Objective: A few studies have reported on short-term outcomes of patients receiving imaging-guided injections into the foot articulations, but none have compared patient responses depending on the anatomic site injected. This study includes a large sample size facilitating the investigation of postinjection pain reduction overall and by specific articulation.
Materials and methods: Three hundred forty-eight patients with imaging-guided diagnostic or therapeutic injections into the foot articulations, with complete preinjection and 20- to 30-minute postinjection numeric rating scale pain data were included. The proportions of patients reporting clinically relevant pain reduction (≥ 50%) were calculated overall and for specific subgroups. The risk ratio comparing patients with osteoarthritis to those without osteoarthritis was calculated. Analysis of variance was used to compare outcomes between subgroups of patients based on injection site. The unpaired Student t test was used to compare responses of men versus women, those with and without a diagnosis of osteoarthritis, and more experienced versus less experienced radiologists.
Results: Sixty-four percent of patients (224/348) reported clinically relevant pain reduction. The average decrease overall was 56% (SD, 36). Injections into the Lisfranc articulation were significantly more effective (61% pain reduction, p = 0.007) compared with other sites, with 74% of patients obtaining clinically relevant pain relief. Patients with osteoarthritis reported more relief (62%) compared with those without (50%, p = 0.002). No difference in outcomes comparing musculoskeletal radiologists with residents or fellows in training was found.
Conclusion: Nearly two thirds of patients receiving imaging-guided injections into the foot articulations reported clinically relevant pain reduction. Lisfranc joint injections and patients with a diagnosis of osteoarthritis responded better.