Aims: The evaluation of blood supply of the humeral head in displaced 4-part Òvalgus impactedÒ fractures of the proximal humerus. Methods: 14 patients with acute 4-part valgus impacted fractures of the proximal humerus (9 women and 5 men, average age 43,6 years) were included in the study. The average impaction angle was 42.4û and the lateral displacement of the humeral head between 1–7 mm. Preoperative angiography of the proximal humerus was performed 6 to 12 hours after admission. Fracture þxation was achieved with transosseous suturing of the tuberosities to each other, to the metaphysis and to the articular part of the humeral head avoiding any use of hard material. Postoperative angiography was performed 8 to 10 weeks after the operation. Results: Digital angiographic image processing, using the segmentation technique, showed no statistical difference in the supply of the humeral head before and after the operation. The average blank number of small vessels and the overall area of blood supply (vessels/mm2 ) were about the same (p< 0.01) in 13 patients and no signs of avascular necrosis were seen 18–20 months after the operation. Partial avascular necrosis was seen in one case with 7 mm lateral displacement. Conclusions: Although the small number of cases, transosseous suturing þxation of 4-part valgus impacted fractures seems to preserve the remaining blood supply of the humeral head. The incidence of avascular necrosis is higher in cases with severe lateral displacement.

Purpose: The evaluation of blood supply of the humeral head in displaced 4-part “valgus impacted” fractures with digital angiographic image processing.

Material-Methods: 14 patients with acute 4-part valgus impacted fractures of the proximal humerus (9 women and 5 men, average age 43,6 years) were included in the study. The average impaction angle was 42.4o and the lateral displacement of the humeral head between 1–7 mm. Preoperative angiography of the proximal humerus was performed 6 to 12 hours after admission. Fixation of the fracture was achieved with in situ transosseous suturing fixation of the tuberosities to each other, to the metaphysis and to the articular part of the humeral head avoiding any reduction maneuvers and use of hard material. Postoperative angiography was performed 8 to 10 weeks after the operation.

Results: Digital angiographic image processing, using the segmentation technique, showed no statistical difference in the supply of the humeral head before and after the operation. The average blank number of small vessels and the overall area of blood supply (vessels/mm2) were about the same in 13 patients and no signs of avascular necrosis were seen 18–20 months after the operation. Partial avascular necrosis was seen in one case with 7 mm lateral displacement.

Conclusions: Although the small number of cases, in situ transosseous suturing fixation of the 4-part valgus impacted fractures seems to preserve the remaining blood supply of the humeral head. The incidence of avascular necrosis is higher in cases with severe lateral displacement.