Objective: To evaluate the effectiveness of prosthetic revision using custom-made long stem prosthesis and allograft-prosthesis composite (APC) for aseptic loosening after bone tumor resection.
Methods: Between January 2002 and June 2008, 14 patients with aseptic loosening after bone tumor resection were treated. There were 8 males and 6 females, aged 21-70 years (mean, 43.9 years). The locations were distal femur (8 cases), proximal femur (2 cases), and proximal tibia (4 cases). Pain of the affected limb occurred after 6-31 years of prosthesis replacement and worsened when bearing and walking; 6 patients had shortened limb. The functional results were assessed quantitatively according to the functional rating system of the Musculoskeletal Tumor Society (MSTS). The MSTS score was 16.36 +/- 1.50 before revision. The X-ray films showed obvious prosthetic loosening and subsidence. The average time of symptom was 4.5 years (range, 3-9 years). In 7 patients having severe bone loss (the decrease of the thickness of cortical bone was more than 50%) and the prosthetic subsidence was more than 2 cm, the revision operation with the APC was performed; in 7 patients having less bone loss (the decrease of the thickness of cortical bone was less than 50%), the custom-made long stem prosthesis was performed.
Results: All wound healed by first intention. Two patients had temporary peroneal nerve paralysis and recovered after 3 months. All the patients were followed up 3.6 years on average (range, 2 years and 2 months- 7 years) after revision. After revision, pain was relieved and the range of joint was improved. The MSTS score was 23.43 +/- 2.56 at 12 months after revision showing significant difference when compared with the preoperative score (t = 8.910, P = 0.024). The X-ray films showed that lucency space line around stem cement in 2 patients at 12 months, and no prosthesis loosening and infection occurred.
Conclusion: The prosthetic revision after limb salvage surgery with prosthesis for bone tumors was acceptable. The good functional results can be achieved by the revision with the APC or the custom-made long stem prosthesis according to the bone loss.