Intra-Articular.

Abstract

Osteoarthritis (OA) of the hip and knee is among the most common joint disorders. Intra-articular corticosteroid (IACS) injections are frequently performed to treat OA and other joint-related pain syndromes; however, there is conflicting evidence on their potential benefit. There is a lack of prospective and large retrospective studies evaluating potential joint findings, including increased risk for accelerated OA progression or adverse joint events, after treatment with IACS injection. Four main adverse joint findings have been structurally observed in patients after IACS injections: accelerated OA progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction, including bone loss. Physicians, including radiologists, should be familiar with imaging findings and patient characteristics that may help them identify potential joints at risk for such events. The purpose of this report is to review the existing literature, describe observed adverse joint events after IACS injections, and provide an outlook on how this may affect clinical practice. Additional research endeavors are urgently needed to better understand and identify risk factors prior to intervention and to detect adverse joint events after injection as early as possible to prevent or minimize complications.

Summary

An increased clinical awareness of adverse joint events after intra-articular corticosteroid injections has led to potential imaging findings and patient characteristics that may assist in identifying which joints could be at risk, although high-quality evidence regarding this topic is lacking.

Essentials
  • ■ Adverse joint events after intra-articular corticosteroid (IACS) injection, including accelerated osteoarthritis progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction with bone loss, are becoming more recognized by physicians, including radiologists, who may consider adding these risks to the patient consent.
  • ■ Certain imaging findings and patient characteristics could potentially assist radiologists and other physicians in identifying which joints are at risk for complications after IACS injections combined with local anesthetics.
  • ■ The radiology community should actively engage in high-quality research to further understand these adverse joint findings and how they possibly relate to IACS injections to prevent or minimize complications.
Introduction

Osteoarthritis (OA) is among the most common joint diseases affecting the hip and knee, and the incidence is expected to increase with extended life expectancy and increasing obesity (1). Pain related to OA can be debilitating and can limit an individual’s activity and quality of life (2,3). Nonsurgical approaches, including pain control, are the recommended first-line treatments prior to considering joint replacement in patients with late-stage disease (4). However, many patients with OA are not suitable candidates for joint replacement because of their older age, comorbidities, or both.

Injection of intra-articular corticosteroids (IACSs), usually combined with local anesthetics, is commonly performed to treat pain related to hip and knee OA (5,6). The American College of Rheumatology conditionally recommends IACS injection to treat OA (7), while the Osteoarthritis Research Society International recommends that IACS injection should be considered, particularly in patients with moderate to severe pain whose response to oral analgesic or anti-inflammatory agents is not satisfactory, as well as in those with symptomatic knee OA with effusions or other physical signs of local inflammation (4). Unlike the American College of Rheumatology and Osteoarthritis Research Society International, the American Academy of Orthopedic Surgeons does not currently have recommendations for or against the use of IACS injection of the knee and advises that practitioners should be alert for emerging evidence that clarifies or helps determine the balance between benefits and potential harm. Patient preference should have a substantial influence on the type of treatment selected.

In 2015, Jüni et al performed a systematic meta-analysis on behalf of the Cochrane Musculoskeletal Group to determine the pain and quality of life associated with and the function and safety of IACS when compared with sham injection or no treatment in patients with knee OA (9). That meta-analysis comprised 27 trials that included 1767 participants. The overall quality of evidence was graded as low for all outcomes because treatment effect estimates were inconsistent, there was substantial variation across trials, and most trials had a high or unclear risk of bias. The authors concluded that IACS injections might have resulted in a moderate improvement in pain and a small improvement in physical function; however, the quality of the evidence was low, and the overall results were inconclusive. They also showed that IACS injections appeared to cause as many side effects as the placebo (13% vs 15%), but they emphasized that there was a lack of precise and reliable information about side effects and that only a small number of trials reported adverse joint events. The listed side effects after injection include arthralgia, joint swelling, back pain, and joint stiffness. Maricar et al (10) evaluated structural changes in the knee at MRI and radiography and the response to IACS injections. The authors demonstrated that more severe meniscal damage, greater joint space narrowing, and higher Kellgren-Lawrence grade were associated with a decreased likelihood of a long-term response (6 months). Additionally, baseline synovitis did not correlate with a treatment response.

Another review performed by Law et al focused on current concepts on the use of IACS injections for knee OA, including potential contraindications. The authors concluded that contraindications to IACS injections are all relative based on the best available evidence (11). Contraindications include active superficial skin or soft-tissue infection, suspected joint infection, unstable coagulopathy, anticoagulant therapy, uncontrolled diabetes mellitus, and broken skin at the injection site (11). Of note, anticoagulation treatment is not a general contraindication for IACS injection. Neither contraindications regarding pre-existing articular structural changes nor damage to the joint after IACS injections are mentioned in this review.