Intra-articular ganglion cysts of the knee: clinical and MR imaging features

The purpose of this study was to present clinical and MR imaging features of intra-articular ganglion cysts of the knee. Retrospective review of 1685 consecutive medical records and MR examinations of the knee performed at three imaging centers allowed identification of 20 patients (13 men and 7 women; mean age 35 years), in whom evidence of intra-articular ganglion cyst was seen. Of the 20 ganglion cysts, 5 were found in the infrapatellar fat pad, 10 arose from the posterior cruciate ligament, and 5 from the anterior cruciate ligament. Three of five patients with ganglion cyst in the infrapatellar fat pad had a palpable mass. In 7 of 15 patients with ganglion cyst in the intercondylar notch, exacerbation of pain occurred in a squatting position. On four MR arthrographies, ganglion cysts were an intra-articular round, lobulated, low signal intensity lesion. Five cases of fat-suppressed contrast-enhanced T1-weighted SE images demonstrated peripheral thin rim enhancement. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. The MR appearance of intra-articular ganglion cyst is characteristic and usually associated with the cruciate ligament or the infrapatellar fat pad. Magnetic resonance arthrography has no definite advantage over conventional MR in the evaluation of the lesion. For intra-articular ganglion cyst in the infrapatellar fat pad, fat-suppressed contrast-enhanced MR imaging could be useful, because a thin, rim-enhancing feature of intra-articular ganglion cyst allows it to be distinguished from synovial hemangioma and synovial sarcoma. Received: 29 June 2000 Revised: 13 September 2000 Accepted: 15 September 2000     

Arthroscopic decompression of suprapatellar cyst: case report

Bursae around the knee reduce friction between moving structures. When involution of suprapatellar septum fails to occur (“complete septum”), then suprapatellar bursa may stay completely separated from the knee joint cavity to form a cystic cavity. In the case of the increased volume, suprapatellar bursitis can cause painful suprapatellar swelling. The aim is to point to the possibility of arthroscopic decompression of suprapatellar cyst. In the case presented, the indication for knee arthroscopy was based on clinical examination, ultrasonography and magnetic resonance studies. The preoperative diagnosis was verified intra-operatively, and intra-articular cyst decompression was performed by arthroscopy. At the final examination 8 months postoperatively, the patient still had no pain, swelling and had full range of motion. This minimally invasive operative procedure resulted in a satisfactory anatomic and functional outcome. In this case report, we present a patient with suprapatellar cyst submitted to arthroscopic cyst decompression.     

The quadriceps tendon cyst: an uncommon cause of chronic anterior knee pain

The causes of knee pain are manifold. One of the uncommon causes of chronic anterior knee pain are cysts and ganglia. Magnetic resonance imaging not only reveals the intra-articular pathology but also accurately depicts such cystic structures about the knee. As part of this case report, a cyst of the lateral border of the quadriceps tendon is presented as a cause of such discomfort. Although cystic lesions around the knee are a common clinical problem, the described location is rare. After surgical revision of the lateral border of the quadriceps tendon and excision of the cyst, the patient was found to be asymptomatic.     

Intra-articular cysts and ganglia of the knee: a report of nine patients

Completely intra-articular cysts and ganglia of the knee are rare. They have been found in various locations such as on the anterior or posterior cruciate ligaments, in the infrapatellar fat pad, on the posterior wall of the posteromedial compartment and (very rarely) in connection to the menisci. We analyzed nine patients with intra-articular cysts or ganglia found in a series of 2,400 consecutive arthroscopies. In four patients, the cyst or ganglion was found attached to the anterior part of the ACL, in two patients it was located between the ACL and the PCL, and in the remaining three cases it was found in connection with the meniscus. In three out of the nine patients there was either no or very minor additional pathology found in the knee besides the cyst or the ganglion. We believe that intra-articular cysts and ganglia of the knee can be symptomatic, and excellent or good results after cyst removal can be expected especially when there is little additional pathology.     

The popliteal cyst

A popliteal cyst, originally called Baker’s cyst, is a synovial fluid-filled mass located in the popliteal fossa. The most common synovial popliteal cyst is considered to be a distension of the bursa located beneath the medial head of the gastrocnemius muscle. Usually, in an adult patient, an underlying intra-articular disorder is present. In children, the cyst can be isolated and the knee joint normal. The anatomy, etiopathogenesis, clinical presentation, differential diagnosis, imaging and treatment modalities of the popliteal cyst are presented. The authors try to answer some questions dealing with this condition. Is the cyst isolated, can it be treated as such, is its origin always well-defined and does surgical excision provide a permanent cure?     

Scintigraphic imaging of knee synovitis in osteoarthritis after intra-articular injection of technetium-99m pertechnetate in the unilateral knee

A case of left knee synovitis scintigraphic imaging is presented in a 66-year-old patient with bilateral knee osteoarthritis and a right knee Baker's cyst, who had undergone a 74 MBq (99m)Tc-pertechnetate intra-articular injection in the right knee. The findings in this case were compared with the intravenously injected methylene disphosphonate technetium-99m ((99m)Tc-MDP) scintigraphic findings and could be interpreted as the result of (99m)Tc-pertechenate through blood communication from the right to the left knee. This case implies that (99m)Tc-pertechnetate may be useful in imaging the synovitis in multiple arthroses even up to 60 min after its administration, instead of the 5 min imaging after the injection of (99m)Tc-MDP.     

Ultrasonography of the Knee

Musculoskeletal ultrasonography (MSUS) is a radiologic modality that can help in the evaluation of the knee and its lesions. Both soft tissue and surface bony structures can be sonographically visualized. The extra-articular structures of the knee can be evaluated, specifically the ligaments, bursae, and tendons. Collateral ligaments and the extensor mechanism, especially quadriceps and patellar tendons, are readily visualized. The diagnosis of a Baker's cyst and its complications is a common indication. The intra-articular structures of the knee, with proper maneuvers and transducers, can also be evaluated. The femoral condylar and patella cartilage can be examined for traumatic or degenerative lesions. The anterior and posterior cruciate ligaments can be partially visualized directly, or evaluated indirectly. Loose bodies are readily detectable whether intra-articular or extraneous in a Baker's cyst. Synovial disease can be characterized without the use of radiographic contrast. MSUS can be used as a screening, diagnostic or follow-up radiologic tool in the diseases of the knee.     

Isolated intra-articular pseudorheumatoid nodule of the knee

The authors describe a case of an isolated intra-articular pseudorheumatoid nodule of the knee in an 18-year-old male patient without a diagnosis of rheumatoid arthritis. The patient initially presented with a 3 year history of anterior knee pain and was found to have a 2.8 × 2.1 cm lobulated soft-tissue mass. Histologic findings showed fibrinoid necrosis and chronic inflammatory changes that were consistent with those of a pseudorheumatoid or rheumatoid nodule, and surgical excision of the nodule was curative. A review of the literature revealed no prior cases of an intra-articular pseudorheumatoid nodule or rheumatoid nodule in a patient without clinical or serologic evidence of rheumatoid arthritis.     

Giant synovial cyst of knee treated arthroscopically through a cystic portal

Synovial cysts are well-defined fluid filled cysts that can extend for a variable distance outside the joint space. These cysts can sometimes grow to a large size making its treatment challenging especially when associated with intra-articular pathologies.We describe a case of giant synovial cyst arising from the left knee and extending to the medial proximal calf in a 77-year old female who presented with knee joint pain, episodes of locking and calf mass occurring within 2 months of onset. Imaging studies also showed associated medial and lateral meniscal tears with medial compartment and patellofemoral osteoarthritis. The cyst was treated by disrupting the valvular mechanism using a standard posteromedial portal and complete excision of the cyst wall via a posteromedial cystic portal. The meniscal lesions were dealt with through the standard anterior portals. At 25-month follow up there were no signs of recurrence of the cyst clinically or with MRI. The cystic portal technique is effective in treating a giant synovial cyst of the knee even in the presence of meniscal tears and high grade chondral lesions. An erratum to this article can be found at     

Multilobulated popliteal cyst after a failed total knee arthroplasty

Popliteal cyst is a rare finding after total knee arthroplasty (TKA), but when present, it might indicate a malfunction of the TKA related to generation of wear-particles, or loosening. We present a case of a multilobulated popliteal cyst developing in a patient 8 years after primary TKA. The cyst was associated with a mechanical prosthetic loosening. The primary complaint of the patient was pain in the posterior region of the knee. A two-stage procedure consisting of cyst excision at first, followed after 5 months by a revision TKA was performed. Intraoperatively, a darkish, multilobulated cyst with a well-defined thick wall filled with fluid containing polyethylene debris, communicating with the knee joint was found. After 3 years of follow-up, the patient was satisfied and walked without the support of a cane. The patient presented a satisfactory knee range of motion. Clinical, radiological and ultrasound investigations ruled out popliteal cyst recurrence. A dissecting popliteal cyst associated with a failed TKA should be excised because it contains polyethylene debris that constitutes an induced factor for prosthetic loosening. A two-stage procedure with quite a long time in-between, as presented in this paper, can be a useful alternative to manage such a problem, in particular in very old patients associated with other medical problems.     

An unusual cause for anterior knee pain: strangulated intra-articular lipoma

Lipoma is the most frequently encountered benign soft tissue tumor. However, intra-articular lipomas are rarely seen. Anterior knee pain is a frequent complaint of adults and is of diverse etiology. This 42-year-old female patient had severe anterior knee pain, unresponsive to medical treatment. Magnetic resonance imaging revealed an intra-articular tumor of the knee joint. Arthroscopic intervention and subsequent histological examination resulted in the diagnosis of strangulated lipoma originating from infrapatellar fat pad. We present clinical, radiological and operative features of this rare case of intra-articular lipoma.     

Parameniscal cyst formation after arthroscopic meniscal repair with biodegradable meniscal arrow: a case report

A 22-year-old male underwent an arthroscopic meniscal repair, using meniscal arrows, due to bucket-handle medial meniscus tear. Magnetic resonance images (MRI) at 3 years revealed a large parameniscal cyst protruding into the extra-capsular popliteal space. Arthroscopic partial cystectomy, removing only the intra-articular portion of the cyst was performed, leaving the extra-articular part of the cyst. Sixteen months postoperatively MRI revealed no cyst remnants, and the patient was free of symptoms.     

"Arthrography diagnosis of synovial cysts of the knee.".

A lateral view of the knee in 90 degree flexion can reveal popliteal cysts which do not show on routine arthrography. Flexion causes transfer of intra-articular fluid to the posterior portion of the joint space, lowering pressure within the cyst and allowing it to fill with contrast media.     

High-grade intra-articular liposarcoma of the knee

A high-grade pleomorphic intra-articular liposarcoma of the knee is described in a 48-year-old man, which was diagnosed histologically after arthroscopy of the knee for suspected pigmented villonodular synovitis (PVNS). The patient proceeded to undergo an extra-articular resection with a custom-made prosthesis. This report highlights the need to remember this rare tumour in the differential diagnosis of atypical soft tissue lesions within the knee joint prior to instrumentation.     

关节镜下治疗腘窝囊肿35例报道

目的:探讨关节镜技术治疗腘窝囊肿的方法及其临床疗效。方法:2002年10月至2004年7月,采用关节镜技术对35例腘窝囊肿患者进行治疗,其中男性14例,女性21例,年龄42～68岁,平均49.7岁。窝囊肿均为单侧,其中右膝16例,左膝19例。在处理关节内疾患的同时,在后内侧间室扩大窝囊肿与关节腔之间的通道口。4例巨大囊肿(直径>5cm)同时行后路关节镜下囊壁切除术。根据Rauschning和Lindgren分级方法评定手术效果。结果:本组35例腘窝囊肿患者在术中均可发现伴有关节内疾患,其中内侧半月板撕裂24例,外侧半月板撕裂7例,前交叉韧带撕裂4例,骨性关节炎27例,痛风性关节炎1例。术后未出现血管、神经或手术切口并发症。术后2～3天出院。随访时间6～29个月,平均11个月,94.2%的病例未出现囊肿复发。Rauschning和Lindgren分级结果:术前Ⅰ级4例,Ⅱ级12例,Ⅲ级19例;术后0级30例,Ⅰ级4例,Ⅱ级1例。结论:关节镜下治疗窝囊肿具有创伤小、恢复快、复发率低的优点。     

Probable late congenital syphilis presenting as Clutton joints

A patient who presented with recurrent bilateral knee effusions was found to have positive serum syphilis serology. She was treated with oral erythromycin to a total of 40 grams and intra-articular injection of steroids in the right knee joint. Late congenital syphilitic arthritis is discussed with a review of the literature.     

Superior tibial epiphyseal osteochondroma with intra-articular development. Apropos of 2 cases in children

Two cases of intra-articular development of an osteochondroma in the proximal epiphysis of the tibia are reported. The first case, a 3 year old boy, resulted in blocking of the knee. After resection of the mass the diagnosis was confirmed by pathology. The second patient, an 8 year old boy, had no symptoms and surgery was not performed, although ablation was required of an associated astragalian osteochondroma of tibiotarsal intra-articular development. Relations between these epiphyseal osteochondromata and hemimelic epiphyseal dysplasia and metachondromatosis are discussed.     

Intra-articular calcifying synovial sarcoma mimicking synovial chondromatosis

 A case of intra-articular calcifying synovial sarcoma of the right knee joint in a 27-year-old man is reported. Prior to admission the patient had been suffering pain in the right knee for 5 years. Plain radiographs showed multiple calcified densities in the anterior aspect of the right knee closely mimicking synovial chondromatosis. Histological examination revealed that the lesion was a synovial sarcoma with extensive calcification subjacent to the synovial surface. Although intra-articular calcifying synovial sarcoma is very rare, it is important to be aware of the fact that synovial sarcoma, as well as synovial chondromatosis, can be present as a calcified lesion in the joint cavity.     

Intra-articular extraskeletal myxoid chondrosarcoma of the ankle

We describe an extremely rare case of an intra-articular extraskeletal myxoid chondrosarcoma causing devastating destruction to the ankle joint in a 71-year-old woman, which had been originally excised as a ganglion cyst. Histological analysis of the lesion revealed an extraskeletal myxoid chondrosarcoma. The patient proceeded to curative surgery with a below-the-knee amputation.     

A case of intra-articular synovial lipoma of the knee joint causing patellar dislocation

Intra-articular synovial lipoma is rare and clinically manifested mostly by mass effect and occasionally by torsion of the stalk. Patellar dislocation rarely occurs owing to a mass effect of intra-articular tumor of the knee joint. The authors present a case of large intra-articular synovial lipoma at the lateral gutter of the knee joint, which presents as patellar dislocation. A 19-year-old man visited our clinic due to pain and limitation of motion owing to mass at his left knee. MRI revealed an intra-articular soft tissue mass at the lateral gutter of the knee joint with considerable mass effect displacing patella from the trochlear groove. Excisional biopsy confirmed the diagnosis of lipoma, and the final diagnosis was intra-articular synovial lipoma with clinical information. The final radiograph showed well-aligned patella on the trochlear groove. After marginal excision, there was no recurrence or tumor-related morbidity.