No Evidence of Systemic Inflammation in Symptomatic Patients With Femoroacetabular Impingement

Abstract

Femoroacetabular impingement (FAI) is a common cause of hip pain and represents a major cause of early osteoarthritis. The role of systemic inflammation in pre‐arthritic hip conditions remains largely unknown and uninvestigated. Serum‐free light chains (sFLCs) are inflammatory markers produced by B cells. This study aimed to determine whether there was evidence of systemic inflammation in patients with FAI, defined by sFLCs, and whether this correlated with markers of disease severity. Participants for this study were recruited from a single center (Nuffield Orthopedic Center, Oxford) and were taking part in the Femoroacetabular Impingement Trial. The cohort comprised 115 individuals (38 male, 77 female, mean age 37 years): 57 individuals received surgical intervention and 58 received physiotherapy. All individuals provided patient‐reported outcome measures and serum samples at baseline and follow‐up 8 months post‐randomization. sFLC concentrations were measured in serum samples by immunoturbidimetry. At baseline, for all individuals, mean polyclonal sFLC concentrations were 30.36 mg/l (standard deviation [SD] 9.23). At follow‐up, the mean polyclonal sFLC concentrations were 31.68 mg/l (SD 9.61) in the surgical intervention cohort, and 29.48 mg/l (SD 7.85) in the physiotherapy intervention cohort. There was no significant correlation between sFLC concentrations and any of the patient reported outcome measures, or radiographic measures: average or maximum alpha angle, or center edge angle. In conclusion, in patients with symptomatic FAI there was no systemic inflammation, as defined by sFLC concentrations, and no correlation between sFLC concentrations and measures of disease severity. The lack of inflammation suggests FAI is a mechanical phenomenon. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2189–2196, 2019

Distinct Pattern of Inflammation of Articular Cartilage and the Synovium in Early and Late Hip Femoroacetabular Impingement

“…However, our data on synovial samples are limited because we only took 1 sample from the worst macroscopic area, limiting the investigation of the status of intra-articular synovial inflammation in hip FAI. Furthermore, Talks et al 34 reported that no systemic inflammation, defined by the serum-free light chain concentration in serum samples, was found in patients with symptomatic FAI, suggesting that FAI is localized. However, Bedi et al 3 demonstrated that, compared with age- and activity-matched athletes without FAI, those with FAI had a 24% increase in mean circulating levels of cartilage oligomeric matrix protein (COMP) and a nearly 3-fold elevation in mean circulating levels of C-reactive protein (CRP).…”

RE: Talks BJ, Fernquest S, Palmer A, et al. 2019. No Evidence of Systemic Inflammation in Symptomatic Patients With Femoroacetabular Impingement

“…We are writing in regards to an article by Talks et al 1 that was recently published in the Journal of Orthopaedic Research. The stated aim of the study was to "determine whether there was evidence of systemic inflammation in patients with femoroacetabular impingement (FAI), defined by serum-free light chains (sFLCs), and whether this correlated with markers of disease severity."…”

RE: Normal Serum‐Free Light Chain Concentrations in Femoroacetabular Impingement—Evidence Against a Systemic Inflammatory Response

“…We are writing in response to the letter by Mendias and Bedi, regarding our recent publication in the Journal of Orthopedic Research. 1 Lately, inflammation has been acknowledged as a factor in the pathogenesis of osteoarthritis, with local inflammation contributing to disease progression 2 and systemic inflammation correlating with symptom severity. 3 However, the current literature predominantly suggests that femoroacetabular impingement (FAI) is a mechanical phenomenon: abnormal morphology of the hip joint exposes it to supraphysiologic stress, resulting in recurrent microtrauma of the articular cartilage, which eventually culminates in osteoarthritis of the joint.…”