Diagnostic Validity of Infrapatellar Fat Pad Impingement Syndrome: Performance of Clinical Tests Compared to MRI Imaging
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 50
- 试验地点
- 1
- 主要终点
- The primary endpoint of this study is the diagnostic value of the five clinical tests targeting the infrapatellar fat pad, considered collectively as a test cluster.
研究概览
简要总结
The ETICHOFFA study is a clinical research project aiming to improve the diagnosis of Infrapatellar fat pad impingement syndrome, a common source of anterior knee pain. Although MRI remains the gold standard for diagnosis, clinical testing strategies lack validation. This observational study has two main objectives: to assess the diagnostic accuracy of a cluster of standardized clinical provocation tests for IFP impingement compared to MRI findings, and to identify clinical and subjective characteristics associated with IFP involvement confirmed by imaging.
This observational study will recruit 50 patients aged 18 to 70 years with anterior knee pain rated at least 3 out of 10 in intensity. Participants will complete a secure online questionnaire documenting symptoms, pain distribution, aggravating and relieving factors, and pain intensity at rest, during activity, and daily life. They will also complete three validated scales: the Anterior Knee Pain Scale (AKPS), the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Tampa Scale for Kinesiophobia (TSK).
A standardized clinical examination will be performed, including subpatellar skin temperature measurement, knee swelling assessment, passive range of motion testing, and a series of provocation tests targeting Hoffa's fat pad. Tests will be randomized to reduce bias and considered positive if they reproduce the patient's typical pain with an intensity of at least 2/10. Each participant must also undergo a standardized MRI of the knee within two weeks of the clinical assessment, interpreted blindly by an independent musculoskeletal radiologist.
All data will be anonymized, stored securely, and analyzed using SPSS software. Diagnostic accuracy of clinical tests will be evaluated through sensitivity, specificity, predictive values, and likelihood ratios. Functional outcomes related to taping will also be analyzed.
The study has received ethical approval and adheres to GDPR standards for data protection. Participation is voluntary, with the right to withdraw at any time. The ETICHOFFA study is expected to enhance clinical diagnostic pathways for anterior knee pain associated with Infrapatellar fat pad involvement.
详细描述
Study Protocol Description The ETICHOFFA study is a clinical research project aiming to improve the diagnosis of infrapatellar fat pad (IFP) impingement syndrome, a common but under-recognized source of anterior knee pain. Although magnetic resonance imaging (MRI) remains the diagnostic gold standard, clinical testing strategies for IFP involvement are poorly standardized and lack validated diagnostic performance.
This observational study has two main objectives: (1) to assess the diagnostic accuracy of a cluster of standardized clinical provocation tests for IFP impingement compared to MRI findings, and (2) to identify clinical and subjective characteristics associated with IFP involvement confirmed by imaging.
The sample size of 50 participants was determined by an a priori power calculation. The primary hypothesis is that a composite score based on five clinical provocation tests will yield an area under the ROC curve (AUC) of at least 0.80, a threshold commonly considered indicative of good diagnostic discrimination. The null hypothesis is set at an AUC of 0.50, representing no discriminative ability. Using a two-sided alpha level of 0.05 and a statistical power of 80% (1-β), and assuming a prevalence of positive MRI findings of approximately 33% (i.e., a 2:1 ratio of test negatives to positives), the number of positive cases required was estimated at 11, corresponding to a total of 33 participants (11 positives and 22 negatives). Accounting for a 10% anticipated loss or exclusion rate, the total sample size was increased to 37 participants. However, this calculation is based on idealized assumptions and does not fully capture the uncertainties inherent to clinical research under real-world conditions. Variability in actual IFP prevalence, incomplete or uninterpretable MRI data, and interindividual variability in clinical test responses may all affect the study's effective statistical power. Therefore, a sample size of 50 participants was ultimately planned to ensure robust analysis and compensate for such contingencies.
The study will proceed in the following steps:
Step 1: Patient Inclusion Patients will be eligible if they are aged between 18 and 70 years and experience anterior knee pain with an intensity of ≥ 3/10 on a numerical pain scale on most days over the past month.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age between 18 and 70 years
- •Presence of anterior knee pain with an intensity of ≥3/10 on the Numerical Rating Scale (NRS), on most days over the past month
- •MRI of the knee performed within a maximum of 15 days before or after the clinical examination.
排除标准
- •History of corticosteroid injection treatment within the previous 12 months;
- •Known allergy or skin intolerance to medical adhesives or rigid tape;
- •History of hip or lumbar spine surgery;
- •History of neurological disorders or a diagnosis of fibromyalgia;
- •Contraindication to MRI (e.g., metallic foreign body, incompatible implantable device)
结局指标
主要结局
The primary endpoint of this study is the diagnostic value of the five clinical tests targeting the infrapatellar fat pad, considered collectively as a test cluster.
时间窗: At baseline (post-imaging and clinical assessment)
The overall performance of the test cluster will be analyzed using contingency matrices comparing the combined clinical test results with MRI findings. Various combination strategies will be tested (e.g., ≥2 positive tests out of 5), and the following diagnostic validity indices will be calculated for each threshold: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios (LR⁺, LR-). ROC curves will be generated, and the area under the curve (AUC) will be used as a synthetic indicator of the cluster's discriminative capacity, with an AUC ≥ 0.80 considered clinically meaningful.
次要结局
- Diagnostic performance of individual clinical tests(At baseline (post clinical assessment))
- Post-test probability of Infrapatellar fat pad impingement (Fagan nomogram analysis)(At baseline (post-imaging and clinical assessment))
- Infrapatellar skin temperature at rest (lying position)(At baseline (during initial clinical assessment))
- Presence of intra-articular swelling (Stroke Test)(At baseline (during initial clinical assessment))
- Passive range of motion of the knee (flexion and extension)(At baseline (during initial clinical assessment))
- Anterior Knee Pain Scale (AKPS)(At baseline (during initial clinical assessment))
- Tampa Scale for Kinesiophobia (TSK-11)(At baseline (during initial clinical assessment))
- Body Mass Index (BMI)(At baseline (during initial clinical assessment))
- Location of anterior knee pain (pain localization map)(At baseline (during initial clinical assessment))
- Knee Injury and Osteoarthritis Outcome Score - Patellofemoral subscale (KOOS-PF)(At baseline (during initial clinical assessment))
- Pain intensity at rest (VAS/100)(At baseline (during initial clinical assessment))
- Pain intensity during physical activity (VAS/100)(At baseline (during initial clinical assessment))
- Pain intensity in everyday situations (VAS/100)(At baseline (during clinical interview))