Patella Instability: What You Need to Know, by Dr. Lingaraj

A sudden twist of the knee, intense pain, and a visible deformity — for many patients, this is the alarming moment they first experience patella instability. In this edition of Physioactive’s Singapore Surgeon Insights series, Dr. Lingaraj, orthopedic surgeon at Orthopedic and Hand Surgery Partners Singapore, walks us through everything you need to know about this condition: who is at risk, how it is treated, and how physiotherapy plays a vital role in recovery.

What Is Patella Instability?

The patella, or kneecap, normally glides smoothly in a groove at the front of the knee. Patella instability occurs when the kneecap dislocates — usually shifting outward (laterally) — causing severe pain, rapid swelling, and sometimes a visible deformity. In some cases the kneecap pops back on its own; in others, it needs to be manually pushed back into place, sometimes requiring sedation at an emergency department.

There are three common presentations:

• Acute first-time dislocation: Sudden, severe pain and swelling after a twist or impact.
• Recurrent instability: Repeated dislocations that tend to become less painful over time but cause progressive damage.
• Subluxation: The kneecap partially shifts out of position and returns on its own — a warning sign not to be ignored.

Who Is Most at Risk?

Patella instability is most common in adolescents and children between the ages of 10 and 17, occurring in approximately 50 out of every 100,000 individuals in that age group — making it even more common than ACL injuries. While it can affect anyone, certain anatomical risk factors increase the likelihood of recurrence:

• Trochlear dysplasia: A shallow groove in which the kneecap glides, making it easier to dislocate.
• Patella alta: The kneecap sits higher than normal.
• Increased TT-TG distance: An abnormal relationship between the femur and tibia bones.
• Ligamentous laxity: Joints that are naturally more flexible and prone to movement.

Most of these factors can be identified through an MRI scan, though in more complex cases, a CT scan covering the hip, knee, and ankle may be required.

When Is Surgery Needed?

Not every case requires surgery. For a first-time dislocation without cartilage damage, conservative treatment is often effective: a soft knee brace worn for four weeks, combined with a supervised physiotherapy program focusing on strengthening the quadriceps — particularly the VMO (vastus medialis oblique) muscle.

However, surgical intervention is recommended when:

• There is associated cartilage (osteochondral) injury
• The patient has experienced more than one dislocation
• The patient is young — the younger the first dislocation, the higher the risk of recurrence (up to 50% of first-time patients go on to develop recurrent instability)

MPFL Reconstruction: The Key Surgical Procedure

The primary surgical treatment for patella instability is reconstruction of the MPFL — the medial patellofemoral ligament — a key restraint on the inner side of the knee that prevents the kneecap from shifting outward. This ligament is almost always injured during a dislocation.

In MPFL reconstruction, a tendon graft (taken either from the patient or a donor) is attached to the patella and femur, creating a new restraint that replaces the damaged ligament. Dr. Lingaraj notes that in approximately 90% of patients, MPFL reconstruction alone delivers excellent outcomes, reducing the re-dislocation rate to just 1–5% and allowing full return to sports.

In cases where additional issues are present — such as cartilage damage, a very shallow groove, or significant bone misalignment — further procedures such as lateral release, trochleoplasty, or tibial tubercle transfer may also be performed.

Post-Op Recovery and the Role of Physiotherapy

MPFL reconstruction is typically performed as a day surgery procedure taking one to two hours under general anaesthetic. Because the procedure is minimally invasive, most patients recover from anaesthesia within a few hours and are encouraged to begin mobilizing on the same day. Patients can start walking with crutches on the day of surgery itself — a significant advantage compared to older, more invasive knee procedures.

For patients travelling from Indonesia, Dr. Lingaraj recommends staying in Singapore for at least two weeks following surgery. This allows for proper wound care, initial physiotherapy, and a clinical review before returning home. The general recovery arrangement is structured as follows:

• 0–2 weeks: Crutches required; wound care and initial physiotherapy in Singapore (patients travelling from Indonesia are advised to stay for two weeks)
• 0–6 weeks: Knee brace worn while walking
• 6–9 months: Closely supervised physiotherapy program progressing toward full return to sports

Physiotherapy is not just post-operative — strengthening the muscles around the knee before and after surgery is essential for long-term stability and preventing re-injury.

Don’t Wait for the Next Dislocation

Each time the patella dislocates, it causes more damage to the surrounding cartilage — increasing the risk of long-term complications such as osteoarthritis. Dr. Lingaraj’s advice is clear: seek specialist assessment early, whether it is your first dislocation or you have been managing recurring instability for years.

At Physioactive, our team of experienced physiotherapists works alongside specialists like Dr. Lingaraj to support you at every stage — from conservative rehabilitation to post-surgical recovery. If you are dealing with knee instability or recovering from a patella dislocation, we are here to help you return to full activity safely.

Contact Physioactive today to speak with our team and take the first step toward a stronger, more stable knee.