The Importance of Medial Patellofemoral Ligament (MPFL) Healing After Knee Dislocation

Knee dislocations can be traumatic and challenging injuries, especially when the patella (kneecap) is involved. One of the most critical structures affected during a patellar dislocation is the Medial Patellofemoral Ligament (MPFL). This key stabilising ligament plays a vital role in keeping the kneecap aligned, and ensuring its proper healing is essential for full recovery and preventing recurrent dislocations.

In this guide, we’ll explore the function of the MPFL, what happens when it’s injured during a knee dislocation, and why its healing is crucial for restoring knee stability and function.

What Is the Medial Patellofemoral Ligament (MPFL)?

The MPFL is a strong, band-like ligament located on the inner (medial) side of the knee. It connects the medial femur (thigh bone) to the inner edge of the patella (kneecap), acting as the primary restraint against lateral patellar displacement.

Key Functions of the MPFL:

Stabilises the Patella: Prevents the kneecap from sliding outwards (laterally) during movement.
Guides Proper Patellar Tracking: Helps the kneecap glide smoothly along the femoral groove when bending and straightening the knee.
Maintains Knee Alignment: Works in conjunction with muscles and other ligaments to keep the knee joint stable during activities.

Understanding Patellar Dislocation and MPFL Injury

A patellar dislocation occurs when the kneecap slips out of its groove on the femur, typically moving towards the outside (lateral side) of the knee. This often results in tearing or stretching of the MPFL, as it is the main structure resisting this outward movement.

Common Causes of Patellar Dislocation:

Trauma: A direct blow to the knee or a twisting injury can force the patella out of place.
Sports Injuries: Activities involving jumping, pivoting, or sudden changes in direction (e.g., basketball, soccer) increase the risk.
Anatomical Factors:
- Shallow femoral groove
- High-riding patella (patella alta)
- Ligament laxity (hypermobility)
- Weakness in the quadriceps or hip muscles

Why MPFL Healing Is Crucial After Knee Dislocation

When the MPFL is damaged during a patellar dislocation, it compromises the stability of the kneecap, significantly increasing the risk of recurrent dislocations and chronic instability if not properly treated.

Key Reasons for Prioritising MPFL Healing:

Restoring Patellar Stability:
- A healed MPFL acts as the primary restraint against further lateral displacement of the kneecap, reducing the likelihood of recurrent dislocations.
Preventing Long-Term Joint Damage:
- Repeated dislocations can lead to cartilage damage, increasing the risk of patellofemoral arthritis.
Improving Functional Movement:
- A stable patella allows for smooth knee movement, essential for walking, running, and jumping without pain or restriction.
Reducing Pain and Swelling:
- Proper MPFL healing helps alleviate inflammation, leading to less pain and quicker recovery.
Enhancing Confidence in Movement:
- Knee instability often causes patients to hesitate during activity. A well-healed MPFL restores confidence, reducing the fear of another dislocation.

Recognising Symptoms of MPFL Injury After Patellar Dislocation

While the immediate dislocation event is often obvious, recognising the ongoing signs of MPFL damage is key to effective treatment.

Common Symptoms Include:

Kneecap Instability:
- A feeling that the kneecap is “loose” or may slip out during movement.
Pain on the Inner Side of the Knee:
- Tenderness along the inner patella where the MPFL attaches.
Swelling and Bruising:
- Generalised knee swelling, especially in the initial days post-injury.
Limited Range of Motion:
- Difficulty fully bending or straightening the knee due to pain and swelling.
Weakness in the Quadriceps:
- Disuse and pain can lead to muscle atrophy, affecting knee control.
Recurrent Dislocations or Subluxations:
- In untreated cases, the kneecap may continue to partially or fully dislocate.

Diagnosing MPFL Injuries After Knee Dislocation

Accurate diagnosis is crucial for determining the extent of MPFL damage and guiding treatment.

Evaluation Process:

Medical History & Physical Exam:
- The clinician will ask about the dislocation event, current symptoms, and any history of previous knee injuries.
- Specific tests, like the Apprehension Test, assess patellar stability and the likelihood of further dislocation.
Imaging Studies:
- MRI (Magnetic Resonance Imaging): The gold standard for evaluating soft tissue injuries, providing a clear image of MPFL tears and associated cartilage damage.
- X-rays: Used to assess bone alignment, check for fractures, or identify anatomical predispositions (e.g., patella alta).

Effective Treatment Options for MPFL Healing After Dislocation

The treatment approach depends on the severity of the MPFL tear, the stability of the patella post-dislocation, and individual risk factors.

1. Non-Surgical Management (For First-Time Dislocations Without Severe Damage)

Immediate Care – RICE Protocol:
- Rest: Limit weight-bearing and avoid activities that stress the knee.
- Ice: Apply ice packs for 15–20 minutes every 2–3 hours to reduce swelling.
- Compression: Use a knee sleeve or bandage to control swelling.
- Elevation: Keep the leg elevated to help reduce swelling.
Knee Bracing:
- A patellar-stabilising brace helps guide proper kneecap tracking during early healing.
Physical Therapy:
A structured rehab program is critical for restoring MPFL strength and knee stability.
- Early Stage:
  - Focus on pain management, swelling reduction, and gentle range-of-motion exercises.
  - Isometric quadriceps exercises to prevent muscle atrophy.
- Mid Stage:
  - Gradually increase knee range of motion and begin strengthening exercises targeting the quadriceps, hamstrings, and hip abductors.
  - Emphasis on vastus medialis oblique (VMO) activation to support patellar alignment.
- Late Stage:
  - Incorporate functional exercises, balance training, and sport-specific drills to prepare for a return to activity.
Gradual Return to Activity:
- With proper rehab, many patients can return to sports within 3–4 months, though timelines vary based on severity.

2. Surgical Management (For Severe or Recurrent Dislocations)

Surgery is often recommended in cases of:

Complete MPFL tears with significant patellar instability.
Recurrent dislocations despite conservative treatment.
Anatomical predispositions (e.g., shallow femoral groove) that increase dislocation risk.

Surgical Options:

MPFL Reconstruction:
- A common procedure where a graft (often from the hamstring) is used to reconstruct the torn MPFL, restoring patellar stability.
MPFL Repair:
- In some cases, the torn ligament can be directly repaired without the need for a graft.
Addressing Anatomical Issues:
- In complex cases, procedures like a tibial tubercle transfer (realigning the kneecap) may be performed alongside MPFL reconstruction.

Rehabilitation and Recovery After MPFL Injury or Surgery

Rehabilitation is crucial for ensuring proper MPFL healing and preventing future dislocations, whether treatment is surgical or non-surgical.

Rehab Timeline:

Weeks 1–4:
- Focus on pain and swelling control.
- Use of a knee brace with limited range of motion.
- Begin gentle range-of-motion and isometric exercises.
Weeks 4–8:
- Gradual progression to weight-bearing activities.
- Increased strengthening, especially focusing on the VMO and hip stabilisers.
Weeks 8–12:
- Continue strengthening and begin dynamic exercises (e.g., balance drills, step-ups).
Months 3–6:
- Sport-specific training and return to higher-impact activities.
- Clearance for return to sports typically occurs between 4–6 months, depending on progress.

Pro Tip: Adhering to a structured rehab program and avoiding premature return to activity are essential for reducing the risk of re-injury.

Preventing Future Patellar Dislocations and MPFL Injuries

While not all dislocations are preventable, certain strategies can reduce the risk of recurrence:

Strengthen the Quadriceps and VMO:
- Targeted exercises help stabilise the patella and improve knee control.
Focus on Hip and Core Strength:
- Strong hip abductors and core muscles promote proper lower limb alignment.
Improve Flexibility:
- Maintain balanced flexibility in the hamstrings, quadriceps, and hip flexors.
Incorporate Balance and Proprioception Training:
- Exercises like single-leg stands and wobble board drills enhance knee stability.
Use Supportive Footwear:
- Proper shoes with good arch support help maintain proper knee alignment during activities.

FAQs: MPFL Healing After Knee Dislocation

1. How long does it take for the MPFL to heal after a dislocation?

Non-surgical cases: Healing typically takes 6–12 weeks, followed by gradual return to activity with physical therapy.
Post-surgery: Recovery can take 4–6 months, depending on the procedure and adherence to rehab.

2. Can the MPFL heal on its own after a dislocation?

Mild MPFL injuries may heal with conservative treatment, but complete tears or cases with significant instability often require surgical intervention for optimal recovery.

3. Is surgery necessary after a first-time patellar dislocation?

Not always. Many first-time dislocations can be managed with bracing and physical therapy. However, surgery may be recommended if there’s a complete MPFL tear or if the kneecap remains unstable.

4. Can I return to sports after MPFL reconstruction?

Yes, most patients can return to their previous activity levels post-surgery, typically around 4–6 months after surgery, following a comprehensive rehab program.

5. What happens if the MPFL doesn’t heal properly?

Incomplete healing can lead to chronic patellar instability, increasing the risk of recurrent dislocations and long-term knee issues like cartilage damage and arthritis.

6. How can I prevent future patellar dislocations?

Focusing on strengthening the quadriceps (especially the VMO), improving hip and core strength, and following a tailored rehab program are key strategies for preventing future dislocations.

Final Thoughts: The Importance of MPFL Healing for Knee Stability

The Medial Patellofemoral Ligament is a crucial stabiliser of the knee, and ensuring its proper healing after a dislocation is essential for restoring function, preventing future dislocations, and maintaining long-term knee health. With early intervention, a structured rehab program, and appropriate treatment, most individuals can achieve a full recovery and return to their favourite activities without fear of re-injury.

If you’ve experienced a knee dislocation or are dealing with patellar instability, consult a healthcare provider or physiotherapist to develop a personalised treatment plan and get started on the road to recovery.