The causes and risk factors of complications following operative treatment of fracuture of neck of humerus were analysis.

From 1995 to 1998, 32 cases of fracture of neck of humerus on which operative treatment have been taken were reviewed. The average age was 48.3 years. There were 13 cases of two part fracture, 11 cases of three part fracture and 8 cases of four part fracture, with 4 cases associated with comminution. Closed reduction and pinning was performed in 11 cases. An external fixator was applied in 1 case. Other 18 cases underwent open reduction using various fixation method including 4 K-wires, 2 cannulated screws, 5 plates, 1 Ender nail and 6 tension band wirings combined with screws each. 2 cases were underwent hemiarthroplasty.

Thirteen patients (41%) had postoperative complications. There were 3 nonunion, 2 pin site infection, 2 inferior subluxation of humeral head, 3 impingement syndrome, 1 hardware failure, 1 avascular necrosis of humeral head and 1 glenoid rim erosion. The incidence of postoperative complication was high in ages older than 40 years and the four part and comminuted fractures. The insufficient fixation due to osteoporosis, incomplete reduction, surgical technique and use of inappropriate implant were considered as related causative factures.

The patient's age, the quality of bone, severity of fracture and methods of fixation are all important contributing factors for postoperative complications.