Treatment of early postoperative infections after THA: a decision analysis

Abstract

Background: The treatment for an early postoperative periprosthetic infection after cementless THA that results in the highest quality of life after the control of infection is unknown. Although common treatments include irrigation and débridement with component retention, a one-stage exchange, or a two-stage exchange, it is unclear whether any of these provides a higher quality of life after the control of infection.

Questions/purposes: We projected, through decision-analysis modeling, the possible estimated final health states defined as health-related quality of life based on quality-of-life studies of an early postoperative periprosthetic infection after cementless THA treated by irrigation and débridement, one-stage exchange, or two-stage exchange.

Methods: Publications addressing early postoperative infections after THA were analyzed for the estimated rate of infection control and quality-of-life measures after a specific treatment. Decision analysis was used to model the different treatments and describe which, if any, treatment results in the greatest quality of life after early THA infection.

Results: In the model, a one-stage exchange was the treatment for early THA infection that maximized quality-of-life outcomes if the probability of controlling the infection exceeded 66% with this procedure. If the probability of infection control of a one-stage exchange was less than 66% or that of irrigation and débridement was greater than 60%, then irrigation and débridement appeared to result in the greatest quality-of-life outcome.

Conclusions: A decision analysis using estimates of infection control rate and quality-of-life outcomes after different treatments for an early postoperative infection after THA showed possible outcomes for each treatment.

Level of evidence: Level II, economic and decision analyses. See Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

The decision tree is shown. The initial decision occurs at the root node (first decision point) at the left side of the tree where one of three treatment options is selected. Based on the chance (probability [prob]) of this treatment resulting in a specific outcome (utility), the decision tree then describes sequentially (from left to right) possible further outcomes. The terminal node (right side of each pathway) describes the utility (health-related outcome measure [HRQL]) of the final result of that treatment path. ID = irrigation and débridement.

Fig. 2

The initial decision tree analysis shows the initial choice of one-stage exchange appears to result in the greatest expected benefit. Working from right to left along the branches of the tree, the utility at each branch is multiplied by its respective probability. The sum of these products along each branch that yields the highest number then will predict the pathway with the highest expected outcome.

Fig. 3

A two-way sensitivity analysis comparing the probability of success of an I & D (x-axis) with that of a one-stage exchange (y-axis) shows the treatment that potentially results in the greatest utility. The position of any coordinate on the graph corresponding to a value of success of I & D (x-axis) and success of one-stage (y-axis) predicts the treatment with the greatest outcome. With less than approximately 38% success of I & D and less than approximately 69% success of one-stage exchange, the model predicted a two-stage exchange might result in the greatest health-related quality of life.