Impact of the Indicator ‘Radiographic Pattern’ on the Clinical Presentation and Radiographic Progression of Hip Osteoarthritis - Results from an 8-Year Study

Abstract

Aim: To assess the impact of the 'radiographic pattern' indicator on changes in clinical and radiological parameters and therapeutic responses to common intra-articular therapies in hip osteoarthritis (HOA) at 8-year follow-up.Methods: 400 patients, two therapeutic courses -at baseline -month 0 (M0) and M5, were allocated into three observation groups: Normal saline (IA-NS) as a control group -N = 150, 2.0 ml per dose, single injection (SI) for each course (EC); methylprednisolone acetate (IA-CS) -N = 100, 80 mg/2.0 ml per dose, SI for EC; medium molecular weight HA (MMW-HA) -N = 150, 20 mg/2.0 ml per dose, 3 -weekly injections (M0 -W0, W1, W2) for EC. Each of the latter groups was subdivided into 6 subgroups, according to the radiographic grades (RG) -RG -II/III -Kellgren -Lawrence (K/L) and the radiographic patterns (RPs; atrophic -'A'; normotrophic -'I'; hypertrophic -'H') of the patients, each of them consisted of 25 patients with a fixed gender distribution (F/M ratio = 15/10). The follow-up period was 8 years with assessment of the: Clinical parameters (CPs) -pain on walking (PW by VAS), functional ability (F; by WOMAC -C), patient global assessment (PtGA); laboratory parameters (LPs) -serum CTX-I, urine CTX-II and radiological indicators (RIs) -BMD assessed by DXA, including lumbar spine, total hip and total body; joint space width/joint space narrowing (JSW/JSN)assessed on an x-ray image. RIs were assessed every 12 months, whereas CPs/LPs -every month until M6 visit, every 3 months until M12 visit, and then every 6 months until M96 visit.Results: At baseline, within-group comparisons in all groups found statistically significant differences (SSD; p < 0.001) only between the endmost RPs ('A' vs. 'H'), for all CPs, LPs and BMD values in the absence of SSD in mJSW. During the observation, for all groups, SSDs (p < 0.05) were detected between all RPs ('H' vs. 'I' vs. 'A'), for all assessed indicators, but at different time points according to applied treatment. Furthermore, between groups comparisons found SSD at М12 in JSN for both stages K/L-II (p = 0.004) /K/L-III (p = 0.003), in all RPs of MMW-HA vs. NS. These findings were accompanied by similar changes in mJSW (p < 0.001) found at M36 and in times to conversions to total hip replacement (tTHR) -MMW-HA vs. NS (p < 0.001). The second course led to cumulation of the effect with an increase in the effect size (ES) and effect duration (ED) of the registered OARSI-responses -for both treatment groups (IA-CS/IA-HA; p < 0.001). Conclusion:The observed SSD in clinical, laboratory and radiographic indicators between endmost RPs at baseline and between all RPs during the follow-up -support the existence of distinct subgroups of HOA (the ones associated with individual RPs), each of them with their specific characteristics of AC-breakdown and SB-remodeling ReSeaRch aRTicLeCheck for updates -2019 OARSI recommendations [16] approve IA-HA only for episodes of disease exacerbation, for short-term pain improvement, and only for the knee joints. The recommendations of th...