An Anatomic Study of the Posterior Septum of the Knee

PurposeTo evaluate the posterior septum of the knee and determine the presence of a safe zone that could be removed, without significant damage to blood vessels and nerves.MethodsNineteen fresh unpaired adult human cadaveric knees, with no macroscopic degenerative or traumatic changes, were used in this study. Microscopic evaluation was performed by analysis of H&E, CD-34, and S-100 staining.ResultsThe posterior septum of the knee is rich in type II and type IV mechanoreceptors and blood vessels. The superior half has a greater number of blood vessels (21.52 ± 6.36 v 12.05 ± 4.1, P < .001), higher-caliber vessels (2.2 ± 0.89 μm v 1.41 ± 0.45 μm, P < .006), and a greater number of mechanoreceptors per field (type II, 1.8 ± 1.8 v 0.42 ± 1, P = .04; type IV, 22.6 ± 14 v 14.5 ± 9.4, P = .04) than the inferior half of the septum.ConclusionsThis study has shown that the posterior septum of the knee is highly vascularized and has a great number of type II and IV mechanoreceptors. The presence of these structures is significantly higher in the superior half of the septum.Clinical RelevanceIf debridement of the posterior septum is necessary, it should be done at the inferior aspect so that a greater number of blood vessels and mechanoreceptors can be preserved.