Effect of chronic kidney disease on outcomes following proximal humerus fragility fracture surgery in diabetic patients: A nationwide population-based cohort study

Background The proximal humerus fracture (PHF) is the third most common fragility fracture. Diabetes mellitus (DM) and chronic kidney disease (CKD) are both risks for fragility fractures; however, the interplay of DM and CKD makes treatment outcomes unpredictable. This study aimed to investigate and compare early and late outcomes following proximal humerus fracture fixation surgery in diabetic patients with different renal function conditions. Methods DM patients receiving PHF fixation surgery during 1998–2013 were recruited from Taiwan’s National Health Insurance Research Database. According to their renal function, patients were divided into three study groups: non-chronic kidney disease (CKD), non-dialysis CKD, and dialysis. Outcomes of interest were early and late perioperative outcomes. Early outcomes included in-hospital newly-onset morbidities. Late outcomes included infection, revision, readmission, and all-cause mortality. Results This study included a total of 10,850 diabetic patients: 2152 had CKD (non-dialysis CKD group), 196 underwent permanent dialysis (dialysis group), and the remaining 8502 did not have CKD (non-CKD group). During a mean follow-up of 5.56 years, the dialysis group showed the highest risk of overall infection, all-cause revision, readmission, and mortality compared to the non-dialysis CKD group and non-CKD group. Furthermore, subgroup analysis showed that CKD patients had a higher risk of surgical infection following PHF surgery than non-CKD patients in cases with a traffic accident or fewer comorbidities (Charlson Comorbidity Index, CCI <3) (P for interaction: 0.086 and 0.096, respectively). Also, CKD patients had an even higher mortality risk after PHF surgery than non-CKD patients, in females, those living in higher urbanization areas, or with more comorbidities (CCI ≥3) (P for interaction: 0.011, 0.057, and 0.069, respectively). Conclusion CKD was associated with elevated risks for infection, revision, readmission, and mortality after PHF fixation surgery in diabetic patients. These findings should be taken into consideration when caring for diabetic patients.