Aims. Older adults with hip fractures are at high risk of experiencing complications after surgery, but estimates of the rate of specific complications vary by study design and follow-up period. The aim of this systematic review was to determine the prevalence of complications in older adults after hip fracture surgery. Methods. MEDLINE, Embase, CINAHL, and CENTRAL databases were searched from inception until 30 June 2023. Studies were included if they reported prevalence data of complications in an unselected, consecutive population of older adults (aged ≥ 60 years) undergoing hip fracture surgery. Results. A total of 95 studies representing 2,521,300 patients were included. For surgery-specific complications, the 30-day prevalence of reoperation was 2.31%, surgical site infection 1.69%, and deep surgical site infection 0.98%; the 365-day prevalence of prosthesis dislocation was 1.11%, fixation failure 1.77%, and periprosthetic or peri-implant fracture 2.23%. For general complications, the 30-day prevalence of acute kidney injury was 1.21%, blood transfusion 25.55%, cerebrovascular accident 0.79%, lower respiratory tract infection 4.08%, myocardial infarction 1.98%, urinary tract infection 7.01%, and venous thromboembolism 2.15%. Conclusion. Complications are prevalent in older adults who have had surgery for a hip fracture. Studies reporting complications after hip fracture surgery varied widely in terms of quality, and we advocate for the routine monitoring of complications in registries and clinical trials to improve the quality of evidence. Cite this article: Bone Joint J 2025;107-B(2):139–148

Aims. Patients with metabolic syndrome (MetS) are known to be at increased risk of postoperative complications, but it is unclear whether MetS is also associated with complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Here, we perform a systematic review and meta-analysis linking MetS to postoperative complications in THA and TKA. Methods. The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to the guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE). We assessed the methodological quality of each study using the Newcastle-Ottawa Scale (NOS), and we evaluated the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Data were extracted and meta-analyzed or qualitatively synthesized for several outcomes. Results. Ten cohort studies involving 1,352,685 patients were included. Qualitative analysis suggested that MetS was associated with a higher incidence of cardiovascular events, and meta-analysis showed that MetS increased the risk of all-cause complications (risk ratio (RR) 1.55, 95% confidence interval (CI) 1.28 to 1.89), surgical site infection (SSI; RR 2.99, 95% CI 1.30 to 6.90), urinary tract infection (UTI; RR 2.58, 95% CI 1.03 to 6.43), and 30-day readmission (RR 1.45, 95% CI 1.33 to 1.59). There was insufficient evidence for assessing an association between MetS and venous thromboembolism events, pulmonary or gastrointestinal complications, or mortality. Conclusion. Patients with MetS undergoing THA and TKA are at increased risk of all-cause complications, cardiovascular complications, SSI, UTI, and 30-day readmission. Surgeons should be aware of the increased risk of these complications in MetS, and presurgical protocols for these complications should give special consideration to MetS patients. Cite this article:Bone Joint Res. 2020;9(3):120–129