Table 1 Risk of bias and population characteristics of studies included in this review
From: Predisposing factors for Hoffa’s fat pad syndrome: a systematic review
Study | Study design, level of evidence | Risk of bias | Imaging modality | Parameters evaluated | Patient groups | Number of patients (males, females) | Number of knees | Mean patient age (years) |
|---|---|---|---|---|---|---|---|---|
Zhong et al., 2022 | Non-interventional anatomical study, 4 | Low | Hydrogen proton MR spectroscopy | Hoffa’s fat pad fat fraction, unsaturation index | Patients with osteoarthritis | 48 (16, 32) | 64 | 55 |
Yu, 2022 | Non-interventional anatomical study, 4 | High | MRI | Hoffa’s fat pad oedema following football-related injury | Group 1: football-related knee injuries Group 2: outpatients with acute knee injury | Group 1: 29 (29, 0) Group 2: 31 (31, 0) | Group 1: 31 Group 2: 31 | Group 1: 23.6 Group 2: Range 18–30 |
von Engelhardt et al., 2020 | Non-interventional anatomical study, 4 | Low | MRI | Hoffa’s fat pad dimensions, oedema and fibrosis | Group 1: Hoffa’s fat pad impingement Group 2: patients with other knee pathologies, not including Hoffa’s fat pad impingement | Group 1: 62 (32. 30) Group 2: 255 (164, 91) | Group 1: 62 Group 2: 255 | Group 1: 48 Group 2: 40 |
Kim et al., 2022 | Non-interventional anatomical study, 4 | High | MRI | PPTA, patient sex, age, BMI | Group 1: Hoffa’s fat pad syndrome Group 2: medial patellar plica syndrome Group 3: chondromalacia patella | Group 1: 26 (23,3) Group 2: 86 (72, 14) Group 3: 44 (39, 5) | Group 1: 26 Group 2: 86 Group 3: 44 | Group 1: 30.8 Group 2: 29.2 Group 3: 31.5 |
Cilengir et al., 2021 | Non-interventional anatomical study, 4 | NFT | MRI | Lateral patellar tilt angle | Group 1: lateral patellar tilt angle > 5° Group 2: lateral patellar tilt angle < 5° | Group 1: 406 Group 2: 40 | 446 | NR |
Delorme and Jibri, 2021 | Non-interventional anatomical study, 4 | NFT | MRI | Relationship between Hoffa’s fat pad impingement and patellar tendinosis | Group 1: patellar tendinosis Group 2: control group | Group 1: 94 Group 2: 94 | 188 | NR |
Xiaolong et al., 2021 | Non-interventional anatomical study, 4 | NFT | MRI | ISR, trochlear angle | Superolateral Hoffa’s fat pad oedema | 60 | 60 | NR |
Kim et al., 2020 | Non-interventional anatomical study, 4 | Low | MRI | Cross sectional area, PPTA, ISR, sulcus angle, trochlear inclination, TT-TG distance, patellar alignment and tilt | Group 1: Hoffa’s fat pad syndrome Group 2: control group without knee pathology | Group 1: 46 (29, 17) Group 2: 39 (29, 10) | Group 1: 44 Group 2: 78 | Group 1: 29.2 Group 2: 31.3 |
Kim et al., 2019 | Non-interventional anatomical study, 4 | NFT | MRI | Sulcus angle, ISR, TT-TG distance, patellar alignment and tilt | Group 1: superolateral Hoffa’s fat pad oedema Group 2: patients without superolateral Hoffa’s fat pad oedema | 68 | Group 1: 24 Group 2: 47 | NR |
Campagna et al., 2012 | Non-interventional anatomical study, 4 | NFT | MRI | ISR, age, distance between patellar ligament and lateral trochlear facet | Group 1: superolateral Hoffa’s fat pad oedema Group 2: patients without superolateral Hoffa’s fat pad oedema | Group 1: 30 Group 2: 60 | 90 | NR |
Widjajahakim et al., 2017 | Non-interventional anatomical study, 4 | Low | MRI | ISR, trochlear angle, sulcus angle, trochlear inclination, TT-TG distance, bisect offset | Patients with (152) or without (982) Hoffa’s fat pad oedema | 1134 (421, 713) | 1134 | 66.8 |
Mikkilineni et al., 2018 | Non-interventional anatomical study, 4 | NFT | Ultrasound | Diameter of largest vessel supplying Hoffa’s fat pad, compressibility, vascularity, motion | Group 1: Hoffa’s fat pad impingement Group 2: asymptomatic controls | Group 1: 11 Group 2: 10 | Group 1: 11 Group 2: 10 | NR |
Gürsoy et al., 2018 | Non-interventional anatomical study, 4 | Some concerns | MRI | ISR, trochlear angle, patellofemoral angle | Group 1: superolateral Hoffa’s fat pad oedema Group 2: patients without superolateral Hoffa’s fat pad oedema | Group 1: 50 (17, 33) Group 2: 50 (28, 22) | Group 1: 50 Group 2: 50 | Group 1: 38.6 Group 2: 26.3 |
Mehta et al., 2015 | Non-interventional anatomical study, 4 | Low | MRI | Sulcus angle, TT-TG distance, lateral trochlear inclination, patellar translation, lateral patellar displacement, lateral patellar tilt, trochlear depth | Group 1: superolateral Hoffa’s fat pad oedema Group 2: normal knees | Group 1: 8 (0, 8) Group 2: 8 (0, 8) | Group 1: 16 Group 2: 16 | 19.9 |
Matcuk et al., 2014 | Non-interventional anatomical study, 4 | High | MRI | TT-TG distance, ISR, sulcus angle, lateral trochlear inclination, length of medial patellar facet, patellar angle, patellofemoral angle, patellar length, trochlear cartilage overlap, trochlear cartilage index. length of medial and lateral trochlea, trochlear depth, lateral patellar displacement and tilt, ventral trochlear prominence, length of lateral facet of the patella, largest medial and lateral AP diameters of the femur, sulcus height and patellar cartilage length | Group 1: superolateral Hoffa’s fat pad oedema Group 2: normal knees | Group 1: 65 (24, 41) Group 2: 40 (17, 23) | Group 1: 71 Group 2: 45 | Group 1: 34 Group 2: 28 |
Jibri et al., 2012 | Non-interventional anatomical study, 4 | Low | MRI | ISR, TT-TG, trochlear depth, patellar translation, patellofemoral angle, lateral patellar displacement and lateral patellar tilt | Group 1: superolateral Hoffa’s fat pad oedema Group 2: patients without superolateral Hoffa’s fat pad oedema | Group 1: 100 (24, 76) Group 2: 100 (37, 63) | Group 1: 100 Group 2: 100 | Group 1: 31 Group 2: 33 |
van Middelkoop et al., 2018 | Non-interventional anatomical study, 4 | Low | MRI | ISR, sulcus angle, patellar tilt, translation, patellar cartilage overlap, Wiberg classification, and bisect offset | Patients with patellofemoral pain | 133 (55, 78) | 133 | 30.2 |
Kitagawa et al., 2022 | 2b, low-quality RCT | High | Ultrasound | Effect of manual therapy or hot pack treatment on the flexibility of Hoffa’s fat pad | Group 1: manual therapy Group 2: hot pack application Group 3: control group (relaxed limbs) | Group 1: 21 Group 2: 22 Group 3: 21 | Group 1: 21 Group 2: 22 Group 3: 21 | 20.7 |
Pogacnik Murillo et al., 2017 | 1b, RCT | Some concerns | MRI | Effect of diet and/or exercise on Hoffa’s fat pad volume, surface area, and thickness | Group 1: exercise Group 2: diet-induced weight loss Group 3: diet-induced weight loss + exercise | Group 1: 36 (9, 27) Group 2: 35 (11, 24) Group 3: 35 (9, 26) | Group 1: 36 Group 2: 35 Group 3: 35 | NR |
Steidle-Kloc et al., 2015 | 4, prospective interventional study | NFT | MRI | Effect of weight gain or weight loss on Hoffa’s fat pad volume | Group 1: patients with 20% weight gain Group 2: patients with 20% weight loss | Group 1: 10 (4, 6) Group 2: 9 (1, 8) | Group 1: 10 Group 2: 9 | NR |
Kalsi et al., 2018 | RCT | NFT | MRI | Effect of Tissue-Gene-C on Hoffa’s fat pad synovitis and effusion-synovitis | Group 1: Tissue Gene-C (a TGF-Beta 1 expression vector) Group 2: placebo control | Group 1: 68 Group 2: 34 | Group 1: 68 Group 2: 34 | NR |