To confirm the complex structures of the deep layer of posterolateral corner and the safe range of the posterior capsule incision.

Seven cadaveric knees were obtained ranging in age from 39 to 55 years and male to female ratio was 5 to 2.

The lateral collateral ligament was inserted on 18.3 mm inferiolateral part of the fibular head. The popliteofibular ligament was identified in all cases and 6 of the 7 ligaments were separated into anterior and posterior fascicle. Popliteomeniscal fascicles were divided superoinferiorly and could be identified in all cases. The direct attachment of the popliteal tendon to the tibia was not identified.Safe range of the posterior capsular incision to protect the oblique popliteal ligment and popliteal muscle was 18.7 mm in average.

Covering with thick fibrous tissue, the third layer of the posterolateral ligament should be dissected with sharp blade.Lateral collateral ligament was inserted on anteroinferior portion of the fibular head and popliteofibular ligament was inserted on posterosuperior medial portion of the fibula. The direct attachment of the popliteal tendon to the tibia could not be identified. Careful protection of popliteal muscle would be needed in posterior capsular approach.