Bipartite Patella: Causes, Symptoms, Types & Treatment

What Is Bipartite Patella?

Bipartite patella

Bipartite patella is an asymptomatic condition, wherein the patella comes out as two separate bones incidental findings. Patella, the largest sesamoid bone in the body, is present in front of the knee. This condition is the result of congenital fragmentation of patella. Although, it is normal for patella to get combined in early days of childhood, but sometimes it remains separated.

Though bipartite patella not a cause of serious problem or complications, research shows that it occurs in 2-6% of population but remains unobserved and unnoticed. It is synchondrosis of patella and extremely small percentage i.e. 10% results in pain. Bipartite patella is reported to occur in children and young men, who are actively participate in high intensity sports. Even adults involved in strenuous sports rarely complain about bipartite patella.

The synhondrosis, fibrous and soft tissues that connect the two separate bones gets inflamed due to direct trauma or injury resulting in knee pain. The bipartite patella occurs mainly in boys when compared to girls and the ratio is 9=1.

Types of Bipartite Patella:

Bipartite patella is classified into three types.

  • Type I: Inferior pole caused in 5% of all cases.
  • Type I: Lateral margin caused in 20% of all cases.
  • Type III: Superlateral pole caused in 75% of all cases.

What are the Symptoms of Bipartite Patella?

In many cases, there are no symptoms. However, if it is irritated, the following symptoms can arises on the point of injury:

  • Anterior knee pain
  • Inflammation
  • Localized pain
  • Percussion of two separate bones i.e.patella and bipartite patella.
  • Bony bump.
  • Knee giving away sensation.
  • Dull ache and swelling on synchondrosis.
  • Painful range of motion.

What are the Causes of Bipartite Patella?

Since bipartite patella is asymptomatic and remains unobserved, some factors might trigger the pain and inflammation. They are:

  • Direct blow to the kneecap
  • Awkward falling or landing from jump.
  • Strenuous sports activity.
  • Overuse injury.
  • Minor trauma.
  • Repetitive minor injuries while biking or hill climbing.
  • Increase in traction force on patella by vastus lateralis muscle, which is largest part of the quadriceps femoris.Bipartite patella xray

Diagnosis of Bipartite Patella:

Many times, doctors conduct X-ray for some other conditions and end up finding bipartite patella on X-rays. The term used for this findings is “incidental findings.” MRI and Bone scan can also be conducted for better diagnosis to check whether there are any other complications. CT scan is also conducted but MRI clearly shows any problem with sift tissues or bone marrow.

Treatment of Bipartite Patella:

No treatment is required for bipartite patella because it is remains unnoticed and feels no pain. However, it will cause pain due to direct trauma or injury. Some of the treatments are:

  • Rest: This is very important if you are going through non-surgical route to heal bipartite patella. It will allow the pain to settle down naturally. Otherwise, pain and inflammation will increase at the point of injury. Avoid aggravating activities like jumping, running, deep squatting, climbing stairs. Even stay away from skiing and ice skating. If there is separation of synchondrosis, then doctors advise to take rest for 6 months for complete recovery. Activity modification is also necessary during rest. Restrict or stop immediately, any activity that could cause pain.knee immobilization
  • Immobilization: Immobilization of knee is useful in preventing unnatural and unwanted movements during rest, which could cause further injury or damage to the knee. They will provide stability and support to the knee.
  • Knee braces: Dynamic patellar braces are also beneficial and effective in guiding patella properly in range of motion.  The dynamic brace helps the knee to an extended position up to 30 degrees.
  • NSAIDs: Over-the-counter medications like ibuprofen reduces inflammation and pain.
  • Combined therapy: Physical therapist uses combined therapy of ultrasound and interferential current for alleviating pain and swelling. It is also called as electrotherapy.
  • Physical Therapy: Physical therapy is crucial part of bipartite patella treatment. Once the symptoms subsides, gentle stretching exercises like quadriceps and hip flexors are also performed. It is very important to strengthen the surrounding muscles like thigh, buttocks, calf and tensor fascia latae. Consult your physical therapist before starting any stretching and strengthening exercises on your own. Isometric stretching exercises of quadriceps is also effective.
  • Surgery: If there is persistent pain and inflammation, then doctors may advise surgery. Some of the possible surgeries are open excision of the accessory fragment, lateral retinacular release, vastus lateralis release and ORIF. Open excision is one of the most common treatment for bipartite patella.

Recovery Period for Bipartite Patella:

Patients will get relieved from pain once the bipartite patella is removed with surgery. The recovery depends on the types of conditions and treatment methods used to heal them. However, open excision surgery requires 6 months for complete recovery. In some other cases, it will heal in 2-3 months and patients will return to sporting activities.

Conclusion – Bipartite Patella:

The outlook is good and patients are able to return their normal activities once it gets healed properly. Patients will have a stable knee and full range of motion. Proprioceptive exercises are useful in the long-term for restoring normal knee function and preventing any further injury.