Purpose

To explore the association of baseline trabecular bone structure with incident tibiofemoral (TF) osteoarthritis (OA) and with increase in joint space narrowing (JSN) score.

Methods

The Multicenter Osteoarthritis Study (MOST) includes subjects with or at risk for knee OA. Knee radiographs were scored for Kellgren-Lawrence (KL) grade and JSN at baseline, 30, 60 and 84 months. Knees (KL ≤ 1) at baseline were assessed for incident OA (KL ≥ 2) and increases in JSN score. For each knee image at baseline, a variance orientation transform method (VOT) was applied to subchondral tibial bone regions of medial and lateral compartments. Seventeen fractal parameters were calculated per region. Associations of each parameter with OA incidence and with medial and lateral JSN increases were explored using logistic regression. Analyses were stratified by digitized film (DF) vs computer radiography (CR) and adjusted for confounders.

Results

Of 894 knees with CR and 1158 knees with DF, 195 (22%) and 303 (26%) developed incident OA. Higher medial bone roughness was associated with increased odds of OA incidence at 60 and 84 months and also, medial and lateral JSN increases (primarily vertical). Lower medial and lateral anisotropy was associated with increased odds of medial and lateral JSN increase. Compared to DF, CR had more associations and also, similar results at overlapping scales.

Conclusion

Baseline trabecular bone texture was associated with incident radiographic OA and increase of JSN scores independently of risk factors for knee OA. Higher roughness and lower anisotropy were associated with increased odds for radiographic OA change.

In this paper, our goal is to explore what is known about the role of social touch during development. We first address the neural substrates of social touch and the role of tactile experience in neural development. We discuss natural variation in early exposure to social touch, followed by a discussion on experimental manipulations of social touch during development and "natural experiments", such as early institutionalization. We then consider the role of other developmental and experiential variables that predict social touch in adults. Throughout, we propose and consider new theoretical models of the role of social touch during development on later behavior and neurobiology.

Objective

To examine the relationship of knee malalignment with occurrence of incident and enlarging bone marrow lesions (BMLs) and regression of BMLs.

Methods

Subjects from the Multicenter Osteoarthritis Study aged 50-79 years with or at high risk of knee osteoarthritis were studied. Full-limb radiographs were taken at baseline and hip-knee-ankle mechanical axis was measured. Baseline and 30-month magnetic resonance imaging (MRI) of knees (n = 1782) were semiquantitatively assessed for BMLs. Outcome was defined as a change in BML score in femoral/tibial condyle in medial/lateral compartments. Medial compartment in varus alignment and lateral compartment in valgus alignment were combined to form 'more loaded' compartment, while lateral compartment in valgus and medial compartment in varus were combined to form 'less loaded' compartment. Relative risk (RR) of BML score increase or decrease in relation to malalignment was estimated using a log linear regression model with the Poisson assumption, adjusting for age, gender, body mass index, physical activity scale for the elderly, race and clinic site. Further, results were stratified by ipsilateral meniscal and cartilage status at baseline.

Results

Baseline varus alignment was associated with higher risk of BML score increase from baseline to follow-up in the medial compartment [adjusted RRs (95%CI): 1.5 (1.2-1.9)] and valgus alignment in the lateral compartment [1.4 (1.0-2.1)]. Increase in BML score was more likely in the more loaded compartments [1.7 (1.4-2.0)] in malaligned knees. Regardless of ipsilateral cartilage or meniscus status, adjusted RR for BML score increase was higher in the more loaded compartments of malaligned knees than those with neutral alignment. Decrease in BML score was less likely in the more loaded compartments in malaligned knees [0.8 (0.7-1.0)].

Conclusion

Knee malalignment is associated with increased risk of incident and enlarging BMLs in the more loaded compartments of the tibiofemoral joint.

Objective

There are few guidelines for clinical trials of interventions for prevention of post-traumatic osteoarthritis (PTOA), reflecting challenges in this area. An international multi-disciplinary expert group including patients was convened to generate points to consider for the design and conduct of interventional studies following acute knee injury.

Design

An evidence review on acute knee injury interventional studies to prevent PTOA was presented to the group, alongside overviews of challenges in this area, including potential targets, biomarkers and imaging. Working groups considered pre-identified key areas: eligibility criteria and outcomes, biomarkers, injury definition and intervention timing including multi-modality interventions. Consensus agreement within the group on points to consider was generated and is reported here after iterative review by all contributors.

Results

The evidence review identified 37 studies. Study duration and outcomes varied widely and 70% examined surgical interventions. Considerations were grouped into three areas: justification of inclusion criteria including the classification of injury and participant age (as people over 35 may have pre-existing OA); careful consideration in the selection and timing of outcomes or biomarkers; definition of the intervention(s)/comparator(s) and the appropriate time-window for intervention (considerations may be particular to intervention type). Areas for further research included demonstrating the utility of patient-reported outcomes, biomarkers and imaging outcomes from ancillary/cohort studies in this area, and development of surrogate clinical trial endpoints that shorten the duration of clinical trials and are acceptable to regulatory agencies.

Conclusions

These considerations represent the first international consensus on the conduct of interventional studies following acute knee joint trauma.