Early mortality rate and associated risk factor in patients undergoing primary total hip replacement at Muhimbili Orthopaedic Institute

Abstract

ABSTRACT Background: Hip joint replacement surgery, or Total Hip Arthroplasty (THA), is an effective procedure for elderly patients. It can improve their quality of life and functionality while reducing the direct costs associated with arthritis. With increased THA procedures being performed on patients of different ages, it is essential to identify factors that may affect mortality for better patient care. Objective: This study aimed to identify the early mortality rate and potential risk factors among patients undergoing primary total hip replacement at MOI. Methodology: This was a retrospective cohort study conducted at MOI from January 2020 to December 2021, which involved 173 patients who had undergone Total Hip Replacement (THR). The sample was obtained by reviewing the hospital registry in consecutive order, and the study's primary objective was to determine the early treatment outcome, with a specific focus on patient mortality. Data was collected on various demographic characteristics, including age, gender, ASA status, duration of the procedure, mode of anaesthesia and history of co morbidities. This data was analyzed using SPSS version 20 software. Continuous variables were summarized using mean and standard deviation to measure dispersion around the mean, while categorical variables were summarized using counts or proportions. The study's findings were presented using tables, figures, text and various statistical tests were used to analyze the data. Kaplan-Meier survival plots were used to estimate mortality rates, and log-rank chi-square was employed for group comparisons. Additionally, Cox regression analysis was used to control confounding variables. The significance level for the study was set at 0.05, and any p-value less than or equal to this was considered statistically significant. Result: The study showed that more males (53.6%) participated than females. The participants had an average age of 55.9 years, with a standard deviation of 18.4. The mortality rate for patients undergoing total hip replacement surgery was 7 out of every 100, though it is important to note that over 93% of participants survived beyond the three-month threshold. The Cox regression multivariate analysis found that having hypertension and being seropositive for HIV were independent prognostic factors survival. Hypertension was associated with an increased chance of death by up to 4.8 times higher than not having hypertension, with HR = 4.791 at 95% CI and p = 0.015. The likelihood of death was eleven times higher among participants who were HIV+ compared to those who were HIV-negotiated, with HR = 10.963 at 95% CI and p-value = 0.006. Conclusion: On average, one dies in every fourteen patients undergoing total hip replacement surgery within ninety days’ post-treatment. Hypertensive patients had an increased chance of death of five times non-hypertensive. HIV+ patients had an increased chance of death, up to eleven times higher than HIV tested negative. Therefore, this highlights the different disease profiles of patients in our center hence, necessitating different approaches and strategies to the procedure.