The relationship between the recurrence rate of aggressive tumors and the foramina around the knee joint

Abstract

Objective To introduce the discovery and nomenclature of the intercondylar foramen of femur (IFF) and foramen of tibial intercondylar eminence (FTIE) and research the close relationship between the high recurrence rate of aggressive tumors around the knee joint and the foramina around the knee joint. Methods ①Radiographic observation and measurement: 3D reconstruction of CT scan of 200 patients in our hospital were used to obverse the common feature、position and measure of Inter-condylar foramen of femur and Foramen of tibial intercondylar eminence. ②Anatomical and histological observation: To proof the existence of IFF and FTIE through the anatomy of 15 cases of car accidents or tumor amputations and 60 cases of autopsy. Then the specific location, the surrounding structure, the proximal coverage, the contents, the apical construction, the wall and the bottom tissues of the IFF and FTIE were studied and analyzed. ③Histological and pathological observation of tumor anatomy: Through the study of the distal femur and tibia malignant tumor tissues(including primary bone tumors and metastatic tumors), we observed the relationship between the foraminal structures and the tumor, judged the situation of concealed transmission and two-way spread through the foramina, and analyzed the relationship between tumor recurrence and foraminal structures. ④The synovial membrane of foramina, especially in cases where the synovium was suspected to be involved by the lesions judged by the radiography was analyzed to observe whether the synovium was infiltrated by the tumor. Results IFF and FTIE were the inherent physical structure of the human. Their physiological function was the vascular foramina that lead the branches of arteria media genus into the Intercondylar fossa of femur and tibial intercondylar eminence. Their opening was separated with the joint cavity by the synovial tissues, so IFF and FTIE were isolated with joint cavity by the synovial tissues、meniscus and cruciate ligaments. After invading the IFF and FTIE, the aggressive tumors did not break into the joint cavity immediately, but conceal in the foramina and invade the synovium with specific biological behavior with the sequence: reactive edema, hyperplasia, degeneration, calcification, hyaline degeneration (infiltration in some cases), synovial rupture, and then tumor invasion of the articular cavity. Usually, tumors or recurrence has been observed before synovial rupture. We also observed the tendency of tumors to spread along the arteria media genus to the popliteal vessels, peripheral soft tissues and lymphatic vessels with typical radiographic performance like popliteal lymphadenectasis. Color nodules and tumors in other parts could also invade or metastasize into bone through these foramina. Conclusions IFF and FTIE are foramina nutricium of arteria media genus. They are the inherent physical structure of the human. The foramina play an important role in the spread, concealment and recurrence of peripheralkneeaggressive tumor. Key words: Femur; Tibia; Anatomy; Bone neoplasms