Application of newly designed modular hinged ankle prosthesis in the reconstruction of defect after surgical treatment of malignant tumor at the distal tibia / 中华骨科杂志

ABSTRACT

Objective:To investigate the outcome of surgical treatment of malignant tumor at the distal tibial after reconstruction with modular hinged ankle prosthesis.Methods:The data of 9 patients with malignant tumor at the distal tibia at Musculoskeletal Tumor Center of PKUPH from June 2020 to November 2021 were analyzed retrospectively. They were male patients with age of 17 (14, 24) years (range 11-56 years). There were five tumors at the left sides and four at the right sides. There were eight patients with osteosarcoma who received the neo-chemotherapy. Among eight osteosarcomas, one was Enneking IIA and seven Enneking IIB. Furthermore, there was only one patient with renal carcinama and with solitary metastatic lesion at the distal tibia. After the resection of tumor at the distal tibia, talus cartilage was removed and talus component was fixed by lag screws. The proper tibia component was used to restore the defect of tibia and the reduction of tibia and talus components were performed. The following clinical data were collected baseline demographic features, surgical and follow-up data. The baseline demographic features included gender, age, side, lung or/and other metastasis at initial diagnosis, Enneking stage or systematic progression for renal carcinama, histological type. The surgical data included surgery time, blood loss, length of bone involved by the tumor, prosthesis type. Monitoring data was also recorded complications (ankle pain when loading, talar collapse, component loosing, infection and wound dehiscence), local recurrence, pulmonary and systematic metastasis, radiological image and the function at the last follow-up (MSTS and VAS evaluation).Results:Among these nine patients, the average blood loss was 245.6±103.9 ml (range 100-400 ml) and the mean surgery time was 178.9±56.9 mins (range 120-300 min). No patient was lost during the follow-up period and the average follow-up was 21.4±5.6 months (range 12.5-27.2 months). The excision length of tibia was 14 (11, 17) cm (range 11-28 cm). There were one case with 2# prosthetic base, three cases with 3# and five cases with 4#. Five had cement fixation of prosthetic stem and four had the pressing fixation. No pulmonary and other organ metastasis occurred among eight patients with osteosarcoma and one patient with distal tibia matastasis of renal carcinama. One patient with OShad the local recurrence and received the resection. One sustained the deep infection after four months and received the removal of prosthesis and spacer implant. At the final follow-up, except one with deep infection and receiving the removal of prosthesis and spacer implant, eight patients were assessed for the function. The average MSTS was 97.1%±3.3% (range 93%-100%). The VAS of all patients was 0. One patient with prosthesis removal had no functional evaluation. At the final follow-up, all patients walked without crutch. No breakage and loosening of prosthetic stem, talar collapse, prosthetic sinking and ankle pain occurred at the final follow-up.Conclusion:The early satisfactory outcome can be obtained for patients with segmental defect after resection of malignant tumor at the distal tibia, who received the newly designed modular hinged ankle prosthesis. Meanwhile, it's worth promoting in the reconstruction of large segmental defect at the distal tibia.