# Postoperative Infection Following Hip Arthroscopy in Patients Receiving Preoperative Intra-articular Injections: A Systematic Review and Meta-Analysis

## TL;DR

This study finds that hip arthroscopy patients who receive intra-articular injections within three months before surgery face a higher risk of postoperative infection.

## Contribution

The study identifies a three-month safety window for preoperative intra-articular injections to reduce postoperative infection risk in hip arthroscopy.

## Key findings

- Intra-articular injections anytime before hip arthroscopy increase infection risk compared to no injections.
- Injections within three months before surgery significantly raise infection risk.
- Injections more than three months before surgery do not significantly affect infection risk.

## Abstract

Intra-articular injections prior to hip arthroscopy are often used to diagnose and conservatively manage hip pathologies, such as femoroacetabular impingement, labral tears, and chondral lesions. As a diagnostic tool, the relief of hip pain following an intra-articular injection helps pinpoint the primary source of pain and assists surgeons in recommending arthroscopic intervention for underlying intra-articular pathologies. However, when injections are not sufficiently spaced apart in time prior to hip arthroscopy, there is an elevated risk of postoperative infection. This systematic review aims to assess whether preoperative intra-articular injections prior to hip arthroscopy are associated with an increased risk of postoperative infection and to determine the safety timeframe for administering such injections prior to the procedure. A comprehensive search was conducted in the PubMed, Embase, and Cochrane Library databases to identify studies examining the relationship between preoperative intra-articular injections and postoperative infection following hip arthroscopy. A meta-analysis was conducted to compare the risk of infection between patients who received injections prior to hip arthroscopy at varying intervals and those who did not receive any preoperative injections. Five studies were included (four level III and one level IV), which consisted of 58,576 patients (58.4% female). Injections administered anytime prior to hip arthroscopy posed a significantly higher risk of infection compared to no history of prior injections (risk ratio: 1.45, 95% confidence interval: 1.14-1.85, P = 0.003). However, upon subanalysis, the risk of infection was significantly higher among patients who received injections within three months prior to hip arthroscopy compared to those who did not receive injections (risk ratio: 1.55, 95% confidence interval: 1.19-2.01, P = 0.001). Additionally, no significant difference in infection risk was observed when injections were administered more than three months before hip arthroscopy compared to no injections (risk ratio: 1.05, 95% confidence interval: 0.56-1.99, P = 0.87). The findings suggest that patients undergoing hip arthroscopy who have previously received intra-articular injections may face a statistically higher risk of postoperative infection, particularly when the injection is administered within three months prior to hip arthroscopy. Consequently, surgeons should exercise caution and avoid administering intra-articular injections to patients scheduled for hip arthroscopy within the subsequent three months to mitigate the increased risk of infection.