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.

Aims

Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation.

Introduction. The use of computer navigation has a potential to allow precise tumour resection and accurate reconstruction of the resultant defect. This can be useful in difficult areas such as pelvis, diaphyseal (intercalary) resections and geometric bony resections. Methods. We have carried out resections of musculoskeletal tumours in 7 patients using an existing commercial computer navigation system (Orthomap 3D). CT & MRI scans of each patient were fused preoperatively using navigation software and the tumour margins were marked. The planes of tumour resection were defined on the 3D image generated. During surgery, trackers were attached to bone with tumour and registration performed. Instruments attached to navigation tracker were then used to identify the predetermined resection points. Of the 4 pelvic tumours, 1 had biological reconstruction with extra corporeal irradiation, 3 had endoprosthetic replacement & 1 did not need any bony reconstruction. 1 patient with proximal femur tumour needing extraarticular resection had endoprosthetic replacement. The 2 tibial diaphyseal tumours had biological reconstruction. Results. Examination of the resected specimens revealed tumour free margins. Postoperative radiographs showed resection and reconstruction as planned in all cases. In the patient with extraarticular proximal femur resection the hip joint was inadvertently exposed whilst making the acetabular osteotomy & in one patient with pelvic tumour the intra-operative registration could not be accurately performed as she was overweight and a real time matching of anatomy & virtual images was not achieved. Discussion and Conclusion. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent and thus resection margins can be identified accurately. Our experience so far has been encouraging. Further clinical trials (multicentre) are required to evaluate its long term impact including functional & oncological outcomes

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution.

We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients.

Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control.

The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Cite this article: Bone Joint J 2015;97-B:258–64.

The use of a navigation system in musculoskeletal tumour surgery enables the integration of pre-operative CT and MRI images to generate a precise three-dimensional anatomical model of the site and the extent of the tumour.

We carried out six consecutive resections of musculoskeletal tumour in five patients using an existing commercial computer navigation system. There were three women and two men with a mean age of 41 years (24 to 47). Reconstruction was performed using a tumour prosthesis in three lesions and a vascularised fibular graft in one. No reconstruction was needed in two cases. The mean follow-up was 6.9 months (3.5 to 10). The mean duration of surgery was 28 minutes (13 to 50). Examination of the resected specimens showed clear margins in all the tumour lesions and a resection that was exactly as planned.