Patient characteristics cannot predict the long-term effect of an intra-articular bupivacaine and corticosteroid injection in patients with femoroacetabular impingement: A retrospective cohort study

Abstract

BackgroundTo evaluate predictors for effect of an intra-articular (IA) bupivacaine and corticosteroid injection in patients with femoroacetabular impingement syndrome (FAIS). MethodsAll patients between 18 and 50 years old with FAIS who received an intra-articular (IA) bupivacaine and corticosteroid injection between 2016 and 2019 were eligible for this retrospective study. Two groups were made, the non-arthroscopy group (patients for whom conservative treatment with physiotherapy and an IA bupivacaine and corticosteroid injection was sufficient) and the arthroscopy group (patients who needed an arthroscopy because conservative treatment and an IA bupivacaine and corticosteroid injection failed). Multiple regression analysis was performed to analyse the effect of the IA corticosteroid injection and to predict arthroscopic intervention based on sex, age, body mass index, duration of complaints, alpha angle and abnormal bone morphology. ResultsIn total 103 patients were included; 46 in the arthroscopy group and 57 in the non-arthroscopy group. The groups had similar baseline characteristics. A total of 37 (36%) patients had an effect of 3 months or longer from the IA corticosteroid injection; 31 (54%) were patients in the non-arthroscopy group versus 6 (13%) patients in the arthroscopy group (P < 0.001). Male sex seems to have an negative influence on the duration of the effect of the injection. None of the variables could significantly predict if a patient would undergo arthroscopic intervention (F(7,103) = 8.54, p = 0.3, R2 = 0.11). The effect of the IA injection could not be predicted (p = 0.1; R2 = 0.13). ConclusionThere are no patient characteristics that predict who would and who would not benefit from the IA bupivacaine and corticosteroid injection in patients with FAIS and who would need an arthroscopic intervention within 1 year after the injection. Only male sex seems to have an negative influence on the duration of the effect of the injection.