A retrospective comparative study of complications after total knee replacement in rheumatoid arthritis and osteoarthritis patients

Abstract

BACKGROUND: Total knee arthroplasty (TKA) rates have significantly increased over the past few decades; consequently, so too have the absolute number of complications. International literature expounds on complications in the rheumatoid arthritis (RA) and osteoarthritis (OA) subgroups from the developed context, but these findings cannot be generalised to the developing world, where access to medication, medical facilities and patient characteristics may differ. The purpose of this study was to determine the comparative rates and nature of complications that occur post total knee arthroplasty in RA and OA patients at a single South African quaternary hospital. METHODS: This was a retrospective comparative study of complication rates in two groups following TKA at Inkosi Albert Luthuli Central Hospital (IALCH) arthroplasty unit, between 1 January 2014 and 29 February 2020. The data was collected retrospectively, utilising the digitised patient management system at the hospital. Data extraction included patient demographics, time to surgery, indication for surgery and early complication rates. Descriptive analysis was performed to quantify complications, comparing the two groups. RESULTS: The chart review yielded 332 cases, comprising 41 RA and 291 OA patients. The mean age of the combined participant group was 65 years (standard deviation [SD] 8). Most cases were female (87%, 289 of 332), with males comprising 13% (43 of 332). Concomitant human immunodeficiency virus (HIV) was present in 6% of patients (20 of 332), and 24% (80 of 332) had diabetes mellitus (DM). The absolute number of complications was greater in the OA group, where revision surgery was performed in 3% (8 of 291) of cases, infection occurred in 1% (3 of 291), mechanical complications in 3% (10 of 291), and deep vein thrombosis (DVT) in 1% (2 of 291) of cases. There was one complication, a DVT, in the RA group (2%, 1 of 41). CONCLUSION: In the current study, complications after TKA occurred predominantly in the OA group, 8% (23 of 291) as compared to the RA group, 2% (1 of 41). Complications included DVT, revision surgery, infection and mechanical complications. The study was underpowered to detect significant differences between the groups. Further large-scale investigation will be required to determine if differences in complication rate are significant when low complication incidence is anticipated. Level of evidence: Level 4.