Is the St. Gallen Algorithm for proximal humerus fractures associated with improved outcomes?

Background Proximal humerus fractures are the fourth most common type of fracture in elderly humans, seventh most common overall, and their incidence is rising. In 2019, the St. Gallen Algorithm (SGA) for treatment of proximal humerus fractures was proposed to improve treatment outcomes and reduce secondary surgeries. To date, no external validation of this algorithm has been reported.Methods We performed a retrospective validation study with patients who sustained an isolated proximal humerus fracture between January 2010 and December 2020 at our institution. We calculated the prevalence of patients following the SGA and compared failure rates and Subjective Shoulder Value scores between those following the SGA and not. We also evaluated the entire cohort for predictors of treatment failure.Results The prevalence of patients receiving treatment based on the SGA at our institution was 43% (n = 316). The overall failure rate was 13% (94/730 patients) at a mean follow-up of 22 months. The failure rate was 11% (36/316 patients) for the SGA group and 14% (58/414 patients) for the non-SGA group (P value = .3). Subjective Shoulder Value scores were 89 ± 12 in the SGA group (n = 33) and 90 ± 13 in the non-SGA group (n = 52; P = .7). Kaplan-Meier analysis showed no difference in survivorship between following and not following the SGA. Univariate analysis identified algorithm pathway 10 and Neer fracture type 3 as risk factors for failure. Multivariable analysis suggested a potential association between adherence to the SGA and reduced failure risk; however, this finding should be interpreted cautiously given the borderline statistical significance and limitations of the regression model.Conclusion Following the SGA produced similar results to not following the SGA in terms of failure rate, survivorship, and clinical outcome scores. However, multivariate analysis identifies following the SGA as protective against failure. The findings of this study provide supportive but not definitive evidence for the clinical utility of the SGA as a decision-making aid in the treatment of proximal humerus fractures.