A diagnostic approach to popliteal fossa masses

Baker's cyst with extra- and intra-articular synovial chondromatosis of knee: A case report

Synovial chondromatosis is a rare benign condition characterized by chondral proliferation from synovium forming loose bodies which can occur extra-articularly and intra-articularly. Surgical removal remains the mainstay of treatment for synovial chondromatosis. Due to the risk of recurrence, every case must be followed up with an MRI.

Efficacy and Safety of Musculoskeletal Ultrasound Guided Aspiration and Intra-Lesional Corticosteroids Injection of Ruptured Baker's Cyst: A Retrospective Observational Study

Objective:

The aim of the work was to demonstrate the effectiveness and safety of ultrasonographic guided aspiration performed with corticosteroid injection intra-lesional for ruptured Baker cysts (BCs).

Methods:

Single-center retrospective study that included 42 patients with knee joint disorder associated with ruptured BCs were treated by ultrasonographic guided aspiration of fluid from the cyst and different points from the calf then intra-lesional injection of corticosteroids once or twice, 1 week apart. Follow up were done weekly until complete resolution of symptoms. Visual analog scale (VAS) and Rauschning-Lindgren and Lysholm Knee Scoring Scales (RLC) were used for assessment.

Results:

Clinical parameters (VAS and RLC) improved significantly in all patients at both post injection evaluation visits (1 week and 12 weeks). Ultrasonographic features improved significantly with complete disappearance of free fluid in the calf in 35 (83.3%) cases 1 week after the injection, and in 41 (97.6%) after 12 weeks. As regards BCs only 4 (9.5%) cases showed complete disappearance after 1 week and there was recurrent BCs in 38 (90.5%) cases which required reaspiration. While after 12 weeks, BCs were completely disappeared in 23 (54.8%) cases, most of the relapsed BCs were complex BCs. No side effects were reported in all cases.

Conclusion:

Ultrasonographic guided aspiration followed by injection of corticosteroids intra-lesional is an efficient and safe method for managing ruptured BCs.

Solitary popliteal neurofibroma: an unusual encounter

Diagnosing a popliteal fossa mass can be intriguing at times, and are not always Baker's cysts, as expected. We present an uncommon case of a young lady who presented with a palpable firm mass in the popliteal fossa with no neurological deficit or compromised distal pulsations. On surgical exploration, it was found to be a well defined, firm mass, closely abutting the neurovascular bundle, which on histopathological study revealed a solitary encapsulated neurofibroma.

Use of contrast ultrasound in differentiating thrombosed pseudoaneurysm from sarcoma, prior to surgery

We describe a case of a 69-year-old male with a right-sided popliteal mass following a motor vehicle accident 15 years ago. The mass was indeterminate via multiple modalities (magnetic resonance imaging, digital subtraction angiography, and vascular ultrasound) with biopsy requested prior to surgical removal to determine the appropriate surgical team – vascular versus sarcoma oncologic surgery. Contrast ultrasound was utilized to determine if biopsy was indicated and if so, to determine the most appropriate target. Contrast ultrasound showed no areas of enhancement, therefore biopsy was not performed and the patient safely proceeded to vascular surgery. Pathology confirmed the mass to be a thrombosed pseudoaneurysm of the popliteal artery. We present the benefits of using contrast ultrasound in the work up and diagnosis of a popliteal neoplasm versus suspected vascular complication.

Calf "Arch Sign" Seen on a Tc-99m-MDP Bone Scan Is Indicative of Synovial Fluid Leak in Ruptured Baker's Cysts: Case Reports and Analysis of Literature

The authors present two cases in which the ruptured popliteal (Baker's) cysts remained undetected and were diagnosed only during an isotope investigation. The aim was to describe a specific imaging sign, the "arch sign", that is indicative of ruptured Baker's cysts. In both cases, the whole-body imaging was performed 2 hours after injection of 706.7 MBq of Tc-99m-MDP. Single-photon emission computed tomography (SPECT) imaging was performed to localize an accumulation of the radiopharmaceutical. An analysis of literature was performed to connect these cases with previously reported data and to detect the pathognomonic radio image sign of ruptured popliteal cysts. The arch-shaped distribution of the radiopharmaceutical below the knee joints was seen already on the whole-body bone scan image in both cases. An anterior view of SPECT MIP images showed the arched accumulation of the Tc-99m-MDP bone tracer along the postero-medial aspect of the right calf secondary to synovial fluid leak from a ruptured Baker's cyst. The similar arthroscintigrams were published since 1971 without recognizing this sign as pathognomonic. Tc-99m-MDP bone scanning is sensitive for a Baker's cyst with synovial effusion, and distribution of a radiopharmaceutical in the medial posterior calf in a shape of an arch, the arch sign, may serve as an indicator of a ruptured popliteal cyst.