Excision of proximal fibular aggressive and malignant tumors: a new classification for surgical guidance

Patients with aggressive and malignant tumors of the proximal fibula may require en bloc resection to reduce the recurrence rate. We aimed to analyze the clinical curative effect of the surgical treatment of proximal fibula tumors, and the relationship between a new classification system and functional evaluation of the knee and ankle joint.

Between July 2010 and February 2022, 30 patients with proximal fibula tumors were treated, of which 27 had primary tumors and three had recurrent tumors. The histologic diagnoses were aggressive osteoblastoma (three patients), 'active' osteochondroma (five patients), giant cell tumor of the bone (11 patients), chondrosarcoma (four patients), osteosarcoma (six patients), and metastatic carcinoma (one patient). The surgical methods were divided into four types according to two important anatomical structures-the deep peroneal nerve (DPN) and proximal tibiofibular joint (PTFJ). Brief descriptions of the removal methods are as follows. Type I includes intra-articular resection of the PTFJ and preservation of the DPN. Type II includes the resection of the DPN and intra-articular resection of the PTFJ. Type III includes extra-articular PTFJ resection and preservation of the DPN. Type IV includes extra-articular PTFJ resection and resection of the DPN.

The 30 patients with proximal fibula tumor underwent successful operation. Those who underwent type I and type III procedures had normal ankle function because the DPN was preserved; however, in those who underwent type II and type IV procedures with resection of the DPN, ankle foot orthosis was needed to stabilize the ankle joint because of the resulting drop foot. In those who underwent type I and type II procedures with intra-articular PTFJ resection, the preservation of the lateral collateral ligament, biceps tendon, and popliteal tendon partly protected the structure of the knee joint, leading to postoperative knee joint stability. In those who underwent type III and type IV procedures with extra-articular PTFJ resection, gait abnormalities and knee instability occurred.

The peroneal nerve and PTFJ are adjacent to each other, and resection of proximal fibular tumors is challenging for orthopedic surgeons. The DPN and PTFJ classification can lead to better surgical planning and postoperative functional evaluation. It provides useful information for the standardized treatment of proximal peroneal tumors based on regional anatomy.