Osteochondroma of the proximal humerus with frictional bursitis and secondary synovial osteochondromatosis

We report a case of multiple hereditary exostosis in a 33-year old patient with clinical symptoms of pain and impression of a growing mass of the left shoulder alerting potential risk of malignant transformation of an osteochondroma. Imaging studies illustrated perilesional bursitis surrounding an osteochondroma of the proximal humerus. Malignant transformation was excluded with MRI. Fragments of the osteochondroma were dislocated in the inflammatory synovial bursa illustrating a case of secondary synovial osteochondromatosis

Design optimisation for optically tracked pointers

The use of mechanical pointers in optical tracking systems is needed to aid registration processes of unlocated rigid bodies. Error on the target point of a pointer can cause wrong positioning of vital objects and as such these errors have to be avoided. In this paper, the different errors that originate during this process are described, after which this error analysis is used for the optimisation of an improved pointer design. The final design contains six coplanar fiducials, favored by its robustness and low error. This configuration of fiducials is then analysed theoretically as well as practically to understand how it is performing. The error on tracking the target point of the pointer is found with simulation to be around 0.7 times the error of measuring one fiducial in space. However, practically this error is about equal to the fiducial tracking error, due to the non-normally distributed errors on each separate fiducial

Improved walking distance and range of motion predict patient satisfaction after TKA

Purposes: The focus in the evaluation of total knee arthroplasty has shifted from objective measures of implant position and knee function, to patient-reported outcome measures (PROMs). The relation between these two measures was investigated and the possibility of prediction of the patient satisfaction level was evaluated by defining thresholds for improvement of (1) range of motion (ROM), (2) 6-min walk test (6MWT), (3) sit-to-stand test (STS) and (4) quadriceps force after TKA? Methods: Fifty-seven patients were prospectively tested at preoperative and 6 months postoperative intervals. The ROM, 6MWT, STS-test and quadriceps force were evaluated. Two clusters were created based on the postoperative KOOS, OKS and the satisfaction subscore of the new KSS, cluster 1 consisted of patients with good to excellent PROMs, cluster 2 of patients with poorer PROMs. Patients in each cluster were more similar to each other than to those in the other cluster. Receiver operating characteristic (ROC)-curve analysis was used to identify thresholds for the functional outcomes that established cluster allocation. Multiple logistic regression was used to define a model to predict cluster allocation. Results: Patients with high postoperative PROMs (cluster 1 allocation) showed higher postoperative functional outcomes (p = 5 degrees, OR 6.3, 95% CI 1.23-31.84), 6MWT (>= 50 m, OR 8.2, 95% CI 1.61-42.18) STS (>= 1.05 s, OR 3, 95% CI 0.56-16.07) and normalized Q4 force (>= 1.5 N/BMI, OR 2.5, 95% CI 0.49-12.89) were found to be predictors of cluster allocation. A model to predict the cluster allocation contained gender, ROM improvement and 6MWT improvement (sensitivity 91.1%, specificity 75%). Conclusions: Thresholds for improvement of functional parameters can predict the patient satisfaction cluster. Patients, who are male, improve on the 6-min walk test with 50 m or more and have an increased range of motion of 5 degrees or more, compared to the preoperative situation, are 6-8 times more likely of being satisfied after TKA. These tests are easy to use in clinical practice and can predict the level of patient satisfaction after TKA

Surprising bone and soft tissue lesions of the chest : pictorial review

Although plain radiographs of the chest are usually requested to evaluate the heart, lung, and mediastinum, many bone and soft tissue, metabolic, and congenital lesions can be visible presenting as surprising lesions. Thorough analysis of the lesion characteristics on the chest radiograph, eventually in conjunction with more advanced imaging techniques and in combination with the clinical findings, will lead to the correct diagnosis

Performance evaluation of portfolio insurance strategies using stochastic dominance criteria

This paper evaluates the performance of the stop-loss, synthetic put and constant proportion portfolio insurance techniques based on a block-bootstrap simulation. We consider not only traditional performance measures, but also some recently developed measures that capture the non-normality of the return distribution (value-at-risk, expected shortfall, and the Omega measure). We compare them to the more comprehensive stochastic dominance criteria. The impact of changing the rebalancing frequency and level of capital protection is examined. We find that, even though a buy-and-hold strategy generates higher average excess returns, it does not stochastically dominate the portfolio insurance strategies, nor vice versa. Our results indicate that a 100% floor value should be preferred to lower floor values and that daily-rebalanced synthetic put and CPPI strategies dominate their counterparts with less frequent rebalancing.Portfolio insurance Performance evaluation Stochastic dominance