Valgus unloader knee braces are a conservative treatment option for medial compartment knee osteoarthritis (OA). These braces are designed to reduce painful, and potentially injurious compressive loading on the damaged medial side of the joint through application of a frontal-plane abduction moment. While some patients experience improvements in pain, function, and joint loading, others see little to no benefit from bracing [1]. Previous biomechanical studies investigating the mechanical effectiveness of bracing have been limited in either their musculoskeletal detail [2] or incorporation of altered external joint moments and forces [3]. The first objective was to model the relative contributions of gait dynamics, muscle forces, and the external brace abduction moment to reducing medial compartment knee loads. The second objective was to determine what factors predict the effectiveness of the valgus unloading brace.

Seventeen people with knee OA (8 Female age 54.4 +/− 4.2, BMI 30.00 +/− 4.0 kg/m², Kellgren-Lawrence range of 1–4 with med. = 3) and 20 healthy age-matched controls participated in this study which was approved by the institutional ethics review board. Subjects walked across a 20m walkway with and without a Donjoy OA Assist knee brace while marker trajectories, ground reaction forces, and lower limb electromyography were recorded. The external moment applied by the brace was estimated by multiplying the brace deformation by is pre-determined brace-stiffness. For each subject, a representative stride was selected for each brace condition. A generic musculokeletal model with two legs, a torso, and 96 muscles was modified to include subject-specific frontal plane alignment and medial and lateral contact locations [4]. Muscle forces, and tibiofemoral contact forces were estimated using static optimization [4]. We defined brace effectiveness as the difference in the peak medial contact force between the braced and the unbraced conditions. A stepwise regression analysis was performed to predict brace effectiveness based on: X-ray frontal plane alignment, medial joint space, KL grade, mass, WOMAC scores, unbraced walking speed, trunk, hip and knee joint angles and moments.

The OA Assist brace reduced medial joint loading by approximately 0.1 to 0.2 BW or roughly 10%, during stance. This decrease was primarily due to the external brace abduction moment, and not changes in gait dynamics, or muscle forces. The brace effectiveness could be predicted (R²=0.77) by the KL grade, and the magnitude of the hip adduction moment in early stance (unbraced). The brace was more effective for those that had larger hip adduction moments and for those with more severe OA.

The valgus knee brace was found to reduce the medial joint contact force by approximately 10% as estimated using a musculoskeletal model. Bracing resulted in a greater reduction in joint contact force for those who had more severe OA while still maintaining a hip adduction moment similar to that of healthy controls.

Adequate range of knee motion is critical for successful total knee arthroplasty. While aggressive physical therapy is an important component, manipulation may be a necessary supplement. There seems to be a lack of consensus with variable practices existing in managing stiff postoperative knees following arthroplasty. Hence we did a postal questionnaire survey to determine the current practice and trend among knee surgeons throughout the United Kingdom.

A postal questionnaire was sent out to 100 knee surgeons registered with British Association of Knee Surgeons ensuring that the whole of United Kingdom was well represented. The questions among others included whether the surgeon used Manipulation Under Anaesthaesia (MUA) as an option for stiff postoperative knees; timing of MUA; use of Continuous Passive Motion (CPM) post-manipulation.

We received 82 responses. 46.3% of the respondents performed MUA routinely, 42.6% sometimes, and 10.9% never. Majority (71.2%) performed MUA within 3 months of the index procedure. 67.5% routinely used CPM post-manipulation while 7.3% of the respondents applied splints or serial cast post MUA. 41.5% of the surgeons routinely used Patient Controlled Analgaesia +/− Regional blocks. Majority (54.8%) never performed open/arthroscopic debridement of fibrous tissue for adhesiolysis.

Knee manipulation requires an additional anaesthetic and may result in complications such as: supracondylar femur fractures, wound dehiscence, patellar tendon avulsions, haemarthrosis, and heterotopic ossification. Moreover studies have shown that manipulation while being an important therapeutic adjunct does not increase the ultimate flexion that can be achieved which is determined by more dominant factors such as preoperative flexion and diagnosis. Manipulation should be reserved for the patient who has difficult and painful flexion in the early postoperative period.

The aim of this study was to examine the effects of cement in total knee arthroplasty on markers of inflammation and endothelial dysfunction, as surrogate markers for enhanced risk of vascular disease or precipitation of acute vascular events post-operatively.

A total of 36 patients were recruited, with 18 in each of the cemented and uncemented groups. Both groups were matched for age, sex and body mass index.

Venous blood samples were taken pre-operatively, day 1 and day 7 post-operatively. Serum levels of interleukin 6 (IL6), tumour necrosis factor (TNF□?, e-selectin, Von willebrand factor (vWF), tissue plasminogen activator (tPA) and soluble CD40 ligand were analysed. Also, real time analysis of the expression of CD40 and CD14/CD42a aggregates on monocytes was carried out using flow cytometry. Patients were excluded from the study if there were signs of either superficial or deep infection.

The only variable to demonstrate a significant difference between the two groups was the CD1442a count. There was a significant difference in the first 24 hours (p=0.00) and from day 1 to day 7 (p=0.02)

Our study suggests that the use of bone cement causes a significant rise in CD1442a count which has been linked to atherothrombosis and acute coronary syndromes. These changes may explain the increased incidence of venous thrombosis and thromboembolism post-operatively. However more research required in this field to delineate the exact pathways involved.