The distribution of loose bodies determined on knee magnetic resonance imaging: joint compartments, recesses and bursae including arthroscopic blind spots

MRI of diffuse-type tenosynovial giant cell tumour in the knee: a guide for diagnosis and treatment response assessment

Tenosynovial giant cell tumour (TGCT) is a rare soft-tissue tumour originating from synovial lining of joints, bursae and tendon sheaths. The tumour comprises two subtypes: the localised-type (L-TGCT) is characterised by a single, well-defined lesion, whereas the diffuse-type (D-TGCT) consists of multiple lesions without clear margins. D-TGCT was previously known as pigmented villonodular synovitis. Although benign, TGCT can behave locally aggressive, especially the diffuse-type. Magnetic resonance imaging (MRI) is the modality of choice to diagnose TGCT and discriminate between subtypes. MRI can also provide a preoperative map before synovectomy, the mainstay of treatment. Finally, since the arrival of colony-stimulating factor 1-receptor inhibitors, a novel systemic therapy for D-TGCT patients with relapsed or inoperable disease, MRI is key in assessing treatment response. As recurrence after treatment of D-TGCT occurs more often than in L-TGCT, follow-up imaging plays an important role in D-TGCT. Reading follow-up MRIs of these diffuse synovial tumours may be a daunting task. Therefore, this educational review focuses on MRI findings in D-TGCT of the knee, which represents the most involved joint site (approximately 70% of patients). We aim to provide a systematic approach to assess the knee synovial recesses, highlight D-TGCT imaging findings, and combine these into a structured report. In addition, differential diagnoses mimicking D-TGCT, potential pitfalls and evaluation of tumour response following systemic therapies are discussed. Finally, we propose automated volumetric quantification of D-TGCT as the next step in quantitative treatment response assessment as an alternative to current radiological assessment criteria.

Assessment and Management of Loose Bodies in the Knee Joint and Related Disease: A Narrative Review

BACKGROUND

Loose bodies are frequently encountered during clinical activity and a common finding during knee arthroscopy. Usually, treatment consists of the removal of the loose bodies, which can be challenging even for experienced surgeons. The excision alone is not always the complete treatment, because loose bodies are generally secondary to other diseases that can cause persistent symptoms with the risk of new loose body formation. The aim of this narrative review is to show the clinical, imaging and arthroscopic evaluation of loose bodies in order to plan optimal treatment.

METHODS

A comprehensive search of PubMed was conducted to find the most recent and relevant studies investigating the aetiopathogenesis, the assessment tools and the therapeutic strategies for knee loose bodies and their related diseases.

RESULTS

When dealing with a loose body, the first issue is the evaluation of the intra-articular fragment (location, size, number, symptoms) and its aetiopathogenesis by identifying the underlying pathology (e.g., osteochondritis dissecans, osteoarthritis, chondral defect, tumour-like lesions, rheumatoid arthritis, etc.). In the case of symptomatic intra-articular loose bodies, treatment consists of fragment removal and the management of related diseases (e.g., lifestyle modification, physiotherapy, pharmacological and surgical treatment).

CONCLUSION

Loose bodies are not separate entities and in addition to their pathological aspect, must be evaluated within the context of the underlying disease. Correct assessment and comprehensive management allow for relief of symptomatology and prevention of loose body formation by removal and treatment of the associated diseases.

Sonographic Diagnostic of an Adventitial Bursitis on the Distal Forearm: A Case Report

A bursa is a thin sac filled with viscous fluid to facilitate friction and gliding. In the human body, there are two types of bursae: synovial bursae in well-defined positions and adventitial bursae, which develop in sites where friction or pressure increases. This case study is on a young woman with an old distal radial extremity fracture, with occupational exposure to pressure on distal ulnar forearm. She noticed a small and painful mass, with some mobility on the above-mentioned site. Sonography was used to detect a small fluid accumulation with features of adventitial bursitis. This case presents a rare localization of an adventitial bursitis. It is believed to have developed over the distal ulnar epiphysis, with a small bone malalignment, after an old and consolidated fracture, of the distal radial extremity.

Medial meniscal ossicles: Associated knee MRI findings in a multicenter case-control study

PURPOSE

The purpose of this study was to assess and compare the prevalence of meniscal, ligament and cartilage lesions on knee MRI in a series of age- and sex-matched patients with and without medial meniscal ossicle.

MATERIALS AND METHODS

Forty-two knee MRI examinations obtained in 42 patients (36 men, 6 women; mean age, 42.5±22.2 [SD] years; range: 19-65years) on which a medial meniscal ossicle was present were compared to 42 knee MRI examinations obtained in 42 age- and sex-matched patients (36 men, 6 women; mean age, 41.8±20.6 [SD] years; range: 19-65years) on which no medial meniscal ossicles were present. Two radiologists (R1, R2) blinded to the presence of meniscal ossicle by reading only the fat-saturated intermediate-weighted MR images separately assessed the presence of meniscal, ligament and cartilage lesions on these 84 knee MRI examinations. Prevalence of meniscal and ligament lesions and degree of cartilage degradation at MRI were compared between knees with and those without medial meniscal ossicle.

RESULTS

In knees with medial meniscal ossicle, R1 and R2 detected 33 (79%) and 38 (90%) medial meniscal lesions, respectively that involved the posterior root (n=25/32 for R1/R2), the posterior horn (n=19/14 for R1/R2) or the body (n=8/10 for R1/R2). The prevalence of posterior root tear (60% [25/42]/76% [32/42] for R1/R2) and that of anterior cruciate ligament (ACL) lesions (48% [20/42]/57% [24/42] for R1/R2) as well as the medial cartilage degradation score (3.35±0.87 [SD] for R1 and 3.92±0.78 [SD] for R2) were significantly greater in knees with than in knees without medial meniscal ossicle (root lesions: P<0.01 for both readers; ACL lesions and medial cartilage score: P<0.01 for both readers).

CONCLUSION

On MRI examination, knees with a medial meniscal ossicle demonstrate a greater frequency of medial posterior root tear and of ACL lesions and a greater degree of medial femoro-tibial cartilage degradation by comparison with knees without medial ossicle.