Minimally invasive polyaxial locking plate fixation of proximal humeral fractures: a prospective study.

Background: The surgical treatment for displaced humeral head fractures overlooks a broad variety of surgical techniques and implant systems. A standard operative procedure has not yet been established. In this article, we report our experience with a second-generation locking plate for the humeral head fracture that is applied in a standardized nine-step minimally invasive surgical technique (MIS).

Methods: In a prospective study from May 2008 until November 2009, a cohort of 79 patients with 80 proximal humerus fractures were operated in a MIS procedure using a polyaxial locking plate. Follow-up examination at 6 weeks and 6 months postoperative included radiologic examinations and a clinical outcome analysis by the Constant Score, the Visual Analog Scale for pain, and the Daily Activity Score.

Results: The mean patient age was 65.5 years ± 19 years. According to the Neer classification, there were 18 (22.5%) two-part (Neer III), 48 (60%) three-part (Neer IV), and 14 (17.5%) four-part fractures (Neer IV/V). The operation time averaged 65.6 minutes ± 27 minutes. In 13 patients (16.3%), revision was necessary because of procedure-related complications. After 6 months, the Visual Analog Scale for pain was 2.7 ± 1.6 and the Daily Activity Score showed 19.6 ± 6 points. The average age-related Constant Score after 6 months was 67.5 ± 24 points.

Conclusions: MIS surgery of displaced humeral head fractures can be performed in all types of humeral head fractures leading to low complication rates and good clinical outcome. A standardized stepwise procedure in fracture reduction and fixation is recommended to achieve reliable good results.