The resection of internal hemi-pelvic tumor using computer navigation and the reconstruction assisted by finite element analysis / 中华骨科杂志

ABSTRACT

Objective To analyze the security and effectiveness of the accurate resection and reconstruction of pelvic tumor with computer navigation and to evaluate the feasibility of pelvic ring structure and mechanics reconstruction using finite element analysis.Methors From December 2008 to June 2010,tumor resections assisted by computer navigation technology and pelvic reconstructions with assembly prosthesis designed by finite element analysis were performed in 12 patients with internal hemi-pelvic malignant tumors.There were 8 male and 4 female patients,with the average age of 39.7 years(range,25-53).The malignant tumors involved chondrosarcoma(4 cases),osteosarcoma(2),Ewing sarcoma(2),malignant fibrohistiocytoma(1),and metastatic tumor(3,in which including renal cell carcinoma 1 case,thyroid carcinoma 1,and breast carcinoma 1).According to Enneking staging classification,there were 1 case in Ⅰ A,2 cases in ⅠB,2 cases in Ⅱ A.and 4 cases in Ⅱ B.The local recurrence of tumor and functional results were followed up postoperatively.Results There were no nerves,vessels and pelvic organs injuries intra-operatively.The postoperative X-rays showed that the excised regions were proper to the preoperative schedule and en bloc resections were performed in all patients.All assembly prostheses were in satisfactory position.and the screw fixation was accordance with the finite element biomechanical analysis.All the cases were followed up for average 18.2 months (range,8-26).There were 1 case with local recurrence and pulmonary metastasis,1 case with deep infection,and 1 case with deep vein thrombosis.No prosthesis dislocation,loosening,breaking,and limb length discrepancy occurred in all patients.The average MSTS93 functional score was 70%in all patients at 6 months,and 68 % in 6 patients at 20 months follow.up.Conclusion The resection and reconstruction of pelvic tumor assisted by computer navigation is a safe and effective procedure.The finite element analysis can provide accurate biomechanical guidance to the reconstruction of pelvic ring.