Medial UCL Injuries & Valgus Instability

Question 1

Which phase of throwing places the most stress on the anterior band of the MCL?

Answer 1

Late cocking and early acceleration; uncommon injury in skeletally immature patients

Question 2

Which band of the elbow MCL has the most change of tension from flexion to extension?

Answer 2

the posterior band; anterior band is isometric through FROM

Question 3

Which elbow test for MCL instability has the highest sensitivity?

Answer 3

Moving valgus stress test; thumb is pulled into supination and valgus stress applied to elbow while it is brought through a full arc of motion; pain or apprehension at 70-120° is positive

Question 4

What imaging modality is the best for diagnosing a MCL tear of the elbow?

Answer 4

MR arthrogram

Question 5

How are MCL injuries and/or instability treated?

Answer 5

1) PT, rest and change of mechanics is first line for 6 weeks; 42% return to prior level of play
2) Anterior band of MCL reconstruction (Tommy John); 90% return to prior level of play

Question 6

What is the strongest fixation for MCL reconstruction?

Answer 6

Humeral docking with interference screw fixation of the ulnar side showed strength of 95% of the native MCL; Muscle splitting approach with in-situ ulnar n. decompression a/w lower complication rate

Question 7

During which phase of the overhead throwing cycle is a baseball pitcher most likely to rupture the medial ulnar collateral ligament complex of the elbow?

Answer 7

Early acceleration