Medial Collateral Ligament Injuries — OrthopaedicPrinciples.com

Courtesy: Prof Wolf Petersen, Martin Luther Krakenhaus, Berlin, Germany

Anatomy of the Medial Collateral Ligament Complex

The medial side of the knee consists of three principal ligamentous structures:

1. Superficial Medial Collateral Ligament

Origin: Medial femoral epicondyle
Insertion: Approximately 7–8 centimeters distal to the joint line, below the pes anserinus
Function:
- Primary restraint to valgus stress
- Contributes to control of rotational stability

2. Posterior Oblique Ligament

Runs obliquely from the posterior medial femoral condyle to the posterior medial tibia
Functions:
- Secondary restraint to posterior tibial translation
- Stabilizer against valgus stress, especially in knee extension

3. Deep Medial Collateral Ligament (also described by some as the anterior oblique ligament)

Connects the femur to the proximal medial tibia
Functions:
- Important restraint to anterior tibial translation
- Contributes to valgus and external rotational stability

Additional medial structures:

Posterior capsule
Coronary ligament (connecting medial meniscus to tibia), relevant in ramp-type lesions

Classification of Medial Collateral Ligament Injuries

Medial collateral ligament injuries are traditionally classified into three grades:

Grade I

Stretch injury with minimal fiber disruption
Firm end point
No increased joint laxity

Grade II

Partial tear
Firm end point
Mild to moderate valgus laxity

Grade III

Complete tear
No firm end point
Marked valgus laxity

Healing Potential and Nonoperative Treatment

The medial collateral ligament has good intrinsic healing potential.
Clinical research has shown:
- Isolated Grade I and II injuries respond well to nonoperative treatment.
- Many Grade III isolated superficial ligament tears may also heal with bracing.
- In combined anterior cruciate ligament and medial collateral ligament injuries, nonoperative treatment of the medial side has shown acceptable outcomes in selected cases.

However, not all Grade III injuries behave similarly.

Special Injury Pattern: Distal “Stener-like” Lesion

Occurs when the distal superficial medial collateral ligament avulses and displaces above the pes anserinus.
The displaced stump loses contact with bone.
Healing potential is poor without surgical intervention.

Management:

Surgical repair using suture anchor fixation.
High return-to-sport rates have been reported following repair of these lesions.

Indications for Surgical Treatment in Acute Injuries

Nonoperative Treatment Recommended For:

Grade I injuries
Grade II injuries
Isolated Grade III superficial medial collateral ligament tears without multi-structure involvement

Surgical Treatment Recommended For:

Distal avulsion with interposition (Stener-like lesion)
Proximal avulsions with gross instability
Combined injury of:
- Superficial medial collateral ligament
- Posterior oblique ligament
- Posteromedial capsule
Knee dislocations involving medial structures
Multi-ligament injuries

Acute Multi-Ligament Knee Injuries

Initial Priorities:

Vascular assessment
Neurological examination
Magnetic resonance imaging

If vascular injury is present:

Immediate vascular management

If no vascular injury:

Imaging-guided surgical planning

Surgical Strategy:

Bony avulsions ? Anchor fixation
Peripheral ligament tears ? Suture repair
Intraligamentous tears ? Repair with augmentation (suture tape or graft)
Severe tissue destruction ? Consider graft augmentation

Repair Techniques in Acute Setting

1. Anchor Refixation

Preferred for proximal or distal avulsions
Soft anchors commonly used

2. Suture Repair

For intraligamentous tears
Often augmented with:
- Internal brace (suture tape)
- Graft augmentation in severe cases

Chronic Medial Instability

Chronic instability may result from:

Delayed treatment
Failed healing
Multi-ligament trauma
Untreated vascular emergencies

If instability persists beyond 6 to 12 weeks, reconstruction is generally indicated.

Reconstruction Techniques

1. Plication Technique

Advancement and tightening of native tissue
Historically described but less commonly used today

2. Tenodesis Techniques

Use of pedicled semitendinosus tendon
Non-anatomic reconstruction
May compromise medial hamstring function

3. Anatomic Reconstruction Techniques (Preferred)

a. Superficial Medial Collateral Ligament Reconstruction

Femoral and tibial tunnels placed at anatomic insertion sites

b. Posteromedial Reconstruction

Reconstruction of:
- Superficial medial collateral ligament
- Posterior oblique ligament

c. Anteromedial Reconstruction

Reconstruction of:
- Superficial medial collateral ligament
- Deep medial collateral ligament

Why Preserve Ipsilateral Hamstrings?

Biomechanical research has shown:

Medial hamstrings act as dynamic stabilizers against valgus and rotational stress.
Preserving ipsilateral hamstrings may improve functional outcomes in medial instability.

Graft Choices for Reconstruction

Medial reconstructions require long tubular grafts.

Options include:

Contralateral semitendinosus tendon
Peroneus longus split graft
Rectus femoris tendon
Tubular allografts

Ipsilateral hamstrings are preferably preserved when possible.

Clinical Evaluation of Chronic Instability

Important examination findings include:

Increased medial joint opening compared to lateral side
Positive valgus stress test
Positive dial test
Anteromedial rotational instability
Posterior drawer that increases in internal rotation (suggesting posterior oblique ligament involvement)

Stress radiographs:

Medial joint space widening
Posterior translation greater than 12 millimeters may indicate additional posteromedial or posterolateral injury

Indications for Adding Posterior Oblique Ligament Reconstruction

Posterior drawer increases in internal rotation
Combined posterior cruciate ligament injury
Clinical evidence of posteromedial instability
Severe medial laxity in extension

Routine reconstruction is not necessary for every Grade III medial collateral ligament tear. Decision depends on associated instability pattern.

Acute Repair Versus Reconstruction

Many surgeons favor repair in the acute setting when tissue quality permits.
Repair allows preservation of native tissue.
Reconstruction is considered in:
- Severe tissue destruction
- Poor tissue quality
- Failed prior repair

Key Practical Points

Tibial avulsions respond well to anchor repair.
Intraligamentous tears may require augmentation.
Multi-ligament injuries demand careful assessment of rotational instability.
Chronic instability is best managed with anatomic reconstruction techniques.
Long tubular grafts are required for medial reconstruction.
Preservation of ipsilateral hamstrings is advisable when feasible.

Summary

Most Grade I and II medial collateral ligament injuries heal without surgery.
Selected Grade III injuries can also be treated nonoperatively.
Stener-like distal avulsions require surgical repair.
Multi-structure and knee dislocation injuries require surgical management.
Chronic instability should be treated with anatomic reconstruction tailored to the instability pattern.

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