The purpose of this study is to review the impact of obesity on subsidence and clinical outcome after short stem total hip arthroplasty.

Short stem total hip arthroplasty (THA) has gained popularity due to its bone-sparing technique, but its outcomes in obese patients remain uncertain.

While studies on the mid-term outcome in a general patient cohort provide excellent results in terms of the clinical and radiological outcome as well as the complication rate of short stem THA, data on its use in obese patients is still rare and not sufficiently conclusive. Some studies have found no evidence of increased subsidence in obese patients, while other studies have shown contrary trends.

In this context, the aim of this study was to investigate the relationship between BMI, postoperative subsidence and clinical outcomes in the setting of short stem THA.

Inclusion Criteria:

1. patients who underwent primary short stem hip arthroplasty with Mathys Optimys short stem between 01.01.2018 and 31.12.2020
2. availability of preoperative and postoperative radiographs for assessment of subsidence
3. a minimum BMI of 30kg/m2 for the obese group
4. a minimum follow-up of 24 months.

Exclusion Criteria:

1. former surgeries of the hip in question
2. incomplete clinical data
3. incomplete radiological data

The purpose of this study was to assess the subsidence rates in patients who underwent short stem hip arthroplasty and its association with obesity. To investigate this, an analysis of patient data was conducted together with a follow-up examination, focusing on clinical outcome and radiographic analysis of the subsidence of the stem in obese patients. Hence, two groups based on body mass index were retrospectively evaluated: obese (BMI ≥ 30 kg/m^2) and non-obese (BMI < 30 kg/m^2), with an age of minimum 18 years, but no maximum age.