Clinical and finite element analysis of alcohol-deactivated autograft-prosthesis composite after resection of bone giant cell tumor in distal femur / 中华骨科杂志

ABSTRACT

Objective To evaluate the clinical outcome of alcohol-deactivated autograft-prosthesis composite after resection of bone giant cell tumor in distal femur.Methods From January 2007 to October 2008,5 patients with bone giant cell tumor in distal femur were treated with alcohol-deactivated autograftprosthesis composite,including 3 males and 2 females with an average age of 29.6 years(range,22-40).Three patients were diagnosed with postoperative recurrence,and 2 with pathological fracture.All patients were of Campanacci Ⅲ.Three-dimensional finite element models with 40% bone defect in distal femur were established based on CT images of a healthy volunteer.Three times of body mass load corresponding to the normal walking gait cycle was applied.The influence on stress distribution of femur-cement and prosthesis stem was analyzed.Results All patients were followed up for average 37 months,there was no infection,recurrence,loosening and limb length inequality.The bony healing time was 6 to 11 months.The mean MSTS function score was 25.7(range,25-27).The mean ISOLS graft score was 31.4 (range,28-35).The finite element analysis showed that for the short-term model,the maximum stress was 145.82 MPa in the proximal femur,40.90 MPa in the medial side of 1/4 proximal cement,and 389.24 MPa in the proximal prosthesis stem.The maximum stress was not exceeding the fatigue strength in three sites.For the long-term model,with the bone healing,the maximum stress on three sites decreased to 139.05,36.95,and 253.65 MPa,respectively.Conclusion These results suggest that the alcohol-deactivated autograft-prosthesis composite after resection ot bone giant cell tumor in distal femur can reduce the tumor recurrence and improve the short-term limb function,It is stable in short term and can reduce stress shielding in long term.