Surface Projection of Interosseous Foramen of the Leg: Cadaver Study

Purpose. This study was conducted to identify the surface projection of the interosseous foramen and associated structures of the proximal leg using the average clinician's thumb width as a quick measurement to assist in differential diagnosis and treatment. Methods. Twelve cadavers (5 males and 7 females, age range = 51–91 years, and mean age = 76.9) were dissected for analysis. Location and size of interosseous foramen, location of anterior tibial artery, location of deep fibular nerve, and corresponding arterial branches were measured and converted into thumb widths. Results. Mean thumb width measured among the cadavers was 17.94 ± 3.9 mm. The interosseous foramen measured was approximately 1 thumb width vertically (18.47 ± 3.0 mm) and 1/2 thumb width horizontally (7.32 ± 2.1 mm) and was located approximately 1 thumb width distally to the tibial tuberosity (20.81 ± 6.8 mm) and 2 thumb widths (37.47 ± 4.7 mm) lateral to the tibial ridge. The anterior tibial artery and deep fibular nerve converged approximately 4 thumb widths (74.31 ± 14.8 mm) inferior to the tibial tuberosity and 2 thumb widths (33.46 ± 4.9 mm) lateral to the tibial ridge. Conclusion. Clinicians may identify anatomical structures of the proximal leg with palpation using the thumb width for measurement.