What is Pellegrini-Stieda Disease?
Pellegrini-Stieda lesions are a medical condition named after two surgeons from the early 20th century, Augusto Pellegrini from Italy and Alfred Stieda from Germany. This condition is defined by the process of bone formation in a ligament known as the medial collateral ligament (MCL), particularly where it attaches to a part of the thigh bone known as the medial femoral condyle. Even though Pellegrini and Stieda are credited with identifying this condition, the first description was actually given by a person named Köhler in 1903, which was before Pellegrini and Stieda’s work was published.
When we talk about Pellegrini-Stieda Disease, or Pellegrini-Stieda Syndrome, we’re referring to a situation where a person has the aforementioned bone growth showing on x-rays, along with pain in the inner part of the knee or a limited ability to move the knee. The symptoms of this condition can help doctors provide an accurate diagnosis and appropriate treatment.
What Causes Pellegrini-Stieda Disease?
Pellegrini-Stieda disease is believed to be caused by an injury to the inside knee ligament, leading to damage and immediate inflammation that initiates a delayed bone formation process. This injury is typically seen as a severe trauma causing sideways stress resulting in tearing of the MCL ligament fibers. When first identified by Kohler in 1903, this bone formation was particularly linked to sports activities.
However, some reports from physical medicine and rehabilitation specialists have suggested that continuous tiny injuries from therapeutic knee movements or post-surgery rehabilitation could also be possible causes of Pellegrini-Stieda disease. These causes could lead to the onset of new inside knee pain, swelling, or limited movement in a patient who is actively going through rehabilitation.
In some instances, Pellegrini-Stieda disease has been seen in patients who haven’t had any knee trauma. Instead, these are patients who have experienced a serious spinal cord injury or traumatic brain injury. This abnormal bone development can be challenging to distinguish from other conditions such as heterotopic ossification, which is the process of bone growth in areas where it’s not usually found, and myositis ossificans, a condition where bone tissue forms inside muscle or other soft tissue after an injury. These conditions have a higher occurrence rate among these patients.
Risk Factors and Frequency for Pellegrini-Stieda Disease
The exact number of Pellegrini Stieda cases is not known. However, a study done over seven years by a team from The University of Colorado and The University of Alabama at Birmingham found the term “Pellegrini Stieda” in the knee X-ray reports of 332 patients. This condition usually affects males, particularly those aged between twenty-five and forty years.
Signs and Symptoms of Pellegrini-Stieda Disease
Pellegrini-Stieda Disease usually shows up in a certain way in a medical setting. Here’s a typical example: imagine a 30-year-old man who comes in with a history of having a knee-to-knee collision on the right side during a casual soccer game three weeks ago. After the accident, he had a sharp pain that went away with rest and a cold compress. But now, he’s experiencing new pain on the inside of his right knee and finds it harder to move his knee as freely as before.
Testing for Pellegrini-Stieda Disease
Diagnosing Pellegrini-Stieda syndrome usually involves the use of plain X-rays, which are simple images created by radiation passing through the body. Doctors look for a specific sign on the X-ray image called the Pellegrini-Stieda sign. This sign is a line of density (or opacity) that appears in the soft tissue positioned towards the inner portion of the curved protuberance at the end of the femur, the large bone in your thigh, known as the medial femoral condyle. This density is due to an abnormal hardening or formation of bone within a soft tissue, typically a ligament, in this case, the medial collateral ligament, which gives stability to the inner side of your knee. This abnormal hardening usually occurs about three weeks after the initial injury that caused it.
It’s important that doctors distinguish the Pellegrini-Stieda sign from a similar-looking condition known as a medial femoral condyle avulsion fracture. This is a type of injury where a ligament or tendon yanks a piece of bone away where the ligament or tendon attaches to the bone.
Doctors may also use magnetic resonance imaging (MRI), which gives highly detailed images of the body’s interior structures. On an MRI, the site of the injury at the medial femoral condyle will typically show changes indicating an enthesophyte – this refers to a bony outgrowth at the attachment of a ligament or tendon. In Pellegrini-Stieda syndrome, this happens in the medial collateral ligament, which will appear thickened in the MRI.
Musculoskeletal ultrasound, which uses sound waves to create images of muscles, tendons, ligaments and joints, can also be useful for diagnosing Pellegrini-Stieda syndrome. It can not only spot the Pellegrini-Stieda lesions but can also often show associated swelling or excess fluid (edema) near the area.
Treatment Options for Pellegrini-Stieda Disease
The symptoms of this condition usually last around five to six months as the area hardens or turns to bone. The intensity of the problem will steer the course of treatment. For mild and moderate cases, they’re generally treated with a ‘take it easy’ approach. This could involve anti-inflammatory medications, steroid injections to reduce inflammation and pain, and exercises to maintain joint flexibility.
However, when the condition is severe and doesn’t respond to these methods, surgery may be performed to remove calcified deposits in the medial collateral ligament, a band of tissue on the inner side of the knee. Take note that surgical outcomes can vary. For instance, one study found a high rate of recurrence, while updated research reported more successful results. There’s also a warning from surgical studies; If a large hardened area is removed, it could lead to issues with your ligaments, which might require further surgical repair.
What else can Pellegrini-Stieda Disease be?
When diagnosing knee problems, especially near the inner (medial) side of the knee, healthcare professionals may consider ruling out the following conditions:
- Pellegrini-Stieda Disease
- Medial collateral ligament sprain
- Medial meniscal tear
- Medial femoral condyle avulsion fracture
- Myositis ossificans (muscle inflammation that leads to bone-like formation within the muscle)
- Heterotopic ossification (abnormal bone growth in non-bone tissues)
- Knee osteoarthritis
- Semimembranosus/semitendinosus tendinitis (inflammation of the tendons of specific muscles in the back of the thigh)
Each of these conditions can cause similar symptoms in the knee, so it’s essential for a doctor to carefully evaluate the patient’s condition and possibly perform diagnostic tests to pinpoint the exact cause of their knee pain.
What to expect with Pellegrini-Stieda Disease
Pellegrini-Stieda Disease usually gets better within five to six months with straightforward treatments. These treatments include non-steroidal anti-inflammatories (drugs that reduce pain and inflammation), corticosteroid injections (shots that decrease inflammation), and range-of-motion exercises (physical activities that improve joint flexibility). However, some severe cases don’t improve with these treatments and may need surgery.
Possible Complications When Diagnosed with Pellegrini-Stieda Disease
If Pellegrini-Stieda Disease isn’t treated, it could lead to less flexibility and tightness in the knee joint. This can cause changes in how you walk, difficulties in performing daily activities, and constant pain. Some research indicates that surgery may not always work well, with high chances of the disease coming back. If large lesions are removed during surgery, it could lead to damage in the ligaments, which would then require additional surgery to fix.
Possible complications from untreated Pellegrini-Stieda Disease:
- Restricted flexibility in the knee joint
- Tightness in the knee joint
- Changes in walking pattern
- Difficulty in daily activities
- Constant pain
- High chances of disease recurrence after surgery
- Possibility of ligament damage with large lesion removal during surgery
- Possible need for additional surgery due to ligament damage
Recovery from Pellegrini-Stieda Disease
The standard treatment for most patients includes a rehabilitation program that involves exercises to stretch and move the knee joint and the medial collateral ligament, which is a band of tissue that helps connect your thigh bone to your shin bone at the knee. It’s essential for therapists to customize this program to prevent contracture, which is abnormal shortening or distortion of muscular or connective tissue mainly due to the medial collateral ligament becoming hard from calcification – a process where tissues harden because of calcium buildup.
Preventing Pellegrini-Stieda Disease
Patients are generally advised to keep up with their stretching routines and exercises even after they finish their physical therapy treatments. It’s crucial to avoid being inactive for long periods or keeping your joints still for too long. If you’re in pain, it’s okay to limit manual labor and exercise to less strenuous activities. However, completely stopping all physical activity isn’t the right approach. Also, you don’t need to worry about any restrictions related to bearing weight in regards to this particular condition.
