British Army recruits with low serum vitamin D take longer to recover from stress fractures.

BACKGROUND: Recruits undergoing military training experience a particularly high incidence of stress fractures. The role of combined calcium and vitamin D (25-OHD) deficiency and subsequent supplementation has been well described in the literature, but the role of 25-OHD deficiency alone is less well understood, particularly its influence on recovery once a stress fracture has been incurred. METHODS: Retrospective data of recruits who had incurred stress fractures were collected (n=37). Independent-samples t-tests were conducted in Microsoft Excel to investigate the association between serum-25 OHD and the time taken to recover. RESULTS: Significant differences (p<0.05) were found in the mean time taken to recover from stress fractures when participants were grouped according to serum 25-OHD level. Sufficient levels of serum 25-OHD (>50 nmol/L) at the time of injury resulted in shorter recovery times than all other groups. CONCLUSION: The study demonstrated an association between serum 25-OHD level and the time taken to recover from a stress fracture. The sample population of this study was too small to contribute to the discussion about whether a minimum serum 25-OHD status should be met before entering British Army training, but a larger prospective study should be able to provide the data required for a cost benefit analysis to be conducted and a decision made.

Single injection of PTH improves osteoclastic parameters of remodeling at a stress fracture site in rats.

Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna. SFx was induced in 120 female Wistar rats (300 ± 15 g) during a single loading session. A single PTH (8 µg.100g-1 ) or vehicle (VEH) saline injection was administered 24 h after loading. Rats were divided into four groups (n = 15) and ulnae were examined 1, 2, 6, or 10 weeks following SFx. Two Toluidine Blue and TRAP-stained sections of the SFx were examined for histomorphometric analysis using Osteomeasure™ software. An increase in osteoclast number (N.Oc) and perimeter (Oc.Pm) was observed two weeks following PTH treatment (p < 0.01). At 6 weeks, bone formation was the main activity in BMUs. At 10 weeks, the proportion of healing along the SFx line remained 50% greater in PTH groups (p = 0.839), leading to a 43% reduction in the porosity area of BMU (p = 0.703). The main effect of time was a significant variable along the entire SFx remodeling cycle, with significant interactions between time and treatment type affecting (N.Oc) (p = 0.047) and (Oc.Pm) (p = 0.002). We conclude that a single PTH injection increases osteoclastogenesis by the second week of the remodeling cycle in a SFx in vivo. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Intravenous bisphosphonates and vitamin D in the treatment of bone marrow oedema in professional athletes.

INTRODUCTION: The goal of this retrospective study was to evaluate the safety and efficacy of ibandronate for bone marrow oedema (BMO) syndrome and stress fracture cases, and to demonstrate an additional field of therapeutic importance-the high-performance athlete. PATIENTS AND METHODS: This retrospective study included twenty-five high-performance athletes. Sixty per cent of the athletes were European soccer players and 40.0% other high-class international athletes (3 women and 22 men with an average age of 25.0±4.2), with BMO of the lower trunk or extremity diagnosed by magnetic resonance imaging (MRI). The treatment regimen consisted of high-dose vitamin D supplementation and intravenous ibandronate therapy. RESULTS: The time between the onset of pain and proper diagnosis of BMO was 106.3±104.1 days. Excellent pain reduction (pain at rest and under strain) and improved mobility was reported within the first two weeks after the first ibandronate administration by sixteen patients (64%). The time from first treatment until return to competition (RTC) was on average 102.6±65.2 days in total. If the time from onset of pain until diagnosis was within 40 days, the RTC was significantly reduced (p≤0.05) to almost 50% (63.8±48.1 days) when compared to the athletes with later diagnosis (124.4±63.2 days). CONCLUSIONS: The here-applied therapy regimen of intravenous BPs application and vitamin D supplementation in BMO syndrome has a beneficial effect for high-performance athletes. An early diagnosis and rapid treatment start can reduce the RTC significantly. An optimal bone metabolism with sufficient daily calcium and vitamin D intake is crucial and should not only be strived for the professional but also for the recreational athlete.

Vitamin D supplementation in athletes.

It is well recognized that vitamin D is necessary for optimal bone health. Emerging evidence is finding that vitamin D deficiency can have a profound effect on immunity, inflammation and muscle function. Studies in athletes have found that vitamin D status varies among different populations and is dependent on skin color, early- or late-day training, indoor training and geographic location. Although dietary assessment studies have found that athletes worldwide do not meet the dietary intake recommendations for vitamin D, the most probable reason for poor status is inadequate synthesis due to lack of sun exposure. Studies in athletic populations suggest that maintaining adequate vitamin D status may reduce stress fractures, total body inflammation, common infectious illnesses, and impaired muscle function, and may also aid in recovery from injury. Given that compromised vitamin D status can potentially impact an athlete's overall health and training efficiency, vitamin D status should be routinely assessed so that athletes can be coached to maintain serum 25(OH)D concentration of ≥30 and preferably ≥40 ng/ml. Recommendations will be dependent on the athlete's current 25(OH)D concentration, but can include regular safe sun exposure and/or dietary supplementation combined with increased vitamin D intake.

Teriparatide, vitamin D, and calcium healed bilateral subtrochanteric stress fractures in a postmenopausal woman with a 13-year history of continuous alendronate therapy.

BACKGROUND: Oral bisphosphonates comprise the most widely prescribed class of antiosteoporotic drugs. Recent reports, however, propose a link between prolonged bisphosphonate use and atypical, low-energy, subtrochanteric fractures. OBJECTIVES: The aim was to describe the clinical course of a patient treated long-term with alendronate who developed subtrochanteric stress fractures and to propose a hypothesis to explain teriparatide's potential contribution in healing the patient's stress fractures. RESULTS: Magnetic resonance imaging (MRI) showed classical bilateral stress fractures of the mid-femora. Baseline serum 25-hydroxyvitamin D(3) was low; bone-specific alkaline phosphatase was slightly increased; serum carboxyterminal cross-linking telopeptide of bone collagen and urine aminoterminal cross-linking telopeptide of bone collagen were low to normal, as was serum osteocalcin. Dual-energy x-ray absorptiometry showed osteopenic vertebral bone mineral density and osteoporotic hip values. Treatment with large doses of oral vitamin D increased serum 25-hydroxyvitamin D(3) to normal within 2 months, after which it remained in the normal range with maintenance doses. Thigh pain, present as an initial symptom, intensified, and the MRI appearance of the fractures worsened. Teriparatide treatment commenced, and 6 months later, a repeat MRI showed decreased edema at the fracture sites with faint cortical bridging. Thigh pain and lower limb weakness disappeared over the next year, and complete fracture healing was established (MRI). CONCLUSIONS: Based upon the chronology of fracture healing in our patient and published evidence that teriparatide heals stress fractures in a rat model, we think that teriparatide was probably primary in this patient's positive response to therapy, with calcium, vitamin D therapy, and alendronate discontinuation playing secondary roles.