Oblique popliteal ligament - an anatomical study.

Objective: To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships.

Methods: Eleven cadaver knees were dissected in order to study the anatomy and take measurements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions. For measurement of dimensions, 40 × 12 needles were used for marking the specific points and a caliper. The angles were calculated using the software ImagePro Plus.

Results: The distance from the origin of the oblique popliteal ligament to the tibial plateau was 7.4 mm, the thickness at its origin was 7.3 mm, length was 33.6 mm and the tibial plateau angle 34.8°. The length of the expansion of the proximal oblique popliteal ligament was 39.2 mm, thickness 7.8 mm and angle of the oblique popliteal ligament with its expansion 32.2°.

Conclusion: The oblique popliteal ligament is thick, rises in the semimembranosus and protrudes proximally forming an acute angle with the joint interline, crossing the popliteal fossa. In some cases it has a proximal expansion.