Multimodality imaging assessment of meniscal ossicle

The Role of Ultrasound in the Diagnosis and Treatment of Meniscal Injuries

PURPOSE OF REVIEW

This review evaluates the current understanding of the role of ultrasound in the diagnosis and treatment of meniscal disorders.

RECENT FINDINGS

Ultrasound (US) demonstrates similar sensitivity and specificity when compared to magnetic resonance imaging in the evaluation of meniscal injuries when compared to arthroscopy. Meniscal extrusion (ME) under US can be a reliable metric to evaluate for meniscal root tears in knees with and without osteoarthritis (OA). Sonographic ME is associated with development of OA in knees without OA. US following allograft meniscal transplant may be useful in predicting graft failure. US findings can be used to screen for discoid menisci and may demonstrate snapping of a type 3 discoid lateral meniscus. Shear wave elastography for meniscal injuries is in its infancy; however, increased meniscal stiffness may be seen with meniscal degeneration. Perimeniscal corticosteroid injections may provide short term relief from meniscal symptoms, and intrameniscal platelet-rich plasma injections appear to be safe and effective up to three years. Ultrasound-assisted meniscal surgery may increase the safety of all inside repairs near the lateral root and may assist in assessing meniscal reduction following root repair. Diagnostic US can demonstrate with high accuracy a variety of meniscal pathologies and can be considered a screening tool. Newer technologies such as shear wave elastography may allow us to evaluate characteristics of meniscal tissue that is not possible on conventional imaging. US-guided (USG) treatment of meniscal injuries is possible and may be preferable to surgery for the initial treatment of degenerative meniscal lesions. USG or US-assisted meniscal surgery is in its infancy.

Diagnostic and therapeutic approach to meniscal ossification: a systematic review

PURPOSE

The purpose of this study was to systematically review case reports and case series about meniscal ossicle, to summarize existing evidence. Specifically, to identify the etiology, demographic characteristics, localization, clinical features, diagnostic procedures and treatment options of this rare entity. Although, case reports/ series are of low level of evidence, a systematic review of such studies can provide and help us to gain a better understanding and awareness of meniscal ossicle.

METHODS

Two authors searched three online databases (MEDLINE, SCOPUS and GOOGLE SCHOLAR) from inception until March 2020 for the literature on meniscal ossicle. Inclusion criteria included case series, case reports and case-based reviews, available in full-text version, in English and that concern humans. Reports published in languages other than English were excluded, as well as articles with no electronic full text availability. Case reports using the term "meniscal ossicle" to describe an acute avulsion fracture of the tibial root of the meniscus, were also excluded.

RESULTS

Of 453 initial studies, 38 studies satisfied inclusion criteria. In total 169 patients were included of whom 107 (63%) were males and 62 (37%) were females. Mean age was 44 years (range 12-87). According to Magnetic resonance imaging findings, in 144 knees (86%) the ossicle was localized at the posterior root or horn of the medial meniscus. 60% of the patients had a history of trauma. The predominant symptom in 87% of patients was knee pain. In all patients was detected an intra-articular density structure in computed radiography. 76% had associated meniscal tear, 61% had intraarticular cartilage loss, 34% meniscal extrusion and 28% anterior cruciate ligament injury. Treatment modalities included conservative regimen in 40 patients, while 59 patients underwent surgical excision.

CONCLUSION

The most possible etiology of meniscal ossicle is posttraumatic heterotopic ossification and small occult bony avulsion fracture. It is commonly observed in individuals complaining about knee pain with history of antecedent trauma. The presence of a meniscal ossicle should alert the physician to the high likelihood of the patient having an associated meniscal tear, articular cartilage loss, ACL injury or meniscal extrusion. Along with the meniscal ossicle, the associated meniscal tear should be treated as well.

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.

Ossification of the discoid meniscus: A case report

Meniscal ossification, or bone formation within the substance of the meniscus, is a rare entity. Magnetic resonance imaging allows the unequivocal diagnosis of a meniscal ossification. We aimed to present a case of discoid meniscal ossification, which is quite rare, with the emphasis on imaging findings.

Meniscal ossicle in a professional soccer player

Meniscal ossicles are an unusual finding and a rare cause for knee pain. They are often initially diagnosed as a loose body, chondrocalcinosis or meniscal calcification within the knee joint. Few cases have been reported in the literature. We present a case of a meniscal ossicle with an associated femoral cartilage lesion in a healthy 26-year-old male professional soccer player who presented with swelling and pain. The purpose of this article is to discuss the origins, radiological features, clinical symptoms and prognosis of meniscal ossicles.

Meniscal ossicle

Meniscal ossicle, or bone within the substance of meniscus, is a rare entity and commonly confused with a loose body both clinically and radiologically. MRI is the modality that can definitely diagnose meniscal ossicle and avoid unnecessary diagnostic arthroscopy. Here we report one such case diagnosed using MRI; this patient is doing well without surgery one year after diagnosis.

Meniscal ossicle: a case report

Meniscal ossicle is a cortical or cancellous tissue with central viable marrow surrounded by meniscal cartilage. We present a case of medial meniscal ossicle at its posterior horn. A 21-year-old male military recruit visited our clinic due to left knee discomfort. He had not undergone any notable injury on the knee, but complained of intermittent catching or giving way without locking. Simple radiographs showed a small round bony fragment at posteromedial side of knee joint. The magnetic resonance imaging revealed an intra-substance lesion of meniscus, whose signal is identical to bone. On arthroscopy, the articular cartilage of medial femoral condyle and tibial plateau appeared degenerative with a groove-like scar. The medial meniscus seemed swollen at the posterior horn, but there was no discernible tear in the adjacent meniscus. After piecemeal removal of meniscal substance, a small osseous fragment was identified, which was evacuated via posteromedial portal. The resection of meniscus amounted to a subtotal meniscectomy. The activities of daily living were possible without any trouble even after 9 months of follow-up. This entity should be distinguished from intra-articular loose body, and included in the differential diagnosis of the incidental findings of small ossified density around knee joint.