Shoulder pain acromioclavicular joint with pins and needles in ring and little finger. no injury but pain unbearable ? cause

F sounds neurologic: The sales neurologic. Around the acromioclavicular joint there are nerve brachioplexus and also cervical nerves. This corresponds to around C7. Ask your physician to have you see a neurologist

Cervical spine.: What your feeling in your fingers may be eminating from the cervical spine, and not the shoulder. See an orthopedic spine specialist, who can sort this out.