Rate and Causes of Total Hip Arthroplasty Revision at a Reference Hospital in Tanzania 2008-2018

Background: Total hip arthroplasty (THA) is one of the most successful orthopaedic procedures performed in both developed and developing countries with reported excellent long-term outcomes [1]. Despite good results, failures and need for revision continue to be a substantial problem after primary THA. The worldwide revision burden following primary total hip replacement is about 12.9% [2]. In Tanzania total hip arthroplasty procedures have been performed since 2004 at Muhimbili Orthopaedic Institute (MOI). However, neither the rate of revision nor its causes have been studied and published.

Methodology: This was a hospital based retrospective descriptive study which was conducted at MOI for a period of six months from August 2019-February 2020. The total study population was 950, operated on with total hip arthroplasty (THA) from 2008 to 2018. A systematic random sampling technique was used to obtain a sample size of 206 patients who were enrolled in this study. Demographic data, as well as other pertinent information were extracted from arthroplasty record books and patient’s case notes by using the data extraction forms.

Results: The mean age of the 206 enrolled patients at the time of the study was 58.91±17.64 years (range 18-97 years). More than half (53.4%) were males. Fifteen (7.3%) of the patients had revision THA. Recurrent dislocation (N=7, 46.7%), periprosthetic fracture (N=4, 26.7%), aseptic loosening (N=3, 20%) and infection (N=1, 3.1%) were the indications for revision. On average the time interval between primary and revision total hip arthroplasty was found to be 4.47±2.80 years, with median 4.5 years (range <1-9 years).

Conclusion and Recommendations: The rate of THA revision at MOI from 2008 to 2018 was 7.3%. The main cause of THA revision at MOI was dislocation. In majority of the patients, the time period between primary and revision THA was 4.5 years or less. Further prospective and large studies should be conducted to establish and address the causes of dislocation and other complications following THA at MOI and other orthopaedic institutes.