Clinical outcomes following intramedullary nailing of humerus fractures: a systematic review

The purpose of this study is to systematically review the literature to assess clinical outcomes arising from intramedullary nailing (IMN) of humerus fractures.

Two independent reviewers performed a literature search in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they reported on patient-reported outcomes and range of motion following the use of IMN for humerus fractures between 2000 and 2023.

A total of 88 studies, including 4255 patients, met the inclusion criteria for review. The majority of patients were female, with a mean age of 58.3 ± 12.4 years and a mean follow-up of 21.2 ± 15.2 months. The primary outcome score utilized for postoperative assessment was the Constant-Murley Score (CMS). The mean CMS for all fractures, proximal humerus fractures (PHFs), and humeral shaft fractures were 74.7 ± 12.5, 74.2 ± 12.3, and 77.3 ± 12.1, respectively. The mean CMS in 2-part, 3-part, and 4-part PHFs was 80.8 ± 8.8, 80.4 ± 12.3, and 66.5 ± 11.3, respectively. The primary range of motion measurements measured for postoperative assessment were forward flexion and external rotation. The mean forward flexion for all fractures, PHFs, and humeral shaft fractures was 135° ± 16°, 131° ± 13°, and 143° ± 18°, respectively. The mean external rotation for all fractures, PHFs, and humeral shaft fractures was 46° ± 15°, 43° ± 13°, and 52° ± 16°, respectively.

IMN for humerus fractures provides good functional outcomes in both proximal humerus and humeral shaft fractures. However, functional outcomes in PHFs decreased as the number of displaced fracture parts increased.