Aims. To investigate the benefits of denosumab in combination with nerve-sparing surgery for treatment of sacral giant cell tumours (GCTs). Methods. This is a retrospective cohort study of patients with GCT who presented between January 2011 and July 2017. Intralesional curettage was performed and patients treated from 2015 to 2017 also received denosumab therapy. The patients were divided into three groups: Cohort 1: control group (n = 36); cohort 2: adjuvant denosumab group (n = 9); and cohort 3: neo- and adjuvant-denosumab group (n = 17). Results. There were 68 patients within the study period. Six patients were lost to follow-up. The mean follow-up was 47.7 months (SD 23.2). Preoperative denosumab was found to reduce intraoperative haemorrhage and was associated with shorter operating time for tumour volume > 200 cm. 3. A total of 17 patients (27.4%) developed local recurrence. The locoregional control rate was 77.8% (7/9) and 87.5% (14/16) respectively for cohorts 2 and 3, in comparison to 66.7% (24/36) of the control group. The recurrence-free survival (RFS) rate was significantly higher for adjuvant denosumab group versus those without adjuvant denosumab during the first two years: 100% vs 83.8% at one year and 95.0% vs 70.3% at two years. No significant difference was found for the three-year RFS rate. Conclusion. Preoperative denosumab therapy was found to reduce intraoperative haemorrhage and was associated with shorter operating times. Adjuvant denosumab was useful to prevent early recurrence during the first two years after surgery. Cite this article: Bone Joint J 2020;102-B(2):177–185

We conducted a case-control study to examine the merit of silver-coated tumour prostheses. We reviewed 85 patients with Agluna-treated (silver-coated) tumour implants treated between 2006 and 2011 and matched them with 85 control patients treated between 2001 and 2011 with identical, but uncoated, tumour prostheses.

In all, 106 men and 64 women with a mean age of 42.2 years (18.4 to 90.4) were included in the study. There were 50 primary reconstructions (29.4%); 79 one-stage revisions (46.5%) and 41 two-stage revisions for infection (24.1%).

The overall post-operative infection rate of the silver-coated group was 11.8% compared with 22.4% for the control group (p = 0.033, chi-square test). A total of seven of the ten infected prostheses in the silver-coated group were treated successfully with debridement, antibiotics, and implant retention compared with only six of the 19 patients (31.6%) in the control group (p = 0.048, chi-square test). Three patients in the silver-coated group (3.5%) and 13 controls (15.3%) had chronic periprosthetic infection (p = 0.009, chi-square test).

The overall success rates in controlling infection by two-stage revision in the silver-coated group was 85% (17/20) compared with 57.1% (12/21) in the control group (p = 0.05, chi-square test). The Agluna-treated endoprostheses were associated with a lower rate of early periprosthetic infection. These silver-treated implants were particularly useful in two-stage revisions for infection and in those patients with incidental positive cultures at the time of implantation of the prosthesis.

Debridement with antibiotic treatment and retention of the implant appeared to be more successful with silver-coated implants.

Cite this article: Bone Joint J 2015;97-B:252–7.

Aims. Endoprosthetic reconstruction following distal femur tumour resection has been widely advocated. In this paper, we present the design of an uncemented endoprosthesis system featuring a short, curved stem, with the goal of enhancing long-term survivorship and functional outcomes. Methods. This study involved patients who underwent implantation of an uncemented distal femoral endoprosthesis with a short and curved stem between 2014 and 2019. Functional outcomes were assessed using the 1993 version of the Musculoskeletal Tumour Society (MSTS-93) score. Additionally, we quantified five types of complications and assessed osseointegration radiologically. The survivorship of the endoprosthesis was evaluated according to two endpoints. A total of 134 patients with a median age of 26 years (IQR 16 to 41) were included in our study. The median follow-up time was 61 months (IQR 56 to 76), and the median functional MSTS-93 was 83% (IQR 73 to 91) postoperatively. Results. Overall, 21 patients (16%) encountered complications, and the rate of aseptic loosening was 7% (9/134). The survival rate up to 8.5 years was 93% for aseptic loosening as the endpoint, and 88% for any reason as the endpoint, retrospectively. Conclusion. The use of an uncemented distal femoral endoprosthesis with a short, curved stem demonstrated a low incidence of aseptic loosening and achieved long-term survivorship of up to nine years. Meanwhile, aseptic loosening typically occurs in the early stage postoperatively. Cite this article: Bone Joint J 2024;106-B(9):1000–1007

Aims. Due to its indolent clinical behaviour, the treatment paradigm of atypical cartilaginous tumours (ACTs) in the long bones is slowly shifting from intralesional resection (curettage) and local adjuvants, towards active surveillance through wait-and-scan follow-up. In this retrospective cohort study performed in a tertiary referral centre, we studied the natural behaviour of ACT lesions by active surveillance with MRI. Clinical symptoms were not considered in the surveillance programme. Methods. The aim of this study was to see whether active surveillance is safe regarding malignant degeneration and local progression. In total, 117 patients were evaluated with MRI assessing growth, cortical destruction, endosteal scalloping, periosteal reaction, relation to the cortex, and perilesional bone marrow oedema. Patients received up to six follow-up scans. Results. At the time of the first follow-up MRI, 8% of the lesions showed growth (n = 9), 86% remained stable (101), and 6% decreased in size (n = 7). During the third follow-up, with a mean follow-up time of 60 months (SD 23), 24 patients were scanned, of whom 13% had lesions that had grown and 13% lesions that had decreased in size. After 96 months (SD 37), at the sixth follow-up MRI, 100% of the lesions remained stable. None of the lesions showed malignant progression and although some lesions grew in size (mean 1 mm (SD 0.8)), no malignant progression occurred. Conclusion. We conclude that active surveillance with MRI is safe for ACTs in the long bones in the short- and mid-term follow-up. Cite this article: Bone Joint J 2024;106-B(1):86–92

Aims. The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours. Methods. We retrospectively reviewed 17 patients (13 males and four females) with femoral diaphyseal tumours who underwent JSLSS in our hospital. Results. In all, 17 patients with locally aggressive bone tumours (Enneking stage IIB) located in the femoral shaft underwent JSLSS and reconstruction with 3D-printed modular prostheses between January 2020 and June 2022. The median surgical time was 153 minutes (interquartile range (IQR) 117 to 248), and the median estimated blood loss was 200ml (IQR 125 to 400). Osteosarcoma was the most common pathological type (n = 12; 70.6%). The mean osteotomy length was 197.53 mm (SD 12.34), and the median follow-up was 25 months (IQR 19 to 38). Two patients experienced local recurrence and three developed distant metastases. Postoperative complications included wound infection in one patient and screw loosening in another, both of which were treated successfully with revision surgery. The median Musculoskeletal Tumor Society score at the final follow-up was 28 (IQR 27 to 28). Conclusion. The 3D-printed modular prosthesis is a reliable and feasible reconstruction option for patients with malignant femoral diaphyseal tumours. It helps to improve the limb salvage rate, restore limb function, and achieve better short-term effectiveness. Cite this article: Bone Jt Open 2024;5(4):317–323

Aims. Internal hemipelvectomy without reconstruction of the pelvis is a viable treatment for pelvic sarcoma; however, the time it takes to return to excellent function is quite variable. Some patients require greater time and rehabilitation than others. To determine if psoas muscle recovery is associated with changes in ambulatory function, we retrospectively evaluated psoas muscle size and limb-length discrepancy (LLD) before and after treatment and their correlation with objective functional outcomes. Methods. T1-weighted MR images were evaluated at three intervals for 12 pelvic sarcoma patients following interval hemipelvectomy without reconstruction. Correlations between the measured changes and improvements in Timed Up and Go test (TUG) and gait speed outcomes were assessed both independently and using a stepwise multivariate regression model. Results. Increased ipsilesional psoas muscle size from three months postoperatively to latest follow-up was positively correlated with gait speed improvement (r = 0.66). LLD at three months postoperatively was negatively correlated with both TUG (r = -0.71) and gait speed (r = -0.61). Conclusion. This study suggests that psoas muscle strengthening and minimizing initial LLD will achieve the greatest improvements in ambulatory function. LLD and change in hip musculature remain substantial prognostic factors for achieving the best clinical outcomes after internal hemipelvectomy. Changes in psoas size were correlated with the amount of functional improvement. Several patients in this study did not return to their preoperative ipsilateral psoas size, indicating that monitoring changes in psoas size could be a beneficial rehabilitation strategy. Cite this article: Bone Joint J 2023;105-B(3):323–330

Aims. The preoperative grading of chondrosarcomas of bone that accurately predicts surgical management is difficult for surgeons, radiologists, and pathologists. There are often discrepancies in grade between the initial biopsy and the final histology. Recent advances in the use of imaging methods have shown promise in the ability to predict the final grade. The most important clinical distinction is between grade 1 chondrosarcomas, which are amenable to curettage, and resection-grade chondrosarcomas (grade 2 and 3) which require en bloc resection. The aim of this study was to evaluate the use of a Radiological Aggressiveness Score (RAS) to predict the grade of primary chondrosarcomas in long bones and thus to guide management. Methods. A total of 113 patients with a primary chondrosarcoma of a long bone presenting between January 2001 and December 2021 were identified on retrospective review of a single oncology centre’s prospectively collected database. The nine-parameter RAS included variables from radiographs and MRI scans. The best cut-off of parameters to predict the final grade of chondrosarcoma after resection was determined using a receiver operating characteristic curve (ROC), and this was correlated with the biopsy grade. Results. A RAS of ≥ four parameters was 97.9% sensitive and 90.5% specific in predicting resection-grade chondrosarcoma based on a ROC cut-off derived using the Youden index. Cronbach’s α of 0.897 was derived as the interclass correlation for scoring the lesions by four blinded reviewers who were surgeons. Concordance between resection-grade lesions predicted from the RAS and ROC cut-off with the final grade after resection was 96.46%. Concordance between the biopsy grade and the final grade was 63.8%. However, when the patients were analyzed based on surgical management, the initial biopsy was able to differentiate low-grade from resection-grade chondrosarcomas in 82.9% of biopsies. Conclusion. These findings suggest that the RAS is an accurate method for guiding the surgical management of patients with these tumours, particularly when the initial biopsy results are discordant with the clinical presentation. Cite this article: Bone Joint J 2023;105-B(7):808–814

Aims. To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs. Methods. The medical records of 75 patients who underwent surgery between 2000 and 2020 were retrospectively reviewed, and 44 patients who were alive and available for follow-up (at a mean of 9.7 years postoperatively) were included in the study. Leg length discrepancy was measured on whole-leg radiographs, and functional assessment was performed with PROMs (Toronto Extremity Salvage Score (TESS) and Comprehensive Outcome Measure for Musculoskeletal Oncology Lower Extremity (COMMON-LE)) with two different aspects. The thresholds for unfavourable PROMs were determined using anchor questions regarding satisfaction, and the risk factors for unfavourable PROMs were investigated. Results. The thresholds for favourable TESS and COMMON were 64.8 and 70.4 points, respectively. Multivariate analysis showed that age at surgery (p = 0.004) and postoperative leg length discrepancy (p = 0.043) were significant risk factors for unfavourable TESS results, while age at surgery (p < 0.001) was a significant risk factor for unfavourable COMMON-LE results. Following receiver operating characteristic analysis, the threshold for both TESS and COMMON-LE was 29 years of age at surgery. Additionally, a leg length discrepancy of 8.2 mm was the threshold for unfavourable TESS. Conclusion. Patients aged > 29 years at the time of surgery require appropriate preoperative counselling and adequate postoperative physical and socioemotional support. Reconstruction equivalent to the length of the resected bone can reduce the risk of functional disabilities in daily living. Cite this article: Bone Jt Open 2023;4(12):906–913

Aims. The epiphyseal approach to a chondroblastoma of the intercondylar notch of a child’s distal femur does not provide adequate exposure, thereby necessitating the removal of a substantial amount of unaffected bone to expose the lesion. In this study, we compared the functional outcomes, local recurrence, and surgical complications of treating a chondroblastoma of the distal femoral epiphysis by either an intercondylar or an epiphyseal approach. Methods. A total of 30 children with a chondroblastoma of the distal femur who had been treated by intraregional curettage and bone grafting were retrospectively reviewed. An intercondylar approach was used in 16 patients (group A) and an epiphyseal approach in 14 (group B). Limb function was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system and Sailhan’s functional criteria. Results. At final follow-up, the mean MSTS score was 29.1 (SD 0.9) in group A and 26.7 (SD 1.5) in group B (p = 0.006). According to Sailhan’s criteria, the knee function was good and fair in 14 (87.5%) and two (12.5%) patients of group A, and eight (57.1%) and six (42.9%) patients of group B, respectively (p = 0.062). The lesion had recurred in one patient (6.2%) in group A and four patients (28.6%) in group B. Limb shortening > 1 cm was recorded in one patient (6.2%) from group A and six patients (42.8%) from group B. Joint degeneration was noted in one patient from group A and three patients from group B. Conclusion. An intercondylar approach to a chondroblastoma of the middle two-quarters of the distal femoral epiphysis results in better outcomes than a medial or lateral epiphyseal approach: specifically, better limb function, a lower rate of recurrence, and a lower rate of physeal damage and joint degeneration. Cite this article: Bone Joint J 2024;106-B(2):195–202

Aims. Treatment of high-grade limb bone sarcoma that invades a joint requires en bloc extra-articular excision. MRI can demonstrate joint invasion but is frequently inconclusive, and its predictive value is unknown. We evaluated the diagnostic accuracy of direct and indirect radiological signs of intra-articular tumour extension and the performance characteristics of MRI findings of intra-articular tumour extension. Methods. We performed a retrospective case-control study of patients who underwent extra-articular excision for sarcoma of the knee, hip, or shoulder from 1 June 2000 to 1 November 2020. Radiologists blinded to the pathology results evaluated preoperative MRI for three direct signs of joint invasion (capsular disruption, cortical breach, cartilage invasion) and indirect signs (e.g. joint effusion, synovial thickening). The discriminatory ability of MRI to detect intra-articular tumour extension was determined by receiver operating characteristic analysis. Results. Overall, 49 patients underwent extra-articular excision. The area under the curve (AUC) ranged from 0.65 to 0.76 for direct signs of joint invasion, and was 0.83 for all three combined. In all, 26 patients had only one to two direct signs of invasion, representing an equivocal result. In these patients, the AUC was 0.63 for joint effusion and 0.85 for synovial thickening. When direct signs and synovial thickening were combined, the AUC was 0.89. Conclusion. MRI provides excellent discrimination for determining intra-articular tumour extension when multiple direct signs of invasion are present. When MRI results are equivocal, assessment of synovial thickening increases MRI’s discriminatory ability to predict intra-articular joint extension. These results should be interpreted in the context of the study’s limitations. The inclusion of only extra-articular excisions enriched the sample for true positive cases. Direct signs likely varied with tumour histology and location. A larger, prospective study of periarticular bone sarcomas with spatial correlation of histological and radiological findings is needed to validate these results before their adoption in clinical practice. Cite this article: Bone Jt Open 2024;5(10):944–952

Aims. Due to their radiolucency and favourable mechanical properties, carbon fibre nails may be a preferable alternative to titanium nails for oncology patients. We aim to compare the surgical characteristics and short-term results of patients who underwent intramedullary fixation with either a titanium or carbon fibre nail for pathological long-bone fracture. Methods. This single tertiary-institutional, retrospectively matched case-control study included 72 patients who underwent prophylactic or therapeutic fixation for pathological fracture of the humerus, femur, or tibia with either a titanium (control group, n = 36) or carbon fibre (case group, n = 36) intramedullary nail between 2016 to 2020. Patients were excluded if intramedullary fixation was combined with any other surgical procedure/fixation method. Outcomes included operating time, blood loss, fluoroscopic time, and complications. Fisher’s exact test and Mann-Whitney U test were used for categorical and continuous outcomes, respectively. Results. Patients receiving carbon nails as compared to those receiving titanium nails had higher blood loss (median 150 ml (interquartile range (IQR) 100 to 250) vs 100 ml (IQR 50 to 150); p = 0.042) and longer fluoroscopic time (median 150 seconds (IQR 114 to 182) vs 94 seconds (IQR 58 to 124); p = 0.001). Implant complications occurred in seven patients (19%) in the titanium group versus one patient (3%) in the carbon fibre group (p = 0.055). There were no notable differences between groups with regard to operating time, surgical wound infection, or survival. Conclusion. This pilot study demonstrates a non-inferior surgical and short-term clinical profile supporting further consideration of carbon fibre nails for pathological fracture fixation in orthopaedic oncology patients. Given enhanced accommodation of imaging methods important for oncological surveillance and radiation therapy planning, as well as high tolerances to fatigue stress, carbon fibre implants possess important oncological advantages over titanium implants that merit further prospective investigation. Level of evidence: III, Retrospective study. Cite this article: Bone Jt Open 2022;3(8):648–655

Aims. The ulna is an extremely rare location for primary bone tumours of the elbow in paediatrics. Although several reconstruction options are available, the optimal reconstruction method is still unknown due to the rarity of proximal ulna tumours. In this study, we report the outcomes of osteoarticular ulna allograft for the reconstruction of proximal ulna tumours. Methods. Medical profiles of 13 patients, who between March 2004 and November 2021 underwent osteoarticular ulna allograft reconstruction after the resection of the proximal ulna tumour, were retrospectively reviewed. The outcomes were measured clinically by the assessment of elbow range of motion (ROM), stability, and function, and radiologically by the assessment of allograft-host junction union, recurrence, and joint degeneration. The elbow function was assessed objectively by the Musculoskeletal Tumor Society (MSTS) score and subjectively by the Toronto Extremity Salvage Score (TESS) and Mayo Elbow Performance Score (MEPS) questionnaire. Results. The mean follow-up of patients was 60.3 months (SD 28.5). The mean elbow flexion-extension ROM was 95.8° (SD 21). The mean MSTS of the patients was 84.4 (SD 8.2), the mean TESS was 83.8 (SD 6.7), and the mean MEPS was 79.2 (SD 11.5). All the patients had radiological union at the osteotomy site. Symptomatic osteoarthritic change was observed in three patients (23%), one of whom ended up with elbow joint fusion. Two patients (15.4%) had recurrence during the follow-up period. Surgical complications included two allograft fractures, two plate fractures, three medial instabilities, and two infections. Conclusion. Osteoarticular ulna allograft reconstruction provides acceptable functional outcomes. Despite a high rate of complications, it is still a valuable reconstruction method, particularly in skeletally immature patients who need their distal humerus physis for the rest of hand growth. Cite this article: Bone Jt Open 2024;5(9):749–757

Aims. The aim of this study is to determine the predictors of overall survival (OS) and predictive factors of poor prognosis of conventional high-grade osteosarcoma of the limbs in a single-centre in South Africa. Methods. We performed a retrospective cross-sectional analysis to identify the prognostic factors that predict the OS of patients with histologically confirmed high-grade conventional osteosarcoma of the limbs over ten years. We employed the Cox proportional regression model and the Kaplan-Meier method for statistical analysis. Results. This study comprised 77 patients at a three-year minimum follow-up. The predictors of poor OS were: the median age of ≤ 19 years (hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.92 to 0.99; p = 0.021); median duration of symptoms ≥ five months (HR 0.91; 95% CI 0.83 to 0.99; p < 0.037); metastasis at diagnosis (i.e. Enneking stage III) (HR 3.33; 95% CI 1.81 to 6.00; p < 0.001); increased alkaline phosphatase (HR 3.28; 95% CI 1.33 to 8.11; p < 0.010); palliative treatment (HR 7.27; 95% CI 2.69 to 19.70); p < 0.001); and amputation (HR 3.71; 95% CI 1.12 to 12.25; p < 0.032). In contrast, definitive surgery (HR 0.11; 95% CI 0.03 to 0.38; p < 0.001) and curative treatment (HR 0.18; 95% CI 0.10 to 0.33; p < 0.001) were a protective factor. The Kaplan-Meier median survival time was 24 months, with OS of 57.1% at the three years. The projected five-year event-free survival was 10.3% and OS of 29.8% (HR 0.76; 95% CI 0.52 to 1.12; p = 0.128). Conclusion. In this series of high-grade conventional osteosarcoma of the appendicular skeleton from South Africa, 58.4% (n = 45) had detectable metastases at presentation; hence, an impoverished OS of five years was 29.8%. Large-scale future research is needed to validate our results. Cite this article: Bone Jt Open 2024;5(3):210–217

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

Aims. Radiotherapy is a well-known local treatment for spinal metastases. However, in the presence of postoperative systemic therapy, the efficacy of radiotherapy on local control (LC) and overall survival (OS) in patients with spinal metastases remains unknown. This study aimed to evaluate the clinical outcomes of post-surgical radiotherapy for spinal metastatic non-small-cell lung cancer (NSCLC) patients, and to identify factors correlated with LC and OS. Methods. A retrospective, single-centre review was conducted of patients with spinal metastases from NSCLC who underwent surgery followed by systemic therapy at our institution from January 2018 to September 2022. Kaplan-Meier analysis and log-rank tests were used to compare the LC and OS between groups. Associated factors for LC and OS were assessed using Cox proportional hazards regression analysis. Results. Overall, 123 patients with 127 spinal metastases from NSCLC who underwent decompression surgery followed by postoperative systemic therapy were included. A total of 43 lesions were treated with stereotactic body radiotherapy (SBRT) after surgery and 84 lesions were not. Survival rate at one, two, and three years was 83.4%, 58.9%, and 48.2%, respectively, and LC rate was 87.8%, 78.8%, and 78.8%, respectively. Histological type was the only significant associated factor for both LC (p = 0.007) and OS (p < 0.001). Treatment with targeted therapy was significantly associated with longer survival (p = 0.039). The risk factors associated with worse survival were abnormal laboratory data (p = 0.021), lesions located in the thoracic spine (p = 0.047), and lumbar spine (p = 0.044). This study also revealed that postoperative radiotherapy had little effect in improving OS or LC. Conclusion. Tumour histological type was significantly associated with the prognosis in spinal NSCLC metastasis patients. In the presence of post-surgical systemic therapy, radiotherapy appeared to be less effective in improving LC, OS, or quality of life in spinal NSCLC metastasis patients. Cite this article: Bone Jt Open 2024;5(4):350–360

Aims. Advances in treatment have extended the life expectancy of patients with metastatic bone disease (MBD). Patients could experience more skeletal-related events (SREs) as a result of this progress. Those who have already experienced a SRE could encounter another local management for a subsequent SRE, which is not part of the treatment for the initial SRE. However, there is a noted gap in research on the rate and characteristics of subsequent SREs requiring further localized treatment, obligating clinicians to extrapolate from experiences with initial SREs when confronting subsequent ones. This study aimed to investigate the proportion of MBD patients developing subsequent SREs requiring local treatment, examine if there are prognostic differences at the initial treatment between those with single versus subsequent SREs, and determine if clinical, oncological, and prognostic features differ between initial and subsequent SRE treatments. Methods. This retrospective study included 3,814 adult patients who received local treatment – surgery and/or radiotherapy – for bone metastasis between 1 January 2010 and 31 December 2019. All included patients had at least one SRE requiring local treatment. A subsequent SRE was defined as a second SRE requiring local treatment. Clinical, oncological, and prognostic features were compared between single SREs and subsequent SREs using Mann-Whitney U test, Fisher’s exact test, and Kaplan–Meier curve. Results. Of the 3,814 patients with SREs, 3,159 (83%) patients had a single SRE and 655 (17%) patients developed a subsequent SRE. Patients who developed subsequent SREs generally had characteristics that favoured longer survival, such as higher BMI, higher albumin levels, fewer comorbidities, or lower neutrophil count. Once the patient got to the point of subsequent SRE, their clinical and oncological characteristics and one-year survival (28%) were not as good as those with only a single SRE (35%; p < 0.001), indicating that clinicians’ experiences when treating the initial SRE are not similar when treating a subsequent SRE. Conclusion. This study found that 17% of patients required treatments for a second, subsequent SRE, and the current clinical guideline did not provide a specific approach to this clinical condition. We observed that referencing the initial treatment, patients in the subsequent SRE group had longer six-week, 90-day, and one-year median survival than patients in the single SRE group. Once patients develop a subsequent SRE, they have a worse one-year survival rate than those who receive treatment for a single SRE. Future research should identify prognostic factors and assess the applicability of existing survival prediction models for better management of subsequent SREs. Cite this article: Bone Joint Res 2024;13(9):497–506

Aims. We first sought to compare survival for patients treated surgically for solitary and multiple metastases in the appendicular skeleton, and second, to explore the role of complete and incomplete resection (R0 and R1/R2) in patients with a solitary bony metastasis in the appendicular skeleton. Methods. We conducted a retrospective study on a population-based cohort of all adult patients treated surgically for bony metastases of the appendicular skeleton between January 2014 and December 2019. We excluded patients in whom the status of bone metastases and resection margin was unknown. Patients were followed until the end of the study or to their death. We had no loss to follow-up. We used Kaplan-Meier analysis (with log-rank test) to evaluate patient survival. We identified 506 operations in 459 patients. A total of 120 operations (in 116 patients) were for solitary metastases and 386 (in 345 patients) for multiple metastases. Of the 120 operations, 70 (in 69 patients) had no/an unknown status of visceral metastases (solitary group) and 50 (in 49 patients) had visceral metastases. In the solitary group, 45 operations (in 44 patients) were R0 (resections for cure or complete remission) and 25 (in 25 patients) were R1/R2 (resections leaving microscopic or macroscopic tumour, respectively). The most common types of cancer in the solitary group were kidney (n = 27), lung (n = 25), and breast (n = 20). Results. The one-year patient survival was 47% (95% confidence interval (CI) 38 to 57) for the solitary bony metastases and 34% (95% CI 29 to 39) for multiple bone metastases (p < 0.001). The one-year patient survival was 64% (95% CI 52 to 75) for solitary bony metastases without/with unknown visceral metastases and 23% (95% CI 11 to 36) for solitary bony metastases with visceral metastases (p < 0.001). The one-year patient survival was 75% (95% CI 62 to 89) for a solitary bony metastasis after R0 surgery and 42% (95% CI 22 to 61) for a solitary bony metastasis with R1/R2 surgery (p < 0.001). Conclusion. Our study suggests that the surgical treatment of patients with a solitary bony metastasis to the appendicular skeleton results in better survival than for patients with multiple bony metastases. Furthermore, aggressive treatment of a solitary bony metastasis with R0 surgery may improve patient survival. Cite this article: Bone Joint J 2023;105-B(11):1206–1215

Aims. This study aimed to analyze the accuracy and errors associated with 3D-printed, patient-specific resection guides (3DP-PSRGs) used for bone tumour resection. Methods. We retrospectively reviewed 29 bone tumour resections that used 3DP-PSRGs based on 3D CT and 3D MRI. We evaluated the resection amount errors and resection margin errors relative to the preoperative plans. Guide-fitting errors and guide distortion were evaluated intraoperatively and one month postoperatively, respectively. We categorized each of these error types into three grades (grade 1, < 1 mm; grade 2, 1 to 3 mm; and grade 3, > 3 mm) to evaluate the overall accuracy. Results. The maximum resection amount error was 2 mm. Out of 29 resection amount errors, 15 (51.7%) were grade 1 errors and 14 (48.3%) were grade 2 errors. Complex resections were associated with higher-grade resection amount errors (p < 0.001). The actual resection margins correlated significantly with the planned margins; however, there were some discrepancies. The maximum guide-fitting error was 3 mm. There were 22 (75.9%), five (17.2%), and two (6.9%) grade 1, 2, and 3 guide-fitting errors, respectively. There was no significant association between complex resection and fitting error grades. The guide distortion after one month in all patients was rated as grade 1. Conclusion. In terms of the accurate resection amount according to the preoperative planning, 3DP-PSRGs can be a viable option for bone tumour resection. However, 3DP-PSRG use may be associated with resection margin length discrepancies relative to the planned margins. Such discrepancies should be considered when determining surgical margins. Therefore, a thorough evaluation of the preoperative imaging and surgical planning is still required, even if 3DP-PSRGs are to be used. Cite this article: Bone Joint J 2023;105-B(2):190–197

Aims. This study aimed to compare the performance of survival prediction models for bone metastases of the extremities (BM-E) with pathological fractures in an Asian cohort, and investigate patient characteristics associated with survival. Methods. This retrospective cohort study included 469 patients, who underwent surgery for BM-E between January 2009 and March 2022 at a tertiary hospital in South Korea. Postoperative survival was calculated using the PATHFx3.0, SPRING13, OPTIModel, SORG, and IOR models. Model performance was assessed with area under the curve (AUC), calibration curve, Brier score, and decision curve analysis. Cox regression analyses were performed to evaluate the factors contributing to survival. Results. The SORG model demonstrated the highest discriminatory accuracy with AUC (0.80 (95% confidence interval (CI) 0.76 to 0.85)) at 12 months. In calibration analysis, the PATHfx3.0 and OPTIModel models underestimated survival, while the SPRING13 and IOR models overestimated survival. The SORG model exhibited excellent calibration with intercepts of 0.10 (95% CI -0.13 to 0.33) at 12 months. The SORG model also had lower Brier scores than the null score at three and 12 months, indicating good overall performance. Decision curve analysis showed that all five survival prediction models provided greater net benefit than the default strategy of operating on either all or no patients. Rapid growth cancer and low serum albumin levels were associated with three-, six-, and 12-month survival. Conclusion. State-of-art survival prediction models for BM-E (PATHFx3.0, SPRING13, OPTIModel, SORG, and IOR models) are useful clinical tools for orthopaedic surgeons in the decision-making process for the treatment in Asian patients, with SORG models offering the best predictive performance. Rapid growth cancer and serum albumin level are independent, statistically significant factors contributing to survival following surgery of BM-E. Further refinement of survival prediction models will bring about informed and patient-specific treatment of BM-E. Cite this article: Bone Joint J 2024;106-B(2):203–211

Aims. Venous tumour thrombus (VTT) is a rare finding in osteosarcoma. Despite the high rate of VTT in osteosarcoma of the pelvis, there are very few descriptions of VTT associated with extrapelvic primary osteosarcoma. We therefore sought to describe the prevalence and presenting features of VTT in osteosarcoma of both the pelvis and the limbs. Methods. Records from a single institution were retrospectively reviewed for 308 patients with osteosarcoma of the pelvis or limb treated between January 2000 and December 2022. Primary lesions were located in an upper limb (n = 40), lower limb (n = 198), or pelvis (n = 70). Preoperative imaging and operative reports were reviewed to identify patients with thrombi in proximity to their primary lesion. Imaging and histopathology were used to determine presence of tumour within the thrombus. Results. Tumours abutted the blood vessels in 131 patients (43%) and encased the vessels in 30 (10%). Any form of venous thrombus was identified in 31 patients (10%). Overall, 21 of these thrombi were determined to be involved with the tumour based on imaging (n = 9) or histopathology (n = 12). The rate of VTT was 25% for pelvic osteosarcoma and 1.7% for limb osteosarcoma. The most common imaging features associated with histopathologically proven VTT were enhancement with contrast (n = 12; 100%), venous enlargement (n = 10; 83%), vessel encasement (n = 8; 66%), and visible intraluminal osteoid matrix (n = 6; 50%). Disease-specific survival (DSS) for patients with VTT was 95% at 12 months (95% CI 0.87 to 1.00), 50% at three years (95% CI 0.31 to 0.80), and 31% at five years (95% CI 0.14 to 0.71). VTT was associated with worse DSS (hazard ratio 2.3 (95% CI 1.11 to 4.84). Conclusion. VTT is rare with osteosarcoma and occurs more commonly in the pelvis than the limbs. Imaging features suggestive of VTT include enhancement with contrast, venous dilation, and vessel encasement. VTT portends a worse prognosis for patients with osteosarcoma, with a similar survivability to metastatic disease. Cite this article: Bone Joint J 2024;106-B(8):865–870