Orthopedic & muscular system : current research最新文献

Objective: The use of Long-Duration Ultrasound (LDU) and Platelet-Rich Plasma (PRP) treatments to facilitate injury healing and pain relief are typically utilized independently in sports medicine. Our study aimed to investigate the combined regenerative effect of daily LDU with high-concentration single-injection PRP for treating sport-related musculoskeletal injuries.

Methods: In total, thirty-five competitive athletes (n=35) with grade II sprains and strains and tendinopathies injured during sport and unable to continue to play were sequentially administered PRP (n=20, 20.4 yoa, 18 male, 2 female) or PRP+LDU (n=15, 20.27 yoa, 14 male, 1 female). In the PRP treatment group, each subject was treated with a single injection of PRP consisting of 1.28 billion platelets/mL under ultrasound-image guidance to the injury site. The PRP+LDU treatment group received the same PRP injection procedure with a 14-day, 4 hr per day, 18,720 J ultrasound treatment applied over the injection site. The Numeric Ration pain Scale (NRS, 0-10), Range of Motion (ROM, 0-100%), Clinical Strength numeric score (CS, 0-5), and time of injury to return to sport (days) were measured at baseline and Return to Play (RTP). The global health improvement score (GROC -7 to +7) was measured upon RTP.

Results: All patients completed rehabilitation and returned to the sport after debilitating injuries. PRP+LDU returned athletes to play 21.33 days quicker (p<0.0001), decreased injury pain by 0.88 NRS points (p=0.0086), and improved patient global health by 1.28 points GROC (p<0.0001) over PRP treatment alone (95% Confidence interval, 11.26 to 31.40 days faster). There were no significant differences in strength (p=0.498) or range of motion (p=0.8581) improvement between PRP and PRP+LDU at the RTP or baseline patient demographic variables.

Conclusion: Adding LDU at-home treatment to PRP injection therapy significantly reduces the time to return to sport, increases pain reduction, and improves overall health for patients recovering from sport-related injury. The daily LDU treatment facilitates and enhances regenerative medicine therapies such as PRP.

Objective: Stem cell therapy can be an efficacious treatment option for bone fragility disorders (eg, osteogenesis imperfecta, disuse osteopenia, and osteoporosis), and successful cell therapy application may be dependent on optimal cell engraftment in target bones. The objective of this study was to compare the efficiency of intra-medullar and intra-venous delivery of mesenchymal stem cells (MSC) to improve cell engraftment rate, bone mineral density, and micro-architecture.

Methods: By using six healthy juvenile New Zealand White rabbits, MSC were isolated from cancellous bone harvests and confirmed to have osteogenic capacity by inducing ectopic bone formation. The MSC were cultured, transduced by foamy viral vectors with marker genes for in vivo cell tracking, and expanded. All rabbits had one randomly selected limb receive intra-medullar infusion of 3×10⁷ to 1×10⁸ autologous MSC in the distal femur or the distal femur and proximal tibia. Two of six rabbits also received an intra-venous MSC infusion. At 28 days, MSC bone engraftment was assessed by PCR and the bone density and microstructure assessed by computed tomography and histomorphometry.

Results: The intra-medullar-infused MSC were detected in epiphysis or diaphysis of the distal femurs and/or proximal tibiae. Infused MSC comprised 0.01 to 0.3% of all cells in the bone tissues. The intra-venous-infused MSC were not detected in any location. Neither intra-medullar nor intra-venous MSC infusion altered bone volume, bone mineral density, or cortical bone porosity/thickness. Systemic biodistribution of intra-medullar-infused MSC was not evident.

Conclusions: Our results indicated that intra-medullar infusion can be an effective cell delivery route for stem cell therapy potentially for orthopedic disorders, in preference to systemic administration. Further research is warranted to demonstrate an efficacy of intra-medullar MSC infusion on bone density and micro-architecture using animal models of bone disorders.

The adult skeleton undergoes bone remodeling that consists of bone formation by osteoblasts and bone resorption by osteoclasts. When the amount of bone resorbed is greater than the amount of new bone formed, low bone mass results, putting individuals at increased risk for osteoporosis and osteoporotic bone fracture. Nitrogenous bisphosphonates (NBPs) are the most common first line treatment for conditions of low bone mass. NBPs reduce osteoclast bone resorption by impairing the post-translational modification of small GTPases. Small GTPases play crucial roles in the differentiation, function, and survival of osteoclasts. Understanding the roles of individual small GTPases in osteoclast biology may lead to more targeted therapies for the treatment of low bone mass. In this review, we discuss recent investigations into the in vivo effects of individual GTPase deletion in osteoclasts and the molecular roles for small GTPases in osteoclast biology.