developed local recurrence. Distant metastases occurred in five of 49 patients (10.2%). The mean five-year overall survival (OS) and distant relapse-free survival (D-RFS) were 89.3% (SD 5.1%) and 85.7% (SD 5.5%), respectively. Univariate analysis showed that the occurrence of distant metastasis was a poor prognostic factor for OS (hazard ratio 11.54, 95% confidence interval (CI) 1.92 to 69.17; p < 0.001). Local recurrence was a poor prognostic factor for D-RFS (HR 8.72, 95% CI 1.69 to 45.0; p = 0.002).Conclusion: The diagnosis of LGCOS can be challenging because it may present with non-malignant features and has a low diagnostic accuracy on biopsy. If precisely diagnosed, LGCOS can be successfully treated by surgical excision with wide margins.Cite this article: Bone Joint J 2024;106-B(1):99–106.