In orthopaedic research, it is crucial to determine changes that are statistically significant and clinically meaningful. One approach to accomplish this is by calculating the Minimal Clinically Important Difference (MCID), the Clinically Important Differences (CID), the Minimum Detectable Change (MDC), the Minimal Important Change (MIC), and the Patient Acceptable Symptom State (PASS) values. These tools assist medical professionals in comprehending the patient's viewpoint, enabling them to establish treatment objectives that align with patients' desires and expectations. The present systematic review investigated the MCID, MIC, CID, MDC, and PASS of the most used PROMs to assess patients who have undergone THA. This systematic review followed the 2020 PRISMA guidelines. Web of Science, Embase, and PubMed were accessed in March 2024 without time constraints or additional filters. All the clinical investigations which evaluated data tools (MCID, MIC, CID, MDC, and PASS) to assess the clinical relevance of PROMs in THA were accessed. Articles in Spanish, Italian, German, and English were eligible. Studies with levels of evidence I to III were eligible. Data from 100,824 patients were collected. All relevant demographic data were analysed and summarised. In addition, the MCID, MIC, CID, MDC and PASS of the COMI, HOOS, SF-36, OHS, Oxford-12, PROMIS-PF, SF-12, and WOMAC scores for THA were determined. Current evidence recommends to collect MCIDs based on anchors routinely. These values should be used as complementary tools to determine the clinical effectiveness of a treatment instead of solely relying on statistically significant improvements. Level IV, systematic review and meta-analysis.