Radial/Ulnar collateral ligament sprain

1. How does radial vs. ulnar collateral ligament sprain occur?
2. What is seen clinically in UCL sprain? How is it tested?
3. What is seen clinically in RCL sprain? How is it tested?
4. What imaging is used for UCL/RCL sprain?
5. How are collateral ligament sprains treated?

Answers:
1. UCL sprain occurs via valgus stress across elbow during a throw. RCL sprain occurs via traumatic elbow dislocation.
2. Medial elbow pain after a throw, pop or click, pain with valgus stress test (medial elbow tenderness, increased with valgus stress).
3. Recurrent locking or clicking of the elbow with extension and supination, pain with varus stress test (medial elbow tenderness, increased with varus stress). The lateral pivot-shift test is also used to assess the RCL for posterolateral instability.
4. Plain films, varus (RCL) and valgus (UCL) stress radiographs will show 2mm joint space.
5. Rest ice, NSAIDs, strengthening and stretching rehab, return to play criteria. Surgery if needed.