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Degeneration of the meniscus and the articular cartilage in unicompartmental osteoarthritis of the knee results in progressive deformity of the leg axis. It is the aim of this study to evaluate if a leg axis correction can be achieved by implanting a customised metallic interpositional device for the knee (ConforMIS iForma). Before and after implanting a ConforMIS iForma knee implant, a radiological analysis of the leg axis deviation in the frontal plane was performed prospectively in 27 patients by evaluating anteroposterior single-leg stance radiographs. We achieved a sufficient leg axis correction with an average correction of 3.8 degrees and an averaged small under-adjustment of 0.9 degrees by inserting the ConforMIS iForma interpositional knee implant. Apart from the primary treatment objective of articular surface restitution the ConforMIS iForma knee implant can be reliably used to correct axis deformity occurring with unicompartmental osteoarthritis of the knee. [ABSTRACT FROM AUTHOR]

Rotational adjustment of the femoral component in total knee arthroplasty influences patellar tracking. Sixty patients underwent TKA; the femoral component was placed parallel to the epicondylar axis in 30 patients and the femoral component was placed in 3 degrees external rotation to the posterior condylar axis in 30 patients. The epicondylar axis was identified using an image-guided navigation system. Mean patellar shift was 2.65 degrees for the computer assisted group and 3.50 degrees for the control group. Mean patellar tilt was 4.88 degrees for the computer assisted group and 6.68 degrees for the control group. Aligning the femoral component parallel to the epicondylar axis leads to significantly better patellar tracking. [ABSTRACT FROM AUTHOR]

Static biotests, such as Daphnia and algae tests, are well known in the checking of water quality. Although they are often called acute tests they are not able to identify short-term accidents or time-dependent variations of toxic substances. Biomonitoring systems were set up to serve as early warning systems Biomonitors are 24 h a day working systems, using organisms to indicate changes due to the release of toxic substances. This paper deals with the measurement of changes inthe behavior of Daphnia with the Daphnia toximeter. Speed, speed distribution, height, distance between organisms, number of Daphnia, andfractal dimension are evaluated to account for the appearance of toxic substances. In this way even low concentrations which do not lead to the death of Daphnia can be detected within minutes. Results of the last two years of field experience and laboratory tests are given. [ABSTRACT FROM AUTHOR]

Shear stresses have been implicated in the formation of diabetes-related foot ulcers. The aim of this study was to evaluate the effect of a novel shear-reducing insole on the thermal response to walking, balance, and gait. Twenty-seven diabetes peripheral neuropathy patients were enrolled and asked to take 200 steps in both intervention and standard insoles. Thermal foot images of the feet were taken at baseline (1) following a 5-minute temperature acclimatization and (2) after walking. Testing order was randomized, and a 5-minute washout period was used between testing each insole condition. Sudomotor function was also assessed. Gait and balance were measured under single and dual task conditions using a validated body worn sensor system. The mean age was 65.1 years, height was 67.3 inches, weight was 218 pounds, and body mass index was 33.9, 48% were female, and 82% had type 2 diabetes. After walking in both insole conditions, foot temperatures increased significantly in standard insoles. The intervention insole significantly reduced forefoot and midfoot temperature increases (64.1%, P = .008; 48%, P = .046) compared to standard insoles. There were significant negative correlations with sudomotor function and baseline temperatures (r = .53-.57). The intervention demonstrated 10.4% less gait initiation double support time compared to standard insoles (P = .05). There were no differences in static balance measures. We found significantly lower forefoot and midfoot temperature increases following walking with shear-reducing insoles compared to standard insoles. We also found improvements in gait. These findings merit future study for the prevention of foot ulcer., (© 2014 Diabetes Technology Society.)

Background: The treatment of unicompartmental arthritis in younger patients is challenging. The aim of this study is to report final safety and efficacy analysis results for the iForma patient-specific interpositional device, which is designed for the treatment of isolated medial or lateral compartment arthritis of the knee., Methods: From June 2005 to June 2008 78 subjects (42 men, 36 women) received an iForma implant. The mean age was 53 years, the mean Body Mass Index 29.0. We surveyed the WOMAC scores, the visual analog pain scale and the Knee Society Scores., Results: The mean follow up was 16.4 months. The mean WOMAC knee scores increased from 48.3 before surgery to 71.3 after 24 months. A reduction in pain was achieved for all five pain measures using a standard visual analog scale (VAS). Knee Society Knee Score improved from 39.2 before to 61.9 24 month after surgery. The Knee Society Function Scores improved form preoperative 64.5 to 82.5 2 years postoperative. The preoperative range of motion could be restored. The overall revision rate was 24%. 15 implants were removed early, 4 knees were revised without implant removal., Conclusion: Within narrow indication of patients with unicompartmental disease, the iForma device can provide improvement in knee function and reduction in pain, however, with a significant higher risk of early revision compared to traditional arthroplasty. Respecting this limitation it may be an alternative option for arthritic patients with unicompartmental disease who have contraindications to High Tibial Osteotomy or are too young for knee replacement; the iForma device further has the distinct advantage of time and cost saving compared to those procedures.

Objective: Exact drilling into the ischemic areas of necrotic lesions of the femoral head remains a challenging procedure, particularly in obese patients. This study was conducted to evaluate the precision of fluoroscopically based drilling and the associated radiation exposure in an in-vitro model of adiposis., Materials and Methods: In an in-vitro model of necrotic lesions in adiposis, 20 sawbones were drilled under the guidance of an intraoperative navigation system (VectorVision, BrainLAB, Munich, Germany) and 20 more were drilled conventionally under fluoroscopic control only., Results: A statistically significant difference was found with respect to the distance from the drill tip to the desired mid-point of the lesion, with a mean distance of 0.56 mm for the navigated group and 1.15 mm for the control group. Furthermore, a significant difference was found in the number of drilling corrections required, as well as the radiation exposure time: The navigated group required a mean of 0.35 second drillings or corrections of the drilling direction, compared to 2.45 for the control group, and the duration of radiation exposure was less than 1 second for the navigated group and 3.85 seconds for the control group., Conclusions: Drilling guided by the VectorVision navigation system shows high precision, even under difficult circumstances such as those encountered in adiposis, with a marked reduction in the duration of radiation exposure.

Soft tissue management is a major step in total knee arthroplasty. We aimed to analyze the relationship between sequential medial soft tissue release and the resulting change in the anteroposterior limb axis and the tibiofemoral gaps. Measurements were obtained using a CT-free navigation system (Ci navigation system, DePuy I-Orthopaedics, Munich, Germany). Concerning leg axis, each release step led to significant (P < .001) effects. The highest effect was seen for the 6-cm release in extension and the release of medial collateral ligament in 90 degrees flexion. The medial gap difference was significant for each release step except the 4-cm release in extension. The highest increase resulted when sacrificing the entire posterior cruciate ligament in extension and in 90 degrees flexion. Implementation of computer-assisted surgery allows this first navigation-controlled study, elucidating the effect of soft tissue release in total knee arthroplasty.

Background: Soft tissue management is a major issue in total knee replacement. There have been very few papers dealing with its effect on leg axis and tibiofemoral gap., Methods: In a cadaver specimen study, we analyzed this effect by performing a sequential medial soft tissue release after a mobile-bearing total knee arthroplasty. Measurements were obtained using a CT-free navigation system (Ci navigation system)., Results: We found the highest increase in leg axis and medial gap when releasing the anteromedial tibial sleeve of the capsule 6 cm below the joint line, in extension, and after dividing the medial collateral ligament, in flexion, when releasing the medial half of the posterior cruciate ligament. There were differences in amount of change between extension and flexion, especially when releasing the medial half of the posterior cruciate ligament. In extension, the lateral gap remained the same as in flexion., Interpretation: Implementation of computer-assisted surgery has allowed this first navigation-controlled study investigating the effect of soft tissue release in TKR with rotating platform. Each sequential release step has the desired effect on a.p. leg axis and tibiofemoral gaps. It is important that the differences between the effects in extension and flexion be noted.

The effects of various extracorporal shock wave energy levels and impulse rates were investigated using an in vitro model. In addition, we performed a controlled, randomized study to examine the clinical outcome after treatment for calcific tendinitis of the shoulder. Two groups of 40 patients each received 2000 impulses twice with an energy flux density of 0.23 mJ/mm(2) and then 0.42 mJ/mm(2). The results were evaluated by the Constant and Murley score. Disintegration of the implanted deposits requires an energy of at least 0.42 mJ/mm(2) and 2000 impulses. The clinical trial showed resorption of calcific deposits in 37.5% (0.23 mJ/mm(2)) and 55.0% (0.42 mJ/mm(2)). After 1 year the Constant and Murley score increased from 46 to 68 at 0.23 mJ/mm(2) and from 48 to 73 points at 0.42 mJ/mm(2). Based on our experimental and clinical results it is evident that disintegration of calcific deposits is dose-dependent. Because of the time that elapses until changes became evident on the radiographs, an instant and sole mechanical effect on the calcific deposits is unlikely. Therefore, a combined mechanical and cellular mechanism for absorption of the calcific deposits must be presumed.