A Seoul National University Bundang Hospital (SNUBH) research team has found that pediatric patients with sessile osteochondroma have a higher risk of having lower extremity deformities.

Osteochondroma, a benign tumor characterized by an outgrowth of bone covered by cartilage, is the most common type of bone tumor. While typically not life-threatening, complications can arise as the tumor grows, potentially causing bone deformities or nerve compression.

Early diagnosis and treatment are therefore essential, particularly in pediatric and adolescent patients where the tumor often occurs near the growth plates, especially around the knee.

Osteochondroma can occur either as a solitary tumor, known as solitary osteochondroma, or as multiple growths, termed multiple osteochondromas, the latter being a genetic condition.

While research on limb deformities in cases of multiple osteochondromas is well-established, few studies have focused on deformities caused by solitary osteochondroma.

As a result, the team, led by Professor Sung Ki-hyuk and Doctor Oh Seung-tak of the Department of Orthopedic Surgery, conducted a study aimed to assess the occurrence and risk factors of limb deformities in pediatric patients with solitary osteochondroma around the knee.

The study analyzed 83 patients, finding that 9.6 percent (eight patients) developed limb deformities, including leg length discrepancy (three patients), bowleg (two patients), knock-knee (two patients), or a combination of these deformities (three patients).

Notably, all eight patients who developed deformities were found to have sessile osteochondromas, which are characterized by a broad, flat base without a stalk. Sessile osteochondromas were associated with a 24-fold higher risk of causing deformities compared to pedunculated osteochondromas, which have a stalk-like structure.

Additional factors such as the patient’s age, gender, tumor location, or the distance between the tumor and the growth plate did not show significant correlations with the development of limb deformities.

"Although osteochondroma is the most common benign bone tumor, it is often underestimated when it comes to the potential for causing leg deformities,” Professor Sung said. “Surgical excision is frequently performed for reasons such as pain or cosmetic concerns, but attention to leg alignment, especially in patients with sessile osteochondroma, is crucial.”

The Journal of Orthopaedic Surgery and Research published the results of the study.