The conservative management if isolated humeral shaft fractures is a long, drawn out, painful process for the patient. For the clinician, it involves multiple clinic attendances and repeated radiographic assessment and brace alteration.

The primary reason for conservative management is the excellent results, but a very definite secondary consideration is the high incidence of shoulder pathology after I.M. nailing. This is thought to be due to rotator cuff pathology at the time of surgery. We question the validity of this second argument.

Ten consecutive humeral shaft fractures attending our unit had an MRI of both shoulders carried out during the initial stages of their injury. Two of the ten had retrograde nailing and the remainder was managed conservatively. While there was no patient with an occult coracoid fracture in association with the shaft fracture. We found eight out of ten to have significant signal changes in the subacromial space on the side of the fracture only.

We conclude that there is a significant occult injury to the shoulder at the time of humeral shaft fracture and this may in fact represent a cause for the high incidence of shoulder pain post fracture.