Which cast is used for fracture of the neck of the humerus / recurrent shoulder dislocation?

• A. Shoulder Spica Cast
• B. Abduction Splint/Airplane Cast
• C. Short Arm Posterior Mold
• D. Long Arm Circular Cast

Answer: (B)

Immobilization in abduction positions the shoulder so the humeral head stays seated in the glenoid, which helps both fracture alignment in the neck of the humerus and prevents forward, anterior displacement in recurrent dislocations. The airplane cast (abduction splint) holds the arm away from the body, often with a bit of external rotation, creating a tension on the anterior capsule and subscapularis that reinforces joint stability and supports proper healing of the proximal humerus.

Other casts don’t place the arm in this abducted posture. A shoulder spica holds the arm against the trunk and provides less of the necessary abduction alignment. A short arm posterior mold or a long arm circular cast mainly control the elbow and forearm or keep the arm close to the body, respectively, without the shoulder being held in the abducted position needed to prevent anterior instability and aid fracture healing.