The impact of allergies on patient-reported outcomes after total hip and knee arthroplasty: a systematic review and meta-analysis

IntroductionMetal hypersensitivity has been associated with persistent symptoms after total hip arthroplasty (THA) and total knee arthroplasty (TKA), despite successful joint replacement. Allergies frequently co-occur and have been linked to psychiatric disturbances such as anxiety. There is a knowledge gap regarding the effect of allergies, including metal hypersensitivity, on patient-reported outcome measures (PROMs) after THA and TKA. This study aimed to evaluate the influence of allergies including metal hypersensitivity on PROMs in patients undergoing THA and TKA.Material and MethodsA systematic search PROSPERO (CRD42023475972) was conducted using PubMed, EMBASE, Scopus, and Cochrane databases. Studies that compared allergic and non-allergic adults undergoing primary THA or TKA and reported PROMs were included. Methodological quality was assessed using the MINORS criteria. The mean differences (MD) and standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated. Eight studies, involving 33,808 patients, were included.ResultsFor functional outcomes assessed using SF-12, SF-36, KOOS JR, and HOOS JR, allergic patients demonstrated significantly worse scores (SMD - 0.23, 95% CI -0.36 to -0.09). The WOMAC functional scale also demonstrated poorer results in allergic patients (MD 2.49, 95% CI 0.64 4.35). For pain assessed using the WOMAC pain scale, allergic patients reported significantly greater pain (MD 1.04, 95% CI 0.46 1.62). Changes in mental status assessed using the SF-12 and SF-36 did not show significant differences between the groups (MD -0.46, 95% CI -1.40 to 0.47). In subgroup analysis, patients in the THA subgroup showed significantly worse outcomes (MD -7.20, 95% CI -12.97 - -1.43).ConclusionThis meta-analysis found that patients with allergies, including metal hypersensitivity, generally had worse functional outcomes after THA and TKA than patients without allergies. Further research is required to confirm these findings. Preoperative allergy screening can identify individuals at risk of treatment optimization.