This document describes the standard and optional portals used in knee arthroscopy. The standard portals are the anterolateral, anteromedial, and posteromedial portals. The anterolateral portal is created first and allows visualization of most knee structures. Portal placement is important to avoid damaging structures. Optional portals like the superolateral and posterolateral portals provide additional views but have risks if not carefully placed. Proper portal placement and technique are described to maximize visualization and safety.

1. Knee arthroscopy portals

3. Standard portals
• AL
• AM
• PM
• SL

4. Superolateral
portal

5. Anterolateral
• Created 1st blindly
• Almost all structures clearly visualised except
– PCL
– Anterior portion of lateral meniscus
– Periphery of posterior horn of medial meniscus
• 1cm above lateral joint line
• 1cm lateral to patellar tendon
• 1cm below patella

6. • The trochar and sleeve are inserted at 70° of
knee flexion.
• Firm, gradual pressure applied until there is a
reduction in resistance, indicating that the
trochar has passed through the joint capsule.
• knee is extended to around 20° of flexion and
the trochar advanced, passing through the
patellofemoral joint

7. • Its intra-articular position can be confirmed by
sweeping the arthroscope gently from side to
side – it can be felt to be beneath the patella.
• If it is outside the knee joint, it will not sweep
from side to side.
• position of the arthroscope should be confirmed
before removing the trochar, introducing the
camera and turning on the saline inflow

8. • Portal too near the joint line-
– the ant. horn of the lateral meniscus can be lacerated
– difficulty in maneuvering the scope.
• Too superior to the joint line-
– prevents viewing of the posterior horns of the menisci
and other posterior structures.
• Immediately adjacent to the edge of the patellar
tendon
– can penetrate the fat pad, difficulty in viewing and in
maneuvering the scope within the joint.

10. Anteromedial
• For additional visualisation of lateral
compartment and to probe lateral and medial
compartment structures
• Location similar to AL
• Needle inserted such that it exits just above
medial meniscus

11. Posteromedial
• 1cm above PM joint line in line with lateral border of
medial femoral condyle
• ‘soft spot’ between the tendon of semimembranosus,
the medial head of gastrocnemius and the medial
collateral ligament.
• Before distention of the joint, this small triangle can
be palpated easily with the knee flexed to 90 degrees.
• The knee must be maximally distended with irrigating
solution so that the posteromedial compartment
balloons out like a bubble when the knee is flexed to
90 degrees (saphnous nerve)

12. • For repair or removal of displaced posterior
horn meniscal tears and for removal of
posterior loose bodies that cannot be
displaced into the medial compartment and
removed through an anterior portal.
• For total synovaectomy

13. Superolateral portal
• most useful for viewing the dynamics of the
patellofemoral articulation.
• lateral to the quadriceps tendon and about
2.5 cm superior to the SL corner of the
patella.
• evaluation of patella tracking, patellar
congruity, and lateral overhang of the patella
and for suprapatellar synovectomy

14. Optional portals
• Posterolateral Portal
• Proximal Midpatellar Medial and Lateral
Portals
• Accessory Far Medial and Lateral Portals
• Central Transpatellar Tendon (Gillquist) Portal

15. Posterolateral
• Knee flexed to 90 degrees and joint maximally
distended.
• line drawn along the posterior margin of the
femoral shaft intersects a line drawn along the
posterior aspect of the fibula.
• 2 cm above the PL joint line at the posterior
edge of the IT band and the anterior edge of the
biceps femoris tendon.
• Soft point between the lateral head of
gastrocnemius, LCL and the PL tibial plateau

16. • May damage the articular surface of the
posterior femoral condyle
• plunging in with a sharp trocar into the
popliteal space may damage neurovascular
structures.
• The outflow of irrigation solution on removal
of trocar confirms entry into the joint.
• This portal is useful for assisting with repair
of lateral meniscal tears.

17. Proximal Midpatellar Medial and
Lateral Portals
• view the anterior compartment structures, the lateral
meniscocapsular structures, and the popliteus tunnel
• minimize accessory instrument crowding with the
arthroscope during procedures requiring triangulation
of several instruments into these compartments.
• Viewing posterior horns of the menisci and the tibial
attachment of the PCL may be difficult
• located just off the medial and lateral edges of the
midpatella at the broadest portion of the patella.

18. Accessory Far Medial and Lateral
Portals
• used for triangulation of accessory instruments
into the knee.
• approximately 2.5 cm medial or lateral to the
standard AM and AL portals
• Medially, near the anterior edge of the tibial
collateral ligament;
• laterally, anterior to the fibular collateral
ligament and popliteus tendon.
• the meniscus or the collateral ligament can be
lacerated, or the articular margin of the femoral
condyle can be damaged.

19. Central Transpatellar Tendon (Gillquist)
Portal
• 1 cm inferior to the lower pole of the patella in
the midline of the joint through the patellar
tendon.
• most helpful in ACL reconstruction procedures
after graft harvest has been completed, avoiding
tendon damage.
• If a transpatellar tendon portal is necessary for
posterior compartment evaluation or anterior
compartment triangulation, it is made with the
knee in 90 degrees of flexion to keep the tendon
under tension.