Natural history of complex fractures of the proximal humerus using a three-dimensional classification system.

We studied the nonoperative treatment of proximal humeral fractures in severe injuries usually treated surgically. The natural history of 63 patients was followed prospectively for 2 to 9 years (mean, 42 months) with a nonrandomized protocol. A 3-dimensional classification system based on computed tomography scans was used to categorize the fractures. Assessment was made for range of motion, function via a validated testing instrument (Simple Shoulder Test), analog pain score, avascular necrosis (AVN), and fracture union. Magnetic resonance imaging for early signs of AVN was done in 16 cases. After conservative treatment of complex fractures of the shoulder, motion is considerably compromised but pain is minimal and functional status is acceptable to most individuals in this predominantly older patient population. Status comparable to a successful surgical shoulder fusion is achieved in most cases-Nature's fusion. Contrary to common belief, AVN, even in severely displaced injuries, is rare. Future randomized studies based on a 3-dimensional classification need to be done to compare these natural history results with various types of surgical interventions.