Low kneecap how it occurs its effect on movement and treatment

Patella baja, also known as a low-lying kneecap, is a medical condition that may initially go unnoticed despite its clear impact on joint movement and quality of life. This condition occurs when the patella sits lower than its normal position, leading to an alteration in the knee’s biomechanics and increased friction within the joint during movement.It is often associated with previous knee injuries, surgical procedures, or the development of scar tissue inside the joint that causes shortening of the patellar tendon. Over time, it may result in increasing pain, joint stiffness, and difficulty performing daily activities such as walking, climbing stairs, or fully bending the knee.Therefore, at Deli Medical, early understanding and accurate diagnosis of this condition are essential steps toward effective treatment and preventing potential complications.

What is Patella Baja (Low-Lying Patella)?

Patella Baja, also known as a low-lying kneecap, is a medical condition in which the patella (kneecap) is positioned lower than its normal level in relation to the femur (thigh bone). This change in position disrupts the normal biomechanics of the knee joint, leading to pain, restricted movement, difficulty in bending the knee, and increased pressure inside the joint, which may contribute to early onset osteoarthritis.

Is Patella Baja a serious condition?

It is not always considered a serious condition in all cases. However, it can lead to troublesome complications if not properly managed. It may cause chronic pain, difficulty performing daily activities, and in advanced cases, significant stiffness or knee joint degeneration that affects mobility.

Does a low-lying patella go away on its own?

❌ In most cases, it does not resolve spontaneously, because it is usually caused by structural issues such as:

Shortening of the patellar tendon
Formation of scar tissue (fibrosis) inside the knee

However, conservative treatments such as physiotherapy and medications may help reduce symptoms and pain. Severe cases may require surgical intervention depending on medical evaluation.

What is the difference between Patella Baja and Patella Alta?

Patella Baja: The kneecap is positioned lower than normal.
Patella Alta: The kneecap is positioned higher than normal.

Both conditions affect knee joint function and movement, but each has different causes and requires a specific treatment plan based on diagnosis.

Does Patella Baja cause constant pain?

Yes, it can cause pain in some cases, especially in the front of the knee. The pain usually worsens during:

Climbing or descending stairs
Squatting or prolonged knee bending
Activities that put pressure on the knee joint

The severity of pain varies from one person to another depending on the condition’s cause and degree.

Can I live normally with Patella Baja?

Yes, in mild cases, many people can live relatively normal lives. However, they may notice:

Difficulty with some daily movements
Early fatigue or discomfort in the knee

In more advanced cases, the condition may significantly affect mobility and daily activities.

Is surgery successful in treating Patella Baja?

In general, surgical treatment has good outcomes when:

The condition is accurately diagnosed
The appropriate surgical technique is selected

However, success also depends on:

Commitment to post-operative physiotherapy
A proper rehabilitation program, which may take time to fully restore knee function

Can Patella Baja come back after surgery?

In most cases, results are stable. However, recurrence may occur in rare situations if:

Physiotherapy is not followed properly
New scar tissue develops inside the knee
The underlying cause was not fully addressed

Therefore, careful follow-up after surgery is essential for long-term success.

Types of Patella Baja

1. True Patella Baja

This is the most common clinical type.

It occurs due to:

Shortening of the patellar tendon

It is characterized by:

A true and permanent low position of the patella
Direct involvement of tendon dysfunction

It is commonly seen after:

Knee surgeries
Severe fibrosis
Major injuries

2. Acquired Patella Baja

This type develops after birth due to a specific cause.

It occurs due to:

Joint fibrosis and adhesions
Prolonged immobility
Abnormal tissue healing

It is characterized by:

Gradual lowering of the patella over time

3. Iatrogenic / Post-surgical Patella Baja

This type is related to surgical procedures.

It occurs due to:

Altered knee joint line after surgery
Excessive tension on the tendon during surgery
Changes in knee biomechanics after total knee replacement

4. Pseudo Patella Baja

In this type, the patella is not actually low.

Instead, the issue is:

Elevation of the knee joint line

As a result:

The patella appears low, but its actual position is normal

Causes of Patella Baja

Patella Baja is a condition in which the kneecap sits abnormally low within the knee joint, leading to pain, stiffness, and impaired movement.

Main causes:

1. Previous knee surgeries

The most common cause, including:

ACL reconstruction
Total knee replacement
Patellar tendon repair

Surgery may lead to:

Scar tissue formation
Shortening of the patellar tendon, pulling the kneecap downward

2. Fibrosis and adhesions inside the knee

These may occur after:

Severe injuries
Joint bleeding
Fractures or surgeries

They lead to:

Formation of fibrous tissue that pulls the patella downward

3. Patellar tendon shortening

This may be:

Congenital (rare)
Acquired after injury or surgery

It results in:

Direct lowering of the patella position

4. ⛔ Prolonged Immobilization

Such as:

Long-term knee casting (immobilization in a cast)
Neglecting physiotherapy after injury

Result:

Stiffness and contraction of the tissues around the joint

5. Chronic Inflammation or Recurrent Injuries

Such as:

Patellar tendon inflammation (patellar tendinitis)
Repeated knee injuries

Over time, this may lead to:

Changes in the length and tension of the patellar tendon

6. ⚠️ Surgical Errors (Rare)

May occur after surgery if:

The tendon is tightened incorrectly
Or fixed in an improper position

Symptoms of Patella Baja (Low-Lying Patella)

Symptoms of Patella Baja usually develop gradually, and their severity varies depending on how much the patella has descended and how much the knee joint is affected.

Main symptoms:

1. Anterior knee pain

One of the most common symptoms. The pain is felt at the front of the knee, directly around the kneecap.

It worsens with:

Climbing or descending stairs
Prolonged sitting
Squatting

2. Knee stiffness

Difficulty fully bending or straightening the knee
Feeling of tightness or reduced flexibility in the joint

3. Reduced range of motion

Inability to fully extend the knee
Difficulty achieving full knee flexion

4. Clicking or joint friction

Audible or felt crepitus (crackling sound) during movement
Caused by altered patellar position and increased joint friction

5. Weakness of the quadriceps muscle

Difficulty standing for long periods
Quick fatigue when climbing stairs
Feeling of knee instability during movement

6. Visible change in knee shape

In advanced cases:

The kneecap may appear lower than normal
This may be noticeable when comparing both knees

7. Pain during daily activities

Walking long distances
Standing up from a seated position
Any weight-bearing activity on the knee

Diagnosis of Patella Baja

The diagnosis of Patella Baja is based on a combination of clinical and imaging evaluations, as physical examination alone is not sufficient.

1. Clinical Examination

The doctor evaluates:

Knee shape and patella position compared to normal
Range of motion (flexion and extension)
Pain in the anterior knee during movement
Strength of the quadriceps muscle
Possible clicking or friction during patellar movement

⚠️ However, this is only a preliminary step and not enough for a definitive diagnosis.

2. X-ray Imaging

X-rays are the most important diagnostic tool and include several key measurements:

1. Insall–Salvati Ratio

Insall-Salvati Ratio=Length of patellaLength of patellar tendon ext{Insall-Salvati Ratio} = frac{ ext{Length of patella}}{ ext{Length of patellar tendon}}Insall-Salvati Ratio=Length of patellar tendonLength of patella

Interpretation:

Normal: around 1.0
Patella baja: less than 0.8
Indicates shortening of the patellar tendon or low patellar position

2. Blackburne-Peel Index

Measures the relationship between the patella and the knee joint surface
Especially useful after surgical procedures
Helps determine whether the patella is positioned lower than normal

3. Caton-Deschamps Index

A more precise index used to evaluate patellar height.

Normal range:

Approximately 0.6 to 1.3

In Patella Baja:

Significantly reduced values

3. MRI (Magnetic Resonance Imaging)

Used in complex or unclear cases to:

Evaluate patellar tendon shortening or fibrosis
Detect intra-articular adhesions
Assess cartilage and surrounding soft tissues

4. Comparative or Dynamic Imaging

Comparison between the affected and healthy knee
Helps clearly identify differences in patellar position
Useful in unclear diagnostic cases

Complications of Patella Baja

Complications usually occur if the condition is neglected or left untreated, especially in severe cases.

1. Chronic anterior knee pain

One of the most common complications, which may become persistent or recurrent.

It worsens with:

Stair climbing
Sitting for long periods
Squatting

2. Knee stiffness and limited motion

Difficulty fully bending or straightening the knee
Feeling of reduced joint flexibility

3. Patellofemoral cartilage damage

Caused by abnormal friction between the patella and the femur.

Over time, it may lead to:

Early knee osteoarthritis
Increased pain during movement and weight-bearing

4. Quadriceps muscle weakness

Occurs due to reduced use and persistent pain.

It may result in:

Difficulty standing or walking long distances
A feeling of knee instability

5. Joint Friction and Noise (Crepitus)

Hearing or feeling clicking, cracking, or grinding during movement
Caused by altered joint mechanics and increased friction inside the knee

6. Difficulty Performing Daily Activities

Including:

Climbing and descending stairs
Sitting down and standing up
Walking long distances

7. Early Knee Osteoarthritis

With continued abnormal friction, the condition may progress to:

Knee osteoarthritis
Gradual deterioration of joint function

8. Poor Outcomes of Previous Surgeries

In cases that develop after knee surgeries:

Reduced effectiveness of previous surgical procedures
Persistent pain and stiffness
Delayed or compromised full recovery outcomes

Drug Treatment for Patella Baja (Low-Lying Patella)

Drug therapy is part of the overall treatment plan, but it does not address the root cause of Patella Baja, such as patellar tendon shortening or intra-articular fibrosis. Instead, it mainly aims to relieve pain, reduce inflammation, and improve mobility until physiotherapy or further treatment is started.

1. Pain Relievers

1. Paracetamol

Used for mild to moderate pain
Relatively safe for the stomach
Suitable for short-term use

2. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Such as:

Ibuprofen
Diclofenac
Naproxen

They help:

Reduce pain
Decrease inflammation around the knee joint
Temporarily improve mobility

⚠️ Important notes:

Should be used for a limited period
May cause stomach or kidney issues with long-term use
Preferably taken under medical supervision, especially in chronic patients

2. Intra-Articular Injections

Used in moderate to severe cases when oral medications are not enough.

1. Corticosteroid Injections

Rapidly reduce inflammation and pain
Useful in severe inflammatory cases around the patella

⚠️ Caution:

Should not be overused during the year
Excessive use may weaken surrounding tissues

2. Hyaluronic Acid Injections

Improve joint lubrication
Reduce internal knee friction
Help reduce pain during movement

3. Muscle Relaxants

Used when there is muscle tightness or spasms around the knee
Help reduce stiffness
Improve comfort during movement

4. Joint Support Supplements (Adjunct Only)

Such as:

Glucosamine
Chondroitin

They help:

Support cartilage health
Improve joint function in the long term

⚠️ Note:

Their effect on Patella Baja itself is limited
They are not a primary treatment

Surgical Treatment for Patella Baja

Surgical treatment depends on the underlying cause and severity. There is no single procedure for all patients. The main goals are to elevate the patella, restore knee biomechanics, and reduce pain and friction.

1. Arthrolysis (Release of Adhesions)

Concept

Removal of fibrotic tissue and adhesions that pull the patella downward or restrict its movement.

Procedure

Performed mostly via arthroscopy
Insertion of small instruments into the knee joint
Removal of:
- Fibrotic tissue
- Intra-articular adhesions
Sometimes manual mobilization of the patella is performed

Goal

Improve range of motion
Reduce stiffness
Prepare the knee for physiotherapy

2. Patellar Tendon Lengthening

Concept

Used when the patellar tendon is shortened and pulls the patella downward.

Procedure

Open surgery at the front of the knee
Incision of the patellar tendon
Lengthening using techniques such as:
- Z-plasty technique
- Partial division and re-suturing at a longer length
Fixation of the tendon in its new position

Goal

Restore normal patellar height
Improve anterior knee mechanics

3. Tibial Tubercle Osteotomy (Proximalization)

Concept

Changing the attachment point of the patellar tendon on the tibia.

Procedure

Bone cut at the tibial tubercle
Elevation of the bone fragment attached to the patellar tendon
Fixation using:
- Surgical screws
- Plates
Adjustment of tendon tension after repositioning

Goal

Permanent and precise elevation of the patella
Restoration of knee biomechanics

4. Extensor Mechanism Reconstruction

Concept

Reconstruction of the entire knee extension system:

Quadriceps muscle
Patellar tendon
Patella

Procedure

Removal of damaged tissues
Use of grafts:
- Patient’s own tendons
- Donor tendons (allografts)
Reconnection:
- Muscle → Patella → Tibia
Precise tension adjustment

Goal

Full restoration of knee function
Treatment of severe and complex cases

5. Patellar Tendon Reconstruction

Concept

Replacement or reinforcement of a severely damaged or shortened tendon.

Procedure

Removal of damaged tendon tissue
Replacement using grafts or synthetic materials
Reattachment between:
- Patella
- Tibia
Precise adjustment of length and tension

Goal

Restore normal tendon strength and length
Improve natural knee movement

6. Post-Arthroplasty Correction (After Knee Replacement)

Concept

Used in cases occurring after total knee replacement surgery.

Procedure

Adjustment of the prosthetic joint line
Repositioning of the patella
Replacement or modification of implant components if needed

Goal

Restore knee balance and alignment
Improve movement and reduce pain

Post-Surgical Phase (Very Important)

After any surgical procedure:

Strict physiotherapy adherence
Gradual strengthening of the quadriceps muscle
Progressive return to movement
Regular imaging follow-up

Prevention of Patella Baja

Prevention is very important, especially after knee injuries or surgeries, as most cases are acquired and can be significantly reduced with proper care.