The Follow-up For Extraarticular Total Knee Resection Of Malignant Tumor Around The Joint

PurposeWe attempted to know its postoperative complications and evaluate the clinical effect through follow-up of those patients that had gone through the surgery of extraarticular resection of malignant tumor around knee joint and custom-made prosthesis replacement. Evaluating the diagnostic value of exfoliocytology examination on whether the malignant tumor invades into the knee joint through extracting synovial fluid from those suspected patients based on imaging studies.Methods6 patients from March 2003 to May 2012, inpatient surgery in our hospital, confirmed to be malignant tumor around knee joint by pathologic diagnosis and accepted extraarticular resection and custom-made prosthesis replacement was selected. Three males and three females, aged from 14 to 60 years-old with the mean age of 33. Histologically,2 with osteosarcoma,1 with synovial sarcoma,1 with chondroblastic osteosarcoma,1 with myofibroblastoma,1 with malignant fibrous histiotoma. The tumor of 2 cases located in distal femur,3 in proximal tibia,1 in the knee joint. Preoperative physical and imaging examination,relevant adjuvant chemotherapy, determining the bone cutting length, preparing custom-made prosthesis, postoperative follow-up, lung CT and double lower limbs X-ray film for all those patients. Bone cutting length:femur 5-10cm,8cm on average; tibia 0.5-15cm,7.5cm on average. Prosthesis stem length:femur 125-174mm,149mm on average; tibia 120-169mm,141mm on average. The superior tibiofibular joint was reserved in 2 of the survival.We evaluate the clinical effect through comparison of knee joint mobility, postoperative complications and MSTS score.8 other patients from 2015 to February 2016, inpatient examination of exfoliocytology suspected to be invaded into knee joint by imaging examination.3 males and 5 females, aged from 12 to 60 years-old with the mean age of 27. With patients’consent, we extracted synovial fluid from knee joint and analyzed by Wright staining.ResultsTwo of six patients died from postoperative pulmonary metastases 9 and 26 months after operation respectively. The remaining four patients’ follow-up time range from 46 to 70 months with an average of 56 months. The MSTS score ranged from 67% to 87%, the average is 78%. Two patients of the survived accepted revision surgery because of prosthesis loosening.One patient showed hyperextension with no obvious complications. And another recovered well from the surgery without any postoperative complications. There was no pulmonary metastases indication except the two died.Pathological cells was found in 2 cases, while only red blood cells was found in the rest.ConclusionsIn respect of malignant tumors around knee joint, the extraarticular resection and custom-made prosthesis replacement has become the main method of surgical treatment. Now there is no clear diagnostic criteria for invasion in the knee joint. In most cases, it was based on imaging examination for judgment. It’s of most importance whether the extensor mechanism can get effective reconstruction. Through our research, preoperative exfoliocytology examination may be valuable, but still needs further study. Compared with interarticular resection, the postoperative complications of extraarticular resection increased, especially the prosthesis loosening. The postoperative function of the joint can be well restored.