Soft-tissue thickness radiographic measurement: a marker to evaluate acute periprosthetic joint infection risk in total hip replacement

Abstract

Abstract. The objective of our study was to evaluate the association between acute periprosthetic joint infection (APJI) and radiographic measurement of soft-tissue thickness in elective total hip replacement surgery. A case-control study was conducted to compare the soft-tissue thickness radiographic measurement (SRM) at the hip in patients diagnosed with APJI based on Tsukayama et al. (2003) criteria after total hip replacement with patients that were not infected, at a single institution from 2013 to 2019. To minimize selection bias, each case was matched with two controls using the following methodology: patients of the same sex, with an age variation of ± 5 years, and nearest in surgery date to the cases were selected. All postoperative radiographs were performed in the first 24 h after total hip arthroplasty (THA) surgery as it is protocolized in our institution. Soft-tissue thickness radiographic measurement was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in postoperative anteroposterior hip radiographs. In total, 78 patients were included (26 cases and 52 controls). The SRM median of the cases was 76.19 mm (SD: 26.518) and 53.5 mm (SD: 20.47) in controls. A multivariate logistic regression model showed an independent association between APJI and SRM (odds ratio (OR) = 1.033, 95 % confidence interval (CI) 1.007–1.059, p=0.012). Patients with an SRM greater than 60 mm had a 7-fold increase in the odds of APJI (OR = 7.295, 95 % CI = 2.364–22.511, p<0.001). The results of our study suggest an association between large SRM at the hip and the risk of APJI in patients with primary total hip arthroplasty. SRM may be a helpful and easy tool for evaluating the risk of APJI before elective primary total hip replacement surgery.

Local Soft-Tissue Thickness vs. Body Mass Index as Predictors of Complications After Total Knee or Hip Arthroplasty

“…Multivariate logistic regression showed an independent relationship between PJI and SRM (OR, 1.033, 95% CI, 1.007-1.059, p = 0.012). Patients with an SRM of greater than 60 mm had a 7-fold increase in the odds of PJI (OR, 7.295, 95% CI, 2.364-22.511, p < 0.001) 23 . These results suggest a relationship between a large SRM at the hip and risk of PJI in patients undergoing elective THA.…”

“…Two studies refuted this hypothesis 26,27 . These studies and their results are explained below 17,23-25,28 .…”

“…Five studies revealed that larger STT around the hip is associated with an increased incidence of complications after THA 17,[23][24][25]28 (Table I). Two studies refuted this hypothesis 26,27 .…”

“…By contrast, a case–control study by Fernandez et al included patients undergoing THA using a posterolateral approach for osteoarthritis and evaluated the association between acute periprosthetic joint infection (PJI) and STT within 4 weeks of surgery 23 . Like Bernaus et al, they defined PJI using Tsukayama's criteria, matched each case to 2 control groups (N = 78, 26 cases, 52 controls), and measured SRM in the same way 23,24,35 . There was a 22.64 mm difference in mean SRM for cases (76.19 mm) and controls (53.55 mm).…”

“…Although BMI can be calculated by a simple formula (BMI 5 kg/m 2 ), STT is defined differently between studies. On review of the 7 studies discussing STT and THA complications, 2 studies intraoperatively measured the distance from the most lateral part of the greater trochanter (GT) to the skin, 4 used radiographic lines from different parts of the GT or femoral head to the skin, and 1 created a ratio by measuring the STT laterally on an anterior-posterior (AP) radiograph and dividing it by the femoral diaphyseal diameter 17,[23][24][25][26][27][28] . These measurements are further discussed under the "hips" subsection.…”