Shoulder arthroplasty. Comorbidity as prognostic factor.

INTRODUCTION: Preoperative comorbidity seems to be an important factor for the functional recovery of patients after shoulder replacement, but few studies support this correlation.The purpose of this study was to clinically evaluate the influence of comorbidity in restoring function after shoulder replacement. METHODS: We performed a retrospective analysis of shoulder replacement accomplished at our institution from 2005 to 2016 (n = 70). Demographic data, number of comorbidities, preoperative drugs, type of arthroplasty, and postoperative complications were collected. Functional results were evaluated according to the QuickDASH questionnaire. RESULTS: QuickDASH as continuous data was directly correlated with number of drugs prior to the surgical intervention (R = 0.270, p = 0.024) and number of comorbidities (R = 0.280, p = 0,016); especially neurological disorders (R = 0.338, p = 0.004) and osteoporosis (R = 0.0242, p = 0.043). The QuickDASH score is inversely correlated with patient satisfaction (R = -0.621, p < 0.01) and with gender (male) (R = -0.469, p < 0.001).When the patients were divided into 2 equally sized groups according to the QuickDASH score, statistical significance was found between the group with the worst outcome and female sex (91.2%) (p < 0.001), neurological disorders (p = 0.004), alcohol consumption (p = 0.028) and when shoulder arthroplasty is due to proximal humeral fracture (p = 0.002). CONCLUSION: Better functional results are obtained in patients with less comorbidities.Worse functional results are obtained in patients taking more drugs, in women, alcohol consumers and those after proximal humeral fractures. Preoperative clinical status must be optimized and the patients' comorbidities should be carefully taken into accounting order to ascertain the correct shoulder arthroplasty.