# Skin Temperature Change Following Infected and Non-infected Total Knee Arthroplasty: A Systematic Review

## TL;DR

This systematic review examines how skin temperature changes after knee replacement surgery and whether these changes can help detect joint infections.

## Contribution

The study systematically analyzes skin temperature patterns post-TKA and evaluates their potential as infection markers.

## Key findings

- Non-infected TKA cases show a peak ΔST of 3.42°C at one week, declining to 0.48°C at one year.
- PJI cases show higher and more persistent ΔST elevations, with a 0.78°C difference at one week compared to non-infected cases.

## Abstract

Total knee arthroplasty (TKA) is a common and growing surgical intervention for end-stage knee osteoarthritis. Postoperative changes in skin temperature (ΔST) over the operated knee are well recognised, yet their clinical relevance, particularly as a potential marker for periprosthetic joint infection (PJI), remains uncertain.

This systematic review aimed to define the pattern of skin temperature change following TKA and assess its potential utility in detecting PJI.

A comprehensive literature search was conducted using PubMed, EMBASE, Google Scholar, and the Cochrane Database up to April 2025, adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eleven studies were included, covering a total of 1,212 patients. Inclusion criteria required objective ΔST measurements of the anterior knee in adults (≥18 years) with at least six months of follow-up. Studies on both uncomplicated TKA and TKA complicated by PJI were analysed narratively.

All non-infected cases demonstrated a marked rise in ΔST over the operated knee, peaking within the first week postoperatively with a weighted mean of 3.42°C, followed by a progressive decline to 0.9°C at six months and 0.48°C at one year. In contrast, PJI cases (n=25, conservatively managed) exhibited greater and more persistent ΔST elevations, particularly within the early postoperative period. At one week post-TKA, the infected group had a mean ΔST 0.78°C higher than the non-infected cohort. Patients undergoing revision for PJI (n=3) showed extreme elevations exceeding 4°C, sustained through the first three months postoperatively.

Skin temperature over the knee typically follows a predictable decline after TKA in uncomplicated cases. While elevated or prolonged ΔST may indicate infection, current evidence (limited by heterogeneous methods and small sample sizes) does not support ΔST as a standalone diagnostic marker for PJI. Further large-scale, standardised studies are required to explore its role in early infection detection.