Medial collateral ligament tears cause pain and swelling on the inside of the knee. Most MCL injuries settle with a period of bracing and rehab. But sometimes the healing is complicated by calcification of the MCL — known as a Pellegrini-Stieda lesion, or Pellegrini-Stieda syndrome. So what is it, and how do we treat it?
A Pellegrini-Stieda lesion is a complication of an MCL injury — see that page for the underlying ligament tear.
What is a Pellegrini-Stieda lesion?
A Pellegrini-Stieda lesion is a calcium deposit at the top part of the medial collateral ligament, where it attaches to the thigh bone. The calcification causes pain and stiffness in knee movement. These lesions are most common in men aged 25–40, and typically form weeks after a knee injury.
What causes a Pellegrini-Stieda lesion?
It usually forms after an acute injury to the medial collateral ligament. When the ligament tears, it bleeds and swells. Instead of healing normally, the body deposits calcium in the damaged ligament. Calcium forms within 2–4 weeks of the injury and may take up to 6 months to disappear. Rarely, the condition occurs spontaneously without a history of injury.
Symptoms of Pellegrini-Stieda syndrome
People usually describe a previous injury to the inside of the knee. Symptoms often improve at first, only to worsen after 2–4 weeks, with increasing medial knee pain and restricted movement. Some people can’t fully straighten the knee, and pressing the top part of the MCL is painful.
It’s essential to exclude other causes of inner knee pain, including knee arthritis, an avulsion fracture of the medial femoral epicondyle, semimembranosus tendonitis, and myositis ossificans.
How do we diagnose a Pellegrini-Stieda lesion?
An X-ray usually confirms the diagnosis, showing calcification at the top part of the MCL — the deposits become visible about three weeks after the injury. Calcium can also be seen clearly on ultrasound, but is less obvious on MRI.
Treatment of a Pellegrini-Stieda lesion
Most cases settle with conservative management.
Simple treatment
We use oral anti-inflammatories to reduce pain and swelling, along with rest from sport and range-of-motion exercises to speed recovery. Useful knee mobility exercises include heel slides, seated knee bends, and seated chair slides.
Ultrasound-guided injection
Stubborn cases may need an ultrasound-guided injection. We direct a needle under ultrasound to break up the calcification into smaller pieces, helping the body resorb the calcium — a procedure also called calcium barbotage. A cortisone injection around the calcification can further aid recovery. This needs a doctor experienced in ultrasound-guided interventions.
Surgery
We reserve surgery for cases that fail conservative treatment, excising the calcification while preserving as much normal ligament as possible. Surgical results are unpredictable at best — recent studies show a high recurrence rate, or laxity from removing too much of the medial ligament — so it’s a last resort.
Frequently asked questions about a Pellegrini-Stieda lesion
How long does a Pellegrini-Stieda lesion take to resolve?
Calcium forms within 2–4 weeks of the injury and can take up to 6 months to disappear. Most people improve with anti-inflammatories, ice, and rehab well before the calcium fully resorbs.
Why does my knee pain get worse a few weeks after the original injury?
That delayed worsening is characteristic. The MCL injury initially settles, then calcification forms at 2–4 weeks, bringing a second wave of medial knee pain and stiffness. It’s a useful clue to the diagnosis.
Do I need surgery for a Pellegrini-Stieda lesion?
Rarely. Most settle with anti-inflammatories, rehab, and — if stubborn — an ultrasound-guided barbotage and cortisone injection. Surgery is reserved for cases that fail all of this, and its results are unpredictable.
Can a Pellegrini-Stieda lesion form without an injury?
Usually, it follows an MCL injury, but rarely it appears spontaneously with no clear history of trauma. Imaging confirms the calcification either way.
Is a Pellegrini-Stieda lesion the same as myositis ossificans?
They’re related but different. Both involve abnormal calcium or bone formation in soft tissue after trauma. Still, a Pellegrini-Stieda lesion is specifically at the MCL’s femoral attachment, whereas myositis ossificans forms within a muscle (commonly the thigh).
Final word from Sport Doctor London about the Pellegrini-Stieda lesion
A Pellegrini-Stieda lesion is a calcification of the MCL after trauma, causing inner knee pain and restricted movement. Most cases settle with simple treatments such as ice, anti-inflammatories, and rehab, with an ultrasound-guided injection reserved for stubborn cases and surgery as a last resort.
To book a knee assessment with Dr Masci in London, contact the team here or call +44 (0) 203 488 0350.
I have been diagnosed with PSS while on holiday in Cyprus.
Following a course of anti inflammatory meds and a cortisone injection I was let out of hospital, but the pain has returned.
I ca barely bend my knee and I am treating with ice and rest?
I am due to fly next week – should I try?
Thank you.
Anti-inflammatory treatment should help. I’d continue with oral inflammatories and regular ice.