A case of posterior interosseous nerve palsy: good recovery despite diagnostic delay

It is well established that the outcome of peripheral nerve palsy due to compression by a benign mass is usually good after surgical removal, when performed early. The longest reported duration of posterior interosseous nerve (PIN) palsy prior to full recovery after surgery is 2 years.1 We report a case of PIN lesion with a favourable post-surgical course after 4 years of progressive nerve dysfunction. A 53-year-old man first complained of a dull deep-seated pain in his left elbow 4 years prior to examination at our facility. There was no history of direct trauma. Because of repeated elbow strain caused by sporting activities, his general practitioner suspected “tennis elbow” and prescribed analgesics, with only incomplete pain relief. Over the next years, he gradually developed weakness of the finger extensors IV and V on his left hand. This was subtle at first, but over time became more and more disabling. Wrist immobilisation with a splint was recommended. As the patient noticed an indolent subcutaneous swelling over the left proximal radius, slowly increasing in size, and his finger weakness became …