Minimally invasive plate osteosynthesis for proximal humerus fractures: functional results of treatment

Proximal humeral fractures can safely and effectively be treated with minimally-invasive plate osteosynthesis (MIPO). Twenty-one patients treated with MIPO for 2-, 3-, and 4-part proximal humerus fractures were treated at a mean 6.8 days (range, 1-24 days) after injury and followed for a mean of 24 months (range, 5-38 months). All fractures healed by 8 weeks postoperatively, with reductions "good" in 18 (86%) of patients and "fair" in 3 (14%). There were no infections or nerve or vascular injuries. One patient had loss of reduction that healed but required hardware removal. The neck-shaft angle was measured intraoperatively and at final follow-up, with mean (SD) of 139° (9.3; range, 123°- 156°) and 138° (8.9; range, 123°- 159°), respectively. Mean (SD) displacement from the most superior aspect of the humeral head articular surface to the top of the greater tuberosity was 4.3 (10) mm. Mean (SD) active range of motion was 143° (35.04; range, 80°- 180°) for forward flexion, 118° (46.8; range, 45°- 180°) for elevation, and 33° (19.2; range, 10°- 65°) for external rotation. The mean Disability of the Arm, Shoulder, and Hand (DASH) score was 25.95 (range, 0-80). Excluding patients with associated injuries, a statistically significant difference (P<.05) was found in the DASH scores for those patients with greater tuberosity displacements between 3 mm and 8 mm and those patients with greater tuberosity displacement greater than 8 mm inferior to the articular surface. Clinical outcomes depended upon reduction of the greater tuberosity, which is facilitated by the MIPO technique.