Vitamin D Status of Elite Athletes in Singapore and Its Associations With Muscle Function and Bone Health

Purpose The primary aim of this study is to determine the prevalence of vitamin D deficiency and insufficiency among Asian athletes participating in indoor and outdoor sports in equatorial Singapore.Secondary aims are to examine the relationship between vitamin D status and skeletal muscle strength and performance,and bone density.Methods Serum 25(OH)D concentrations were determined in 95 indoor and outdoor athletes across various sports.Skeletal muscle strength and performance were assessed using the isometric mid-thigh pull(IMTP),drop jump test and 30 m sprint test.Bone Mineral Density(BMD)was measured using Dual-energy X-ray Absorptiometry(DXA).Results Mean serum 25(OH)D concentrations were 28.6±8.9 ng/mL among indoor,and 39.2±13.2 ng/mL among outdoor sport athletes respectively(P<0.05).More indoor sport athletes(62%)had insufficient vitamin D compared to outdoor sport athletes(30%)(P<0.05).Outdoor sport athletes exhibited significantly greater peak force generation than indoor sport athletes(2079±470 N vs.1869±546 N,P=0.027).Other markers of muscle function were not significantly different between groups.Indoor and outdoor sport athletes did not have significantly different BMDs although none of the athletes studied presented with poor BMD.Athletes who were deficient in vitamin D had significantly lower BMD compared to athletes with sufficient vitamin D(P=0.01).Conclusion Forty-seven percent of Singaporean athletes studied had suboptimal vitamin D status.Routine monitoring of vitamin D levels among indoor sport athletes should be in place to ensure optimal health and performance.

Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury

Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.

The status of the cervical spine in preschool children with a history of congenital muscular torticollis

Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocleidomastoid muscle. Purpose: The study aimed to investigate passive range of motion (PROM) for rotation and lateral flexion, and muscle function of the cervical spine in children that had a history of CMT as infants. Study design: a prospective cohort study. Patient sample: 58 children at the age of 3.5 to 5 years that had been treated for CMT have infants participated in the study. Method: PROM was measured with protractors and muscle function was estimated with a modified Muscle Function Scale. Data from infancy were taken from earlier records. Result: PROM in rotation of the neck was mean 98.7&#176 and PROM in lateral flexion of the neck was mean 69.1&#176. Symmetric PROM of the neck was found in 74% of the children for rotation and in 88% of the children for lateral flexion. Multiple regression showed that gender and PROM in rotation as infants had a significant impact on asymmetric PROM. Forty-five percent of the children had some degree of muscular imbalance in the lateral flexors of the neck. Conclusion: Possible risk factors for later asymmetric PROM are: gender, birth weight, gestation week and PROM in rotation as infants. These factors ought to be taken into consideration when developing guidelines for long-term follow-up.

The technique of utilizing a single gracilis functional muscle transfer to restore quadriceps function following sarcoma surgery

Aim:Quadriceps strength and knee extension,the most important factors limiting the ability to rise from a chair,are crucial for walking at an appropriate speed,ascending and descending stairs,and performing activities such as running,dancing,and jumping.Resection of the anterior compartment of the thigh,including all four quadriceps muscles,for the treatment of a sarcoma is uncommon;however,when necessary,it is very debilitating and adversely affects a patient's quality of life without functional reconstruction.Currently,there are a limited number of complex and difficult reconstructions to restore quadriceps function that have been described with variable outcomes.We describe a simple technique that employs a single gracilis functional muscle transfer to replace essential quadriceps function.Methods:This is a case series describing the use of either a free or pedicled single gracilis muscle to restore quadriceps function following sarcoma resection.Results:Four patients underwent an anterior compartment sarcoma resection that resulted in a large segmental defect and/or denervation of all four quadriceps muscles such that no quadriceps function would remain without reconstruction.All four patients underwent a functional reconstruction using a single gracilis.Three of the living patients achieved British Medical Research Counsel Grade 4 strength,can achieve full knee extension,are able to navigate stairs,and are able to ambulate without a brace.The fourth patient unfortunately was deceased in under three months following his tumor resection.Conclusion:Despite its small size in comparison to the quadriceps muscles,with physiotherapy and training,the gracilis muscle demonstrates the capacity to hypertrophy and replace quadriceps function following limb salvage surgery.

Complex upper extremity injuries:targeted muscle reinnervation,free functional muscle transfer,and vascularized composite allotransplantation

Restoration of upper extremity function poses a unique surgical challenge.With considerations ranging from ensuring appropriate skeletal support and musculotendinous and ligamentous anatomy,restoring adequate vascularity and innervation,and providing sufficient soft tissue coverage,upper extremity injuries present a diverse range of reconstructive problems.Recent history has been marked by an expansion of novel techniques for addressing these complex issues.Sophisticated modalities,such as targeted muscle reinnervation,free functional muscle transfer,and vascularized composite allotransplantation,have become some of the most powerful tools in the armamentarium of the reconstructive surgeon.This review article aims to define the distinguishing features of each of these modalities and reviews some of their unique advantages and limitations.

Advances in functional limb reconstruction in the irradiated setting

The management of extremity soft tissue sarcoma is constantly evolving, and, in recent decades, limb salvage has been the main goal. More commonly, this is being achieved with a combination of neo-adjuvant radiotherapy,followed by wide excision and soft tissue reconstruction in the form of vascularised soft tissue transfer. Although limb salvage is now readily achievable, the resultant functional disabilities following excision of major musculotendinous and neurovascular structures can be life changing. In recent years, there has been a move towards functional limb reconstruction in the form of free functioning muscle transfer. This paper reviews the advances in functional limb reconstruction in the setting of preoperative radiation and reports our experience in this challenging reconstructive field.