Patellar Instability

Patient Stories

When my experience with Hospital for Special Surgery first began, I was in a poor position mentally and physically, and my outlook on things weren’t the best. I had been competitively playing soccer in the Tri-State area since I was four-years-old. My soccer career included playing competitively in the highest division of the Monmouth and Ocean County  (NJ) Soccer Association… Read more “Thomas Guardino”

Thomas Guardino
Brick, NJ

I just wanted to take a moment and share my story and wonderful experience with The Women’s Sports Medicine Center and Doctor Sabrina Strickland at Hospital for Special Surgery. As you can see, I am not “local” to NYC. It is an effort to come to Manhattan, but the effort it well worth it. I have had a lifetime of… Read more “Paulette Gangemi”

Paulette Gangemi
Lambertville, NJ

Since adolescence, I have had knee pain and subluxation and many knee surgeries. Knee pain was a part of my life for over twenty years, but it became increasingly worse to the point where I had episodes of significant swelling every other week. It began interfering with my work, my commute, and limited my activities with my family. I was… Read more “Maureen Suhr”

Maureen Suhr
Merrick, NY

I first injured myself playing basketball when I had just turned eleven years old. I was side shuffling to block a shot when my right knee locked and I fell down, dislocating my patella. I did not know what happened and when I was told I would be out of sports for some time, I was devastated. Physical therapy and… Read more “Katherine Trumble”

Katherine Trumble
Tinton Falls, NJ

I have dealt with knee pain for eight years and finally decided to take the necessary measures to live a pain-free life. I came to HSS with hopes of being able to run, Irish-dance, take yoga, and have zero pain in daily activities. I have been active in various team sports throughout the years, but the pain increased when I… Read more “Sarah Perry”

Sarah Perry
Staten Island, NY

When I was in 7th grade I dislocated my knee cap for the very first time. It wasn’t until I was in 8th grade when it dislocated again and my parents and I knew something was wrong with my knees. I didn’t go to HSS right away because we didn’t know if it would be that serious. We just went… Read more “Ava Harrison”

Ava Harrison Westfield, NJ
Westfield, NJ

I am 27 years old. A few years ago my knee cap was on the left side of my knee and half of my cartilage was gone on the right side of my knee. So my doctor down here told me he could not do it and he sent me up to HSS see Dr. Shubin Stein. She looked at… Read more “Laura Carhart”

Laura Carhart
Redbank, NJ

My left kneecap started dislocating and subluxating in early adolescence, when I was playing soccer and basketball regularly and also growing tall rather quickly (I wound up close to 5’8). Over the next 15 years, the condition was a constant in my life–I lived with the pain when my kneecap popped out of place a couple of times each year.… Read more “Seyward Darby”

Seyward Darby
Brooklyn, NY



Patellofemoral Instability is when the kneecap (patella) either slips partially out of the track of the joint—this is called subluxation—or is completely dislocated. When this happens, the knee snaps outward, causing the MPFL (medial patellofemoral ligament) to tear or stretch. This usually occurs when playing a sport, and results in the buckling of the knee, followed by a fall. 

The Medial Patellofemoral Ligament (MPFL) is: The ligament that attaches the inside part of the kneecap (or patella) to the long bone of the thigh, also called the femur.

People at risk for subluxation and dislocation include:

  • Athletes who experience a traumatic dislocation while competing
  • Young patients (commonly females) who are loose jointed

 The risk factors of Patellofemoral Instability are:

  • A shallow (or absent) groove on the trochlea or femur
  • An abnormal lateral attachment of the patellar tendon on the tibia (shin)
  • Knock knees
  • High riding kneecap

 Signs of dislocation include:

  • Significant swelling of the knee
  • An “apprehension sign," or anxious response to the doctor pushing the patella outward  in an attempt to mimic the dislocation

 Having an MRI after a kneecap dislocation reveals damage to the ligament (the MPFL), as well as bruises on inside of the patella, and on the outside of the femur. The MRI also helps your doctor evaluate the knee for evidence of cartilage injury, which is common after dislocations.

Treatments for Patellar Instability

Non-Surgical Treatment

If your injury doesn't require surgery, your knee will usually be placed in a brace for a few days to several weeks to allow any swelling and pain to subside. Your orthopedist may also drain fluid from the knee to reduce discomfort if there is considerable swelling.

Physical therapy is started within the first 1 to 2 weeks after the dislocation. Your sessions will generally continue for 2 to 3 months after a dislocation, and recovery can take as long as 4 to 5 months.

After your first dislocated kneecap, you have an increased risk of it happening again.  Although the injured ligaments do heal during recovery, they usually do so in a stretched-out state, further contributing to the risk of another instability episode.

Surgical Treatments

News & Research

Surgical FAQs