Legg-Calvé-Perthes Disease Produces Chronic Hip Synovitis and Elevation of Interleukin-6 in the Synovial Fluid

Abstract

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder of ischemic osteonecrosis of the femoral head. Hip joint synovitis is a common feature of LCPD, but the nature and pathophysiology of the synovitis remain unknown. The purpose of this study was to determine the chronicity of the synovitis and the inflammatory cytokines present in the synovial fluid at an active stage of LCPD. Serial MRI was performed on 28 patients. T2-weighted and gadolinium-enhanced MR images were used to assess synovial effusion and synovial enhancement (hyperemia) over time. A multiple-cytokine assay was used to determine the levels of 27 inflammatory cytokines and related factors present in the synovial fluid from 13 patients. MRI analysis showed fold increases of 5.0 AE 3.3 and 3.1 AE 2.1 in the synovial fluid volume in the affected hip compared to the unaffected hip at the initial and the last follow-up MRI, respectively. The mean duration between the initial and the last MRI was 17.7 AE 8.3 months. The volume of enhanced synovium on the contrast MRI was increased 16.5 AE 8.5 fold and 6.3 AE 5.6 fold in the affected hip compared to the unaffected hip at the initial MRI and the last follow-up MRI, respectively. In the synovial fluid of the affected hips, IL-6 protein levels were significantly increased (LCPD: 509 AE 519 pg/mL, non-LCPD: 19 AE 22 pg/mL; p ¼ 0.0005) on the multi-cytokine assay. Interestingly, IL-1b and TNF-a levels were not elevated. In the active stage of LCPD, chronic hip synovitis and significant elevation of IL-6 are produced in the synovial fluid. Further studies are warranted to investigate the role of IL-6 on the pathophysiology of synovitis in LCPD and how it affects bone healing.

Knee loading protects against osteonecrosis of the femoral head by enhancing vessel remodeling and bone healing

“…There are several etiologic risk factors such as trauma [3, 4], excessive corticosteroid use [5–7], excessive alcohol intake [8], Legg-Calve-Perthes disease [9, 10], etc. Debilitated blood supply to the femoral head commonly leads to necrosis and collapse of the femoral head [11].…”

Synovial osteochondromatosis in a 14-year-old boy with a history of Legg–Calve–Perthes disease

“…Additionally, the radiological appearance of the synovial osteochondromatosis was very much in keeping with the classical appearance of primary synovial osteochondromatosis, that is, multiple loose bodies of similar size. As Legg–Calve–Perthes disease has been described in association with osteochondritis dissecans [7] and with chronic synovitis [8] and since these conditions have been associated with secondary synovial osteochondromatosis [1], we assume that the changes associated with Legg–Calve–Perthes in our case render secondary synovial osteochondromatosis the more likely diagnosis. Nonetheless, secondary synovial chondromatosis can only be distinguished histologically from primary synovial chondromatosis [3]; however, a histological specimen was not obtained in this patient.…”

The management of platelet-rich plasma in ONFH treatment: A systematic review

“…Osteonecrosis of the femoral head is associated with synovitis characterized by a series of inflammatory cells and proinflammatory cytokines in necrotic lesion and synovium [33,34]. Previous research has found that the synovium is saturated by CD4+ T cells, macrophages, and some CD8+ T cells during the ONFH pathogenesis [35].…”