Patellofemoral Ligament Reconstruction (PFL)
Learn about MPFL reconstruction, kneecap instability, patellar dislocation treatment, recovery, and rehabilitation options.
Patellofemoral ligament reconstruction, more commonly referred to as MPFL reconstruction, is a surgical procedure used to treat recurrent kneecap instability or repeated patellar dislocations.
Patellar instability commonly affects adolescents and young adults, particularly those involved in sport or physical activity. Recurrent dislocations can lead to pain, apprehension during movement, cartilage damage, and ongoing instability of the knee.
MPFL reconstruction aims to restore stability to the kneecap and reduce the risk of further dislocation episodes.
Dr Alex Nicholls provides assessment and treatment for patellar instability and paediatric sports knee injuries, with treatment recommendations tailored to the individual patient’s anatomy, symptoms, activity level, and instability pattern.
What Is Patellar Instability?
The patella (kneecap) sits within a groove at the front of the femur and moves as the knee bends and straightens.
Patellar instability occurs when the kneecap partially or completely moves out of this groove.
This may happen:
During sport
Following twisting injuries
During changes in direction
Occasionally during everyday movement
Some patients experience a single dislocation, while others develop recurrent instability.
What Is the MPFL?
The medial patellofemoral ligament (MPFL) is one of the primary soft tissue restraints helping keep the kneecap positioned correctly.
When the kneecap dislocates, the MPFL is often stretched or torn.
Damage to this ligament can contribute to:
Recurrent dislocations
Ongoing instability
Apprehension during activity
Difficulty returning to sport
Symptoms of Patellar Instability
Symptoms may include:
The kneecap “slipping out” of place
Recurrent dislocations or subluxations
Pain at the front of the knee
Swelling after instability episodes
Apprehension during twisting or pivoting movements
Difficulty trusting the knee during activity
Some patients may also experience clicking, catching, or feelings of instability during sport.
Diagnosing Patellar Instability
Assessment generally involves:
Clinical examination
X-rays
MRI imaging
Alignment assessment
Imaging helps evaluate:
MPFL injury
Cartilage damage
Bone bruising
Trochlear anatomy
Limb alignment
Associated structural factors contributing to instability
Understanding the underlying causes of instability is an important part of treatment planning.
Non-Surgical Treatment Options
After a first-time dislocation, initial management may include:
Physiotherapy
Strengthening programs
Activity modification
Bracing
Rehabilitation
Treatment aims to improve:
Quadriceps strength
Movement control
Patellar tracking
Knee stability
Not all patients with patellar instability require surgery.
When Is MPFL Reconstruction Considered?
MPFL reconstruction may be considered when:
Patellar dislocations continue to recur
The knee remains unstable despite rehabilitation
There is ongoing apprehension during activity
Structural instability factors are present
Returning to sport is limited by instability
Treatment decisions depend on:
Frequency of instability episodes
Anatomy
Age and skeletal maturity
Activity demands
Associated cartilage injury
What Happens During MPFL Reconstruction?
MPFL reconstruction involves reconstructing the damaged ligament using a graft.
The goal is to improve kneecap stability and reduce recurrent dislocation.
In some patients, additional procedures may also be considered depending on:
Alignment
Trochlear shape
Patellar height
Associated cartilage or bone abnormalities
Surgical planning is individualised based on the patient’s anatomy and instability pattern.
MPFL Reconstruction in Children and Teenagers
Patellar instability commonly affects adolescents and young athletes.
In younger patients, treatment planning takes into account:
Growth plates
Skeletal maturity
Alignment
Sporting activity
Ongoing development
Paediatric and adolescent instability patterns may differ from adults, which can influence treatment recommendations.
Dr Alex Nicholls maintains a particular interest in paediatric and adolescent knee injuries and sports knee surgery.
Recovery After MPFL Reconstruction
Recovery after MPFL reconstruction is gradual and structured.
Early Recovery
The initial phase focuses on:
Swelling management
Restoring knee movement
Walking progression
Protecting the reconstruction
Bracing and temporary activity restrictions may be required during early recovery.
Rehabilitation
Physiotherapy commonly focuses on:
Strength rebuilding
Quadriceps control
Balance and movement training
Patellar tracking
Functional rehabilitation
Recovery progression depends on the procedure performed and overall knee function.
Return to Sport After MPFL Reconstruction
Return to sport depends on:
Knee stability
Strength recovery
Functional movement
Rehabilitation progression
Confidence during activity
The timing varies between individuals and depends on the sport and physical demands involved.
Why Early Assessment Matters
Recurrent patellar instability may increase the risk of:
Cartilage injury
Ongoing instability
Reduced activity levels
Recurrent dislocations
Assessment by a knee specialist can help determine:
Why instability is occurring
Whether structural factors are contributing
What treatment options may be appropriate
Frequently Asked Questions
What is MPFL reconstruction?
MPFL reconstruction is surgery performed to restore stability to the kneecap after recurrent patellar dislocations or instability.
Does every kneecap dislocation require surgery?
No. Many first-time dislocations are initially managed without surgery using rehabilitation and physiotherapy.
What causes recurrent kneecap instability?
Patellar instability may relate to ligament injury, anatomy, alignment, muscle control, or a combination of factors.
How long does recovery take after MPFL reconstruction?
Recovery varies depending on the individual patient, associated procedures, and rehabilitation progression.
Can teenagers have MPFL reconstruction surgery?
Yes. MPFL reconstruction may be performed in adolescents, although growth plates and skeletal maturity are considered during planning.
Will I need physiotherapy after surgery?
Physiotherapy is commonly recommended to assist with strength, movement, and rehabilitation following surgery.
Evidence-Based Knee Care
Dr Alex Nicholls maintains an active involvement in orthopaedic research and education relating to paediatric knee injuries, sports knee surgery, and knee instability conditions.
Treatment recommendations are based on clinical assessment, imaging findings, instability patterns, activity goals, and the individual anatomy of each patient.