BackgroundThe aim of the study was to assess gait in total knee arthroplasty (TKA) patients, using a technique that can to be used on a routine basis in a busy orthopaedic clinic.MethodsA total of 103 subjects were recruited: 29 pre-op TKA patients; 17 TKA patients at 8 weeks post-op; 28 TKA patients at 52 weeks post-op; and 29 age-matched controls. Inertial measurement units (IMUs) were used to assess gait. Limb segment angles, knee angle and temporal parameters of gait were calculated. Specific gait parameters were quantified, and data analysed using MANOVA and discriminant analysis.ResultsThe gait of TKA patients as a group was only slightly improved at 12 months when compared with the pre-operative group, and both groups were significantly different to controls in several variables. Knee flexion range in stance was the most important variable in discriminating between patients and controls; knee flexion range in swing was the only variable that showed a significant difference between pre- and post-operative patients. When considered individually, only 1/29 patient was within the normal range for this variable pre-operatively, but 9/28 patients were within the normal range 12 months post-operatively.ConclusionsEven after 12 months after surgery, many TKA patients have not improved their gait relative to pre-operative patients. Routine gait assessment may be used to guide post-operative rehabilitation, and to develop strategies to improve mobility of these patients.

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Objective-Abdominal aortic aneurysm (AAA) is characterized by widening of the aorta. Once the aneurysm exceeds 5.5 cm, there is a 10% risk of death due to rupture. AAA is also associated with mortality due to other cardiovascular disease. Our aim was to investigate clot structure in AAA and its relationship to aneurysm size. Methods and Results-Plasma was obtained from 49 controls, 40 patients with small AAA, and 42 patients with large AAA. Clot formation was studied by turbidity, fibrin pore structure by permeation, and time to half lysis by turbidity with tissue plasminogen activator. Plasma clot pore size showed a stepwise reduction from controls to small to large AAA. Lag phase for plasma clot formation and time to half lysis were prolonged, with smaller AAA samples showing intermediate response. Clot structure was normal in clots made with fibrinogen purified from patients compared with controls, suggesting a role for other plasma factors. Endogenous thrombin potential and turbidity using tissue factor indicated that the effects were independent of changes in thrombin generation. Conclusion-Patients

The article demonstrates robust clinical evidence that MSCs have significant potential for the regeneration of hyaline articular cartilage in patients. The majority of clinical trials to date have yielded significantly positive results with minimal adverse effects. However the clinical research is still in its infancy. The optimum MSC source, cell concentrations, implantation technique, scaffold, growth factors and rehabilitation protocol for clinical use are yet to be identified. A larger number of randomised control trials are required to objectively compare the clinical efficacy and long-term safety of the various techniques. As the clinical research continues to evolve and address these challenges, it is likely that MSCs may become integrated into routine clinical practice in the near future.

We demonstrate robust evidence that MSCs have the potential to regenerate articular cartilage. We also identify the complexity of designing a suitable preclinical model and the challenges in considering its clinical application such as type of MSC, scaffold, culture construct and the method by which growth factors are delivered. Of great interest is further characterization of the factors that may prevent MSC-derived chondrocytes to undergo premature hypertrophy and to understand what enables the terminal developmental pathway for permanent hyaline cartilage regeneration. Despite this, there is an abundance of evidence suggesting that MSCs are a desirable cell source and will have significant impact in tissue engineering of cartilage in the future.