Assessing Risk to Articular Cartilage and the Calcaneofibular Ligament During Fibular Nailing: A Cadaveric Study.

Background: Traditional surgical fixation of ankle fractures with plates and screws carries risks such as wound complications, hardware prominence, and soft tissue irritation. Intramedullary (IM) fibular nailing provides a minimally invasive alternative with potentially lower complication rates. Although prior studies have examined the risk posed by fibular nailing to the peroneal tendons and nerves, data remained limited regarding its impact on other adjacent structures especially the calcaneofibular ligament (CFL) and the articular cartilage of the distal fibula, structures whose injury could contribute to joint instability, persistent pain, or degenerative change.

Methods: This study assessed the risk and extent of damage to anatomical structures during IM nail fixation on 10 cadaveric lower extremities. Risks were categorized based on distances from the nail to the CFL, anterior talofibular ligament (ATFL), sural nerve (SN), superficial peroneal nerve (SPN), peroneus longus, peroneus brevis (PB), and articular cartilage: high-risk (0-5 mm), moderate-risk (5.1-10 mm), or low-risk (>10 mm).

Results: Macroscopic evaluation identified the CFL, ATFL, and PB as high-risk structures. The CFL was damaged in 3 of 10 specimens, ranging from 14% to 64% of its width. The average distances to the CFL (1.20 mm), ATFL (3.43 mm), PB (3.19 mm), and articular cartilage (3.45 mm) fell in the high-risk range, although no significant damage was observed to the articular cartilage, ATFL, SN, or SPN.

Conclusion: This study further confirms that IM fibular nailing is a generally safe and reliable option for treating ankle fractures. However, attention should be given to the potential for iatrogenic damage to high-risk soft-tissue structures, particularly the CFL and peroneal tendons. Although cartilage was always spared in this cadaveric study, its proximity warrants surgical caution.

Clinical relevance: These findings clarify the soft tissue risks associated with IM nailing and may provide guidance for orthopaedic surgeons and patient discussions, emphasizing the importance of proper technique to preserve soft tissues.