OTA 2005 Posters

Scientific Poster #58 Basic Science

Submuscular Plating of Distal Tibia and Fibula: Anatomy of the Saphenous and Superficial Peroneal Nerve

Amer J. Mirza, MD (n); Allison Moriarty, BS (n);

Tom Ellis, MD (a-Zimmer Educational Grant);

Oregon Health and Sciences University, Portland, Oregon, USA

Purpose: This anatomic study in cadaveric specimens was conducted to define the relationship of superficial peroneal nerve, saphenous nerve, and saphenous vein in submuscular fixation of the distal fibula and tibia.

Methods: Ten adult cadaver lower extremities were instrumented with the Zimmer precontoured periarticular plates for the distal tibia and fibula. A 20-hole tibial plate and a 21-hole fibular plate were used. Plates were inserted submuscularly through 2-cm incisions proximally and distally along the distal tibia and fibula. The plates were fixed to the bone with 2.0-mm Kirschner wires. All holes for the fibular plate were filled. Screw holes 1 through 10 distally were filled for the tibial plate. Dissection of the superficial peroneal nerve, saphenous nerve, and saphenous vein were performed along their respective course. For the superficial peroneal nerve, measurements were made from the tip of the lateral malleolus to the exit point from the fascia of the lateral compartment and the closest point to the fibular plate. For the saphenous nerve and vein, measurements were made from the tip of the medial malleolus. The position of the nerve and vein in relation to the anterior and posterior border of the distal tibia was recorded. All measurements were made with calibrated calipers.

Results: The average distance of superficial peroneal nerve to the fibular plate at its closest point was 0.9 cm (SD 0.4). The superficial peroneal nerve exited the lateral compartment between screw holes 11 to 19 for the fibular plate at an average distance of 11.4 cm (SD 3.5) from the tip of the lateral malleolus. The nerve was injured in one specimen at screw hole 13. The saphenous nerve crossed the posterior cortex of the distal tibia 9.9 cm (SD 2.8) and the anterior cortex 3.0 cm (SD 1.4) proximal to the medial malleolus. The saphenous vein had a similar course, crossing the posterior cortex of the tibia 9.3 cm (SD 3) and the anterior cortex 2.5 cm (SD 0.4) from the tip of the medial malleolus. The vein and nerve were injured in all the specimens. This occurred consistently at 1.5 cm to 4.7 cm from the tip of the medial malleolus.

Conclusion/Significance: The superficial peroneal nerve, saphenous nerve, and saphenous vein are at risk during percutaneous submuscular plating of the distal fibula and tibia. Careful dissection proximally for the fibula and distally for the tibia can minimize the risk of damage to these structures.