Study: Intra-articular cortisone injection provided little pain relief in FAI patients

Despite an initial significant improvement, pain relief decreased at 14 days post-injection.

Issue: September 2013

SAN ANTONIO — Researchers found no significant pain reduction in most patients at 14 days after intra-articular injection of cortisone for femoroacetabular impingement and labral tears, according to a study presented at the Arthroscopic Association of North America Annual Meeting.

Perspective from Benjamin G. Domb, MD

“Intra-articular cortisone injection has limited clinical benefit in 63% of the patients with symptomatic femoroacetabular impingement and labral tear,” Bruce A. Levy, MD, of Mayo Clinic, Rochester, Minn., said. “Our data showed absolutely no difference in pain relief between the different steroid preparations.”

Levy and the investigators noted there was lack of clinical evidence on the efficacy of cortisone injections in patients with femoroacetabular impingement (FAI) and labral tears. They retrospectively reviewed 35 patients with symptomatic FAI and labral tears confirmed on MRI who underwent fluoroscopic-guided intra-articular injections of cortisone with local anesthetic. All of the patients included in the study had a minimum of 50% pain relief during the phase when the local anesthetic was administered. The researchers excluded patients who had prior ipsilateral hip surgery. Patients had a mean age of 34 years, and study included 29 women and six men. Twenty percent of patients had Tonnis grade 0 osteoarthritis (OA) and 80% of patients had Tonnis grade 1 OA.

MRI-confirmed tears

The investigators rated pain using the Numeric Rating Scale (NRS) and collected NRS scores prospectively at the following times: pre-injection; in the first 24 hours post-injection (the anesthetic phase); and 14 days post-injection. The patients were compared at each time period for three different steroid preparations: methylprednisolone in 21 patients; triamcinolone in 12 patients; and betamethasone in two patients.

“A two-point absolute change was considered the minimal amount of significant pain relief,” Levy said.

NRS scores

The mean pre-injection NRS score was seven points, the 24-hour score was one point and the 14-day score was four points. In all, 13 patients reported a change of greater than two points on the NRS pain scale at 14 days, while 63% of patients said they had less than two points on the NRS pain scale at 14 days. Of the 63% who had less than two points of pain relief, 21 patients showed no pain relief. The average pain relief after cortisone injection was 9.4 days.

“As a group, the Numeric Rating Scale scores significantly improved at immediate post-injection compared to baseline. However, pain relief significantly diminished from immediate to 14 days post-injection for each patient,” Levy said. “We found no significant difference in pain reduction between the different steroid preparations.”

The study was limited by its retrospective design, small cohort and lack of control group, according to Levy. “There were no previously published data that we are aware of assessing the therapy to benefit intra-articular hips in this setting,” he said. – by Renee Blisard Buddle

Reference:

Levy B. Paper #SS-29. Presented at: Arthroscopy Association of North America Annual Meeting; April 25-27, 2013; San Antonio.

For more information:

Bruce A. Levy, MD, can be reached at Mayo Clinic, 200 First St., SW, Rochester, MN 55905.
Disclosure: Levy receives royalties from VOT Solutions and Arthrex and is on the speaker’s bureau for the Canadian Orthopaedic Association.

Perspective

Benjamin G. Domb, MD

The authors of this study attempted to determine the efficacy of intra-articular cortisone injections in patients with labral tears in the setting of femoroacetabular impingement (FAI). They reviewed a cohort who underwent a steroid injection, and then subsequently had hip arthroscopy to address the labral tear and FAI. They found no change in the amount of pain at 14 days post-injection in 66% of patients, concluding there is limited clinical benefit to steroid injection for patients with labral tears and FAI.

The results of this study are not surprising as the cause of pain in the hip — the abnormal abutment of the femoral head/neck against the acetabular rim — is not addressed with an injection. The mechanical disruption and damage to the labrum continues. Because injection fails to address the underlying cause of pain, we do not offer steroid injection as a definitive treatment modality for patients with labral tears and FAI.

Although injections do not have lasting therapeutic value in FAI, we frequently utilize diagnostic intra-articular injections for patients with FAI whose source of pain is not clear. In these instances, temporary relief with a diagnostic injection provides important evidence that there is an intra-articular source of pain. Diagnostic injections are particularly useful when there may be multiple coexistent sources of pain, such as those that may occur in the “hip-spine syndrome.” In addition, intra-articular steroid injections remain useful in patients who have too much arthritis for a hip arthroscopy. In such patients, serial steroid injections may provide sufficient pain relief to delay total hip replacement.

Benjamin G. Domb, MD

Clinical Assistant Professor

American Hip Institute

Chicago

Disclosures: Domb receives research support from American Hip Institute.