Return to sport after muscle injury

Platelet-Poor versus Platelet-Rich Plasma for the Treatment of Muscle Injuries

ABSTRACT

Muscle injury in sport results in significant lost time and potential for reinjury for athletes. Autologous blood product, namely, platelet-rich plasma (PRP), has been investigated for possible augmentation of the treatment timeline with prevention of reinjury; however, conflicting results have been identified. A growing body of basic science and clinical literature is forming that supports the use of platelet-poor plasma (PPP) for muscle injury. The purpose of this study was to provide a background of the basic science of PRP versus PPP for muscle injury and to identify and review the clinical evidence for both autologous blood products, including the author's clinical experience utilizing the blood products. At the tissue level, PRP causes myoblast proliferation while PPP has led to myoblast induction, potentially identifying improved native muscle healing. Conflicting studies have been identified for the use of PRP for muscle injury. A growing body of positive results for PPP was identified, but high-quality comparative studies are needed.

Return to Play in the Professional Athlete

The management of any injury in elite athletes poses unique challenges distinct from the general population because the goal is rapid recovery and return to play (RTP) while simultaneously managing residual symptoms and minimizing risk of reinjury. The time required for treatment, recovery, and return to peak performance can have consequences for both the athlete and his or her team: financial implications, psychological stressors, team dynamics, and future performance. RTP after an injury in the professional athlete requires a complex decision-making process with many stakeholders. Several factors influence this decision, not the least of which is the type and mechanism of injury. This article provides an overview of the RTP process including nonmedical factors that may influence this decision, common injuries seen in professional athletes, injury patterns particular to certain popular sports, and imaging guidelines for such injuries.

Porous Se@SiO2 nanoparticles improve oxidative injury to promote muscle regeneration via modulating mitochondria

Background: Acute skeletal muscle injuries are common among physical or sports traumas. The excessive oxidative stress at the site of injury impairs muscle regeneration. The authors have recently developed porous Se@SiO₂ nanoparticles (NPs) with antioxidant properties. Methods: The protective effects were evaluated by cell proliferation, myogenic differentiation and mitochondrial activity. Then, the therapeutic effect was investigated in a cardiotoxin-induced muscle injury rat model. Results: Porous Se@SiO₂ NPs significantly protected the morphological and functional stability of mitochondria, thus protecting satellite cells from H₂O₂-induced damage to cell proliferation and myogenic differentiation. In the rat model, intervention with porous Se@SiO₂ NPs promoted muscle regeneration. Conclusion: This study reveals the application potential of porous Se@SiO₂ NPs in skeletal muscle diseases related to mitochondrial dysfunction.

The use of platelet-rich plasma (PRP) in the treatment of gastrocnemius strains: a retrospective observational study

The aim of the present retrospective observational study was to evaluate the time of functional recovery following a specific combined therapeutic approach characterized by an active exercise therapy carried out immediately after Platelet-rich plasma (PRP) injections for the treatment of the muscular lesion of the distal musculotendinous junction of the gastrocnemius medial head.Medical records of 31 subjects treated with three PRP intra-lesional ultrasound guided injections and 30 patients treated with the standard therapeutic approach (control group) were analyzed. Both groups followed the same rehabilitation therapy. Patients in the control group were able to start active exercise with a significant delay when compared to the PRP treated subjects: 17 ± 7.2 days and 9 ± 3.8 days (p = 0.0001), respectively. This delay was mainly due to the persistence of pain in the subjects in the control group. The time necessary to return to walk without pain was significantly shorter in the PRP treated group: 24.27 ± 12.36 days versus 52.4 ± 20.03 days in the control group (p < 0.001) as well as the time needed to fully return to practice the previous sport activity: 53.33 ± 27.74 days versus 119.3 ± 43.87 days in the control group (p < 0.001).The present study showed that ultrasound guided delivery of PRP into the site of muscle injury has to be considered a valid therapeutic approach with the potentiality of significantly reduce time and costs for reaching a complete functional recovery.

[Biomechanical screening for injury prevention : The importance of 3D-motion analysis in high performance sports]

Standardized clinical diagnostic procedures cannot assess the functionality of the anatomical structures in sport-specific movement. Biomechanical screening is able to detect deficits but is not sufficiently and objectively precise with the current clinical examination tools including conventional imaging techniques. The fields of use of functional testing methods are versatile and range from injury prevention analysis, screening during rehabilitation phases up to the return-to-play decision. Using simple musculoskeletal function analysis it is difficult to assess the risk of injuries. The main advantage of instrumented 3D-motion analysis is its potential to generate objective, reliable and reproducible data with exact joint angles, muscle activity, as well as loading inside the joints during movement. These marker-based motion analysis procedures are more time-consuming and more cost intensive and necessitate in particular biomechanical and medical knowledge to assess the analytical data in terms of clinical relevance. In the absence of scientific studies on biomechanical analyses in professional sports, this study shows preliminary approaches to this topic.

Role of transforming growth factor-β in muscle damage and regeneration: focused on eccentric muscle contraction

High-intensity eccentric muscle contraction induces muscle damage. Damaged muscles recover through different processes, including degeneration, inflammation, regeneration, and fibrosis; some of these processes are mediated through the actions of cytokines. The transforming growth factor-beta (TGF-β) is one such cytokine involved in muscle recovery and repair. In this regard, TGF-β regulates the skeletal muscle inflammatory response, inhibits muscle regeneration, regulates extracellular matrix remodeling, and promotes fibrosis. Although some studies have suggested that inhibition of TGF-β after muscle damage promotes muscle regeneration and recovery, other studies have noted that TGF-β inhibition actually reduces muscle strength because it leads to incomplete muscle regeneration. Despite the importance of TGF-β in the repair of damaged muscles, most studies have focused on examining its role in muscle diseases such as chronic inflammatory diseases or Duchenne’s muscular dystrophy. Here, we have reviewed the existing literature for examining the role of TGF-β in muscle damage and regeneration after eccentric muscle contraction.

Extracorporeal Shock Wave Therapy Accelerates Regeneration After Acute Skeletal Muscle Injury

BACKGROUND

Muscle injuries are among the most common sports-related lesions in athletes; however, optimal treatment remains obscure. Extracorporeal shock wave therapy (ESWT) may be a promising approach in this context, because it has gained increasing importance in tissue regeneration in various medical fields.

HYPOTHESIS

ESWT stimulates and accelerates regenerative processes of acute muscle injuries.

STUDY DESIGN

Controlled laboratory study.

METHODS

Adult Sprague-Dawley rats were divided into 4 experimental groups (2 ESWT+ groups and 2 ESWT- groups) as well as an uninjured control group (n ≥ 6 in each group). An acute cardiotoxin-induced injury was set into the quadriceps femoris muscle of rats in the experimental groups. A single ESWT session was administered to injured muscles of the ESWT+ groups 1 day after injury, whereas ESWT- groups received no further treatment. At 4 and 7 days after injury, 1 each of the ESWT+ and ESWT- groups was euthanized. Regenerating lesions were excised and analyzed by histomorphometry and immunohistochemistry to assess fiber size, myonuclear content, and recruitment of satellite cells.

RESULTS

The size and myonuclear content of regenerating fibers in ESWT+ muscle was significantly increased compared with ESWT- muscle fibers at both 4 and 7 days after injury. Similarly, at both time points, ESWT+ muscles exhibited significantly higher contents of pax7-positive satellite cells, mitotically active H3P⁺ cells, and, of cells expressing the myogenic regulatory factors, myoD and myogenin, indicating enhanced proliferation and differentiation rates of satellite cells after ESWT. Mitotic activity at 4 days after injury was doubled in ESWT+ compared with ESWT- muscles.

CONCLUSION

ESWT stimulates regeneration of skeletal muscle tissue and accelerates repair processes.

CLINICAL RELEVANCE

We provide evidence for accelerated regeneration of damaged skeletal muscle after ESWT. Although further studies are necessary, our findings support the view that ESWT is an effective method to improve muscle healing, with special relevance to sports injuries.

Spanish Consensus Statement: The Treatment of Muscle Tears in Sport

On the 21st of March, 2015, experts met at Clínica CEMTRO in Madrid, Spain, under the patronage of The Spanish Society for Sports Traumatology (SETRADE), The Spanish Federation of Sports Medicine (FEMEDE), The Spanish Association of Medical Services for Football Clubs (AEMEF), and The Spanish Association of Medical Services for Basketball Clubs (AEMB) with the aim of establishing a round table that would allow specialists to consider the most appropriate current general actions to be taken when treating muscle tears in sport, based on proven scientific data described in the medical literature. Each expert received a questionnaire prior to the aforementioned meeting comprising a set of questions concerning therapeutic indications generally applied in the different stages present during muscle repair. The present Consensus Document is the result of the answers to the questionnaire and resulting discussion and consensus over which are the best current indications in the treatment of muscle tears in sport. Avoiding immobilization, not taking nonsteroidal anti-inflammatory drugs (NSAIDs) randomly, fostering early mobilization, increasing vascularization of injured, site and regulating inflammatory mechanisms—without inhibiting these from the early stages of the recovery period—all stood out as main points of the Consensus Document. Additionally, there is controversy concerning cell stimulation techniques and the use of growth factors or cell inhibitors. The decision concerning discharge was unanimous, as was the criteria considered when it came to performing sport techniques without pain.