The patient presented with pain in the left knee and a palpable tender bony lump over the proximal medial tibial border. She was an enthusiastic amateur athlete and had had intermittent pain over at least several months.
The patient presented with pain in the left knee and a palpable tender bony lump over the proximal medial tibial border. She was an enthusiastic amateur athlete and had had intermittent pain over at least several months.
Left knee lateral and frontal radiographs were performed. The AP knee radiograph showed a smooth ossification at the tibial insertion of left tibial collateral ligament (TCL) with increased conspicuity of the ligament suggesting early calcification.
These appearances are thought to be due to low-grade trauma to the tibial collateral ligament and its insertion (1). Such ossification at tendon insertion sites (enthesophyte formation) is common. Around the knee they are more common in patients involved in energetic sports such as skating, football and skiing. In the majority of cases appearances are an incidental finding. Management of acute symptoms is conservative with rest to the joint, systemic non-steroidal anti-inflammatory drugs, local anaesthetic/steroid joint injections and gentle leg exercises(2).
Various theories have been postulated but the accepted theory is of deposition of hydroxypatite or calcium pyrophosphate dihydrate crystal in the ligament and local periosteal proliferation of osteoblasts and osteoclasts as a result of trauma. Men are affected more than women are, as they are more likely to sustain trauma during work or activities and typically present between the ages of 25 and 40 years. There may be antecedent history of trauma to the affected knee either as a single episode or repeated micro trauma. The radiographic signs take at least three weeks after the initial injury (2).
Calcification or ossification of TCL was first noted as a radiographic finding by Kohler in 1903. Pellegrini described clinical findings in 1905 and Stieda presented a series of cases in 1907. The Pelligrini-Stieda sign applies to calcification or ossification locally at the origin of the ligament adjacent to the medial femoral condyle. Depending on the degree of involvement, it can be cresentic, fusiform or triangular(2). Treatment by surgical excision for relief of symptoms is reported (3). This is not the appearance of this case.
Tibial collateral ligament insertion ossification
Based on the provided X-ray images and the patient's clinical presentation of the left knee, a localized, irregular calcification or small patchy bony overgrowth can be observed at the medial margin of the proximal tibia (suspected at the attachment site of the tibial collateral ligament). The surrounding soft tissue appears generally intact, without obvious structural destruction or extensive signs of fracture. There is no significant narrowing of the knee joint space, and the articular surfaces remain relatively regular.
In this case, the patient is relatively young, engages in sports frequently, and presents with localized pain and a palpable tender mass on the medial side of the tibia, suggesting repeated pulling or stress at the ligament or tendon periosteum. These findings are most consistent with enthesopathy or calcific changes in the ligament insertion.
Considering the patient's age, symptoms, long-term sports history, and radiographic findings of localized calcification/ossification at the medial tibial attachment point, the most likely diagnosis is:
Calcification or ossification at the Tibial Collateral Ligament Insertion (Enthesopathy), related to repetitive minor trauma and sports activities.
If there is any remaining doubt, an MRI can be performed to assess soft tissues and ligament integrity. Other differential diagnoses could be considered if clinical symptoms persist or worsen.
Based on this diagnosis, the primary goals of treatment and rehabilitation are to reduce inflammation, alleviate pain, and minimize the risk of re-injury. Specific approaches may include:
Surgery is considered only if conservative treatment fails, pain is persistent, or if there is significant associated structural damage. In young patients with a small area of involvement and tolerable pain, surgery is usually unnecessary.
Throughout the rehabilitation process, it is critical to avoid repetitive excessive traction and secondary injuries. If any exercise causes significant pain, it should be stopped, and the treatment plan should be adjusted under the guidance of a professional physician or rehabilitation therapist.
This report is a reference-based medical analysis derived from the provided information and does not replace in-person consultation or expert medical advice. If you have any questions or experience worsening symptoms, please seek medical attention at a qualified healthcare facility.
Tibial collateral ligament insertion ossification
