MCL and Posteromedial Corner

AnatomyMCL anatomy


1. Seebacher's 3 layers of the medial knee


Layer 1

- sartorius and sartorius fascia


Layer 2

- superficial MCL

- posterior oblique ligament

- semimembranosus


Layer 3

- deep MCL (meniscofemoral and meniscotibial ligament)

- posteromedial capsule 


2. MCL


Superficial MCL

- triangular in shape

- origin: 3 mm proximal and 5 mm posterior to the epicondyle

- insertion: 6 cm distal to the joint line onto posteromedial tibia, deep to pes anserinus

- anterior margin free


Deep MCL

- deep to MCL

- origin: inferior to medial epicondyle

- insertion: 1 cm below joint line

- meniscofemoral and meniscotibial ligaments

- capsular thickening


3. Posteromedial corner (5 components)


Dold et al. JAAOS 2017


Medial Knee AnatomyOblique popliteal ligamentMedial knee anatomy


i) Posterior oblique ligament (POL)

- behind / posterior  the superficial MCL

- origin: femur posterior and distal to adductor tubercle

- insertion: central arm onto posterior tibia below articular surface and the posteromedial capsule


ii) Semimembranosus

- attaches to the posteromedial corner of the tibia just below the joint line

- also has extensions blending with POL and OPL

- important dynamic stabiliser


iii) Oblique Popliteal Ligament (OPL)

- extension of semimembranosus

- extents laterally towards lateral femoral condyle

- thickens posteromedial capsule


iv) posteromedial joint capsule


v) posterior horn of medial meniscus


4. Pes anserinus


Runs superficial to MCL

- 3 components: sartorius, gracilis, semitendinosus

- "Say Grace before Tea"

- the saphenous nerve and small saphenous vein emerge between sartorius and gracilis


Function of MCL and Posteromedial corner


MCL primary valgus stability at 30o flexion

Secondary restraint to

- anterior translation

- external rotation


Secondary static medial stabilisers

- contribute to medial stability in full extension


- posteromedial corner



Secondary dynamic medial stabilisers

- pes anserinus

- semimembranosus




Valgus force +/- external rotation

May hear a pop




Discreet tenderness at femoral or tibial insertion of MCL


1. Valgus stress test at 30° flexion and full extension


Remember to test both sides, and compare to contralateral side


Gapping at 30° flexion

- isolated injury to MCL


MCL increased valgus at full extension


Gapping in full extenstion

- injury to a secondary stabilizer

- ACL / PCL / posteromedial corner


2.  Anteromedial rotational instability (AMRI)


Assessing for injury to posteromedial corner


a) valgus stress test with foot external rotated (see medial gapping with forward subluxation of the anteromedial tibia)


b) anterior drawer test at 90o with foot externally rotated (again will see forward subluxation of the anteromedial tibia)


Posteromedial corner review article


3.  Assess ACL / PCL


MCL Grading


Fetto and Marshall Clin Orthop 1978


Grade I / Pain at 30° flexion no opening


Indicates sprain but no tear of MCL


Grade II / Some laxity at 30° flexion, none in full extension


Partial tear of MCL


Grade III / Laxity in full extension


Complete tear of MCL and posteromedial corner

Possible disruption to ACL / PCL



Grade III MCL - opening in full extension


Associated Injuries


1.  ACL 


Willinger et al. KSSTA 2021

- 60% of ACL injuries involve an injury to the superficial MCL


2. Posterior oblique ligament


Sims et al. AJSM 2004

- 99% of patients with grade III MCL injury had POL injury


2.  Meniscus




Usually normal in acute injury


Bony avulsions (rare)


MCL Bony Avulsion

Bony avulsion of MCL on femoral side


Pellegrini-Stieda Lesion 

- calcification at insertion of femoral MCL

- indicative of chronic injury


Pellegrini Steida Lesion






Grade I: intact ligament with periligamentous oedema

Grade II: partial tearing with surrounding oedema

Grade III: complete ligament tear




Femoral avulsion


Tibial side: wave sign, ensure that the MCL is no flipped above pes anserinus as will not heal (analogous to Stener lesion)


MCL acute grade 3 Femur MRIMCL acute femoral avulsion

Acute femoral avulsion


MCL Midsubstance Tear MRI 1Acute MCL avulsion with rollback

Midsubstance MCL tears


MCL tibial avulsion 1MCL tibial avulsion 2


Wave sign indicative of tibial avulsion, with ligament retracted above pes anserinus / hamstring tendons


MCL Chronic Femoral Thickening on MRIMCL Chronic Femoral Thickening

In the chronic setting see thickening of the MCL





- medial drive through sign

- excessive opening of medial compartment

- may see lift off of the medial meniscus with injury to deep MCL / meniscotibial ligament

- may see injury above medial medial meniscus with injury to deep MCL / meniscofemoral ligament


Arthroscopic Lift off of medial meniscus in MCL injuryMCL injury arthroscopy

Meniscotibial ligament injury                                    Meniscofemoral ligament injury


Isolated MCL Management


Non operative Management



- isolated injury to MCL (grade I / II)

- no ACL / PCL / posteromedial corner / meniscal injury

- no displaced tibial avulsion of MCL


Grade I / II


Control pain & inflammation

- RICE / analgesia / weight bear as tolerated

- muscle-strengthening exercises once FROM

- begin jogging once pain free

- grade I: typically, 1 - 3 weeks return to sport

- grade II: can be 6 - 8 but sport dependent

- usually, a brace is not necessary


Lundblad et al. KSST 2019

- 130 MCL injuries UEFA elite soccer players

- use of brace in grade II associated with longer return to play


Grade III


Ensure no concomitant injury

Consider a hinge brace

Can consider extension block but risk stiffness


Combined Ligament Injury




Grade II MCL


Millett et al J Knee Surg 2004

- early ACL reconstruction with non operative management MCL in 18 patients

- at 2 year follow up no graft failure or valgus instability


Zaffagnini et al JBJS Br 2011

- 3 year follow up of ACL reconstruction with grade II MCL treated nonop

- no impact on AP instability on KT-1000 at 3 year follow up

- all patients had some residual ML instability on Telos stress xrays




Halinen et al. Am J Sports Med 2006

- RCT of acute ACL reconstruction in patients with grade III MCL

- early ACL reconstruction

- operative v non operative management of MCL in 47 patients

- no difference in the two groups with regards outcome or stability


Westermann et al. Arthroscopy 2019

- MOON group

- 1.1% (27/2586) had grade III MCL with ACL

- 16 managed operatively, 11 managed nonoperatively

- patients managed operatively had worse outcomes scores both before and after surgery


Operative Management of Grade III MCL injuries




Displaced bony femoral avulsion

Displaced tibial avulsion above pes anserinus or into joint

Chronic grade III MCL / posteromedial corner injury with instability

Grade III MCL in setting of ACL / PCL ligament injury


Bony MCL Avulsion


Elevate VMO and repair with staples or screw


MCL Bony Avulsion IntraopMCL Bony Avulsion Intraop 2


MCL Bony Avulsion ORIF APMCL Bony Avulsion ORIF Lateral


MCL repair


Tibial side


MCL Stener LesionDistal Tibial Advancement 1Distal tibial advancement repair MCL



MCL Tibial AvulsionMCL Tibial Avulsion Double Row Repair


Femoral side


Hughston Procedure

- advance femoral attachment of MCL and POL

- tighten POL anteriorly onto MCL

- consider imbricating semimembranosus to decrease slack


Proximal MCL Advancemetn 1Proximal MCL Advancement 2Proximal MCL Advancement 3

Advancement of proximal MCL / POL with screw, and imbrication / tightening of POL


MCL Reconstruction APMCL Reconstruction Lateral

Tightening of proximal MCL / POL with sutures


MCL Advancement APMCL Advancement Lateral

Advancement of femoral MCL and staple / suture anchor fixation




Delong et al. Arthroscopy 2015

- systematic review of all repair techniques

- 16 papers with 355 knees

- 75% had side to side difference of < 3 mm

- 6% failure rate


3.  Reconstruction of MCL and posteromedial corner


A.  Single bundle anatomic allograft MCL reconstruction (no POL)


MCL Reconstruction Tendoachilles allograftMCL Reconstruction tendoachilles allograft

Bony fixation with screw of femoral side, screw and soft tissue washer fixation on tibial side


Marx technique MCL reconstruction with tendoachilles allograft PDF


Marx technique MCL reconstruction with tendoachilles allograft Vumedi


Femoral attachment

- 4 mm proximal and posterior to medial epicondyle

- 40o anterior to avoid notch

- 40o proximal to avoid PCL tunnel


Tibial attachment

- 6 cm from joint line

- just posterior to pes attachment


B.  Single bundle anatomic hamstring autograft MCL reconstruction (no POL)


MCL Reconstruction 2 IncisionMCL Isometric Point



- harvest both hamstrings and leave attached distally

- re-routed more posteriorly on tibia around screw / soft tissue washer or with anchors (recreates tibial insertion)

- femoral attachment is 12 mm distal and 8 mm anterior to adductor tubercle (attachment of adductor magnus)

- femoral attachment is 3 mm proximal and 4 mm posterior to femoral epicondyle

- isometric centre on fluoroscopy is line of intersection of posterior femoral condyle and blumensaat's line

- drill femoral tunnel and fix with screw


LaPrade surgical technique PDF


C.  Double bundle anatomic reconstruction of MCL and POL



- use separate hamstring tendons to recreate MCL and POL


Vumedi video


Surgical Approach to Medial Knee



- knee flexed to 90o, over bolster

- tourniquet

- sandbag under hip



- hockey stick medial incision

- halfway between borders of tibia

- extends proximally to adductor tubercle

- distally to pes anserinus


Superficial dissection

- protect the saphenous nerve and small saphenous vein

- emerges from between sartorius and gracilis

- divide medial patella retinaculum from VMO down

- divide sarfascia over pes anserinus

- reflect pes anserinus inferiorly


Deep dissection

- elevate VMO to identify proximal insertion of superficial MCL

- expose superficial MCL running from medial epicondyle down to tibia under pes

- popliteal oblique ligament and semimembranosus are posterior to MCL

- can expose posterior capsule by carefully reflecting medial gastrocnemius posteriorly