[Limb salvage surgery for osteosarcoma around the knee in children and adolescent patients].

OBJECTIVE: To discuss the reconstruction methods and treatment effects of osteosarcoma around the knee in skeletal immature children and adolescent patients.

METHODS: Between October 1996 and December 2005, 89 children and adolescent patients with osteosarcoma around the knee received limb salvage surgery. The average age was 13 years old. Tumor involved distal femur in 52 cases, proximal tibia in 36 cases, and both parts in one patient. Different limb salvage methods, including tumor recycle bone reimplantation (n = 20), partial endoprosthesis (n = 19) and total knee megaprosthesis replacement (n = 50) were chosen according to both the age of the patient and the skeletal. Expandable and special designed pediatric prosthesis some times might also be considered.

RESULTS: After average follow up of 42 months, 4 cases of local recurrence and 11 of metastasis occurred in tumor recycle bone group; 1 case of local recurrence and 4 of metastasis in partial endoprosthesis group; another 4 cases of local recurrence and 9 patients died of disease in total knee megaprosthesis group. The five-year survival rate was 47.1%, 71.7% and 68.2% in 3 groups respectively. There were 3 deep infections in all the cases, 2 subluxations and 1 amputation after operation for limb ischemia in partial endoprosthesis group. The average functional score of MSTS 93 was 21.43 point, 23.40 point and 25.32 point; and the average leg length discrepancy was 5.48, 4.50 and 3.12 cm in 3 groups respectively.

CONCLUSIONS: Partial-joint prosthesis or other methods which can avoid injury of the opposite epiphysis should be used to decrease the possibility of limb length discrepancy and ease the following revised arthroplasty. For patient with almost mature skeletal, total knee megaprosthesis may be a proper choice for better function result.