Navigation-assisted surgery for bone and soft tissue tumors with bony extension

Abstract

Background: The navigation system was introduced to orthopaedic surgery in the 1990s. More recently, CT-based navigation systems have been used more commonly in spine and joint replacement surgery because of their precision.

Questions/purposes: The aim of our study was to evaluate the accuracy and efficacy of navigation-assisted excision of bone and soft tissue tumors.

Methods: From 2006 to 2009, we performed navigation-assisted surgery in 16 patients, 11 males and five females, with a mean age of 39 years (range, 13-70 years). We diagnosed nine benign bone tumors and seven malignant bone and soft tissue tumors. In two patients, the malignant soft tissue tumors infiltrated the adjacent bones. Nine excisional biopsies for benign tumors and seven en bloc excisions for malignant tumors were performed. In all cases, the point registration method was performed using 10 skin markers, which were placed around the tumor. Each excisional difference between the preoperative and postoperative plans was evaluated histologically or by postoperative CT.

Results: The mean accuracy of this system, which was determined using skin markers, was 0.93 mm (range, 0.6-1.2 mm). All biopsy and excision samples were evaluated by pathologic examination and postoperative CT imaging. The mean difference between the planned margin and postoperative CT or excised histologic specimen was 0 mm to 4 mm. The mean followup was 34 months (range, 10-54 months). There were no local recurrences, except for excision of skip metastases in a patient with a chordoma.

Conclusion: We report our experience with navigation-assisted surgery for bone and soft tissue tumors. Navigation-assisted surgery could be indicated for sufficiently reliable, accurate, and minimally invasive resections.

Fig. 1A–F

(A) A radiograph of the right tibia of a 70-year-old woman with a phosphaturic mesenchymal tumor showed no remarkable lesions. (B) On coronal T2-weighted MRI, the lesion showed a homogeneously low signal intensity. (C) The data were transferred and recorded on the system computer and reconstructed as 3-D images on a TV monitor. (D) The trephine was guided by the Kirschner wire and a 12-mm-diameter area was excised. (E) A specimen excised en bloc. This was not the real center of the tumor. The 2.0-mm wire was slight, fine, and eccentrically bent. (F) A postoperative CT scan showed that the tumor was filled with bone cement.

Fig. 1A–F

(A) A radiograph of the right tibia of a 70-year-old woman with a phosphaturic mesenchymal tumor showed no remarkable lesions. (B) On coronal T2-weighted MRI, the lesion showed a homogeneously low signal intensity. (C) The data were transferred and recorded on the system computer and reconstructed as 3-D images on a TV monitor. (D) The trephine was guided by the Kirschner wire and a 12-mm-diameter area was excised. (E) A specimen excised en bloc. This was not the real center of the tumor. The 2.0-mm wire was slight, fine, and eccentrically bent. (F) A postoperative CT scan showed that the tumor was filled with bone cement.

Fig. 2A–C

A 76-year-old woman had myxoid liposarcoma with a bony lesion on the right hip. (A) A planned excision line was made for the CT image. (B) Each Kirschner wire was placed on the excision line. The excision was made using chisels on the outside of each wire. (C) The tumor was excised with margins of at least 6 mm. The patient was disease-free for 42 months after surgery.

Fig. 2A–C

A 76-year-old woman had myxoid liposarcoma with a bony lesion on the right hip. (A) A planned excision line was made for the CT image. (B) Each Kirschner wire was placed on the excision line. The excision was made using chisels on the outside of each wire. (C) The tumor was excised with margins of at least 6 mm. The patient was disease-free for 42 months after surgery.

Fig. 3A–B

A 40-year-old woman had osteosarcoma of the right tibia and (A) a femoral skip lesion that showed bone formation on the CT scan. A planned excision line was made for the CT image. (B) The tumor was excised successfully with margins of at least 10 mm.