Biomechanical comparison of lag screw and non-spiral blade fixation of a novel femoral trochanteric nail in an osteoporotic bone model.

There is no consensus regarding the advantages of the lag screw type over the blade type for treating femoral trochanteric fractures. We aimed to investigate whether non-spiral blade (Conventional-Blade, Fid-Blade) nails provide better biomechanical fixation than lag screws in a severe osteoporotic bone model. Different severities of osteoporotic cancellous bone were modelled using polyurethane foam blocks of three densities (0.24, 0.16, and 0.08 g/cm3). Three torsional tests were performed using each component for each density of the polyurethane block, and the maximum torque was recorded; subsequently, the energy required to achieve 30° rotation was calculated. Using a push-in test, the maximum force was recorded, and the energy required to achieve 4-mm displacement was calculated. For 0.08-g/cm3 density, the peak torques to achieve 30° rotation, energy required to achieve 30° rotation, peak force to achieve 4-mm displacement, and energy required to achieve 4-mm displacement were significantly greater for Conventional-Blade and Fid-Blade than those for Lag Screw. The fixation stability of the blade-type Magnum nail component is better than that of the lag screw type under any test condition. The blade-type nail component may have better fixation stability than the lag screw type in a severe osteoporotic bone model.

Zoledronic acid sequential therapy could avoid disadvantages due to the discontinuation of less than 3-year denosumab treatment.

INTRODUCTION: Rapid descent in bone mineral density (BMD) and ascent in bone turnover marker (BTM) occur within the short period following denosumab (Dmab) discontinuation. In addition, the incidence of vertebral fracture also rises within the short period. The purpose of this study is to investigate the effects of sequential therapy using zoledronic acid (ZOL) on any adverse events after Dmab discontinuation. MATERIALS AND METHODS: This study was a multicenter retrospective observational study, and the subjects were osteoporosis patients who visited our institutions between 2013 and 2018. We performed sequential therapy using ZOL for 30 patients who had difficulty continuing Dmab, due to physical or social reasons, and investigated the fracture incidence and BMD/BTM changes at 4 time points (at the start of Dmab, the start of ZOL, 6 months after ZOL and 12 months after ZOL). RESULTS: No new vertebral/nonvertebral fractures were observed at each time point after switching from Dmab to ZOL in any of the 30 patients. The BMD/BTM changes were evaluated in 18 of the 30 cases, since all data of lumbar/femoral neck BMDs and TRACP-5b at 4 time points was only available in 18 cases. BMDs significantly increased at each time point compared with that at the start of Dmab. Serum TRACP-5b significantly decreased at each time point compared with that at the start of Dmab. CONCLUSION: It was suggested that sequential therapy using ZOL could suppress the decrease of BMD, and increase of BTM, if the period of Dmab administration was less than 3 years.

Efficacy of non-steroidal anti-inflammatory drugs on zoledronic acid-induced acute-phase reactions: randomized, open-label, Japanese OZ study.

INTRODUCTION: Zoledronic acid infusion is used to treat osteoporosis but patients, especially Japanese patients, often experience acute-phase reactions (APRs). In this multicenter, randomized, open-label, parallel-group study, we examined the efficacy of the most commonly used non-steroidal anti-inflammatory drug loxoprofen in Japan in reducing the incidence rate of zoledronic acid-induced APRs and body temperature, and investigated risk/protective factors for APRs in this population. MATERIALS AND METHODS: Patients aged ≥ 60 years with primary osteoporosis (n = 368) were allocated randomly to zoledronic acid plus loxoprofen (ZOL + LOX) or zoledronic acid alone (ZOL). All patients received 5-mg zoledronic acid infusion on day 1, and patients in the ZOL + LOX group also received 120 mg and 180 mg of oral loxoprofen on days 1 and 2, respectively. Adverse events and body temperature were recorded during the 7-day observation period. RESULTS: The incidence rates of APRs were 34.4% (64/186 patients) and 47.8% (87/182 patients) in the ZOL + LOX and ZOL groups, respectively (P = 0.0109). The proportions of patients with increased body temperature (≥ 1 °C and ≥ 37.5 °C) were similar in both groups (P = 0.1186). Past bisphosphonate users had a significantly lower incidence rate of APRs than treatment-naïve patients (odds ratio 0.444, 95% confidence interval 0.285-0.692, P = 0.0003). CONCLUSIONS: Zoledronic acid-induced APRs appeared to be suppressed by loxoprofen. Known risk/protective factors, including prior osteoporosis treatment, were applicable to Japanese patients.

In-vivo postoperative motion analysis of metal and ceramic bipolar hip hemiarthroplasty.

BACKGROUND: We hypothesized that ceramic bipolar shows less impingement between stem neck and outer head compared to metal bipolar, because of its low coefficient of friction with the acetabulum cartilage. In this paper, a three dimensional (3D) postoperative motion analysis has been used to assess the different motion characteristics of metal and ceramic bipolar hip hemiarthroplasty systems. METHODS: This study was conducted on 40 patients divided in two matched cohorts: 20 patients with metal bipolar and 20 patients with the ceramic bipolar. We obtained motion pictures from standing position to maximum abduction in flexion by fluoroscopy then analyzed by 2D-3D image matching method. The motion range of the "Outer head angle", "Stem neck angle" and the "Stem neck and outer head angle" was compared between the metal bipolar group and the ceramic bipolar group. RESULTS: The metal bipolar group's inner head's range of movement was greater than the ceramic bipolar group. Impingement between stem neck and outer head occurred in 30% of metal group patients. There were no impingement cases for the ceramic bipolar group. CONCLUSIONS: The ceramic bipolar shows less impingement between stem neck and outer head compared to the metal bipolar. Ceramic bipolar may reduce the typical bipolar related complication and exert less effect on the acetabular cartilage due to less surface coefficient of friction.

Influence on the bone mineral density and bone metabolism marker after the interruption and reinitiation of monthly minodronate therapy in postmenopausal women with osteoporosis.

OBJECTIVES: The purpose of this study was to investigate the influences of interruption and reinitiation of monthly minodronate therapy on the bone mineral density (BMD) and bone metabolism markers in postmenopausal women with osteoporosis. METHODS: Study patients were included if they had been administered monthly minodronate therapy for ≥6 months, interrupted the therapy, and reinitiated the therapy for ≥12 months. The BMD and bone metabolism markers were assessed at 4 time points: initiation, interruption, reinitiation and 1 year after reinitiation of therapy. RESULTS: A total of 23 patients were enrolled. The mean monthly minodronate treatment period was 23.8 ±â€¯12.9 months following a mean interruption period of 11.9 ±â€¯5.4 months. Once increased by monthly minodronate treatment for 2 years on average, the BMD of lumbar spine and radius did not significantly decrease even after an interruption for 1 year on average. However, the BMD of the femoral neck did decrease after interruption. The BMD of the lumbar spine and radius increased further after 1 year of monthly minodronate retreatment. The BMD of the femoral neck did not change. Once decreased after the treatment for an average of 2 years followed by an interruption for 1 year, bone metabolism markers increased gradually but did not recover to baseline levels. A potent suppressive effect on bone resorption was noted. The change rate was greater for the bone formation marker procollagen 1 N-terminal propeptide. CONCLUSIONS: Monthly minodronate treatment increases BMD and reduces bone metabolism markers. The effect lessens after treatment interruptions, and can be restored by retreatment.

More radial shortening after low-energy Colles' fractures is associated with type 2 diabetes mellitus among postmenopausal women, irrespective of bone mineral density.

BACKGROUND: Recent meta-analysis data reveal that patients with type 2 diabetes mellitus (DM) have a higher risk of fracture, despite higher bone mineral density (BMD), than patients without type 2 DM. The purpose of this study was to compare BMD and distal radial shortening after low-energy Colles' fractures among Japanese postmenopausal women aged ≥50 years with type 2 DM with those in women without it (non-DM). METHODS: One-hundred and ten postmenopausal women aged ≥50 years with distal radius fractures resulting from a fall were enrolled in this study. Twelve patients had DM. BMD, type I collagen cross-linked N-telopeptide (NTX), undercarboxylated osteocalcin (ucOC), estimated glomerular filtration rate (eGFR), grip strength of the unfractured hand, unipedal standing time, and the degree of radial shortening were measured. RESULTS: There were no significant differences in age and body height between the two groups. The DM group had significantly greater body weight and body mass index than the non-DM group. BMDs of the lumbar spine and proximal hip were significantly higher in the DM group than in the non-DM group. NTX, ucOC, grip strength, and the percentage of women with unipedal standing time <15 s did not differ between the two groups. Stepwise regression analysis identified DM and shorter unipedal standing time as significant factors associated with more radial shortening, and identified more radial shortening and lower eGFR as significant factors associated with DM. CONCLUSIONS: More radial shortening after low-energy Colles' fractures was significantly associated with type 2 DM among postmenopausal women aged ≥50 years, irrespective of BMD.

Clinical results of volar locking plate for distal radius fractures: conventional versus minimally invasive plate osteosynthesis.

OBJECTIVES: The purpose of this study was to compare the postoperative radiologic and clinical outcomes of conventional plate osteosynthesis (C) with minimally invasive plate osteosynthesis (M) using a transverse skin incision without cutting the pronator quadratus muscle for distal radius fractures. DESIGN: Retrospective consecutive cohort with prospective data collection. SETTING: One community teaching hospital. Surgical treatment was performed by a single surgeon. PATIENTS: Sixty-six patients (C group, 36; M group, 30) underwent open reduction and internal fixation of dorsally displaced distal radius fractures with the volar locking plating system from June 2006 to August 2008. Their mean age was 63.5 years and the mean follow-up period was 22.7 months. MAIN OUTCOME MEASURES: Radiologic parameters (volar tilt, radial inclination, ulnar variance), range of motion, grip strength, and Disability of the Arm, Shoulder, and Hand score were evaluated at each examination. The visual analog scale of wrist pain and evaluations of cosmetic problems were assessed at the final follow-up. RESULTS: The groups did not differ significantly in all main outcomes. In the M group, the mean values of the Disability of the Arm, Shoulder, and Hand score at 2 weeks postoperatively (P = 0.06) and visual analog scale (P = 0.07) were lower and the mean value of the patient's satisfaction score of cosmetic problems (P = 0.08) was higher than those in the C group, but no statistically significant differences were apparent in these values. CONCLUSION: No significant differences were found between the minimally invasive plate osteosynthesis and conventional plating for distal radius fractures based on the data from postoperative radiologic and clinical outcomes.