Medial Elbow Instability S53.449A 841.1

 elbow ligaments

throwing athlete picture

ICD-9 Classification / Treatment
Etiology / Natural History Associated Injuries / Differential Diagnosis
Anatomy Complications
Clinical Evaluation Follow-up Care
Xray / Diagnositc Tests Review References

synonyms: medial collateral ligament sprain, medial elbow instability, elbow UCL rupture, UCL instability, ulnar collateral ligament tear


Medial Elbow Instability ICD-10


A- initial encounter

D- subsequent encounter

S- sequela

Medial Elbow Instability ICD-9

  • 841.1 (sprain and strain of elbow; ulnar collateral ligament)

Medial Elbow Instability Etiology / Epidemiology / Natural History

  • Throwing exposes the medial elbow to high tension forces and the lateral elbow to high compression forces.
  • Repetitive valgus stresses to the elbow occuring during the late cocking and acceleration phases of throwing can lead to MCL incompetence, ulnar neuritis and posteromedial olecranon impingement.
  • Associated with Baseball, javelin, and raquet sports (tennis, )

Medial Elbow Instability Anatomy

  • Valgus stability to the elbow is provided by: MCL, olecranon/trochlear articulation, flexor-pronator muscle mass (FCU is primary, FDS is secondary), radiocapitellar articulation,
  • Elbow MCL consists of anterior bundle, posterior bundle and transverse segment
  • Anterior bundle: origin=inferior aspect of the medial epicondyle. Insertion=sublime tubercle of ulna. Primary restraint to valgus stress at the elbow.
  • Posterior bundle; Origin=medial epicondyle slightly posterior to its most inferior portion. Insertion=broadly onto the olecranon
  • See also Elbow Anatomy.

Medial Elbow Instability Clinical Evaluation

  • Pain localized to the medial elbow generally in the late-cocking or acceleration phases of throwing. May or may not have preceeding injury.
  • Acute injury may be associated with a "pop" sensation.
  • Medial elbow tenderness, loss of throwing velocity.
  • Associated ulnar neuritis causing paresthesias in the posteromedial elbow to the ring and small fingers may be the first complaint.
  • Elbow effusion: uncommon. Pts with large effusion will hold the elbow flexed 70° to 80°, which corresponds with the greatest capsular volume. (Timmerman LA,AJSM 1994;22: 26–32, 1994).
  • Valgus Stress Test: valgus load applied to elbow with the elbow flexed 20° . Positive results = reproduction of medial elbow pain and valgus laxity greater on injured side as compared to contralateral side.
  • Moving Valgus Stress Test: rapid extention from full flexion while maintaining a constant valgus stress. Positive result = reproduction of medial elbow pain.
  • Milking maneuver: patient or examiner pulls on the patient's thumb creating a valgus stress, witht he patient's forearm suppinated and elbow flexed 90°. Medial elbow pain indicates medial elbow instability.

Medial Elbow Instability Xray / Diagnositc Tests

  • A/P, Lateral and oblique elbow xrays. Generally normal. May show MCL calcification, medial humeral osteophytes, ulnar osteophytes, posterior olecranon spurring or loose bodies may be seen in chronic cases.
  • Valgus stress xrays: >3mm medial opening on side-to-side comparisions is diagnositic of valgus instability
  • MRI arthrogram: study of choice for elbow MCL injury. Evaluate for T sign of ulnar avulsion, humeral MCL avulsion or midsubstance tearing. Normal MCL appears as a thin band of low intensity along the medial elbow. Tearing is indicated by signal attenuation or absence. (Timmerman LA, AJSM 1994;22:26), (Munshi M, Radiology 2004;231:797), (Schwartz ML, Radiology 1995;197: 297).
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  • CT arthrography: sensitivity of 86%, specificity of 91%. (Timmerman LA, AJSM 1994;22:26),

Medial Elbow Instability Classification / Treatment

  • Non-operative: Rest from throwing. Physical therapy with stretching, flexor-pronator strengthening and modalities. May start sport-specific activites at 3 months focused on adjusting patients throwing mechanics. 42% return to previous level of competition at an average 24.5 weeks after diagnosis (Rettig AC, AJSM 2001;29:15).
  • Throwing athlete, failed non-op treatment: MCL Reconstruction.
  • Non-throwing athlete, failed non-op treatment; women: MCL Reconstruction or capsular plication / MCL repair (Argo D, AJSM 2006;34:431).

Medial Elbow Instability Associated Injuries / Differential Diagnosis

Medial Elbow Instability Complications

  • Posteromedial olecranon impingement
  • Ulnohumeral arthritis

Medial Elbow Instability Follow-up Care

  • 9weeks: start isotonic strengthening with concentric flexor-pronator and eccentric elbow flexor training.
  • Full speed pitching not recommended for 12 months after reconstruction.

Medial Elbow Instability Review References