Yes, I've heard about it. Here's a study on it in psoriatic arthritis:
From European League Against Rheumatism
http://www.eular.orgFRI0143 INTRAARTICULAR INJECTION OF INFLIXIMAB IN RELAPSING KNEE EFFUSION IN PSORIATIC ARTHRITIS: A PILOT STUDY
L. Niccoli1, F. Cantini1, G. Porciello1, L. Storri1, C. Nannini1, A. Padula2, I. Olivieri2, L. Boiardi3, C. Salvarani3
1II Division of Medicine-Rheumatology Unit, Hospital of Prato, Prato, 2Department of Rheumatology of Basilicata, Ospedale S.Carlo, Potenza, 3Division of Rheumatology, Arcispedale S.maria Nuova, Reggio Emilia, Italy
Background: Some patients with psoriatic arthritis (PsA) continue to experience recurrent knee effusion despite repeated local corticosteroid injections and a good clinical response to immunosuppressive therapy of other articular manifestations.
Objectives: To evaluate the efficacy and safety of intraarticular knee injections of infliximab in a clinical series of patients with PsA who had refractory knee effusion.
Methods: We treated 3 females (median age 46 ys.) with PsA who experienced monthly recurrent, abundant knee effusion with local injection of infliximab at the dose of 50 mg diluted in 5 ml of saline solution at 6-week intervals. This dose was arbitrarily chosen. The median duration of the disease was 88 months. All 3 patients were receiving methotrexate (10 to 15 mg/week/im) and infliximab 5 mg/Kg/iv every 8 weeks. The 3 patients respectively received this therapy for 16, 14 and 12 months with remission of other articular symptoms at month 2, 3 and 3, respectively. Knee effusions relapsed every 6-8 weeks despite repeated fluid aspiration followed by local injection of 40 mg of methylprednisolone acetate. All aseptic procedure precautions were carried out before the injections. The first injection was done through the same needle used for arthrocentesis after a complete fluid aspiration. Fluid analysis for bacterial infections was performed. The following injections were done with the needle of the drug-filled syringe if joint effusion was absent. At the time of injection, patients were clinically and sonographically assessed for the presence of fluid in the knee joint. Moreover, patients were clinically evaluated for the presence of symptoms and signs of local infection every 2 weeks.
Results: Before the first injection, patient 1 had bilateral knee effusion and 160 ml and 150 ml of synovial fluid were aspirated from the right and left knee, respectively. 120 ml of fluid was aspirated from the right knee of the second patient and 100 ml fluid from the left knee of the third patient. Patient 1 did not experience any further knee fluid effusion over a 4-month follow up period. Patient 2 had a recurrence after 5 weeks but did not relapse anymore over the next 4 months. The third patient experienced a good response with no recurrence of fluid effusion during the next 3 months of follow up. None of the patients developed neither symptoms and signs of local infection nor local or systemic signs of adverse events due to infliximab.
Conclusion: Local knee injections of infliximab at the dose of 50 mg may represent an effective and safe therapy in patients with PsA and refractory knee effusions.
(though not in any way implying that you are old)