Restricting the movement of any broken bone is critical to healing. To immobilize a broken collarbone, you'll likely need to wear an arm sling.The length of time immobilization is needed depends on the severity of the injury. Union of the bone usually takes three to six weeks for children and six to 12 weeks for adults.If a baby has suffered a broken collarbone during labor and delivery, healing typically occurs without specific treatment.Pain control and careful handling of the baby are usually all that's needed.nion of the bone usually takes three to six weeks for children and six to 12 weeks for adults. If a baby has suffered a broken collarbone during labor and delivery, healing typically occurs without specific treatment. Pain control and careful handling of the baby are usually all that's needed.