ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion-Part II: shoulder, elbow, wrist and hand

Magnesium and its alloys as orthopedic biomaterials: a review.

Control of biodegradation of biocompatable magnesium alloys

Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided.

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Prosthetic Joint Infection

Stem cells respond to nanoscale surface features, with changes in cell growth and differentiation mediated by alterations in cell adhesion. The interaction of nanotopographical features with integrin receptors in the cells' focal adhesions alters how the cells adhere to materials surfaces, and defines cell fate through changes in both cell biochemistry and cell morphology. In this Review, we discuss how cell adhesions interact with nanotopography, and we provide insight as to how materials scientists can exploit these interactions to direct stem cell fate and to understand how the behaviour of stem cells in their niche can be controlled. We expect knowledge gained from the study of cell-nanotopography interactions to accelerate the development of next-generation stem cell culture materials and implant interfaces, and to fuel discovery of stem cell therapeutics to support regenerative therapies.

Harnessing nanotopography and integrin–matrix interactions to influence stem cell fate

Stress shielding and bone resorption in shoulder arthroplasty.

The radiographs of sixty-four patients with seventy humeral head replacements were reviewed for signs of stress shielding. Forty-nine were implanted for rheumatoid arthritis, twenty-one for osteoarthritis. The radiographic follow-up averaged 5. 3 years. Measurements of cortex thickness were performed in four regions along the stem of the implant and the differences between the post-operative radiograph and radiograph at follow-up were calculated. The size of the stem in relation to the diameter of the humerus was calculated using validated measures, resulting in the relative stem size. A reduction of 1.6 millimeters or more was considered to be a significant reduction, because this lay outside of the calculated 95% normal range for the group as a whole. In six patients (9%) a significant reduction, in cortical thickness was observed in the proximal lateral region of the humeral stem. Five of these had rheumatoid arthritis and one osteoarthritis. In the stress shielding group the relative stem size was found to be significantly higher (p=0. 013) than in the non-stress shielding group (0. 58 versus 0. 48). Osteoporosis, especially present in rheumatoid arthritis, could well be a risk factor. It was concluded that stress shielding is a long-term complication of shoulder arthroplasty and that the relative stem size is an important factor in its genesis. These resorptive processes may lead to a higher risk of failure of the implant and gives an increased risk for mid-stem fractures, due to cantilever loading. It is also desirable to preserve the proximal bone stock, considering the difficulties that arise when, for whatever reason, revision of the implant is necessary.

Stress shielding and bone resorption in shoulder arthroplasty

3D shoulder position measurements using a six-degree-of-freedom electromagnetic tracking device

Background and Purpose. In many physical therapy programs for subjects with adhesive capsulitis of the shoulder, mobilization techniques are an important part of the intervention. The purpose of this study was to compare the effectiveness of high-grade mobilization techniques (HGMT) with that of low-grade mobilization techniques (LGMT) in subjects with adhesive capsulitis of the shoulder. Subjects. One hundred subjects with unilateral adhesive capsulitis lasting 3 months or more and a ≥50% decrease in passive joint mobility relative to the nonaffected side were enrolled in this study. Methods. Subjects randomly assigned to the HGMT group were treated with intensive passive mobilization techniques in end-range positions of the glenohumeral joint, and subjects in the LGMT group were treated with passive mobilization techniques within the pain-free zone. The duration of treatment was a maximum of 12 weeks (24 sessions) in both groups. Subjects were assessed at baseline and at 3, 6, and 12 months by a masked assessor. Primary outcome measures included active and passive range of motion and shoulder disability (Shoulder Rating Questionnaire [SRQ] and Shoulder Disability Questionnaire [SDQ]). An analysis of covariance with adjustments for baseline values and a general linear mixed-effect model for repeated measurements were used to compare the change scores for the 2 treatment groups at the various time points and over the total period of 1 year, respectively. Results. Overall, subjects in both groups improved over 12 months. Statistically significant greater change scores were found in the HGMT group for passive abduction (at the time points 3 and 12 months), and for active and passive external rotation (at 12 months). A statistically significant difference in trend between both groups over the total follow-up period of 12 months was found for passive external rotation, SRQ, and SDQ with greater change scores in the HGMT group. Discussion and Conclusion. In subjects with adhesive capsulitis of the shoulder, HGMTs appear to be more effective in improving glenohumeral joint mobility and reducing disability than LGMTs, with the overall differences between the 2 interventions being small. [Vermeulen HM, Rozing PM, Obermann WR, et al. Comparison of high-grade and low-grade mobilization techniques in the management of adhesive capsulitis of the shoulder: randomized controlled trial.]

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Comparison of high-grade and low-grade mobilization techniques in the management of adhesive capsulitis of the shoulder: randomized controlled trial.

http://www.ece.uvic.ca/~bctill/papers/mocap/Meskers_etal_1997.pdf

Piet M. Rozing

Papers

Stress shielding and bone resorption in shoulder arthroplasty.

Stress shielding and bone resorption in shoulder arthroplasty

3D shoulder position measurements using a six-degree-of-freedom electromagnetic tracking device

Comparison of high-grade and low-grade mobilization techniques in the management of adhesive capsulitis of the shoulder: randomized controlled trial.

In vivo estimation of the glenohumeral joint rotation center from scapular bony landmarks by linear regression