Visualization of the posteromedial compartment in the knee: Comparison between a posterolateral transseptal approach with a standard anterior transnotch approach when repairing posterior lesions of the medial meniscus.

Abstract

Introduction: Visualization and exposure of the medial meniscus in the posterior compartment during knee arthroscopy can be challenging. Using a posterolateral transseptal approach can help to have a better visualization to ensure a better meniscal repair in the posterior compartment.

Hypothesis: The posterolateral transseptal approach allows a better visualization of the posterior segment of the medial meniscus when compared to a trans notch approach.

Material and methods: A controlled laboratory study using 12 human cadaveric knees were included in this arthroscopic study. The first step was to visualize the posterior medial compartment by transnotch viewing. A posteromedial portal was then created, and a meniscal suture was positioned as medial as possible under direct visualization by an all inside technique with a suture hook. Afterwards the posterolateral transseptal portal was created and a second meniscal suture was positioned as medial as possible with the same technique. Finally, by dissection, a posterior arthrotomy was performed allowing us to directly measure the length of the medial meniscus (at its meniscocapsular junction) from its posterior root to respectively the first and second suture, representing the two different approaches. The safety was evaluated by extended dissection of the neurovascular posterior structures.

Results: The mean paired difference between the first and second suture was 6.75 ± 2.56 mm (CI95% = 5.19; 8.31, P ≈ 0.001). No nerve or vascular lesion were observed during dissection.

Discussion: A transseptal viewing portal offers better exposure and visualization of the medial meniscus in the posterior compartment and can be safely performed. When repairing meniscal lesions in the posterior compartment, it is commonly advised to insert a knot at least every 5 mm. Our study has demonstrated a significant difference in distance of 6.75 mm when using a transseptal approach, which provides an argument for its utilization during posterior meniscal repair enabling the operator to better repair meniscal lesion and potentially improve the healing process.

Level of evidence: III; Case/Control anatomical study on cadaveric specimens.