presented with a three-month history of pain in the left groin, aggravating during exercise. On physical examination there was localized tenderness at the left side of the symphysis pubis. No soft tissue swelling or skin discoloration was noted. Routine blood analysis revealed no elevation of inflammatory parameters.
A soccer player presented with a three-month history of pain in the left groin, aggravating during exercise. On physical examination there was localized tenderness at the left side of the symphysis pubis. No soft tissue swelling or skin discoloration was noted. Routine blood analysis revealed no elevation of inflammatory parameters.
Plain radiograph of the symphysis pubis shows an osteolytic lesion with unsharp and irregular borders on the medial and inferior aspect of the left pubis. Part of the lesion is delineated by a sclerotic rim. Bone scintigraphy of the pelvis demonstrates a marked tracer uptake at the left pubis with extension to the inferior pubic ramus.
Coronal SE T1-weighted MR image of the pelvis shows decreased signal intensity of the bone marrow at the left pubic bone (arrow), compared to the contralateral side.
On axial turbo SE T2-weighted MR image of the pelvis the lesion presents as a focal area of increased signal intensity (arrow). No associated soft tissue mass is seen.
Based upon the clinical history and imaging findings, the differential diagnosis includes a tumor or tumor-like condition, osteomyelitis, and chronic avulsive injury. Biopsy showed normal hyalin cartilage and reactive bony sclerosis, as seen with chronic avulsive injury.
Chronic avulsive injury is a painful condition which results from chronic muscle overuse and repetitive microtrauma at the musculotendinous insertion at the apophysis in young patients. Indeed, in the immature skeleton the weakest link in the musculotendinous unit is the apophysis. Apophyses are traction epiphyses that act as the origins or insertions of muscles and tendons.
The apophyses of the pelvis are common sites of acute and chronic avulsive injury. In this case, overuse of the gracilis, adductor longus and adductor brevis muscles results in chronic avulsive injury at the symphysis pubis. This is known as the gracilis-adductor syndrome.
It has been reported in young athletes, especially soccer players. Kicking a soccer ball with the leg externally rotated, results in forceful adduction and violent flexion of the hip. Acute avulsions demonstrate a separation of the apophysis from the underlying bone, while the repeated microtrauma in chronic avulsive injuries gives rise to bony lysis and reactive sclerosis. However, due to the repetitive character of the injury, the bony lysis predominates over the reparative sclerosis. The ability of tissue repair is out-paced by recurring injury.
The resulting radiographical image may be very confusing and simulate a motheaten pattern as seen with Ewing’s sarcoma or other aggressive lesions. The combination of osteolysis and sclerosis may even be misinterpreted as osteomyelitis. Because of the radiological resemblance of the lesion with osteomyelitis, the gracilis-adductor syndrome has been called traumatic osteitis pubis.
Correct diagnosis is established by confrontation of the typical clinical history (chronic adductor muscle overuse), the age of the patient (location at the apophysis), and the radiological findings.
The MR imaging features include a pattern of bone marrow edema within the pubic bone, that may extend in the medial and inferior aspect of the pubic ramus, causing a low signal intensity on the T1-weighted and a high signal intensity on the T2-weighted images. Sacral stress fractures or sacroiliac joint degeneration are seen in association with the gracilis-adductor syndrome, as abnormal stress maybe transmitted across the pelvic ring.
Chronic avulsive injury of the hip
1. X-ray Imaging: Focal bone destruction and reactive sclerosis are observed near the left side of the pubic symphysis, presenting a “moth-eaten” appearance. The continuity of the local cortical bone remains generally intact.
2. Bone Scan: Increased radiotracer uptake is observed at and around the left side of the pubic symphysis, indicating increased local bone activity and abnormal metabolism.
3. MRI: Marked bone marrow edema signals can be seen in the medial and inferior region of the pubic ramus, presenting as low signal on T1-weighted sequences and high signal on T2/STIR sequences. Abnormal signals are also noted at the tendon attachment sites, suggesting an inflammatory or reparative response due to chronic traction injury.
Based on the patient's age (14 years old), sports history (soccer), clinical symptoms (local pain, worsened with activity), and imaging findings of coexisting bone destruction and repair, bone marrow edema, and traction at the attachment points, the most consistent diagnosis is Chronic Avulsion Injury (Gracilis-Adductor Syndrome, also known as “Traumatic Osteitis Pubis”).
(1) Frequency: Begin with 3–4 sessions per week, 20–30 minutes each of low-intensity rehabilitative exercises. Increase to 4–5 times per week as tolerated.
(2) Intensity: Start with very low to low-intensity activities (e.g., gentle walking on flat surfaces, basic stretching). Once local pain and tenderness improve significantly, gradually introduce muscle strengthening exercises (e.g., resistance training with body weight or resistance bands).
(3) Time: Initially, each session can last 20–30 minutes and be divided into multiple segments. As pain and fatigue subside, extend to 30–45 minutes per session.
(4) Type: Emphasize stretching, joint mobility, and stability exercises. Core strengthening (e.g., bridge exercises, planks) can be added. Later, gradually transition to low-impact aerobic activities (such as elliptical or swimming).
(5) Progression: After 2–3 weeks of consistent training with symptom relief and basic muscle strength regained, gradually reintroduce some sport-specific drills (e.g., light soccer practice), but continue to avoid intense kicking. Adjust training content and intensity according to pain levels to prevent reinjury.
In cases of bone fragility or other underlying conditions, seek evaluation and guidance from healthcare professionals. Adjust the rehabilitation pace and training methods to ensure safety.
Disclaimer: This report is a reference-based analysis relying on the provided medical history and imaging data. It does not replace an in-person consultation or professional medical advice. If you have any concerns or if symptoms worsen, please seek timely care at a certified medical institution.
Chronic avulsive injury of the hip
