Arthroscopic Treatment of Popliteal Cyst Through the Posterior Portal: A Comprehensive Clinical Study

BACKGROUND A popliteal cyst, often perceived as benign, poses potential harm and symptoms. This study focused on arthroscopic treatment through the posterior knee portal at our medical center, aiming to assess its efficacy, safety, and long-term outcomes compared to traditional methods. MATERIAL AND METHODS A retrospective analysis of 20 patients (9 males and 11 females) with symptomatic popliteal cysts (January 2020 to December 2022) undergoing arthroscopic treatment via the posterior knee portal was conducted. Data on demographics, clinical presentation, preoperative imaging, surgical techniques, intraoperative findings, and postoperative Rauschning and Lindgren scores were collected and analyzed. RESULTS With a mean follow-up of 13.6 months (range: 12 to 36 months), all patients had associated intra-articular lesions and were treated. Degenerative cartilage damage was most common (65.0% of cases). The Rauschning and Lindgren score significantly improved after surgery (P<0.05), with no recurrence evident on MRI in any patients. CONCLUSIONS Arthroscopic treatment through the posterior knee portal has good potential for popliteal cyst management. This minimally invasive approach offers benefits such as direct visualization, precise cyst excision, and concurrent treatment of intra-articular pathologies.

New-Generation 0.55 T MRI of the Knee-Initial Clinical Experience and Comparison With 3 T MRI

OBJECTIVES

The aim of this study was to compare the detection rate of and reader confidence in 0.55 T knee magnetic resonance imaging (MRI) findings with 3 T knee MRI in patients with acute trauma and knee pain.

MATERIALS AND METHODS

In this prospective study, 0.55 T and 3 T knee MRI of 25 symptomatic patients (11 women; median age, 38 years) with suspected internal derangement of the knee was obtained in 1 setting. On the 0.55 T system, a commercially available deep learning image reconstruction algorithm was used (Deep Resolve Gain and Deep Resolve Sharp; Siemens Healthineers), which was not available on the 3 T system. Two board-certified radiologists reviewed all images independently and graded image quality parameters, noted MRI findings and their respective reporting confidence level for the presence or absence, as well as graded the bone, cartilage, meniscus, ligament, and tendon lesions. Image quality and reader confidence levels were compared ( P < 0.05 = significant), and clinical findings were correlated between 0.55 T and 3 T MRI by calculation of the intraclass correlation coefficient (ICC).

RESULTS

Image quality was rated higher at 3 T compared with 0.55 T studies (each P ≤ 0.017). Agreement between 0.55 T and 3 T MRI for the detection and grading of bone marrow edema and fractures, ligament and tendon lesions, high-grade meniscus and cartilage lesions, Baker cysts, and joint effusions was perfect for both readers. Overall identification and grading of cartilage and meniscal lesions showed good agreement between high- and low-field MRI (each ICC > 0.76), with lower agreement for low-grade cartilage (ICC = 0.77) and meniscus lesions (ICC = 0.49). There was no difference in readers' confidence levels for reporting lesions of bone, ligaments, tendons, Baker cysts, and joint effusions between 0.55 T and 3 T (each P > 0.157). Reader reporting confidence was higher for cartilage and meniscal lesions at 3 T (each P < 0.041).

CONCLUSIONS

New-generation 0.55 T knee MRI, with deep learning-aided image reconstruction, allows for reliable detection and grading of joint lesions in symptomatic patients, but it showed limited accuracy and reader confidence for low-grade cartilage and meniscal lesions in comparison with 3 T MRI.

A complex assessment of patients with knee osteoarthritis and Baker's cyst: observational study

In our observational study, we performed the clinical and functional examination, analyzed imagistic and histological findings and evaluated the correlation between previous aspects in patients with primary knee osteoarthritis (PKOA) and Baker's cyst (BC). The correlations were made to better understanding of BC in patients with PKOA and optimal choosing for treatment. Seventy patients with painful PKOA (ACR criteria) and BC were assessed. We evaluated knee pain using a 100 mm VAS and functional status using the pain, stiffness and functional subscales of WOMAC index. All patients were imagistic examined (ultrasonography and MRI). Thirty-eight patients with PKOA and simple BC respond to conservative treatments. Thirty-two patients with PKOA and complex BC need surgical removal (arthroscopic decompression ± open excision in larger cysts). For these patients, it is performed histological assessment. Any medical team that manages a PKOA patient with BC may develop the treatment plan based upon not only the size of BC, symptoms and other associated conditions but also on the WOMAC scoring and complex anatomic and histological data about BC.

[Giant Baker's cyst treated with intralessional methotrexate]

INTRODUCTION

Synovial cyst is composed by a fibrous wall; lining by a thin layer of synovial cells containing synovial fluid, the prototype of these, in the knee is the Baker's cyst, which is located abnormally in the gastrocnemius semimembranous bursa. Baker's cyst prevalence ranges from 5 - 38%. Clinical diagnosis is supported by the presence of increased volume of soft tissues located in the popliteal region.

CLINICAL CASE

A 74 year-old woman with longstanding active rheumatoid arthritis who developed a large, recurrent Baker's cyst. The Baker's cyst had two flare-ups of pain and soft tissue swelling which eventually limited knee movements; was treated with needle aspiration guided by ultrasound and synovectomy with methotrexate twice. At 18-months follow-up, the patient remains without evidence of recurrence.

CONCLUSIONS

Local infiltration of methotrexate represents an alternative therapy for those refractory Baker's cyst with partial response to conventional treatment, where the surgical procedure carries a high risk.

[A man with a swelling of the knee]

A 72-year-old male presented with a dorsomedial swelling of the knee. X-rays showed isolated ossificated cartilage particles. The particles, which were found to be in a popliteal cyst, were surgically removed and analyzed by the pathologist. The diagnosis was synovial osteochondromatosis . Isolated synovial osteochondromatosis inside a popliteal cyst is uncommon.

[Treatment of popliteal cyst by arthroscopy in 20 cases]

OBJECTIVE

To explore the treatment methods and the effects of popliteal cyst with arthroscopy.

METHODS

From January 2009 to January 2010,20 patients with popliteal cyst were treated with internal drainage under arthroscope, meanwhile, their joint disease were treated. There were 9 males and 11 females with an average age of (55.7 +/- 7.7) years (ranged, 46 to 70). The lump was found for 1-22 months with an average of (6.2 +/- 2.4) months and accompanying with knee pain of different degrees. All diagnosis depended on B ultrasound or MRI, which clearly showed communication of cyst and articular cavity. According to the grade of Rauschning and Lindgren,grade II was in 8 cases and grade III was in 12 cases. The clinical effects were evaluated by the grade of Rauschning and Lindgren.

RESULTS

All the patients were followed up from 6 to 18 months with an average of 12 months. No injuries of blood vessels and nerve or incision infection were found. The grade of Rauschning and Lindgren improved obviously in all patients, grade 0 was in 13 cases, grade I in 6 cases, grade II in 1 case at the 6 months after operation.

CONCLUSION

The method not only can cure the popliteal cyst, but also can solve the disease of joint, which is avoiding re-operation and decreasing some shortages of traditional operation, can obtain good function recovery and satisfactory medium-term effects.

Arthroscopic treatment of popliteal cyst

OBJECTIVE

To review the results of arthroscopic treatment of popliteal cysts in our centre and analyse outcomes including complications.

DESIGN

Retrospective study.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

From July 2007 to July 2009, 11 patients with symptomatic popliteal cysts were treated arthroscopically. All of them had preoperative magnetic resonance imaging to confirm the diagnosis, identify the valvular opening, and the associated intra-articular pathology. We used the Rauschning and Lindgren criteria for evaluation.

RESULTS

Intra-articular pathology like cartilage degeneration and meniscus tear were commonly associated with popliteal cysts. All patients achieved symptomatic improvement after treatment and the recurrence rate was low. No major complications were encountered. We failed to identify (and correct) any valvular opening in one patient.

CONCLUSION

From our experience, we conclude that arthroscopic treatment of popliteal cyst with correction of the valvular opening and treatment of associated intra-articular pathology is effective and safe.

Arthroscopic treatment of popliteal cysts: clinical and magnetic resonance imaging results

PURPOSE

This study examined the functional and magnetic resonance imaging (MRI) outcomes of popliteal cysts with combined intra-articular pathologies that were treated arthroscopically by decompression and a cystectomy through an additional posteromedial cystic portal.

METHODS

From January 2003 to March 2008, 31 patients were treated with a modified arthroscopic technique to decompress a popliteal cyst. The connecting valvular mechanism was found in all cases at the posteromedial compartment through the anterolateral viewing portal, and it was corrected by resecting the capsular fold through the posteromedial working portal. For cysts with multiple fibrous septa, an additional portal, the so-called posteromedial cystic portal, was used for complete cyst removal. The functional outcome was evaluated by use of the Rauschning and Lindgren knee score. All patients were evaluated by MRI, which documented the popliteal cyst and associated intra-articular lesions preoperatively and at follow-up.

RESULTS

All patients could return to their previous daily activities with few or no limitations, and no additional surgery was required after a mean follow-up of 36.1 months (range, 12 to 72 months). The Rauschning and Lindgren knee score showed improved clinical features at the final follow-up in 94% of patients. The follow-up MRI study showed that the cyst had disappeared in 17 knees (55%) and had reduced in size in 14 knees (45%) in the 31 patients. The mean cyst size was reduced significantly from 6.8 to 0.8 cm (P < .0001).

CONCLUSIONS

The described arthroscopic technique with or without an additional posteromedial cystic portal is effective for treating popliteal cysts with combined intra-articular lesions. More importantly, follow-up MRI showed that the cyst size was reduced or it had disappeared in all cases, although there was no association between the cyst's disappearance and the follow-up clinical score.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Ultrasound imaging for the rheumatologist XXVI. Sonographic assessment of the knee in patients with psoriatic arthritis

Psoriatic arthritis (PsA) is an arthropathy associated to psoriasis, which is part of the spondyloarthropathy family, and which may present with various forms, from mono-oligoarthritis to symmetric polyarthritis mimicking rheumatoid arthritis. In longstanding disease, the symmetric polyarthritis is the most common pattern of PsA, involving small joint of hands, feet, wrists, ankles and, very frequently, knees. Other common features are represented by the inflammation of enthesis and tendons. Ultrasound (US) examinations were performed using a Logiq 9 (General Electric Medical Systems, Milwaukee, WI) equipped with a multifrequency linear probe, working at 10-14 MHz. One-hundred and sixty-six knee joints were investigated in a total of 83 patients. Prior to US assessment, all patients underwent a clinical examination by an expert rheumatologist who recorded the presence/absence of pain, tenderness (detected by palpation and/or active or passive mobilisation of the knee), and knee swelling. Sixty-two (74.7%) knee joints were found clinically involved, while at least one US finding indicative of joint inflammation was obtained in 70 (84.3%) knee joints. In the 59% of the patients we noticed synovial hypertrophy. Enthesitis was present in 39.7% of the subjects studied. This study demonstrated that US detected a higher number of inflamed knee joints and enthesis with respect to clinical assessment in PsA patients.

Sclerotherapy of Baker's cyst with imaging confirmation of resolution

BACKGROUND

Baker's cysts are commonly encountered in pain management practices.

OBJECTIVE

To ascertain if sclerotherapy treatment of a Baker's cyst could produce objectively verifiable MRI imaging changes.

DESIGN

Case report.

METHODS

A 52-year-old white male with a posterior horn of the medial meniscus tear and a large Baker's cyst who had failed conservative care and drainage was imaged before treatment with sclerosing. Three injections of 12.5% dextrose and anesthetic with sodium morrhuate were injected intraarticular into the right knee after drainage.

RESULTS

The Baker's cyst resolved on both postoperative imaging after the completion of care as well as on physical examination.

CONCLUSIONS

Prolotherapy in this case study seemed to be an effective treatment for Baker's cyst in this patient.

Arthroscopic all-inside suture of symptomatic Baker's cysts: a technical option for surgical treatment in adults

Synovial fluid caused by repeated effusions may replete the gastrocnemius-semimembranosus bursa (GSB) communicating with the knee joint. Fluid trapped inside the GSB through an alleged unidirectional valve-like mechanism forms a so-called Baker's cyst. Since a significant association of Baker's cysts with knee joint disorders has been reported, treatment should primarily address articular lesions causing recurrent effusions. Arthroscopic surgery provides an effective treatment in that both the cyst and associated joint disorders can be optimally visualized and accordingly treated. In the present paper an all-inside arthroscopic technique for suturing the gateway to the GSB through an anterolateral viewing portal and a posteromedial working portal is proposed. The rationale underlying this technique is that no conclusive evidences exist that the one-way valve-like mechanism is purely anatomical. A retrospective study was conducted on 22 patients (9 males and 13 females, mean age 56 +/- 10 SD years) affected by a symptomatic Baker's cyst associated to knee joint disorders. Pre- and post-operative evaluation at 2 year follow-up consisted of clinical assessment by Rauschning and Lindgren criteria and magnetic resonance imaging (MRI). The results showed that 96% of patients showed clinical improvement. Baker's cyst disappeared in 64% of patients, reduced in 27% and persisted in 9% on MRI. All patients with cyst reduction exhibited clinical amelioration. Our results suggest the all-inside arthroscopic suture technique would improve Baker's cyst-related symptoms by either disappearance or reduction of the cyst. We believe the availability of multiple arthroscopic techniques to treat symptomatic Baker's cysts could broaden the therapeutic armamentarium of knee arthroscopists.

Cystic adventitial disease of the popliteal artery: An argument for the developmental theory

Cystic adventitial disease is a rare non-atheromatous cause of popliteal artery disease. We report a case of a 54-year-old patient with claudication of the right calf caused by cystic adventitial disease. Intra-operatively, a communication between the adventitia and the knee joint was identified. Connections between the adventitial cyst and the nearby joint have been reported in the literature that support the developmental theory. This theory suggests that cystic adventitial disease is a developmental manifestation of mucin-secreting cells derived from the mesenchyme of the adjacent joint. This case is the first, to our knowledge, in which a communication between joint and adventitia has been clearly documented by operative findings.

Arthroscopic cystectomy for popliteal cysts through the posteromedial cystic portal

In the treatment of patients with popliteal cysts (Baker's cysts), we generally need to address the intra-articular pathologies, most commonly, medial meniscal tears and concomitant connecting valvular mechanisms responsible for the formation and recurrence of the cyst. We introduce here an arthroscopic technique that can treat the associated intra-articular pathology and correct the valvular mechanism of the capsular fold. The most important step is to locate the opening connection between the joint cavity and the popliteal cyst at the posteromedial compartment. The opening is found at the posteromedial side of the medial head of the gastrocnemius after inferior displacement of the capsular fold, which overlies the opening. It is helpful to rotate the bevel of the arthroscope upward to the 11-, 12-, and 1-o'clock positions for most effective visualization of the capsular fold. After the opening connection of the cyst is found, the capsular fold is resected with basket forceps and a shaver inserted through the posteromedial portal to correct the valvular mechanism. Furthermore, we have developed an additional "posteromedial cystic portal," which is located directly above the popliteal cyst and can be effectively used in cystectomy, especially in treatment of cysts that consist of septa and nodules. Arthroscopic popliteal cyst removal with use of an additional posteromedial cystic portal can be effective in treating a cyst with multiple fibrous septa or membranes.

Unusual lateral presentation of popliteal cyst: a case report

The commonest cyst to occur in the popliteal region is the popliteal cyst and over the past years it has received much clinical attention. The commonest position of the popliteal cyst is in the posterosuperior aspect of the medial femoral condyle. The present case report describes a rare case of popliteal cyst, which was found on the postero-superior aspect of the lateral condyle of the femur. Interestingly, there are fewer reports of popliteal cysts occurring in the postero-superior aspect of the lateral condyle. We as anatomists describe the topographical anatomy of an unusual presentation of popliteal cyst in the postero-superior aspect of the lateral popliteal region and discuss its clinical significance. Anatomical knowledge of such anomalies may be important for clinicians, orthopedic surgeons and academicians in routine clinical practice.

“Intermittent Claudication Intermittence” as a Manifestation of Adventitial Cystic Disease Communicating with the Knee Joint

In this report, we describe a patient with adventitial cystic disease of the popliteal artery, in which direct communication via a duct-like structure between the cystic lesion and the knee-joint synovium resulted in recurrent episodes of intermittent claudication and complete symptom-free intervals (intermittent claudication intermittence). This unusual observation could shed more light on the debated etiology of the disease. Moreover, it emphasizes the importance of complete excision of the cyst along with the presenting anatomic connection with the knee joint.

Osteoarthritis of the knee: association between clinical features and MR imaging findings

PURPOSE

To prospectively evaluate the association between clinical features and structural abnormalities found at magnetic resonance (MR) imaging in patients with osteoarthritis (OA) of the knee.

MATERIALS AND METHODS

The study was approved by the institutional medical ethics review board. Written informed consent was obtained from each patient. MR images of the knee were obtained from 205 (42 [20%] men, 163 [80%] women; median age, 60 years; range, 43-77 years) patients in whom symptomatic OA at multiple joint sites was diagnosed. MR images were analyzed for various abnormalities of OA. All patients were interviewed concerning pain and stiffness in the knee that was imaged. Odds ratios (ORs) with 99% confidence intervals (CIs) were used to determine the association between the imaging findings and clinical features of OA.

RESULTS

A large joint effusion was associated with pain (OR, 9.99; 99% CI: 1.28, 149) and stiffness (OR, 4.67; 99% CI: 1.26, 26.1). The presence of an osteophyte in the patellofemoral compartment (OR, 2.25; 99% CI: 1.06, 4.77) was associated with pain. All other imaging findings, including focal or diffuse cartilaginous abnormalities, subchondral cysts, bone marrow edema, subluxation of the meniscus, meniscal tears, or Baker cysts, were not associated with symptoms.

CONCLUSION

Findings of this study indicate that only two associations exist between clinical symptoms and structural findings found on MR images in patients with OA of the knee.

Arthroscopic treatment of popliteal cyst and visualization of its cavity through the posterior portal of the knee

In regard to arthroscopic treatment of popliteal cysts, we explored the refuted pathology for popliteal cysts proposed by others. Here we introduce an arthroscopic technique using posterior portals to treat a popliteal cyst based on our observation that the opening of the cyst in the joint is a slit-like structure in the posterior wall of the capsule. By disrupting this slit-like structure with our procedure, the popliteal cyst ceased to be palpable and was no longer symptomatic. This technique also provides excellent arthroscopic visualization of the cavity of the popliteal cyst through the knee joint approach. After completion of the resection of the opening, we can easily insert an arthroscope into the cavity of the popliteal cyst from the posteromedial portal through the resected opening. Arthroscopic visualization of the cavity of the cyst showed that the inside wall of the cavity was smooth and had no synovitis. We believe that to disrupt this slit structure is the most pathologically reasonable procedure to treat popliteal cysts surgically.

New insights into the development of popliteal cysts

Background

This prospective study was designed to investigate the aetiology of popliteal (Baker's) cysts.

Methods

Some 426 legs in 312 individuals were investigated with ultrasonography for the presence of a popliteal cyst. Participants included healthy volunteers, patients with a painful knee, and a group of patients with signs and symptoms of deep vein thrombosis (DVT). The location, thickness and content of all cysts were recorded. In addition, the popliteal fossa was dissected in four cadaver knees.

Results

The prevalence of popliteal cyst increased with age and was significantly higher in those aged over 50 years (P &lt; 0·001). Compared with controls (incidence 3·0 per cent), cysts were more common in patients with DVT symptoms (9·5 per cent; P = 0·141) and those with painful knees (19·8 per cent; P &lt; 0·001). All cysts were located in the posteromedial aspect of the popliteal fossa; the majority extended between the deep fascia and the medial head of the gastrocnemius muscle. At this level an area without external support of the posterior capsule was identified between the two expansions of the semimembranosus muscle from the medial side (the oblique popliteal ligament and the expansion over the popliteus muscle) and the posterior cruciate ligament from the lateral side. This area was also located in the knee dissections. No association was found between popliteal cyst and acute DVT.

Conclusion

Popliteal cysts are relatively common in patients over 50 years old with a painful knee or with signs and symptoms of DVT. They form in the posteromedial popliteal fossa because the synovial capsule does not provide anatomical support in this region.

Intramuscular dissection of Baker's cysts: report on three cases

Baker's cysts are fluid distensions of the gastrocnemius-semimembranosus bursa and are the most common cystic lesion around the knee. Typically cysts enlarge along intermuscular planes around the knee. We report three cases in which the expanding cyst did not respect these planes and dissected along an intramuscular route as confirmed by MR imaging. Such behaviour by Baker's cysts is hitherto unreported in the literature. Possible mechanisms to account for this phenomenon are discussed.

Periarticular lesions detected on magnetic resonance imaging: prevalence in knees with and without symptoms

OBJECTIVE

To evaluate, using magnetic resonance imaging (MRI), the prevalence of periarticular lesions in older persons with or without knee pain, and to assess the association of these lesions with knee pain.

METHODS

Subjects ages 45 years and older, with or without knee pain, were recruited from Veterans Affairs medical centers and from the community. Weight-bearing posteroanterior, skyline, and lateral radiographs were obtained in all subjects. Subjects were divided into 3 groups: those with radiographic OA (ROA) and knee pain (n = 376), those with ROA and no knee pain (n = 51), and those with neither ROA nor knee pain (n = 24). A single knee (the more symptomatic one in subjects with knee pain) was imaged with a 1.5T scanner using T1- and T2-weighted and proton-density spin-echo imaging sequences. MRIs were read for the presence of periarticular lesions, which were categorized (according to their general location) as being either peripatellar (prepatellar, superficial infrapatellar, deep infrapatellar) or "other periarticular lesions" (semimembranosus-tibial collateral ligament bursitis, anserine bursitis, iliotibial band syndrome, tibiofibular cyst).

RESULTS

Patients with knee pain had more severe radiographic disease than did subjects who were asymptomatic. Peripatellar lesions (prepatellar or superficial infrapatellar) were present in 12.1% of the patients with knee pain and ROA, in 20.5% of the patients with ROA and no knee pain, and in 0% of subjects with neither ROA nor knee pain (P = 0.116). However, other periarticular lesions were present in 14.9% of patients with both ROA and knee pain, in only 3.9% of patients with ROA but no knee pain, and in 0% of the group with no knee pain and no ROA (P = 0.004).

CONCLUSION

Although peripatellar lesions are equally common among subjects with knee pain and those without knee pain, other periarticular lesions (including bursitis and iliotibial band syndrome) are significantly more common among subjects with knee pain and may contribute to pain in these individuals.

Ultrasonography is superior to clinical examination in the detection and localization of knee joint effusion in rheumatoid arthritis

OBJECTIVE

Musculoskeletal ultrasonography allows real-time imaging of joint structures and may be used to complement clinical examination in rheumatological practice. We compared ultrasonography (US) with clinical examination (CE) in the detection of effusion, suprapatellar bursitis, and Baker's cyst of the knee in rheumatoid arthritis (RA) in order to determine whether US provided additional clinical information.

METHODS

A total of 22 patients with RA (ACR criteria) underwent independent clinical and US examination of both knees for suprapatellar bursitis, knee effusion, and presence of Baker's cyst. US was performed using an ATL HDI 3000 machine with L7-4 MHz and CL10-5 MHz probes. Clinical examination was performed using standard techniques by an experienced rheumatologist. Patients with previous knee surgery were excluded from the study.

RESULTS

A total of 44 knees were examined at a total of 130 sites (one patient was unable to lie prone for US of popliteal fossae). US detected soft tissue abnormality (suprapatellar bursitis, knee effusion, or Baker's cyst) at 54/130 (42%) sites, while CE detected soft tissue abnormality at 36/130 (28%) sites. US detected 17 (39%) cases of suprapatellar bursitis in 44 knees, 7 (16%) of which were detected on CE. US detected 27 (61%) knee joint effusions in 44 knees, 16 (36.36%) of which were detected on CE. US detected 10 (23.81%) Baker's cysts in 42 knees, 2 (4.76%) of which were detected on CE. Taking US of the knee as the gold standard, CE was specific but not sensitive in the detection of soft tissue abnormality of the knee in RA.

CONCLUSION

US is more sensitive than CE in the detection of suprapatellar bursitis, knee effusion, and Baker's cyst in RA. CE underestimates knee inflammation in RA. This has implications for the use of CE as a component of standardized disease activity scores and in guiding knee joint aspiration.

Prevalence and size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections in asymptomatic knees on MR imaging

OBJECTIVE

The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees.

MATERIALS AND METHODS

MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured.

RESULTS

Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees.

CONCLUSION

Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

[Synovial sarcoma in clinical practice--description of selected cases]

Clinically, synovial sarcoma becomes apparent as a growing mass. Initial presentation and the course may be variable. We discuss 4 characteristic patients.

CASE 1

A 37 year-old female patient presented with a mass in her thigh after two consecutive resections of a malignant hemangioendothelioma.

HISTOLOGY

Biphasic synovial sarcoma (G II).

CASE 2

A tumor was enucleated in the adductors of a 42 year-old female patient.

HISTOLOGY

Biphasic synovial sarcoma (G I). 2 years later local tumor recurrence (G I) occurred. Treatment was provided by wide resection and radiotherapy. CASE 3: Resection of a suspected neurinoma in the thigh of a 34 year-old male patient.

HISTOLOGY

Biphasic synovial sarcoma, positive margins. CASE 4: A 74 year- old female patient receiving anticoagulants was symptomatic due to intracranial tumor hemorrhage of a metastasis of a previously unknown synovial sarcoma of her popliteal fossa. The primary tumor was initially misdiagnosed as Baker's cyst, causing a deep vein thrombosis.

HISTOLOGY

Angioinvasive synovial sarcoma (G II). Survival: 11 months.

THERAPY

Wide resection and postoperative irradiation in cases 1-3. Indication for the irradiation in case 2 and 3 was due to the inadequate operation. An amputation was performed in case 4 because of infiltration of the neurovascular structures.

CONCLUSION

The presentation of synovial sarcoma does not differ from other soft tissue sarcomas. Patients should be treated in specialized centers to reduce inadequate operations. Outcome and rate of metastatic disease suggest the need for improved adjuvant treatment modalities.

[Recurrence of Baker's cysts with regard to operation procedure and intraarticular pathology]

During the period from January 1990 to December 1998 65 patients were operated upon for a Baker's cyst. 41 patients (43 operations) were subjected to a clinical and sonographical follow-up examination and interrogation. In 11 cases, the cysts were merely removed, while an open synovectomy was carried out four times (rheumatics) in addition to the removal of the cysts, and arthroscopy with exstirpation was performed in 28 cases. The total recurrence rate was 14 % (6/43). Any significant differences between the groups were not found (p = 0.291). The overall complication rate was 18.6 %. In case of recurrence, the clinical results were significantly worse (p = 0.036). Apart from technical aspects of operation, the not quantifiable correlation between grade of chondromalacia and the formation of effusions following joint degeneration has to be discussed as a cause for recurrences. If both interventions are carried out in one course, there is no increased operative risk. Especially in cases with intraarticular pathological symptoms arthroscopy should precede each cyst exstirpation. With regard to the frequency of recurrence, the patients' expectation should be preoperatively objectified.

Two cases of tibial nerve compression caused by uncommon popliteal cysts

We report 2 cases of a popliteal mass of very unusual origin that induced compression neuropathy. The signs and symptoms could have been mistaken for those of a common Baker's cyst. Several recent studies have shown that the cause of Baker's cyst formation should be sought within the joint because of a communication between the gastrocnemio-semimembranosus bursa and the joint cavity. These 2 cysts had no communication with the articular joint, thus suggesting that the surgeon perform an open exploration of the popliteal fossa in the search for other cystic formations with origins and features different from Baker's cysts.

[Rheumatologic manifestations of Behcet's disease: report of 309 cases]

PURPOSE

To define the epidemiology and clinical features of Behçet's disease, giving special attention to unusual forms.

METHODS

We retrospectively reviewed the medical records of 309 cases with joint manifestations among 450 cases of Behçet's disease seen over a 20-year period who met the International Study Group of Behçet's disease criteria.

RESULTS

Joint manifestations were present in 68.3% and were inaugural in 34.5%. The knee and ankles were the joints most commonly affected. Monoarthritis, oligoarthritis and polyarthritis were seen respectively in 12, 13.5 and 19.8%. Sacroiliitis is observed in 6%. Unusual forms included destructive polyarthritis (two cases), popliteal cyst (two cases), myositis (two cases) and ankylosing spondylitis (two cases).

CONCLUSION

Joint manifestations are common in Behçet's disease. They are frequently associated with erythema nodosum and necrotic pseudofolliculitis. Polyarthritis is not rare. Their unusual forms deserve to be known.

Intraneural ganglion of the peroneal nerve: importance of timely diagnosis

Peroneal nerve ganglion cysts typically present because of a palpable mass or symptoms and signs of entrapment neuropathy, including pain, diminished sensation, and motor weakness. Surgical treatment is usually successful when performed early, but, when diagnosis is delayed, intraneural growth and invasion may cause irreversible axonal injury and footdrop. This case report illustrates the importance of timely diagnosis when treating a ganglion of the peroneal nerve and reviews the appropriate workup, differential diagnosis, and treatment.

Midcalf ultrasonography for the diagnosis of ruptured Baker's cysts

Clinically significant and palpable enlargement of the gastrocnemio-semimembranosus bursa is known as a Baker's cyst. Baker's cysts may rupture, resulting in a swollen, painful leg that is clinically indistinguishable from acute deep vein thrombosis. For this reason, ruptured Baker's cysts are sometimes called pseudothrombophlebitis. The purpose of this study was to determine the incidence of ruptured Baker's cysts, and to evaluate the role of ultrasonography in the diagnosis of this condition. The hospital records of 106 patients (43 men and 63 women) who were referred to the vascular surgical department at Saitama Medical Center with unilateral or bilateral swollen legs between June 1997 and June 2000 were reviewed retrospectively. The total number of affected limbs was 125, being 52 right legs and 73 left legs. Deep vein thrombosis was the most common cause of swollen legs, being diagnosed in 44.8%. No specific anatomical derangement was found in 39 limbs (31.2%), and these were defined as idiopathic. Lymphedema was also common, being diagnosed in 16 limbs. Ruptured Baker's cysts were observed in three limbs, with an incidence of 2.4%. In all of these patients, a large hypoechoic space was seen behind the calf muscles and this sonolucent area was easily detected by a conventional scanner, being pathognomonic of a ruptured Baker's cyst.

Cystic adventitial disease of the popliteal artery: elongation into the media of the popliteal artery and communication with the knee joint capsule: report of a case

Cystic disease of the popliteal artery is a rare disorder in which most cases involve the formation of an adventitial cyst that disturbs the popliteal artery blood flow. We present herein the case of a patient presenting with popliteal artery occlusion due to compression by a cyst which formed at the media of the popliteal artery. The onset occurred during a baseball game in which he played catcher. Preoperative magnetic resonance imaging demonstrated a communication of the cyst with the adjacent knee joint. This unusual case could provide important clues to help identify the pathogenesis of this disease.

Knee effusions, popliteal cysts, and synovial thickening: association with knee pain in osteoarthritis

OBJECTIVE

To evaluate the association of effusions, popliteal cysts, and synovial thickening with knee symptoms in older persons with and without radiographic (XR) osteoarthritis (OA), using magnetic resonance imaging (MRI).

METHODS

Subjects with and without knee symptoms were recruited from Veterans Affairs and community sources. All had weight-bearing knee radiographs. Subjects were divided into 3 groups: Knee pain/XROA group had knee symptoms and radiographic OA; No knee pain/XROA group had no knee symptoms and radiographic OA; and No knee pain/no XROA group had no knee symptoms and a normal radiograph. A single knee was imaged using a 1.5 T MR scanner using T1 and T2 weighted and proton density SE imaging sequences. MRI were read for effusion, popliteal cysts, and synovial thickening.

RESULTS

The mean age of subjects was 67.0 years (66.6% male). We studied 381 subjects with Knee pain/XROA, 52 with No knee pain/XROA, and 25 with No knee pain/no XROA. The prevalence of moderate or larger effusions was: Knee pain/XROA 54.6%, No knee pain/XROA 15.6%, and No knee pain/no XROA 11.1%. Popliteal cysts were present in 33.0% of Knee pain/XROA subjects, 28.0% No knee pain/XROA, and 9.1% No knee pain/no XROA. After adjusting for the severity of radiographic OA, there was a difference between those with and without knee pain in prevalence of moderate or larger effusions (p < 0.001) and synovial thickening, independent of effusion (p < 0.001), but not in the prevalence of popliteal cysts. Further, among those in Knee pain/OA group, synovial thickening was associated with the severity of knee pain.

CONCLUSION

Effusions and popliteal cysts are common in middle aged and elderly people. After adjusting for the degree of radiographic OA, moderate or large effusions and synovial thickening were more frequent among those with knee pain than those without pain, suggesting these features are associated with the pain of knee OA. In those with knee symptoms, synovial thickening is uniquely associated with the severity of knee pain.

Sonographic detection of Baker's cysts: comparison with MR imaging

OBJECTIVE

The objective of this study was to assess the ability of sonography to reveal Baker's cysts using MR imaging as a gold standard.

MATERIALS AND METHODS

The study group consisted of 36 consecutive knees in 36 patients evaluated with both MR imaging and sonography. Inclusion criteria included axial proton density-weighted or T2-weighted MR images, a sonography report that documented the evaluation of the popliteal region of the knee, and sonographic and MR images that were available for review. The MR images were retrospectively reviewed for the presence of Baker's cyst (fluid signal between the semimembranosus and medial gastrocnemius tendons). Sonography reports were compared with the MR imaging results. The sonographic images were also retrospectively reviewed to determine whether any characteristic findings on sonography were significantly associated with the presence of Baker's cyst on MR imaging.

RESULTS

Retrospective review of MR images revealed 21 Baker's cysts, one myxoid liposarcoma, one meniscal cyst, and 13 examinations with normal findings. The sonography reports revealed that the 21 Baker's cysts were correctly diagnosed, whereas the meniscal cyst and myxoid liposarcoma were misdiagnosed as Baker's cysts. Retrospective review of sonographic images showed a 100% sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the diagnosis of Baker's cyst when hypoechoic or anechoic fluid was present between the semimembranosus and medial gastrocnemius tendons. No other sonographic characteristics were significant.

CONCLUSION

Identification of fluid between the semimembranosus and medial gastrocnemius tendons in communication with a posterior knee cyst indicates Baker's cyst with 100% accuracy.

Two-stage operation for treatment of a large dissecting popliteal cyst after failed total knee arthroplasty

A symptomatic popliteal cyst after total knee arthroplasty (TKA) is rare, occurring most frequently as a result of intra-articular knee pathology. We present a case of a large dissecting popliteal cyst 7 years after TKA with symptoms of severe calf pain and functional disability. The symptomatic cyst was excised completely in a first-stage operation, and the severely worn TKA was corrected by a second-stage surgical procedure. The patient in this report was pain free and had satisfactory range of knee motion 5 years after the index revision TKA, without recurrence of effusion or popliteal cyst formation.

Ganglion cysts associated with cruciate ligaments of the knee: a possible cause of recurrent knee pain

Intraarticular ganglia of the knee are uncommon; however, these ganglion cysts may produce knee discomfort without a clear etiology. We present the cases of 10 patients with ganglion cysts arising from cruciate ligaments of the knee joint who underwent arthroscopic excision after MR examination. The MR findings, clinical features and arthroscopic findings were evaluated comparatively. Diagnoses were confirmed by means of a histological study after arthroscopic excision. The cysts were fluid-filled, with low T1-weighted signal intensity and high T2-weighted signal intensity. Except for two patients with recent accidents, the remaining eight presented chronic pain without any history of trauma. Pain was the most frequent clinical sign. It was associated with knee extension in 3 cases and with flexion in 3 cases. In 7 cases, cysts were exclusively associated with the anterior cruciate ligament (ACL). Only in one case was a cyst associated with an ACL rupture. Four patients presented meniscal lesions. All ganglia appeared solitary in each knee. Postarthroscopy evolution was painless in 8 patients. Histologic diagnoses corresponded to ganglion cysts. The tissues from the patient with the ACL rupture presented a fibrous reaction with myxoid degeneration forming intraligamentary ganglion cysts.

MR imaging of Baker cysts --prevalence and relation to internal derangements of the knee

RATIONALE AND OBJECTIVES

To evaluate the prevalence of popliteal cysts in patients studied with magnetic resonance (MR) imaging. Cyst presence and volume will be related to other internal derangement of the knee.

MATERIALS AND METHODS

Three hundred and eighty-two consecutive patients with a MR study of the knee were included. Images were obtained in the three spatial orthogonal planes and evaluated through consensus. Four categories were established for the Baker cyst and synovial fluid (absence, minimum, moderate and massive), and the presence of meniscal, cruciate ligaments and cartilage lesions were recorded. Statistical analysis was carried out with bivariate analysis (chi(2) of Pearson and Gamma tests).

RESULTS

From the 382 patients, 145 had Baker cysts (38.0%). Cyst content was minimum in 99, moderate in 34 and massive in 12. Joint effusion was observed in 269 patients (70.4%), being minimal in 140 patients, moderate in 119 and massive in ten. Meniscal lesions were observed in 195 patients (51%), while 58 patients (15%) had a cruciate ligament lesion. Baker cyst had a statistically significant direct relationship with the presence and quantity of synovial fluid (P=0.002) and with the presence and type of meniscal lesion (P=0.01) but not with cruciate ligaments or cartilage lesions.

CONCLUSIONS

The prevalence of Baker cysts in MR studies of the knee is high. Its presence and volume are related to the quantity of synovial fluid, and to the presence and severity of meniscal lesions.

[Pigmented villonodular synovitis. A rare differential diagnosis of popliteal space-occupying lesion]

Pigmented villonodular synovitis (PVNS) is a disease that involves the lining of joints, bursae and tendon sheaths. The incidence is low and estimated to be 1.8 patients per million population. The cause of PVNS is unclear and discussed to be either inflammatory or neoplastic. PVNS has been described in 2 forms different for prognosis and treatment (nodular and diffuse). The articular form almost appears in the knee joint as we describe below in a 14 year-old patient. PVNS was first defined in 1941 by Jaffe e.a. [7]. Because of the uncommon occurrence of the disease it is difficult to amass patient series to allow confirmed statements on therapy and outcome. Larger patient series raise out of long periods of time. Differences in outcome and recurrence rates exist for the nodular and diffuse form. Clinical findings are moderate pain and swelling of joints due to effusion and synovial proliferation. Magnetic resonance imaging shows typical findings. Surgical procedures are recommended as open or arthroscopic synovectomy for the diffuse form of PVNS, local excision for the nodular form and arthrodesis or prosthetic replacement for joint destruction.

Modification of beta 2-microglobulin with D-glucose or 3-deoxyglucosone inhibits A beta 2M amyloid fibril extension in vitro

beta 2-microglobulin (beta 2M) is a major constituent of amyloid fibrils (fA beta 2M) deposited in patients with A beta 2M amyloidosis. Recently, advanced glycation end products (AGE) of beta 2M and fA beta 2M have been suggested to play an important role in the pathogenesis of A beta 2M amyloidosis. We first characterized the states of AGE modification of fA beta 2M. Western blot analysis with a monoclonal anti-AGE antibody showed that purified fA beta 2M was naturally modified with AGE. Immunohistochemical studies of amyloid-deposited tissue have revealed a patchy distribution of the AGE-modified area in the amyloid deposits. Then we modified beta 2-m either with D-glucose or with 3-deoxyglucosone (3-DG) and investigated the effect of these modification on fA beta 2M extension in vitro, using the recently established first-order kinetic model of fA beta 2M extension in vitro. Western blot analysis and enzyme linked immunosorbent assay with a monoclonal anti-AGE antibody showed that these sugar-modified beta 2M contained AGE. During the incubation of fA beta 2M with native beta 2-m at 37 degrees C, the fluorescence of thioflavin T increased without a lag phase and proceeded to equilibrium. On the contrary, only a slight increase in fluorescence was observed during the incubation of fA beta 2M with sugar-modified beta 2M. Moreover, sugar-modified beta 2M exhibited a dose-dependent inhibitory effect on the extension reaction of fA beta 2M with native beta 2M. These results may suggest that in some in vivo situations, the modification of beta 2-m with AGE could play an inhibitory role for the formation of fA beta 2M.

Anterior arthroscopic synovectomy plus capsuloplasty with a pedicle graft for the treatment of rheumatoid popliteal cysts

OBJECTIVE

To assess the value of arthroscopic synovectomy plus capsuloplasty with a pedicle graft in patients with rheumatoid cysts of the knee.

METHODS

We examined 31 rheumatoid knees in 9 men and 22 women with an average age of 52.5 years at time of operation. Postoperative clinical symptoms were investigated in comparison with each factor examined before the operation.

RESULTS

Postoperative results showed that 74% of the patients were grade 0 (no swelling or pain), 23% were grade 1 (swelling and slight discomfort after strenuous work or sports), and 3% were grade 2 (swelling and tenderness after normal activities). The improvement rate of the patients with arthroscopic synovectomy plus pedicle graft capsuloplasty was significantly higher than that of the untreated controls or patients with arthroscopic synovectomy or pedicle graft capsuloplasty. The preoperative degree of joint effusion, acceleration in the erythrocyte sedimentation rate, radiographic grades, and histological activity in the knee joint at the time of operation were correlated with the final clinical symptoms.

CONCLUSION

Our method may be useful for preventing recurrence of rheumatoid popliteal cysts.

Superficial venous thrombosis presenting as a painful popliteal fossa mass in a child

We report an unusual case of superficial venous thrombosis in a cyanotic 12-year-old child who had undergone recent appendectomy. Although compression, color Doppler, and duplex ultrasound techniques remain the keys to the diagnosis of venous thrombosis, SieScape sonography was beneficial in demonstrating the extent of the thrombi and their location along a superficial thrombosed vein.

[Baker's cyst--current surgical status. Overview and personal results]

Baker's cysts were treated operatively in 19 patients in the Department of Traumatology of the University of Cologne from 1988 to 1997. The subjective and objective results were evaluated with a questionnaire and a clinical examination and sonography (follow-up: 95%). All patients were examined before surgery, sonography and X-ray of the knee were performed. We differentiated between the congenital primary cyst (39%), and the secondary form, which was always associated with an intraarticular lesion (61%). Arthroscopy was performed in all secondary forms of Baker's cyst. Postoperative complications were two reinterventions due to one hematoma and one effusion. Patient's evaluation of operation result was "excellent" in 61% and "good" in 39% of cases. All knee joints had a full range of motion. There was only one case of a recurrent cyst. The primary form of Baker's cyst has always to be extirpated, according to our clinical experience. The extirpation of the secondary Baker's cyst and the relevance of arthroscopy and treatment of the basic disease have to be discussed.

Nerve entrapment by a firmly wrapped Baker cyst

Baker's cysts as a clinical entity are among the most infrequent cause of peripheral nerve entrapment and usually produce a strong positive pressure within the knee resulting in the rupture of the joint capsule. An unusual case with muscular and sensorial weakness due to compression of the peroneal nerve around the fibular head by a Baker cyst is presented in this article. Clinical and electromyographical findings shown peroneal nerve entrapments in the popliteal fossa. Peroneal nerve decompression by synevectomy resulted in clinical and electromyographical improvement.

Popliteal cysts in children: a retrospective study of 62 cases

Popliteal cysts in children are usually asymptomatic and are usually found fortuitously by the parents. This study presents a series of 62 children with popliteal cysts. Among the 51 patients who received no treatment, the cysts had already disappeared at the time of the study in 43 patients; the remaining 8 patients are under 14 years of age and are without complaints. This study confirms the hypothesis that the primary popliteal cyst in children usually disappears before the age of 18. Surgery presents unnecessary risks for the patient ; moreover, the chance of recurrence after surgery is real.

Lipoma arborescens of the knee

Lipoma arborescens is a rare intra-articular lesion, characterised by diffuse replacement of the subsynovial tissue by mature fat cells, producing prominent villous transformation of the synovium. The aetiology of this benign condition is unknown. We describe six cases involving the knee, discussing the symptoms, diagnosis and treatment.