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

Fast Algorithms For Josephson Junction Arrays : Bus--bars and Defects

We critically review the fast algorithms for the numerical study of two--dimensional Josephson junction arrays and develop the analogy of such systems with electrostatics. We extend these procedures to arrays with bus--bars and defects in the form of missing bonds. The role of boundaries and of the guage choice in determing the Green's function of the system is clarified. The extension of the Green's function approach to other situations is also discussed.Comment: Uuencoded 1 Revtex file (11 Pages), 3 Figures : Postscript Uuencode

In-vitro validation of a device measuring the tibio-femoral contact forces and moments for efficient assistance during ligament balancing in total knee arthroplasty

Ligament balancing in total knee arthroplasty is believed to have an important influence on the joint stability and prosthesis lifetime. In order to provide quantitative information and assistance during the ligament balancing phase, a device that intraoperatively measures knee joint forces and moments has been developed

In-vitro evaluation of a force-sensing device for ligament balancing in TKA

Component loosening and instability are common causes of dysfunction after Total Knee Arthroplasty (TKA) and it is generally assumed that such complications are due to tibio-femoral misalignment or ligamentous imbalance. During the surgery, the ligamentous force balance is currently qualitatively assessed by the surgeon through manual trial movements of the limb. In order to improve this procedure, we developed a force-sensing device to intraoperatively measure knee joint forces and moments. The aim of this device is twofold: a) using tibio-femoral forces and moments make quantifiable measurements of what surgeons describe as a balanced knee joint b) help surgeons during TKA to reach this balance state

Do synovial leptin levels correlate with pain in end stage arthritis?

Purpose: We evaluated whether synovial fluid (SF) leptin concentrations correlate with pain severity in patients with hip or knee endstage osteoarthritis (OA) and whether they mediate the association between increased joint pain and (1) female gender and (2) obesity. Methods: We conducted a cross-sectional study including patients with primary hip and knee OA undergoing joint replacement between January and December 2010. SF leptin concentrations obtained on the day of surgery were assessed. Main outcome was pain severity measured pre-operatively using WOMAC and VAS pain scales. Results: A total of 219 patients were included, 123 hip and 96 knee arthroplasties. Mean age was 72years, 59% were women. Mean SF leptin levels were 22.9 (±25.6) ng/ml in women and 5.4 (±5.9) ng/ml in men. Levels >19.6ng/ml (highest quartile) were significantly associated with increased pain on both WOMAC (mean difference −9.6, 95% CI −15.1 to −4.0) and VAS scale (mean difference 0.8, 95% CI 0.2-1.3). Associations remained unchanged after adjusting for age, co-morbidities, contra-lateral arthritic joint, OA site, and disability. The associations observed between increased pain and female gender or obesity were substantially reduced after adjusting for SF leptin. Conclusion: Joint pain is associated with SF leptin concentrations. Increased pre-operative pain observed in women and obese may be related to high intra-articular leptin level