Proximal Humerus Nailing: a Randomized Clinical Trial Between Curvilinear and Straight Nails

Background: Intramedullary nailing of displaced proximal humerus fractures is an attractive option in the elderly patient. However, in recent reports, some existing intramedullary nails have shown high rate of complications, so new designs are being developed. The objective of the present study is to report on outcomes and complications when comparing a straight to a curvilinear nail design.

Methods: We prospectively include 54 patients with Neer's 2- or 3-part proximal humerus fractures. Two were lost to follow-up, 26 were surgically treated with a new straight humeral nail (MultiLoc, Synthes) mean age 69 (range, 47-87 years), and 26 with a curvilinear nail (Polarus, Acumed) mean age 71 (range, 38-89 years). At final follow-up (average 14 months), patients underwent a clinical and radiographic evaluation. Clinical outcome was assessed with the adjusted Constant score.

Results: All but 1 fracture went on to radiographic union. Mean Constant score in the Polarus nail was 72.7 ± 16.0 and 83.3 ± 16.7 in the MultiLoc (P = .246). Symptoms related with rotator cuff disease were present in 19/26 patients (73%) and in 9/26 (34.6%), respectively (P = .001). The mean neck-shaft angle at final follow-up was 135° in the MultiLoc group and 130° in the Polarus group (P > .05). Reoperation rate was 42% for Polarus and 11.5% for MultiLoc.

Conclusion: Straight intramedullary nails had a comparable union rate to an accepted curvilinear design, with a much lower incidence of complications. Rotator cuff pain and dysfunction can be minimized with the use of newer generation straight nails.