Sports Medicine Imaging

Imaging Modalities in Sports - Sporty Scan Snapshot

• X-ray:
  • First-line: fractures, dislocations, bony alignment.
  • Stress views: ligamentous instability.
  • Quick, accessible; poor soft tissue detail, radiation.
• Ultrasound (USG):
  • Dynamic imaging: tendons, ligaments, muscles, effusions.
  • Real-time, no radiation; guides interventions. Operator-dependent.
• CT Scan:
  • For: complex fractures, loose bodies, detailed bone anatomy.
  • CT arthrography: if MRI contraindicated for cartilage/labrum.
  • High radiation.
• MRI:
  • Choice for: internal derangements (ligaments, tendons, cartilage, menisci, bone marrow).
  • MR Arthrography: enhances intra-articular structures.
  • Superior soft tissue contrast; no radiation.

⭐ MRI is the modality of choice for most internal derangements of joints, offering superior soft tissue contrast.

Shoulder & Elbow Injuries - Overhead Overloads

• Shoulder:
  • Impingement: Subacromial bursitis, supraspinatus tendinopathy. MRI: bursal fluid, tendon signal ↑.
  • Rotator Cuff (RC) Tears: 📌 SITS. Supraspinatus common. Partial/full-thickness. MRI: fluid defect.
  • SLAP Lesions: Superior Labrum Anterior-Posterior tear (biceps anchor). MRI/MRA: labral high signal.
  • Internal Impingement: Articular RC tears (infraspinatus), posterior labral injury.
  • Little Leaguer's Shoulder: Proximal humeral epiphysiolysis (SH-I). X-ray/MRI: physeal widening.
• Elbow:
  • Epicondylitis: Medial (Golfer's - flexor), Lateral (Tennis - extensor). MRI: tendon thickening, ↑T2 signal.
  • UCL Injury: Valgus stress. MRI/MRA: thickening, tear. "T-sign" (MRA) for partial undersurface tear.
  • Little Leaguer's Elbow: Medial epicondyle apophysitis/avulsion; OCD capitellum.

⭐ A Bankart lesion, an injury to the anteroinferior glenoid labrum, is commonly associated with anterior shoulder dislocation.

Knee Injuries - Twists, Tears & Trauma

• Anterior Cruciate Ligament (ACL) Tear

  • Mechanism: Non-contact pivoting, valgus stress, hyperextension.
  • MRI: ↑ T2 signal, discontinuity, abnormal anterior tibial translation, abnormal ACL slope (sagittal).
  • Associated: "Kissing" bone bruises (lateral femoral condyle, posterior tibial plateau), Segond fracture.

  ⭐ A Segond fracture, an avulsion fracture of the lateral tibial condyle at the site of attachment of the lateral capsular ligament, is pathognomonic for an ACL tear.

• Meniscal Tears

  • Mechanism: Twisting injury on a flexed knee.
  • MRI: Abnormal signal extending to an articular surface (Grade 3 tear).
  • Types: Longitudinal, radial, horizontal, bucket-handle (📌 "double PCL sign" or "absent bow tie" sign), complex.

• Posterior Cruciate Ligament (PCL) Tear

  • Mechanism: Dashboard injury, fall onto flexed knee with plantarflexed foot.
  • MRI: ↑ T2 signal, discontinuity, posterior tibial sag.

• Collateral Ligament Tears

  • Medial Collateral Ligament (MCL): Valgus stress. MRI: Thickening, periligamentous edema, tear. Pellegrini-Stieda disease (chronic).
  • Lateral Collateral Ligament (LCL): Varus stress. Often associated with posterolateral corner (PLC) injuries.

Ankle, Foot & Stress Injuries - Landing Zone Lowdown

• Ankle:
  • Lateral Sprain (ATFL, inversion); Syndesmotic Sprain (high, external rotation).
    • Ottawa: X-ray for malleolar pain + tenderness OR no weight-bearing.
  • Maisonneuve Fracture: Prox. fibula # + medial injury.
  • Achilles: Tendinopathy (US); Rupture (Thompson, MRI/US).
• Foot:
  • Calcaneal #: Fall, ↓Bohler's (<20°). Talus #: Neck, AVN risk.
  • Navicular Stress #: "N" spot.
  • 5th MT #: Jones (Z2, non-union) vs. Pseudo (Z1).
  • Lisfranc Injury: Tarso-metatarsal disruption. Fleck sign.
  • Plantar Fasciitis: US: fascia >4mm.
• Stress Injuries:
  • Stress Fx Imaging: X-ray late; MRI early (edema).
    • Common Sites: Tibia, metatarsals (March #), navicular (high-risk).
  • Shin Splints (MTSS): Tibial periostitis.

⭐ MRI is the most sensitive imaging modality for the early detection of stress fractures, revealing bone marrow edema often before X-rays become positive.

High‑Yield Points - ⚡ Biggest Takeaways

• MRI is gold standard for soft tissue sports injuries (ligaments, tendons, menisci, cartilage).
• ACL tears often show bone bruises (kissing contusions) on MRI, especially lateral femoral condyle & posterior tibial plateau.
• Critical meniscal tears: bucket-handle, radial, root tears. Two-slice touch rule on MRI.
• Rotator cuff tears: Supraspinatus most common. MRI/USG for full vs. partial-thickness.
• Stress fractures: MRI (marrow edema) or bone scan for early diagnosis before X-ray.
• Shoulder impingement: Imaging shows acromial morphology, bursitis, rotator cuff tendinopathy.