PhD defence S.H. (Saskia) van Bergen

Brief summary on the aim of the doctoral thesis:

The dissertation describes the epidemiology, treatment, and outcomes of humeral shaft fractures. Humeral shaft fractures can be treated nonoperatively with functional bracing of operatively with plate osteosynthesis or an intramedullary nail. The research in this dissertation was carried out as the preferred treatment of humeral shaft fractures was subject to scientific debate.

This dissertation first describes a systematic literature review and pooled analysis, which suggests that even though all treatment modalities result in satisfactory outcomes, plate osteosynthesis seems to result in the most favorable outcomes. Furthermore, it describes the results of the HUMMER study, a multicenter prospective cohort study with 29 participating centers designed to compare operative and nonoperative treatment of a closed humeral shaft fracture AO type 12A and B. This study shows that Operative treatment is associated with a more than twofold reduced risk of nonunion, earlier functional recovery, and a better range of motion of the shoulder and elbow joint than nonoperative treatment. Besides that, it showed that the rate of complications as well as secondary surgical interventions was higher in the nonoperative group.

When comparing outcomes after operative treatment, the study showed that plate osteosynthesis of a humeral shaft fracture in adults results in faster recovery, especially of the shoulder function. Besides that, it was found that plate osteosynthesis was associated with fewer implant-related complications and surgical reinterventions than nailing. Therefore, the authors concluded plate osteosynthesis should be the preferred operative treatment strategy for humeral shaft fractures AO type 12 A and B. As secondary analysis, the consequences of radial nerve palsy at presentation and postoperative radial nerve palsy in patients with a closed humeral shaft fracture were described. This showed that radial nerve palsy in humeral shaft fractures, either at presentation or postoperative, has a low occurrence rate and a high rate of spontaneous functional recovery. Therefore, treatment of humeral shaft fractures should not be guided by the presence of radial nerve palsy at presentation or risk of postoperative radial nerve palsy.

Furthermore, the cost-utility and cost-effectiveness of operative versus nonoperative treatment in patients with a humeral shaft fracture were analyzed. It was found that, due to the limited effect of the treatment a humeral shaft fracture on quality of life measured with the EQ-5D, the cost-effectiveness in terms of costs per QALY (€111,860) exceeds the acceptability limit. The incremental costs of €2,880 per meaningful difference in DASH are well below this limit and suggest that operative treatment for a humeral shaft fracture is cost-effective.

The last part of the dissertation describes the fracture type, treatment, and outcome of humeral shaft fractures in adult polytraumatized patients. This showed that humeral shaft fractures in adult polytraumatized patients were most often AO-type A and treated operatively. In this population, rates of radial nerve palsy at presentation and nonunion were relatively high. Besides that, patients still reported upper extremity disability at approximately five years post trauma.

Finally, the general discussion and future perspectives are discussed in Chapter 8.