Ganglion cysts of the cruciate ligaments

Purpose:
To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings. Material and Methods:
We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations. Results:
Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment. Conclusion:
MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations.     

Ultrasound of the knee

Ultrasound is emerging as a viable imaging modality in the diagnosis and assessment of the musculoskeletal system. Advantages of ultrasound include its easy availability and multiplanar capability, as well as economic advantages. Unlike magnetic resonance imaging, ultrasound demonstrates the fibrillar microanatomy of tendons, ligaments and muscles, enhancing its diagnostic capability. The ability to compress, dynamically assess structures and compare easily with the contralateral side is advantageous. The patient’s exact point of clinical tenderness can be correlated with underlying anatomical structures and associated pathology. The main strength of knee ultrasound is the assessment of para-articular disease. The specific structures best suited for ultrasound assessment include tendons, muscles and ligaments, as well as periarticular soft tissue masses. Joint effusions, synovial thickening, bursal fluid collections, intra-articular loose bodies, ganglion cysts, ligament and tendons tears, tendonitis and occult fractures can be diagnosed. With experience, ultrasound is a time-efficient, economical imaging tool for assessment of the knee. Received: 28 November 2000 Revision requested: 26 January 2001 Revision received: 10 April 2001 Accepted: 10 April 2001     

Imaging assessment of anterior knee pain and patellar maltracking

Anterior knee pain is a common complaint in the orthopaedic clinic. The differential diagnosis is wide and the principal goal of initial assessment is to detect remediable causes. The majority of patients do not have a specific disease and increasingly interest has focused on the role of patello-femoro-tibial morphology and of patellar maltracking in the aetiology of anterior knee pain. Classification in this group of patients is poor and there is no uniform agreement on which patient groups benefit from treatment and which treatment is best. Much of the literature involves relatively small numbers of patients, is poorly controlled and there is little agreement on outcome measures [1, 2]. The purpose of this review is to outline the current status of the imaging assessment of recalcitrant anterior knee pain with particular reference to patellar maltracking. Received: 8 January 2001 Revision requested: 15 March 2001 Revision received: 11 May 2001 Accepted: 23 May 2001     

Synovial osteochondromatosis complicating pilon fracture of the tibia

A case of previously undiagnosed synovial osteochondromatosis complicating a tibial pilon fracture is presented. The entrapment of osteochondral bodies within the fracture margin prevented complete reduction of the fracture and necessitated surgical intervention. Received: 27 December 2000 Revision requested: 26 January 2001 Revision received: 19 March 2001 Accepted: 21 March 2001     

Severe toxic osteoblastoma of the humerus associated with diffuse periostitis of multiple bones

Toxic osteoblastoma is a rare variant of an uncommon primary bone tumour that has been described only once before in the world medical literature. It is characterised by systemic features including fever, weight loss and a striking diffuse periostitis in association with an osteoblastoma, resulting in delayed diagnosis. Early recognition of this condition could prevent inappropriate therapies and reduce morbidity. Received: 7 November 2000 Revision requested: 6 December 2000 Revision received: 9 March 2001 Accepted: 10 March 2001     

Autogenous osteochondral ”plug” transfer for the treatment of focal chondral defects: postoperative MR appearance with clinical correlation

Objective: To describe the MR appearance following autogenous osteochondral ”plug” transfer for the treatment of focal chondral defects of the knee. Design and patients: Twenty-nine 1.5-T MR knee studies including dynamic gadolinium enhancement were performed on 21 patients following autogenous osteochondral ”plug” transfer. Three musculoskeletal radiologists retrospectively reviewed images to evaluate graft and donor site appearance and MR findings were correlated with clinical outcomes. Results: MR images demonstrated graft protuberance (n=12/21; range 1–2 mm), depression (n=2/21; range 1 mm), and surface incongruity: mild (n=17/21), moderate (n=2/21), marked (n=1/21). The T2 signal of graft cartilage was similar to that of adjacent cartilage in 25 of 29 examinations, and increased in four. Graft cartilage thickness relative to adjacent cartilage was <50% in six patients, 50–100% in 15. Graft enhancement in bone was absent at 2 weeks, but present at between 4 and 6 weeks following surgery. All patients had clinical follow-up examinations and knee outcome survey scores were obtained in 15 patients with follow-up greater than 3 months after surgery. All patients demonstrated the expected short-term progressive clinical improvement. Conclusion: MR images reveal a wide range of appearances following osteochondral ”plug” transfer. Minor variations in graft orientation and surface congruity do not result in adverse clinical outcome in the short term. Received: 8 January 2001 Revision requested: 21 February 2001 Revision received: 6 March 2001 Accepted: 6 March 2001     

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     

Popliteal vascular malformation simulating a soft tissue sarcoma

Differentiation of vascular abnormalities from soft tissue sarcomas may be difficult on clinical grounds, but is usually possible on imaging criteria. We report the MRI and digital subtraction angiography (DSA) findings in a patient presenting with a mass behind the knee. We discuss differentiating features and review the literature of similar cases. Received: 28 January 1999 Revision requested: 23 February 1999 Revision received: 29 March 1999 Accepted: 30 March 1999     

Tuberculous infection of the gracilis muscle and tendon clinically mimicking deep venous thrombosis: sonographic findings

Musculoskeletal tuberculosis usually involves the spine. Tuberculous infection of muscles and tendons is rare. A patient with tuberculous infection of the gracilis muscle and tendon is reported. Lower extremity Doppler ultrasound was initially performed, as the physical examination mimicked deep vein thrombosis. Sonography identified the abnormal muscle and tendon and was then used to guide aspiration. The sonographic appearance of the gracilis muscle and tendon is described and compared with correlative MR images. Received: 21 December 1998 Revision requested: 31 January 1999 Revision received: 30 March 1999 Accepted: 31 March 1999     

Pigmented villonodular synovitis of the hip presenting as a retroperitoneal mass

We present an unusual case of diffuse pigmented villonodular synovitis (PVNS) of the hip presenting as a large retroperitoneal mass in an asymptomatic 39-year-old man. Initial imaging characteristics and findings on core needle biopsy suggested soft tissue sarcoma. However, incisional biopsy showed findings of PVNS. The patient underwent radical synovectomy and total joint replacement, with no change in the large retroperitoneal component after 15 months of follow-up. Received: 15 June 2000 Revision requested: 8 September 2000 Revision received: 14 March 2001 Accepted: 15 March 2001     

Evaluation of ganglion cysts using vastly undersampled isotropic projection reconstruction (VIPR)

For some atypical para-articular ganglia, the presence of a joint connection is highly controversial. The proper preoperative diagnosis and identification of this joint connection for ganglion cysts is important for patient treatment and outcome. MRI is the imaging modality of choice when evaluating such lesions, but the detection of subtle joint connections remains difficult with conventional MR protocols. We investigated the utility of a steady-state free-precession acquisition with isotropic high resolution using the vastly undersampled isotropic projection reconstruction (VIPR) pulse sequence to determine if joint connections for ganglion cysts could be seen more effectively, using the knee region as a model. We evaluated four patients: two with peroneal intraneural ganglion cysts, one with adventitial cystic disease of the popliteal artery, and one patient with a more typical extraneural (intramuscular) cyst. Both conventional MR and VIPR techniques were used. In our clinical experience, we found VIPR to be superior to conventional MR techniques in detecting and depicting joint connections in typical and atypical ganglion cysts around the knee.     

Intra-articular entrapment of the medial collateral ligament: radiographic and MRI findings

Displacement of the medial collateral ligament (MCL) into the medial knee joint is an extremely rare finding associated with MCL tears, and is easily diagnosed on magnetic resonance imaging. A case of intra-articular interposition of the MCL during a severe knee injury is presented. A radiolucent ”fat stripe” sign and adjacent skin dimpling on radiographs may be relatively specific indicators of this injury. Received: 18 March 1999 Revision requested: 17 May 1999 Revision received: 1 July 1999 Accepted: 2 July 1999     

Multimodality imaging assessment of meniscal ossicle

A case of meniscal ossicles occurring in the left knee of a 23-year-old woman is presented. Radiographs showed two calcified lesions at the posteromedial aspect of the knee which were interpreted as loose bodies. Sonography, computed tomography arthrography and magnetic resonance imaging showed the fragments within the posterior horn of the medial meniscus permitting a diagnosis of meniscal ossicles. These techniques can detect meniscal ossicles and exclude intra-articular loose bodies. Received: 7 February 2000 Revision requested: 14 March 2000 Revision received: 18 April 2000 Accepted: 24 April 2000     

Gout: radiographic findings mimicking infection

Objective: To describe radiographic features of gout that may mimic infection. Design and patients: We report five patients with acute bacterial gout who presented with clinical as well as radiological findings mimicking acute bacterial septic arthritis or osteomyelitis. Three patients had delay in the appropriate treatment with the final diagnosis being established after needle aspiration and identification of urate crystals under polarized light microscopy. Two patients underwent digit amputation for not responding to antibiotic treatment and had histological findings confirming the diagnosis of gout. Conclusion: It is important for the radiologist to be aware of the radiological manifestations of acute gout that can resemble infection in order to avoid inappropriate diagnosis and delay in adequate treatment. The definitive diagnosis should rely on needle aspiration and a specific search for urate crystals. Received: 11 April 2000 Revision requested: 5 May 2000 Revision received: 9 April 2001 Accepted: 10 April 2001     

Spontaneous progression of vertebral intraosseous pneumatocysts to fluid-filled cysts

Intraosseous pneumatocyst is a relatively rare condition, and its natural course is not known. We report two cases of intraosseous pneumatocyst of vertebra with resorption of gas and its replacement with fluid shown on follow-up cross-sectional imaging. The mechanism influencing the course of these appearances is unclear. However, the benign nature of intraosseous pneumatocyst needs to be recognized and biopsy avoided. Received: 21 November 2000 Revision requested: 28 December 2000 Revision received: 28 February 2001 Accepted: 7 March 2001     

Extra-articular soft tissue ganglion cyst around the knee: focus on the associated findings

The aim of this study was to evaluate MR imaging findings of the associated findings in surrounding tissues of the extra-articular soft tissue ganglion cysts around the knee. We retrospectively reviewed MR images of 30 patients who had surgically confirmed extra-articular soft tissue ganglion cysts around the knee with focus on the associated findings in surrounding tissues, such as muscle, subcutaneous fat, bone, and nerve. The most common associated finding was the visualization of channel between ganglion cyst and the joint, which was demonstrated in 20 cases (continuous type in 12 cases and discontinuous type in 8 cases). Other associated findings were seen in 15 cases; pericystic edema (n=9), bony remodelling (n=3), and nerve involvement (n=3). The bony remodelling involved the proximal metaphysis of tibia in all 3 cases. Two patients with nerve involvement had deep peroneal nerve in subacute phase and one involved common peroneal nerve in chronic phase. The MR imaging is a useful imaging modality to evaluate the associated findings in extra-articular soft tissue ganglion cysts around the knee. The evaluation of these associated findings is helpful for the differentiation of ganglion cysts from other cystic lesions around the knee.     

Ganglion cysts at the gastrocnemius origin: a series of ten cases

Objective To describe ganglion cysts arising close to the origin of the medial and lateral head of gastrocnemius as identified on magnetic resonance (MR) imaging. Design and patients We present a series of ten cases of ganglion cysts arising close to the gastrocnemius origin from the medial and lateral femoral condyles. These were collected over a 6-year period from our imaging database. All patients attended for routine MR imaging of the knee with a variety of clinical presentations. Data collected included patient demographics, ganglion size, ganglion site, clinical presentation and ancillary MR imaging findings. The ten patients in this series consisted of seven males and three females, five right and five left knees, age range 27–68 years, mean age 40.6 years. Results The mean maximal dimension of the ganglion cysts was 26 mm, range 15–40 mm. The medial gastrocnemius origin was involved in eight patients and the lateral origin in two patients. The MR imaging findings consisted of both uni- and multi-loculated cysts, often containing numerous septations with fluid signal characteristics. The cysts were extra-capsular with no clear communication with the joint. One patient presented with a popliteal soft tissue mass and none of the cases required surgical intervention for cyst removal. Conclusions MR imaging may identify ganglion cysts arising in an intra- or extra-articular site around the knee. This series documents the MR imaging characteristics of ganglion cysts arising close to the gastrocnemius origin and discusses the relevance of this imaging finding.     

A synovial ganglion of the knee: two cases in athletes

The objective of the study is to describe two cases of proximal tibiofibular ganglion cysts in high level athletes. In May 2003 and March 2005 two athletes (one tennis player in the top eighty of the Italian national ranking and a gymnast belonging to the Italian rhythmic gymnastics national team) were referred to our institution complaining of postero-lateral knee discomfort and the presence of localized swelling over the fibular head and the antero-lateral aspect of the leg, with a clinically suspected diagnosis of ganglion cyst of the proximal tibiofibular joint. Ultrasonography clearly detected the fluid-filled structures while magnetic resonance imaging confirmed the diagnosis, also showing precisely the anatomic relationship between the ganglions and the surrounding structures. Both athletes underwent surgical excision and the histological examination was compatible with a proximal tibiofibular joint ganglion cyst; as yet they have had no recurrence.     

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.     

Solitary osteosclerotic plasmacytoma: association with demyelinating polyneuropathy and amyloid deposition

A 51-year-old man presented with a 1-year history of polyneuropathy necessitating the use of a wheelchair. Initial diagnosis was idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) and associated monoclonal gammopathy. Investigations for multiple myeloma, including bone marrow aspiration and biopsy, were negative. What was initially felt to be an incidental osteosclerotic focus noted on the radiographic bone survey was eventually shown to be a solitary osteosclereotic plasmacytoma with associated amyloid. This dramatically altered treatment. This case emphasizes the importance of including osteosclerotic plasmacytoma in the differential diagnosis of a focal sclerotic bone lesion in the clinical setting of polyneuropathy. These lesions are less likely to progress to multiple myeloma than lytic plasma cell neoplasms, and the presence of polyneuropathy often results in earlier diagnosis and treatment with enhanced prospect of cure. The finding of amyloid deposition within the osteosclerotic lesion may be of prognostic importance. Received: 30 November 2000 Revision requested: 15 January 2001 Revision received: 16 April 2001 Accepted: 18 April 2001