New perspectives on surgical accuracy analysis of image-guided bone tumour resection surgery

Surgical Management of Sacral Bone Tumors: A Retrospective Analysis of Outcomes, Complications, and Survival

Background: Primary malignant bone tumors are exceedingly rare, with an incidence of 0.5 to 1 per million, and sacral localization is even more uncommon, representing only 1-3.5% of these tumors. These malignancies are often diagnosed late due to their asymptomatic nature until they present as large, advanced intrapelvic tumors. Management is complicated by the need for precise surgical intervention and the consideration of adjuvant therapies based on tumor histology and patient factors. Methods: We conducted a single-center, retrospective analysis of patients who underwent complete, partial, or hemisacrectomy for primary malignant bone tumors or recurrent sacral metastases. Excluded were patients with metastatic disease not necessitating sacrectomy. Data collected included demographics, clinical characteristics, tumor types, resection status, adjuvant therapies, recurrence, metastasis, and complications. Surgical approaches were categorized as posterior, anterior, or combined anterior-posterior. The primary outcomes were overall survival and disease-free survival, while the secondary outcomes focused on complication rates and functional outcomes. Results: The study included 19 patients (7 females, 12 males) with a mean age of 48.9 years at the time of surgery. Primary malignancies were present in 90% of patients. Surgical approaches varied: 20% underwent double access and 5% anterior access only, and the remainder had posterior approaches. High partial sacrectomy (above S3) was performed in 20%, while low sacrectomy (at or below S3) was performed in 80%. Complete resection with clean margins (R0) was achieved in 65% of cases, while 35% had R1 resections with microscopic tumor remnants. Root resection was necessary in 25% of patients. Local recurrence occurred in 25% of patients, with two requiring reoperation and neurological sacrifice. Distant metastases were observed in 20% of cases. Postoperative complications affected 60% of patients. The most common issues were surgical wound dehiscence with delayed healing (35%) and visceral changes affecting the bowel and urination (25%). No mechanical complications were reported. Conclusions: Sacrectomy remains a challenging procedure with substantial morbidity and variability in outcomes. The choice of surgical approach-posterior, anterior, or combined-depends on tumor location and extent. While posterior-only approaches are often preferred for lower sacral lesions, combined approaches may be necessary for more extensive tumors. Survival and disease-free survival rates are influenced by resection margins and the biological behavior of the tumor. Wide-margin resections (R0) are associated with lower local recurrence rates but do not eliminate the risk of distant metastases.

What to choose in bone tumour resections? Patient specific instrumentation versus surgical navigation: a systematic review

Patient specific instrumentation (PSI) and intraoperative surgical navigation (SN) can significantly help in achieving wide oncological margins while sparing bone stock in bone tumour resections. This is a systematic review aimed to compare the two techniques on oncological and functional results, preoperative time for surgical planning, surgical intraoperative time, intraoperative technical complications and learning curve. The protocol was registered in PROSPERO database (CRD42023422065). 1613 papers were identified and 81 matched criteria for PRISMA inclusion and eligibility. PSI and SN showed similar results in margins (0-19% positive margins rate), bone cut accuracy (0.3-4 mm of error from the planned), local recurrence and functional reconstruction scores (MSTS 81-97%) for both long bones and pelvis, achieving better results compared to free hand resections. A planned bone margin from tumour of at least 5 mm was safe for bone resections, but soft tissue margin couldn't be planned when the tumour invaded soft tissues. Moreover, long osteotomies, homogenous bone topology and restricted working spaces reduced accuracy of both techniques, but SN can provide a second check. In urgent cases, SN is more indicated to avoid PSI planning and production time (2-4 weeks), while PSI has the advantage of less intraoperative using time (1-5 min vs 15-65 min). Finally, they deemed similar technical intraoperative complications rate and demanding learning curve. Overall, both techniques present advantages and drawbacks. They must be considered for the optimal choice based on the specific case. In the future, robotic-assisted resections and augmented reality might solve the downsides of PSI and SN becoming the main actors of bone tumour surgery.

Current Concepts in the Resection of Bone Tumors Using a Patient-Specific Three-Dimensional Printed Cutting Guide

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.

A bifunctional zoledronate sustained-release system in scaffold: Tumor therapy and bone repair

It is of great challenges to repair bone defect and prevent tumor recurrence in bone tumors postoperative treatment. Bone scaffolds loaded with zoledronate (ZOL) are expected to solve these issues due to its osteogenesis and anti-tumor ability. Furthermore, ZOL needs to be sustained release to meet the requirement of long-term therapy. In this study, ZOL was loaded into amination functionalized mesoporous silicon (SBA15NH₂), and then incorporated into poly (L-lactic acid) to prepare PLLA/SBA15NH₂-ZOL scaffold via selective laser sintering technology. On one hand, ZOL of local release not only can inhibit growth and proliferation of bone tumor cells but also inhibit osteoclast differentiation through competitive binding of receptor activator of nuclear factor (NF)-kB (RANK) in osteoclast precursors. On the other hand, amination function could change the surface charge of mesoporous silica to positive charge to enhance the absorption of ZOL, mesoporous structure and abundant amino groups of SBA15NH₂ play a barrier role and form hydrogen bond with phosphate groups of ZOL, respectively, thereby achieving its sustained release. The results showed that the loading amount of ZOL was 236.53 mg/g, and the scaffold could sustainedly release ZOL for more than 6 weeks. The scaffold inhibited proliferation of osteosarcoma cells through inducing apoptosis and cell cycle arrest. TRAP staining and F-actin ring formation experiment showed the scaffold inhibited differentiation and mature of osteoclast. Pit formation assay indicated that bone resorption activity was inhibited strongly.

Complex joint-preserving bone tumor resection and reconstruction using computer navigation and 3D-printed patient-specific guides: A technical note of three cases

In selected extremity bone sarcomas, joint-preserving surgery retains the natural joints and nearby ligaments with a better function than in traditional joint-sacrificing surgery. Geometric multiplanar osteotomies around bone sarcomas were reported with the advantage of preserving more host bone. However, the complex surgical planning translation to the operating room is challenging.

Using both Computer Navigation and Patient-Specific Guide may combine each technique's key advantage in assisting complex bone tumor resections. Computer Navigation provides the visual image feedback of the pathological information and validates the correct placement of Patient-Specific Guide that enables accurate, guided bone resections. We first described the digital workflow and the use of both computer navigation and patient-specific guides (NAVIG) to assist the multiplanar osteotomies in three extremity bone sarcoma patients who underwent joint-preserving bone tumor resections and reconstruction with patient-specific implants. The NAVIG technique verified the correct placement of patient-specific guides that enabled precise osteotomies and well-fitted patient-specific implants. The mean maximum deviation errors of the nine achieved bone resections were 1.64 ​± ​0.35 ​mm (95% CI 1.29 to 1.99). The histological examination of the tumor specimens showed negative resection margin. At the mean follow-up of 55 months (40–67), no local recurrence was noted. There was no implant loosening that needed revision. The mean MSTS score was 29 (28–30) out of 30 with the mean knee flexion of 140° (130°–150°).

The excellent surgical accuracy and limb function suggested that the NAVIG technique might replicate the surgical planning of complex bone sarcoma resections by combining the strength of both Computer Navigation and Patient-Specific Guide. The patient-specific approach may translate into clinical benefits. The translational potential of this article:

The newly described technique enhances surgeons’ capability in performing complex joint-preserving surgery in bone sarcoma that is difficult to be achieved by the traditional method. The high precision and accuracy may translate into superior clinical outcomes.