Six months ago, Tuan experienced sharp pain in his right heel and joint stiffness after prolonged lying or sitting. He needed a few minutes of ankle rotation to regain mobility. As an amateur marathon runner, he reduced training and underwent medical treatment and physical therapy, which provided some relief. However, the pain recurred when he increased his running distance.

Doctor Nguyen Quang Ton Quyen, Deputy Head of the Department of Orthopedics and Traumatology at Tam Anh General Hospital Hanoi, stated that Tuan's right heel contained a small accessory bone called Os Trigonum. This caused posterior ankle impingement syndrome. Os Trigonum is a small congenital accessory bone located in the heel, behind the talus bone, found in only a small percentage of the population. This excess bone has no function, similar to the appendix, and typically causes no symptoms.

Individuals who frequently use their heels, such as marathon runners, soccer players, and ballet dancers, may experience pain when the accessory bone continuously rubs against the tendons and joint capsule at the back of the ankle. This leads to impingement and compression in the talocalcaneal space.

Excess bone (bone spur) in Tuan's heel (left) after endoscopic removal (right). Photo: Tam Anh General Hospital

To completely resolve the condition and enable Tuan to return to sports, Doctor Quyen prescribed endoscopic surgery. During the 30-minute procedure, Tuan received spinal anesthesia. The doctor made two small incisions behind the heel, inserted endoscopic instruments to debride inflamed tissue, and removed the bone spur.

The minimally invasive surgery did not significantly impact Tuan's physical condition. He wore an ankle brace for the initial two weeks and walked gently. A physical therapist guided him through a specialized sports medicine rehabilitation protocol to prevent muscle atrophy and muscle imbalance in one leg during the period of reduced activity.

After one month, Tuan walked normally. He resumed running after three months without experiencing heel pain, and the muscle strength in both legs showed no significant difference. He continued specialized rehabilitation to fully restore his performance and running achievements.

A physical therapist measures Tuan's leg muscle strength using specialized equipment. Photo: Tam Anh General Hospital

Doctor Quyen noted that posterior ankle impingement syndrome, caused by the accessory Os Trigonum bone, is often mistaken for other heel inflammatory conditions like Achilles tendinitis. It is less common, making it easily overlooked without thorough examination. In older individuals, this condition is often associated with ankle joint degeneration, tendons, and joint capsules, causing dull pain and chronic inflammation. For younger individuals, excessive ankle joint activity leading to repetitive microtrauma is the primary cause of Os Trigonum syndrome.

Depending on activity levels, doctors prescribe individualized treatment methods for patients. These include conservative treatment with medication, physical therapy, or surgery when other methods fail. Athletes with high, competitive activity needs require a specialized protocol, combining physical therapy and intensive sports rehabilitation after surgery.

Doctor Quyen recommends that if prolonged posterior ankle pain occurs, increasing with extensive running, tiptoeing, full ankle flexion, or ascending/descending slopes or stairs, runners should rest and visit a specialized sports medicine hospital for effective examination and treatment.

Thanh Long