Infrapatellar fat pad volume and Hoffa‐synovitis after ACL reconstruction: Association with early osteoarthritis features and pain over 5 years

Abstract

Infrapatellar fat pad (IPFP) morphology and Hoffa‐synovitis may be relevant to the development and progression of post‐traumatic osteoarthritis (OA). We aimed to compare IPFP volume and Hoffa‐synovitis in participants with anterior cruciate ligament reconstruction (ACLR) and uninjured controls, and to determine their association with prevalent and worsening early knee OA features and pain in participants post‐ACLR. We assessed IPFP volume and Hoffa‐synovitis from magnetic resonance imaging (MRI) in 111 participants 1‐year post‐ACLR and 20 uninjured controls. Patellofemoral and tibiofemoral cartilage and bone marrow lesions (BMLs) were assessed from MRIs at 1 and 5 years post‐ACLR, and worsening defined as any longitudinal increase in lesion size/severity. IPFP volume and Hoffa‐synovitis prevalence were compared between groups with analysis of covariance and χ 2 tests, respectively. Generalized linear models assessed the relation of IPFP volume and Hoffa‐synovitis to prevalent and worsening features of OA and knee pain (Knee injury and Osteoarthritis Outcome Score—Pain Subscale, Anterior Knee Pain Scale). No significant between‐group differences were observed in IPFP volume (ACLR 34.39 ± 7.29cm3, Control 34.27 ± 7.56cm3) and Hoffa‐synovitis (ACLR 61%, Control 80%). Greater IPFP volume at 1‐year post‐ACLR was associated with greater odds of patellofemoral BMLs at 1‐year (odds ratio [OR] [95% confidence intervals]: 1.104 [1.016, 1.200]) and worsening tibiofemoral cartilage lesions at 5‐year post‐ACLR (OR: 1.234 [1.026, 1.483]). Hoffa‐synovitis at 1‐year post‐ACLR was associated with greater odds of worsening patellofemoral BMLs at 5‐year post‐ACLR (OR: 7.465 [1.291, 43.169]). In conclusion, IPFP volume and Hoffa‐synovitis prevalence are similar between individuals 1‐year post‐ACLR and controls. Greater IPFP volume and Hoffa‐synovitis appear to be associated with the presence and worsening of some early OA features in those post‐ACLR, but not pain.

Effusion-synovitis worsening mediates the association between body mass index and Kellgren-Lawrence progression in obese individuals: data from the Osteoarthritis Initiative

“…Both effusion-synovitis and Hoffa synovitis were shown to be associated with KL grade, joint space width, joint space narrowing, and total subchondral bone marrow lesion volume 33 . Of interest, the prevalence of Hoffa-synovitis prevalence was similar between participants with or without knee injury 34 . After stratification by sex, effusion-synovitis differed between cases and controls in both women and men, whereas Hoffa-synovitis differed only in women.…”

Assessment of the Impact of Physical Activity on the Musculoskeletal System in Early Degenerative Knee Joint Lesions in an Animal Model

“…In their study, Hart et al assessed the volume of the Hoffa fat body in patients after anterior cruciate ligament reconstruction and found that the thickening of the Hoffa fat body may be responsible for the early stage of OA of the entire knee. As suggested by the authors, the volume and metabolic activity of IPFP may be an important marker of early OA [ 63 ]. Further studies are required to evaluate IPFP in early OA.…”

Risk factors of cartilage lesion after anterior cruciate ligament reconstruction

“…In addition, Hart et al (2022) found that the presence of a larger subpatellar fat pad and Hoffa’s synovitis after ACLR would increase the patient’s odds of having patellofemoral and tibiofemoral cartilage injury at 1 year post-operatively. At 5 years post-operatively, this chance was even seven times as high.…”