Clinical and radiologic outcomes following resection of primary proximal fibula tumors: Proximal fibula resection outcomes

Abstract

Reconstruction of the lateral collateral ligament (LCL) and biceps femoris tendon following proximal fibula resection is controversial. Postoperative knee instability and peroneal nerve dysfunction affect outcome. This study aimed to determine functional, clinical, and radiological outcomes of patients who underwent en bloc proximal fibula resections and to compare clinical and radiological instability rates for primary repair after type I and type II resections. Materials and Methods: Eleven patients with primary tumors of the proximal fibula were included. Musculoskeletal Tumor Society (MSTS) score and Lysholm knee score were used in the evaluation of functional outcomes. Clinical outcome was assessed using knee range of motion and knee varus stress test. Radiological outcome was assessed using varus stress knee radiographs. Knee stability was evaluated using the varus stress test at 30 of knee flexion and varus stress knee radiographs and graded in millimeters. Results: Of the 11 tumors, 6 (54.6%) underwent type I resection. In five (45.4%) patients, type II resection was performed. The mean follow-up period was 32 + 13.9 months (range, 12-55 months; median, 27 months). The mean knee joint lateral opening, MSTS score, and Lysholm knee score with type I versus type II resection were 5.7 + 1.2 mm versus 6.4 + 1.1 mm (p ¼ 0.247), 28.7 + 1.8 (95.6%) versus 20.4 + 7.7 (68%) (p ¼ 0.011), and 92.2 + 8.8 versus 62.8 + 20.4 (p ¼ 0.026), respectively. Postoperative complications of all patients included one (9.1%) deep tissue infection and one (9.1%) long-term knee instability. In one patient (9.1%) who underwent type II resection, above-the-knee amputation was performed after local recurrence. Conclusions: Primary repair of the LCL and biceps femoris tendon to the surrounding soft tissues after resection of proximal fibular tumors provides good clinical outcomes. Primary repair is a simple technique to perform with minimal morbidity. Peroneal nerve palsy was a problem, especially in type II resections.

Surgical Management of Benign Tumors of the Proximal Fibula

“…The LCL and surrounding neurovascular structures represent surgical considerations when trying to achieve a low recurrence rate and optimal functional outcome. 36 …”

“… 41 In type II resections, the biceps tendon and LCL are resected 2.5 cm proximal to their fibular attachment site, possibly complicating reattachment. 36 , 41 Attempts to revise the Malawer dichotomy have been proposed; Erler et al 9 and Dieckmann et al 8 endorsed supplementary resection techniques based on the tumor size and quantity of structures removed, respectively. Despite these proposed refinements, the Malawer criteria remain prevalent as foundational resection procedures.…”

“…Surgical detachment of the LCL and BFT can provide an additional source of impaired postoperative function, and evidence demonstrates that reattachment after an en bloc resection improves functional outcomes. 31 , 36 , 66 …”

“…Arikan et al 36 analyzed six patients who underwent type I resection with LCL and BFT reattachment to the surrounding soft-tissue structures, rather than the tibial metaphysis, and all patients recorded some level of knee instability, varying from grade 1 to grade 2. Agarwal et al 67 concluded similar rates of instability after LCL reattachment to soft-tissue structures.…”

“… 42 , 66 This deficiency is largely attributed to the decreased LCL and BFT stump length (9.0 ± 2.5 cm versus 21.7 ± 9.0 cm; P = 0.018) and the extent of tissue removed compared with type I resections. 36 , 42 An inability to reattach the ligamentous structures further contributes to the instability of the proximal tibiofibular joint, which may also produce secondary deficiencies in ankle mobility. 24 Accordingly, type II resections are rarely indicated for benign lesions of the proximal fibula, unless extended tumor involvement of adjacent anatomical structures commands a widespread resection.…”