Janus Kinase Inhibitor Upadacitinib in Elderly-Onset Rheumatoid Arthritis With Hip Osteoarthritis: A Case Report

Area of Science:

• Rheumatology
• Orthopedics
• Pharmacology

Background:

• Evaluating hip pain in older adults with established osteoarthritis (OA) is complex when elderly-onset rheumatoid arthritis (EORA) coexists.
• Conventional disease-modifying antirheumatic drugs (DMARDs) and corticosteroids often provide insufficient control for EORA superimposed on end-stage hip OA.
• Radiographic structural improvement in the hip joint is rarely observed with existing treatments for EORA.

Purpose of the Study:

• To report a case of EORA developing in a patient with end-stage hip OA.
• To evaluate the efficacy and radiographic impact of upadacitinib (UPA), a Janus kinase (JAK) inhibitor, in this complex clinical scenario.
• To explore the potential for inflammatory control to influence structural findings in coexisting hip OA and EORA.

Main Methods:

• A case report of a 78-year-old male patient with end-stage hip OA who developed EORA.
• Treatment involved corticosteroids and conventional DMARDs, followed by initiation of upadacitinib (UPA) due to persistent high disease activity.
• Clinical and radiographic assessments were performed throughout the treatment course, including evaluation of C-reactive protein (CRP), Simplified Disease Activity Index (SDAI), and Disease Activity Score 28-CRP (DAS28-CRP).

Main Results:

• The patient achieved marked clinical improvement and corticosteroid discontinuation after initiating UPA monotherapy.
• Disease activity significantly decreased (SDAI to 3.0, DAS28-CRP to 1.5), with substantial improvement in hip-related symptoms.
• Follow-up radiographs showed subtle improvements in joint space narrowing and subchondral bone delineation within 6 months of UPA treatment.
• Despite symptom relief, persistent gait disturbance necessitated total hip arthroplasty, with intraoperative findings revealing only mild synovial inflammation.

Conclusions:

• Tight inflammatory control with upadacitinib (UPA) in end-stage hip OA complicated by EORA can lead to symptomatic relief and potential radiographic changes.
• In cases of coexisting hip OA and EORA, repeat imaging after effective inflammation suppression may help differentiate pain sources and interpret structural findings.
• This case highlights the potential benefit of JAK inhibitors in managing complex inflammatory arthritis superimposed on degenerative joint disease.