Posterior Elbow Medial Capsule

ligamentum capsulare posterius mediale cubiti

The posterior medial capsule of the elbow reinforces the posterior aspect of the medial collateral ligament complex, running from the medial epicondyle to the medial olecranon. The posterior bundle of the UCL forms a distinct thickening of this posterior capsule.

Region: Upper Arm

Biomechanics

Function & Actions

Posterior medial elbow stability; limits valgus stress in elbow flexion above 90 degrees; the posterior bundle is taut in flexion while the anterior bundle is taut in extension.

Clinical Relevance

Clinical Notes

Posterior medial capsule scarring produces posteromedial elbow impingement in throwing athletes, where the posteromedial olecranon impinges against the medial condyle in the acceleration phase. Valgus extension overload syndrome involves both UCL stress and posterior medial capsular scarring. Arthroscopic posteromedial debridement addresses osteophytes and capsular scar simultaneously.

Pathology

Common Injuries & Conditions

Posteromedial Elbow Impingement

Posterior medial capsule scarring and olecranon osteophyte formation from repetitive valgus loading in throwing athletes producing posteromedial elbow pain at ball release, treated by arthroscopic debridement of the posteromedial compartment.