Sports injuries frequently involve joints, ligaments, tendons, and cartilage. While clinical examination is important, MRI is the gold standard for evaluating soft tissue and bone marrow injuries in athletes. It helps guide management, return-to-play decisions, and surgical planning.
📌 Why MRI in Sports Injuries?
- Non-invasive & radiation-free imaging.
- High sensitivity for ligament, tendon, cartilage, and meniscal tears.
- Detects bone marrow edema, stress fractures, and occult injuries.
- Provides multiplanar views of complex anatomy.
🦵 MRI in Knee Sports Injuries
The knee is the most commonly injured joint in sports.
1. Ligament Injuries
- ACL (Anterior Cruciate Ligament):
- Most common sports ligament injury.
- Findings: Fiber discontinuity, abnormal course, bone bruise in lateral femoral condyle & tibial plateau (“kissing contusion”).
- PCL (Posterior Cruciate Ligament): Thicker than ACL; tears often post-traumatic dashboard injuries.
- Collateral Ligaments (MCL/LCL):
- MCL injuries are frequent in contact sports.
- MRI: Thickening, high signal on T2, adjacent soft-tissue edema.
2. Meniscal Injuries
- Horizontal, vertical, bucket-handle tears (double PCL sign).
- MRI grading:
- Grade 1–2 → Intrasubstance signal not reaching articular surface.
- Grade 3 → Signal extending to surface (true tear).
3. Cartilage Injuries
- Chondral defects, osteochondral lesions, chondromalacia patellae.
- MRI can map cartilage thickness and surface irregularity.
4. Bone/Other
- Bone marrow contusions, stress fractures.
- Popliteal cysts, bursitis.
💪 MRI in Elbow Sports Injuries
The elbow is prone to throwing, racquet, and weightlifting injuries.
1. Ligament Injuries
- Ulnar Collateral Ligament (UCL):
- Critical in baseball pitchers.
- MRI: Thickening, increased T2 signal, partial/full-thickness tear.
- Lateral Collateral Ligament Complex: Less common; causes posterolateral rotatory instability.
2. Tendon Injuries
- Common extensor tendon (lateral epicondylitis – “Tennis Elbow”):
- Tendinosis: thickened tendon, increased signal.
- Partial tears: focal fiber discontinuity.
- Common flexor tendon (medial epicondylitis – “Golfer’s Elbow”).
3. Osteochondral Lesions
- Capitellar osteochondritis dissecans in young athletes.
- MRI: Subchondral bone changes, cartilage defect, loose bodies.
4. Other Findings
- Stress fractures, joint effusions, bursitis.
📌 Teaching Pearls
- Knee → ACL rupture with bone bruise is the most classic sports MRI finding.
- Elbow → UCL tear is hallmark of throwing athletes.
- MRI is superior for early detection of subtle cartilage and tendon pathology.
🧾 MRI in Sports Injuries: Knee vs Elbow
| Feature | Knee Sports Injuries | Elbow Sports Injuries |
|---|---|---|
| Most Common Ligament Injury | ACL tear (non-contact pivoting, football, basketball) | UCL tear (throwing athletes, baseball pitchers) |
| Other Ligaments | PCL (dashboard, contact sports), MCL/LCL sprains | Lateral collateral ligament (posterolateral instability, less common) |
| Meniscus / Labrum | Medial > lateral meniscus tear; bucket-handle tear → “double PCL sign” | No meniscus, but valgus stress injuries can affect joint capsule |
| Cartilage / Osteochondral | Chondral defects, osteochondritis dissecans (femoral condyle, patella) | Capitellar osteochondritis dissecans (young athletes, pitchers, gymnasts) |
| Tendon Pathology | Quadriceps/patellar tendinosis, hamstring injuries | Lateral epicondylitis (“Tennis Elbow”), medial epicondylitis (“Golfer’s Elbow”) |
| Bone Changes | Bone marrow edema, contusions (“kissing contusion” with ACL tears), stress fractures | Stress fractures of olecranon, subchondral bone marrow changes |
| Classic MRI Signs | – ACL tear + lateral femoral condyle/tibial plateau bone bruise |
- “Double PCL sign” in bucket-handle tear | – High T2 signal + thickened UCL
- Tendinosis/tear at common extensor origin (tennis elbow) |
| Clinical Relevance | Crucial for return-to-play decisions in pivot sports | Guides surgical vs conservative management in throwing athletes |
