Abstract:
Introduction: Revision total knee arthroplasty (TKA) is a complex and technically demanding surgery usually following a failed primary TKA.It is projected that by the year 2030, TKA revisions in the United States will grow by approximately 600%, to an estimated 268,200 cases per year where the acceptable worldwide revision rate is between 4.9-7.9%. However, in sub Saharan Africa revision total knee arthroplasty has been rarel y studied. To our
knowledge, this is the first study to estimate the prevalence and causes of TKA revision at
Muhimbili Orthopedic Institute, Tanzania.
Objective: To determine the rate and indications for revision total knee arthroplasty in patients operated at Muhimbili Orthopedic Institute between 2007 and 2018.
Materials and Method: Retrospectively, data for all primary TKA and revision TKA procedures performed from 2007 to 2018 was collected for the rate and causes of failures, demographics, and time elapse from primary TKA to revision TKA.Data was collected from patient care notes and arthroplasty register books using data extraction forms then analyzed by SPSS version 24.It was summarized including frequency distribution, proportions, means and SD. Proportion was determined for categorical variables while mean/median and standard deviation was determined for numerical variables. Ethical clearance was obtained from the MUHAS Research and Publication Committee.
Results: Overall, 607 primaries TKA procedures were carried out in this period2007-2018. The overall revisions following primary TKA in this period was 40 cases, indicating a revision incidence rate of 6.59%, 95% CI 4.75-8.8%. Two thirds (60%) of patients who had TKA revision were females. The predominant cause of revision TKA was aseptic loosening of implants which occurred among 19 participants (3.1%) followed by infections in 13 patients (2.14%) revision. Other causes for revision were knee instability (1.2%), and knee stiffness (0.2%). The total follow-up time to revision was 165.5years and the median duration from initial surgery until revision was 3.8 years, IQR 1.4-6.6 years.
Conclusion: The overall revision TKA surgeries for a period of 11 years (2007-2018) was 40 cases with the incidence rate of 6.59%. Most of the revisions were due to aseptic loosening of implants (3.1%) and knee infections (2.1%). More females underwent TKA revision in this period of follow up compared to males. The median time to revision was 3.8 years.
