Ultrasound in the diagnosis of popliteal cysts

Association of complicated Baker's cysts with knee pathologies as compared to simple Baker's cysts

Baker's cysts (BCs) are known to be associated with intra-articular pathologies. BCs can be classified into 2 types: simple and complicated. Although some studies have focused on BC using magnetic resonance imaging (MRI), which is the gold standard examination, no study has compared knee MRI features in patients with simple and complicated BCs. To assess the relationship between the type of BC (simple vs complicated) and other knee pathologies using MRI. Seventy patients who underwent knee MRI examination due to symptomatic knee were retrospectively recruited from April 2011 to April 2021 at a single hospital. In the knee MRI images, the following were assessed: type (simple or complicated), morphology, volume of BCs, thickness of the suprapatellar recess, presence of synovial proliferation of the suprapatellar recess, grade of knee joint effusion, presence of meniscal tear, and extent of meniscal extrusion. The patients were classified into 2 groups according to the type of BC: simple BC and complicated BC. The differences between the 2 groups were evaluated for all variables. Finally, 52 patients were included in this study, 15 were classified as "simple BC" group and 37 as "complicated BC" group. The volume of complicated BC (median: 4.6, interquartile range - IQR: 1.6-12.4) was significantly greater than that of simple BC (median: 0.7, IQR: 0.3-3.7; P = .007). The presence of synovial proliferation in the suprapatellar recess was significantly higher in complicated BC (91.9%) than that in simple BC (46.7%; P = .001). The thickness of the suprapatellar recess was significantly greater in complicated BC (median: 7.5, IQR: 5.8-10.7) than that in simple BC (median: 4.3, IQR: 2.3-7.6; P = .020). The medial meniscus extrusion was greater in complicated BC (median: 4.1, IQR: 2.8-5.1) than that in simple BC (median: 2.5, IQR: 1.8-4.4; P = .037). After adjusting these P-values using the Holm method, only the presence of synovial proliferation in the suprapatellar recess remained significant (P = .010). Using knee MRI images, we demonstrated that complicated BCs are more associated with intra-articular pathologies than simple BCs; such as cyst volume, amount of the knee joint effusion, synovial proliferation and medial meniscal extrusion. Among them, the presence of synovial proliferation was the most significant factor associated with complicated BCs.

The development of musculoskeletal radiology for 100 years as presented in the pages of Acta Radiologica

During the last 100 years, musculoskeletal radiology has developed from bone-only radiography performed by everyone to a dedicated subspecialty, still secure in its origins in radiography but having expanded into all modalities of imaging. Like other subspecialties in radiology, it has become heavily dependent on cross-sectional and functional imaging, and musculoskeletal interventions play an important role in tumor diagnosis and treatment and in joint diseases. All these developments are reflected in the pages in Acta Radiologica, as shown in this review.

Clinical, Radiographic, and Ultrasound Findings Between Simple and Complicated Baker's Cysts

PURPOSE

The aim of the study was to compare the clinical, radiographic, and ultrasound findings between simple and complicated Baker's cysts.

METHODS

Forty-seven knees with Baker's cysts in 45 patients with knee pain were identified from a chart review. Baker's cysts were classified as simple or complicated according to ultrasound findings. Clinical data, including duration of knee pain, visual analog scale score, Kellgren-Lawrence grade, ultrasound findings, including the size and sonomorphology of the BC, severity of osteophytosis, thickness of joint effusion, meniscal tear, and synovial proliferation of the two types of BC, were compared.

RESULTS

There were 22 knees with a simple cyst and 25 knees with a complicated cyst. The thickness of the suprapatellar effusion in complicated Baker's cysts (5.7 ± 3.0 mm) was significantly greater than that in simple Baker's cysts (3.8 ± 3.2 mm), and the presence of synovial proliferation in the suprapatellar recess was significantly higher in complicated Baker's cysts (22 knees, 88.0%) than in the simple Baker's cysts (12 knees, 54.5%). However, there were no significant differences in demographic, radiographic, and other ultrasound parameters between the two types of BC.

CONCLUSIONS

Synovial proliferation with larger effusion in the suprapatellar recess was more associated with complicated BC than simple BC.

Sonography in Differential Diagnosis of Deep Venous Thrombosis of the Leg

The lower extremities of 60 consecutive symptomatic patients were examined first by ultrasound (US) and then by phlebography. Deep venous thrombosis was found in 17 patients by means of venography. A hematoma was detected by US in six legs without thrombosis. A popliteal cyst was observed by US in five cases; one patient had a concurrent deep venous thrombosis. It was concluded that symptomatic patients with a negative phlebography should be examined by US for correct diagnosis and treatment, although US cannot replace phlebography.

Popliteal cysts in adults: a review

OBJECTIVE

To review the epidemiology, clinical presentation, pathogenesis, imaging, differential diagnosis, complications, and treatment of popliteal cysts.

METHODS

References were taken from MEDLINE from 1985 to 1998 under the subject "Popliteal Cyst" with subheadings of Radiography, Ultrasonography, and Radionuclide Imaging. Other pertinent references were used. Childhood cysts were excluded.

RESULTS

Depending on the studied population and the imaging technique, 5% to 32% of knee problems may have these cysts, with 2 age-incidence peaks of 4 to 7 years and 35 to 70 years. In older patients there is usually coexistent joint pathology. Symptoms may arise in the popliteal fossa from the cyst itself or be dominated by knee pain from coexisting knee pathology. Many cysts are asymptomatic. Physical examination will miss one half of these cysts. Pathogenesis depends on the connection between the joint and bursa, with a valvelike effect allowing passage of fluid from the joint into the bursa with subsequent distention producing these cysts. Some bursae have no such joint-bursal communication, and the cysts arise primarily as bursitis of the gastrocnemio-semimembranosus bursa. Imaging is performed by plain x-ray, ultrasound, arthrography, computerized axial tomography, magnetic resonance imaging, or nuclear scan; sonography is the method of choice. Complicated cysts with extension or rupture into the calf mimic phlebitis, an important differential diagnosis. Asymptomatic cysts found incidentally need no treatment; most symptomatic cysts respond to intra-articular corticosteroid injections. Surgical excision is rarely necessary.

CONCLUSIONS AND RELEVANCE

Popliteal cysts are fairly common, may not be found on physical examination, require imaging (preferably sonography) to be identified, mimic phlebitis when extending into the calf, and often respond to intra-articular steroid or, rarely, surgical resection.

Real-time ultrasound diagnosis of deep vein thrombosis: a comparison with venography

A prospective study comparing real-time ultrasound scanning with contrast venography in the diagnosis of deep venous thrombosis of the lower limb was performed in a group of 46 patients. The sensitivity of ultrasound scanning for thrombus within the iliofemoral segment, femoral vein, and popliteal vein was 94% with a specificity of 100%. Additional information obtained by ultrasound included the diagnosis of popliteal cysts, pelvic and inguinal lymphadenopathy, popliteal haematoma, and traumatic arterial aneurysm. Real-time ultrasound scanning is a rapid and non-invasive alternative to contrast venography in the diagnosis of lower limb deep venous thrombosis.