Ulnar Nerve Entrapment Neuropathy (cubital tunnel syndrome)
This is a condition in which the ulnar nerve, which is a large nerve that runs in a groove at the back and inner aspect of the elbow (supplying muscles in the forearm and hand as well as sensation to the little and ring finger), becomes pinched or trapped.  It is characterised by pain at the back and inner aspect of the elbow associated with  pins and needles or numbness radiating down the inner aspect of the forearm into the little and ring fingers.

Symptoms often first develop at night although, as the pinching becomes more severe, daytime symptoms will be present as well.  Patients later on in the condition often also notice that they are becoming clumsy, i.e. dropping items easily.  Diagnosis is based on clinical examination which can confirm the irritability of the nerve at the back of the elbow often combined with nerve conduction studies which are specific nerve tests that will diagnose this condition in most patients.  Although early on in the condition splints to prevent the elbow bending can be used at night the most effective long-term solution is surgery to release the pinching of the nerve at the back of the elbow.  As with many conditions surgery is generally most effective when performed early in this condition as if the nerve has been trapped for a prolonged period of time (in excess of twelve months) the nerve may  not fully recover and consequently pins and needles and numbness may persist even after the nerve has been released.  

Often in younger patients they will present with similar symptoms but in these patients the symptoms are often caused by the nerve subluxating out of its normal groove and flicking forwards over the bony prominence on the inside of the elbow as the elbow is fully bent.  Non-operative treatment is ineffective in treating a subluxing nerve and this will require surgery to relieve the symptoms.