Vitamin D is well known to exert multiple functions in bone biology, autoimmune diseases, cell growth, inflammation or neuromuscular and other immune functions. It is a fat-soluble vitamin present in many foods. It can be endogenously produced by ultraviolet rays from sunlight when the skin is exposed to initiate vitamin D synthesis. However, since vitamin D is biologically inert when obtained from sun exposure or diet, it must first be activated in human beings before functioning. The kidney and the liver play here a crucial role by hydroxylation of vitamin D to 25-hydroxyvitamin D in the liver and to 1,25-dihydroxyvitamin D in the kidney. In the past decades, it has been proven that vitamin D deficiency is involved in many diseases. Due to vitamin D’s central role in the musculoskeletal system and consequently the strong negative impact on bone health in cases of vitamin D deficiency, our aim was to underline its importance in bone physiology by summarizing recent findings on the correlation of vitamin D status and rickets, osteomalacia, osteopenia, primary and secondary osteoporosis as well as sarcopenia and musculoskeletal pain. While these diseases all positively correlate with a vitamin D deficiency, there is a great controversy regarding the appropriate vitamin D supplementation as both positive and negative effects on bone mineral density, musculoskeletal pain and incidence of falls are reported.

Diagnostic studies, Level I.

I.

Therapeutic study, Level I.

No abstract

Prospective case series, II.

Numerous studies have described a correlation between smoking and reduced bone mass. This not only increases fracture risk but also impedes reconstruction/fixation of bone. An increased frequency of complications following surgery is common. Here, we investigate the effect of smoking on the clinical outcome following total joint arthroplasty (TJA). 817 patients receiving primary or revision (including clinical transfers) TJA at our level-one trauma center have been randomly interviewed twice (pre- and six months post-surgery). We found that 159 patients developed complications (infections, disturbed healing, revisions, thrombosis, and/or death). Considering nutritional status, alcohol and cigarette consumption as possible risk factors, OR was highest for smoking. Notably, mean age was significantly lower in smokers (59.2 ± 1.0a) than non-smokers (64.6 ± 0.8; p < 0.001). However, the number of comorbidities was comparable between both groups. Compared to non-smokers (17.8 ± 1.9%), the complication rate increases with increasing cigarette consumption (1–20 pack-years (PY): 19.2 ± 2.4% and >20 PY: 30.4 ± 3.6%; p = 0.002). Consequently, mean hospital stay was longer in heavy smokers (18.4 ± 1.0 day) than non-smokers (15.3 ± 0.5 day; p = 0.009) or moderate smokers (15.9 ± 0.6 day). In line with delayed healing, bone formation markers (BAP and CICP) were significantly lower in smokers than non-smokers 2 days following TJA. Although, smoking increased serum levels of MCP-1, OPG, sRANKL, and Osteopontin as well as bone resorption markers (TRAP5b and CTX-I) were unaffected. In line with an increased infection rate, smoking reduced 25OH vitamin D3 (immune-modulatory), IL-1β, IL-6, TNF-α, and IFN-γ serum levels. Our data clearly show that smoking not only affects bone formation after TJA but also suppresses the inflammatory response in these patients. Thus, it is feasible that therapies favoring bone formation and immune responses help improve the clinical outcome in smokers following TJA.

BackgroundOpen wedge high tibial osteotomy (HTO) is an established method for the treatment of patients with varus malalignment and medial compartment osteoarthritis. In these patients, health-related quality of life (HRQL) can be improved by using this procedure. The purpose of the present study consisted in evaluating HRQL up to 18 months after HTO, comparing the results to values of the German normal population, and in analyzing the impact of preoperative HRQL on the postoperative clinical result. It was hypothesized that normal values in physical and mental health can be achieved within 18 months after operation. Study design: Prospective case series. Level of evidence: IV.Methods120 patients were included in this prospective case series from 12/2008 to 12/2011. All patients underwent open wedge HTO without a bone graft using the TomoFixTM plate. HRQL was assessed by using the SF-36 questionnaire, preoperatively, as well as 6, 12, and 18 months postoperatively. Regular scoring, norm-based scaling, and the physical and mental component summary scores (PCS and MCS) were evaluated. Clinical outcome was assessed by using Lequesne, Lysholm, HSS and IKDC Score.ResultsHRQL could be described in 96 patients. The PCS of HRQL showed a statistically significant pre- to postoperative improvement (30.2 ± 13.4 to 45.9 ± 13.5 after 18 months). A reduced preoperative mental component summary score (MCS) resulted in lower values of each clinical score (p < 0.05) and in a prolonged duration of incapacity for work (MCS < 50:15.0 ± 12.8 weeks, vs. MCS ≥ 50: 9.1 ± 4.8 weeks, p < 0.05). MCS values improved from the pre- to postoperative measurements and comparable values to the normal population were reached already within 6 months after surgery (46.0 ± 14.9 pre-operatively and 48.5 ± 13.7 after 6 months), and after 18 months even a score of 49.5 ± 12.4 was achieved.ConclusionLower preoperative mental component score results in reduced postoperative clinical outcome and prolonged duration of incapacity for work after HTO. In contrast to PCS, MCS showed comparable values to the normal population within 6 months after HTO.