The role of vitamin D and vitamin D deficiency in orthopaedics and traumatology-a narrative overview of the literature.

Vitamin D is considered to play an important role in musculoskeletal health. It's classical function is the regulation of calcium and phosphate homeostasis, thus ensuring a balanced bone metabolism that is characterised by an equal amount of bone resorption and bone formation. In the past decades, a plethora of pre-clinical and clinical studies reporting on potential health-beneficial properties of vitamin D have emerged. Moreover, there is an abundance of reports highlighting vitamin D deficiency and insufficiency in patients with almost innumerable diseases. Further, it is estimated that more than one billion people globally are affected by insufficient vitamin D levels. As such, research on vitamin D has been particularly popular over the past years. In orthopaedics and traumatology, most studies describe favourable effects of vitamin D in general. However, the relative importance of vitamin D is oftentimes debated. In this narrative review of the literature, we consider first, the properties of vitamin D and how vitamin D, vitamin D deficiency and the vitamin D receptor (VDR) impact on musculoskeletal health. Secondly, we provide an overview of studies reporting the prevalence of vitamin D deficiency in traumatology and diverse orthopaedic diseases including bone oncology. Lastly, we emphasise recent findings and touch on future perspectives in vitamin D research.

Vitamin D Deficiency: The Missing Etiological Factor in the Development of Juvenile Osteochondrosis Dissecans?

BACKGROUND: Vitamin D deficiency can result in rickets and hypocalcemia during infant and childhood growth. There is an increasing interest in the role of vitamin D with regards to childhood bone health. Osteochondrosis dissecans (OD) is a common disease affecting different joints. To date, the exact etiology of OD still remains unclear. The aim of this study was to evaluate a possible association of vitamin D deficiency and juvenile OD. METHODS: A retrospective chart review of the years 2010 to 2015 of all orthopaedic patients with an initial diagnosis of juvenile OD admitted to undergo operative treatment of the OD was performed. Patient demographics, medical history, information on sports activity (if available) and serum vitamin D (25-OH-D) level on admission date were obtained. For statistical comparison, we measured baseline prevalence of vitamin D insufficiency in age-matched orthopaedic patients presenting at the department of pediatric orthopaedics. RESULTS: A total of 80 patients were included in this study. Overall, 97.5% (n=78) of tested patients in the OD group had serum vitamin D levels below the recommended threshold of 30 ng/mL (mean value of 10.1 ng/mL (±6.7 ng/mL)). Over 60% (n=49) were vitamin D deficient, 29 patients (37%) showed serum levels below 10 ng/mL corresponding to a severe vitamin D deficiency. Of note, only 2 patients (2.5%) reached serum vitamin D levels above the recommended threshold of 30 ng/mL. No statistical difference was found in respect to sports activity level before onset of the symptoms (P=0.09). Statistical analysis found a significant difference in vitamin D levels between patients with OD and patients without an OD (P=0.026). CONCLUSIONS: We found an unexpected high prevalence of vitamin D deficiency in juveniles diagnosed with OD presenting with significant lower mean 25-OH-D level compared with a control group. These results suggest that vitamin D deficiency is potentially associated with the development of OD. Thus, vitamin D deficiency might be an important cofactor in the multifactorial development of juvenile OD. For this reason, supplementation of vitamin D might not only be a potential additional therapy but also be a possible preventative factor in patients with juvenile OD. However, future prospective studies are needed to confirm this preliminary data. LEVEL OF EVIDENCE: Level III-this is a case-control study.

Applications of patient-specific 3D printing in medicine.

Already three decades ago, the potential of medical 3D printing (3DP) or rapid prototyping for improved patient treatment began to be recognized. Since then, more and more medical indications in different surgical disciplines have been improved by using this new technique. Numerous examples have demonstrated the enormous benefit of 3DP in the medical care of patients by, for example, planning complex surgical interventions preoperatively, reducing implantation steps and anesthesia times, and helping with intraoperative orientation. At the beginning of every individual 3D model, patient-specific data on the basis of computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound data is generated, which is then digitalized and processed using computer-aided design/computer-aided manufacturing (CAD/CAM) software. Finally, the resulting data sets are used to generate 3D-printed models or even implants. There are a variety of different application areas in the various medical fields, eg, drill or positioning templates, or surgical guides in maxillofacial surgery, or patient-specific implants in orthopedics. Furthermore, in vascular surgery it is possible to visualize pathologies such as aortic aneurysms so as to improve the planning of surgical treatment. Although rapid prototyping of individual models and implants is already applied very successfully in regenerative medicine, most of the materials used for 3DP are not yet suitable for implantation in the body. Therefore, it will be necessary in future to develop novel therapy approaches and design new materials in order to completely reconstruct natural tissue.