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

Abstract

» Body mass index (BMI) is a nonspecific measure of general fat composition that demonstrates little conclusive or definitive association with surgical site complications after total knee and total hip arthroplasty.» Quantifying soft-tissue thickness (STT) around the joint of interest has shown positive correlations with complications and is arguably a better predictor than BMI.» In this literature review, 14 articles (7 discussing hips and 7 discussing knees) discussing the association of STT, BMI, and surgical site complications after total hip and knee arthroplasty were scrutinized and summarized to present relevant information necessary to compare STT with BMI.» Five of the 7 studies involving hips and 4 of the 7 studies involving knees show a positive relationship between STT and outcomes including complications and infection, with some claiming STT as a stronger predictor of surgery site problems than BMI.» Since many variables, such as STT measurement technique, surgical outcomes, sample sizes, and surgical approach, varied between the studies, definitive inferences are difficult to make and future studies of bigger sample size and higher power should focus on the described measurement techniques.

Accurate surgical posterior tibial slope alteration can be achieved in total knee arthroplasty regardless of surgeon skill level or local soft tissue thickness—A retrospective radiograph‐based study

“…Conflicting evidence exists as to whether obesity, represented by an increased BMI, has an impact on implant placement in TKA [5,7,31]. However, given BMI's limitations in describing local fat distribution [9], local soft tissue thickness (LSTT) might be a more appropriate parameter to investigate regarding its impact on complications and implant placement in total joint arthroplasty (TJA) [26]. Following this rationale, several studies examined LSTT in relation to complications after TKA [35,37,39] but only one study reported on the impact of LSTT on implant placement [30].…”

Association of Radiographic Soft Tissue Thickness With Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up

“…12 Further, surgical site thickness has been shown to be a risk factor for infection, wound complications, and early failure following total knee and hip arthroplasty. 14,25,31 In a retrospective review of 1110 patients undergoing a total hip arthroplasty, Sprowls et al 35 found that the surgical site thickness was predictive of infection and associated with revision surgery (odds ratio: 1.022 [1.004-1.041]; P = .02). They suggest that a radiographic measure accurately captures surgical site adipose compared with BMI and was potentially a modifiable risk factor.…”

“…Moreover, preoperative radiographic soft tissue thickness has been suggested as a predictor of outcomes following hip, knee, and shoulder arthroplasty. 25,26,28,33,36,38,41 In hip arthroplasty, measurements included the distance from the tip of the greater trochanter to the skin along a perpendicular line to the femoral diaphysis, whereas knee arthroplasty focused on prepatellar and pretubercular thickness measurements. 26,36,38 Shoulder arthroplasty measured the deltoid muscle and subcutaneous fat thickness using concentric circles centered on the humeral head.…”