RESUMEN
Slightly focused high-energy shockwave (HESW) therapy is characterized by a wide focal area, a large therapy zone, easy positioning and less pain during treatment. The objective of this study was to perform for the first time an in vivo test of the slightly focused HESWs for osteoporotic fractures. Bilateral proximal tibial osteotomies were made in 30 ovariectomized (OVX) Sprague-Dawley rats and secured with internal fixation. The osteotomy site in the left tibia was subsequently treated with slightly focused HESWs with the energy flux density of 0.26 mj/mm(2), shock repetition frequency of 1 Hz and 2000 shocks (OVX + HESW group). The contralateral right tibia was not treated and served as the control (OVX group). Roentgenographic examination 2, 4, 6, and 8 weeks after osteotomy showed that HESW treatment accelerated tibia fracture healing in osteoporotic rats. Histological examination 2, 4, and 8 weeks after HESW treatment showed a greater inflammatory reaction in the OVX + HESW group, with more mature collagen and trabeculae than in the OVX group. Micro computer tomography (Micro-CT) scanning after 4 and 8 weeks showed that bone volume (BV), bone volume/tissue volume (BV/TV), mean trabecular thickness (Tb.Th), and mean trabecular number (Tb.N) were about 45.0% and 33.1%, 18.4% and 20.1%, 38.2% and 20.9%, 26.7% and 28.4%, respectively, higher in the treatment group than in the control group (P < 0.05); and the mean trabecular separation (Tb.Sp) was about 16.7% and 27.3% lower in the treatment group (P < 0.05). Four and eight weeks after HESW treatment, the maximum compressive callus endurance was about 72.3% and 25.5%, respectively, higher in the treatment group than in the control group (P < 0.05). These results show that slightly focused HESW therapy has a beneficial effect on osteoporotic tibial fracture healing. Slightly focused HESWs could increase callus endurance, induce bone formation, and improve trabecular bone microarchitecture and biomechanical properties.
RESUMEN
With the increasing longevity and the growing size of the aging population, China is among the developing countries with the greatest burden of osteoporotic fractures (OFs). Identification of individuals at high fracture risk to provide early treatment in developing countries with limited resources remains a challenge. Our aim was to calculate the FRAX® values in a selected mainland Chinese population the day before the occurrence of an OF and to compare the results with the Osteoporosis Foundation (NOF) thresholds. To define a population at high fracture risk, we selected patients in the orthopedic emergency cohort from Shanghai Sixth People's Hospital, China. To calculate the FRAX® the day before the actual OF, the actual fracture was not considered as a previous fracture. Subjects with a FRAX® value lower than the NOF thresholds were not considered at high risk. One-hundred ninety-eight patients were included with a mean age of 69.9 ± 10.1 years old, and 78.8 % were female. Major fracture sites included hip (41.9 %), proximal humerus (22.2 %), forearm (27.8 %), spine (6.6 %), and pelvis (1.5 %). Overall, only two (1.0 %) patients had a 10-year major fracture probability ≥20 %, and 84 (42.4 %) patients had a 10-year hip fracture probability ≥3 %. More than half of the population was not identified to be at high risk by the FRAX® BMI (body mass index). For age groups 55-59, 60-69, 70-79, and 80-90 years old, respectively, the mean FRAX® BMI values (major OF/hip fracture) were 3.5/0.7, 5.7/1.8, 8.2/4.7, and 8.6/4.8 %. Dual-energy X-ray absorptiometry was available for 58 patients, and 41.2 % had a T-score ≤ -2.5 standard deviation (lumbar spine and/or femoral neck and/or total hip). Only six (17.6 %) patients with a normal or osteopenic BMD were classified at high risk by the FRAX® BMD (bone mineral density). The NOF thresholds could only identify fewer than half of the studied population to be at high risk the day before an actual OF, and the 10-year hip fracture probability seemed to perform better than the 10-year major fracture probability. Prospective population-based studies are needed to validate the prediction of Chinese FRAX® model and to establish ideal thresholds.