Lateral Knee Compartment Portals: A Cadaveric Study Defining a Posterolateral Viewing Safety Zone

Area of Science:

• Orthopedic Surgery
• Arthroscopy
• Knee Anatomy

Background:

• Posterolateral knee injuries often require specialized arthroscopic visualization.
• Standard arthroscopic portals may limit access to the posterolateral region.
• Defining safe accessory portal placement is crucial for effective surgical intervention.

Purpose of the Study:

• To establish a reproducible "safe zone" for accessory arthroscopic portals in the lateral tibiofemoral compartment.
• To evaluate the feasibility of placing one or two accessory portals for enhanced posterolateral viewing.
• To correlate accessory portal placement with key intra- and extra-articular knee structures.

Main Methods:

• Ten cadaveric knees were used to create standard and accessory posterolateral portals.
• Accessory portal placement was guided by identifying the lateral knee surface "soft spot".
• Measurements were taken from accessory portals to the capsular fold, popliteus tendon, peroneal nerve, lateral collateral ligament (LCL), and biceps tendon.

Main Results:

• Accessory portal A was located an average of 8.8 mm from the popliteus tendon and 11.6 mm from the LCL.
• Accessory portal B was located further from the LCL (20 mm) and popliteus tendon (17.3 mm) compared to portal A.
• Both accessory portals were consistently placed within safe distances from critical neurovascular structures.

Conclusions:

• Accessory portals can be safely created in the lateral tibiofemoral compartment using intra- and extra-articular landmarks.
• These portals provide improved visualization of the posterolateral knee region.
• The use of accessory portals, individually or combined, can facilitate arthroscopic repair of posterolateral structures.