Baker\'s cysts, commonly incidental findings, can occasionally present as intramuscular dissecting cysts within the medial gastrocnemius muscle. This case report highlights the ultrasound features and differential diagnoses of intramuscular dissecting Baker\'s cysts through the examination of three distinct cases: a 64-year-old woman with severe osteoarthritis, an 80-year-old man with a palpable mass in the popliteal fossa, and a 37-year-old man with early degenerative arthropathy. Each case was investigated using ultrasound, revealing fusiform hypoechoic fluid collections with heterogeneous echostructure parallel to the medial gastrocnemius muscle bundle and lacking posterior reinforcement. The clinical context and ultrasound findings were critical in differentiating these cases from other conditions, such as superficial thrombophlebitis, intramuscular seroma, and intramuscular myxoma. These cases emphasize the role of ultrasound in diagnosing intramuscular dissecting Baker\'s cysts. Accurate diagnosis requires careful consideration of ultrasound features in conjunction with clinical findings.

UNASSIGNED: Popliteal cysts are secondary to degenerative changes in the knee joint. After total knee arthroplasty (TKA), 56.7% of patients with popliteal cysts at 4.9 years follow-up remained symptomatic in the popliteal area. However, the result of simultaneous arthroscopic cystectomy and unicompartmental knee arthroplasty (UKA) was uncertain.
UNASSIGNED: A 57-year-old man was admitted to our hospital with severe pain and swelling in his left knee and the popliteal area. He was diagnosed with severe medial unicompartmental knee osteoarthritis (KOA) with a symptomatic popliteal cyst. Subsequently, arthroscopic cystectomy and unicompartmental knee arthroplasty (UKA) were performed simultaneously. A month after the operation, he returned to his normal life. There was no progression in the lateral compartment of the left knee and no recurrence of the popliteal cyst at the 1-year follow-up.
UNASSIGNED: For KOA patients with a popliteal cyst seeking UKA, simultaneous arthroscopic cystectomy and UKA are feasible with great success if managed appropriately.

In previous studies, good results have been reported after arthroscopic treatment of popliteal cysts and concomitant intra-articular pathology. However, only a few studies have reported the associated factors with residual popliteal cysts. The aim of this study was to examine the clinical and radiographic outcomes and investigate the factors associated with the recurrence of popliteal cyst after arthroscopic cyst decompression and cyst wall resection.
The authors hypothesized that residual popliteal cyst after arthroscopic decompression and cystectomy would be associated with degenerative cartilage lesions.
From December 2010 to December 2018, 54 patients with popliteal cysts were treated with arthroscopic decompression and cyst wall resection through an additional posteromedial cystic portal. Magnetic resonance imaging (MRI) or ultrasonography was used to observe whether the popliteal cyst had disappeared or decreased. The maximum diameter of the popliteal cyst was measured after surgery. The patients were classified into the disappeared and reduced groups according to the treatment outcome. Age, sex, symptom duration, preoperative degenerative changes based on the Kellgren-Lawrence (K-L) grade, cartilage lesions according to the International Cartilage Repair Society (ICRS) grades, synovitis, functional outcomes, and associated intra-articular lesions were compared between the two groups. The functional outcome was evaluated on the basis of the Rauschning and Lindgren knee score. The study included 22 men and 32 women, with mean age of 49.6 years (range, 5-82 years). According to the ICRS grade system, 28 (51.8%) patients had grade 0 to II, 26 (48.2%) patients had grade III to IV.
Follow-up radiographic evaluation revealed that the cyst had completely disappeared in 20 patients (37%) and reduced in size in 34 (63%). The mean cyst size was decreased significantly from 5.7cm (range, 1.7-15cm) to 1.7cm (range, 0-6.4cm), and the Rauschning and Lindgren knee score showed improved clinical features in all the patients. Between the disappeared and reduced groups, the presence of degenerative cartilage lesions (p=0.022, odds ratio 8.702, 95% confidence interval: 1.368-55.362) showed statistically significant differences.
Through the posteromedial cystic portal, cysts were completely removed in approximately 40% of patients, and the size was reduced in 60% of patients. Presence of degenerative cartilage lesion represents an associated risk factor for residual popliteal cyst. These findings could be helpful in ensuring explaining poor prognostic factors.
IIIb; retrospective cohort study.

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.

Popliteal cysts represent one of the commonest knee pathologies in the adult population. The vast majority of cases may be treated conservatively as symptoms tend to resolve spontaneously. However, few patients may experience persistent pain and nerve-related symptoms not responding to conservative management. We present a case of a 46-year-old patient who suffered from tibial nerve palsy due to a popliteal cyst that was treated successfully with combined open and arthroscopic procedure. It is important to understand that popliteal cysts rarely may lead to tibial nerve entrapment and in selected cases operative management may be indicated.

Nowadays, magnetic resonance imaging (MRI) has a high ability to distinguish between soft tissues because of high spatial resolution. Image processing is extensively used to extract clinical data from imaging modalities. In the medical image processing field, the knee\'s cyst (especially Baker) segmentation is one of the novel research areas. There are different methods for image segmentation. In this paper, the mathematical operation of the watershed algorithm is utilized by MATLAB software based on marker-controlled watershed segmentation for the detection of Baker\'s cyst in the knee\'s joint MRI sagittal and axial T2-weighted images. The performance of this algorithm was investigated, and the results showed that in a short time Baker\'s cyst can be clearly extracted from original images in axial and sagittal planes. The marker-controlled watershed segmentation was able to detect Baker\'s cyst reliable and can save time and current cost, especially in the absence of specialists it can help us for the easier diagnosis of MRI pathologies.

The authors present a case of a Baker\'s cyst in the right leg of an 86-year-old woman, whose presentation was more typical for a deep venous thrombosis. Both conditions have inflammation and acute calf pain. The clinical manifestations, imaging findings, and treatment of this common emergency department presentation are discussed.

A ruptured Baker\'s cyst is a rare presentation and may mimic deep vein thrombosis (DVT) or acute thrombophlebitis. In rare cases, it may present with infection or compartment syndrome. We present our experience related to a case of a ruptured Baker\'s cyst and its management. A 54-year-old female presented to us with knee pain, which was initially managed conservatively. After six weeks, she came to us with severe pain and swelling in her left calf and foot. It was an acute presentation and DVT was suspected initially. Ultrasound color Doppler showed no DVT and then MRI revealed it to be a ruptured Baker\'s cyst. The patient was subsequently managed conservatively and her condition improved in 12 weeks of follow-up. A high index of suspicion and knowledge is required to diagnose a ruptured Baker\'s cyst, and most of the patients respond well to conservative management.

Baker\'s cyst is a distention or enlargement of the gastrocnemius-semimembranosus bursa toward the popliteal fossa which is usually associated with intra-articular pathologies. Rupture or dissection of the Baker\'s cyst results in extravasation of the cyst content into the calf within intermuscular space under the fascia. This clinical entity, also called pseudothrombophlebitis, is a self-limited condition that usually resolves with supportive treatment. However, in patients using anticoagulants, excessive hemorrhage may cause compartment syndrome in case of cyst rupture. Early diagnosis of compartment syndrome is the most important step in preventing permanent disability. Therefore, compartment syndrome should be kept in mind and ruled out in a patient with pseudothrombophlebitis syndrome under anticoagulation therapy.

Synovial chondromatosis of the knee is a rare benign neoplasm of the synovium. Likewise, uncertainty on management still prevails. Though rare, it nevertheless warrants greater emphasis than it receives in the literature to allow correct diagnosis and accurate early surgical intervention. It predominantly involves the anterior compartment of the knee and disseminated disease is extremely rare. The optimal approach for surgical treatment of such an extensive synovial chondromatosis of knee remains unclear. Herein, we describe a case of extensive generalized synovial chondromatosis of the knee extending into the Baker\'s cyst in a 30 years old female. A diagnosis of synovial chondromatosis was made by clinical evaluation and MR imaging and confirmed by histopathological examination. Patient was successfully treated by open radical synovectomy of knee using both anterior and posterior approaches in a single step procedure.