Surgery-Induced Changes and Early Recovery of Hip-Muscle Strength, Leg-Press Power, and Functional Performance After Fast-Track Total Hip Arthroplasty: A Prospective Cohort Study.

Surgery-induced changes and early recovery of hip-muscle strength, leg-press power, and functional performance after fast-track total hip arthroplasty: a prospective cohort study.

PLoS One. 2013; 8(4): e62109
Holm B, Thorborg K, Husted H, Kehlet H, Bandholm T

By measuring very early changes in muscle strength and functional performance after fast-track total hip arthroplasty (THA), post-operative rehabilitation, introduced soon after surgery, can be designed to specifically target identified deficits.Firstly, to quantify changes (compared to pre-operative values) in hip muscle strength, leg-press power, and functional performance in the first week after THA, and secondly, to explore relationships between the muscle strength changes, and changes in hip pain, systemic inflammation, and thigh swelling.Prospective, cohort study.Convenience sample of patients receiving a THA at Copenhagen University Hospital, Hvidovre, Denmark, between March and December 2011.Thirty-five patients (65.9±7.2 years) undergoing THA.Hip muscle strength, leg-press power, performance-based function, and self-reported disability were determined prior to, and 2 and 8 days after, THA (Day 2 and 8, respectively). Hip pain, thigh swelling, and C-Reactive Protein were also determined.Five patients were lost to follow-up. Hip muscle strength and leg press power were substantially reduced at Day 2 (range of reductions: 41-58%, P<0.001), but less pronounced at Day 8 (range of reductions: 23-31%, P<0.017). Self-reported symptoms and function (HOOS: Pain, Symptoms, and ADL) improved at Day 8 (P<0.014). Changes in hip pain, C-Reactive Protein, and thigh swelling were not related to the muscle strength and power losses.Hip muscle strength and leg-press power decreased substantially in the first week after THA - especially at Day 2 - with some recovery at Day 8. The muscle strength loss and power loss were not related to changes in hip pain, systemic inflammation, or thigh swelling. In contrast, self-reported symptoms and function improved. These data on surgery-induced changes in muscle strength may help design impairment-directed, post-operative rehabilitation to be introduced soon after NCT01246674. HubMed – rehab


Sensorimotor plasticity after music-supported therapy in chronic stroke patients revealed by transcranial magnetic stimulation.

PLoS One. 2013; 8(4): e61883
Amengual JL, Rojo N, Veciana de Las Heras M, Marco-Pallarés J, Grau-Sánchez J, Schneider S, Vaquero L, Juncadella M, Montero J, Mohammadi B, Rubio F, Rueda N, Duarte E, Grau C, Altenmüller E, Münte TF, Rodríguez-Fornells A

Several recently developed therapies targeting motor disabilities in stroke sufferers have shown to be more effective than standard neurorehabilitation approaches. In this context, several basic studies demonstrated that music training produces rapid neuroplastic changes in motor-related brain areas. Music-supported therapy has been recently developed as a new motor rehabilitation intervention.In order to explore the plasticity effects of music-supported therapy, this therapeutic intervention was applied to twenty chronic stroke patients. Before and after the music-supported therapy, transcranial magnetic stimulation was applied for the assessment of excitability changes in the motor cortex and a 3D movement analyzer was used for the assessment of motor performance parameters such as velocity, acceleration and smoothness in a set of diadochokinetic movement tasks. Our results suggest that the music-supported therapy produces changes in cortical plasticity leading the improvement of the subjects’ motor performance.Our findings represent the first evidence of the neurophysiological changes induced by this therapy in chronic stroke patients, and their link with the amelioration of motor performance. Further studies are needed to confirm our observations. HubMed – rehab


Human tendon stem cells better maintain their stemness in hypoxic culture conditions.

PLoS One. 2013; 8(4): e61424
Zhang J, Wang JH

Tissues and organs in vivo are under a hypoxic condition; that is, the oxygen tension is typically much lower than in ambient air. However, the effects of such a hypoxic condition on tendon stem cells, a recently identified tendon cell, remain incompletely defined. In cell culture experiments, we subjected human tendon stem cells (hTSCs) to a hypoxic condition with 5% O2, while subjecting control cells to a normaxic condition with 20% O2. We found that hTSCs at 5% O2 had significantly greater cell proliferation than those at 20% O2. Moreover, the expression of two stem cell marker genes, Nanog and Oct-4, was upregulated in the cells cultured in 5% O2. Finally, in cultures under 5% O2, more hTSCs expressed the stem cell markers nucleostemin, Oct-4, Nanog and SSEA-4. In an in vivo experiment, we found that when both cell groups were implanted with tendon-derived matrix, more tendon-like structures formed in the 5% O2 treated hTSCs than in 20% O2 treated hTSCs. Additionally, when both cell groups were implanted with Matrigel, the 5% O2 treated hTSCs showed more extensive formation of fatty, cartilage-like and bone-like tissues than the 20% O2 treated cells. Together, the findings of this study show that oxygen tension is a niche factor that regulates the stemness of hTSCs, and that less oxygen is better for maintaining hTSCs in culture and expanding them for cell therapy of tendon injuries. HubMed – rehab