Does the Precision of Dual-Energy X-ray Absorptiometry for Bone Mineral Density Differ by Sex?

Given larger bone size in men, bone mineral density (BMD) precision might differ between sexes. This study compared dual-energy X-ray absorptiometry BMD precision of 3 International Society for Clinical Densitometry-certified technologists in older men and women. Each technologist scanned a cohort of 30 men and 30 women (total n = 180) by using a Lunar iDXA densitometer (GE Healthcare, Madison, WI). Each volunteer had 2 lumbar spine and bilateral hip scans with repositioning between examinations. BMD least significant change was calculated. Age and body mass index did not differ between men and women. Mean height and weight were greater in men, 174.6 cm ± 6.9 and 81.6 kg ± 11.1 respectively, (p < 0.0001) than in women, 161.5 cm ± 5.9/69.1 kg ± 14.2, respectively. Bone area was greater in men (p < 0.0001) at all sites. BMD least significant change was statistically better (p < 0.05) in women at the mean total femur (0.014 vs 0.018 g/cm²) and left femoral neck (0.025 vs 0.038 g/cm²), but not different at either total femur, the right femoral neck, or lumbar spine (all p > 0.05). In conclusion, statistically significant male/female differences in BMD precision were observed at the mean total femur and left femoral neck. Given the small magnitude of difference in g/cm² and inconsistent pattern, that is, no right femoral neck difference, there is virtually no clinical difference in BMD precision between sexes. These data do not support a need for sex-specific precision analyses.     

The relationship of the Phantom® Lapidus Intramedullary Nail System to neurologic and tendinous structures in the foot: An anatomic study

BackgroundThe purpose of our cadaveric study was to determine the proximity of nail insertion and interlocking mechanisms in the Phantom® Lapidus Intramedullary Nail System to neurologic and tendinous structures in the foot.MethodsWe used 10 fresh-frozen human lower-extremity specimen cadavers. For each specimen, the Nail System was inserted as described in the published technique guide. We then performed dissection on the tibialis anterior tendon, extensor hallucis longus tendon, and medial dorsal cutaneous branch of the superficial peroneal nerve and we measured and averaged the distances from each of these structures from the nail.ResultsThe tibialis anterior tendon was in closest proximity to the insertion of the proximal medial interlock K-wire with an average distance of 0.4 mm from the tendon. The extensor hallucis longus tendon was in closest proximity to nail insertion with an average distance of 1.2 mm. The medial dorsal cutaneous branch of the superficial peroneal nerve was in closest proximity to the distal interlock K-wire with an average distance of 7.5 mm.ConclusionsThe tibialis anterior tendon, extensor hallucis longus tendon, and the medial dorsal cutaneous branch of the superficial peroneal nerve are at risk with the insertion of the nail system. Blunt dissection should be performed using this system with a path to bone before instrumentation to reduce the risk of nerve and tendon injury in the foot.     

Internal fixation of femoral neck fractures with posterior comminution: a biomechanical comparison of DHS® and Intertan nail®

Background and purpose

Internal fixation is a therapeutic mainstay for treatment of undisplaced femoral neck fractures and fractures without posterior comminution. The best treatment for unstable and comminuted fractures, however, remains controversial, especially in older patients. The present study was designed to assess the utility of the Intertan Nail® (IT) for stabilization of comminuted Pauwels type III fractures compared to dynamic hips screw (DHS).

Methods

Randomized on the basis of bone mineral density, 32 human femurs were assigned to four groups. Pauwels type III fractures were osteomized with a custom-made saw guide. In 16 specimens the posteromedial support was removed and all femurs were instrumented with an IT or a DHS. All constructs were tested with nondestructive axial loading to 700N, cyclical compression to 1,400N (10,000 cycles), and loading to failure. Outcome measures included number of survived cycles, mechanical stiffness, head displacement and load to failure.

Results

Postoperative mechanical stiffness and stiffness after cyclical loading were significantly reduced in all constructs regardless of the presence of a comminution defect (p = 0.02). Specimens stabilized with the IT had a lower construct displacement (IT, 8.5 ± 0.5 mm vs. DHS, 14.5 ± 2.2 mm; p = 0.007) and sustained higher failure loads (IT, 4929 ± 419 N vs. DHS, 3505 ± 453 N; p = 0.036) than the DHS constructs.

Interpretation

In comminuted Pauwels type III fractures, the fixation with the IT provided sufficient postoperative mechanical strength, comparable rate of femoral head displacement, and a similar tolerance of physiological loads compared to fractures without comminution. The absence of the posteromedial support in comminuted fractures tended to reduce the failure load regardless of the fixation method.     

Optimizing Suprathel®-therapy by the use of Octenidine-Gel®

Objective

A prospective, randomized, non-blinded, clinical study was conducted to evaluate the feasibility and practicability as well as pain reduction and ease of handling of Flammazine^® versus Octenidine-Gel^® as a primary local antiseptic before synthetic skin substitute application in partial-thickness burns.

Methods

Thirty patients with a median age of 42 years suffering from second-degree burns were included in the study. Burns were randomly selected, one area was treated with Flammazine^®/gauze, another area in the same patient was treated with Octenidine-Gel^®/gauze as initial antiseptic treatment. Within 24 h the first gauze change was performed followed by wound inspection, disinfection and synthetic skin substitute application. The study focused on patient pain score, analysis of wound bed and ease of handling of the two local antiseptic agents.

Results

There was a significant difference between Flammazine^® versus Octenidine-Gel^® regarding patient pain score and ease of handling. Octenidine-Gel^® was less painful (p < 0.05) and easier to handle (p < 0.05). There was no significant difference for wound bed evaluation between the two antiseptic agents. A tendency for better wound bed preparation was seen with the use of Octenidine-Gel^®.

Conclusion

Based on the findings of this study Octenidine-Gel^® is recommended as a local antiseptic agent, because when compared to Flammazine^®, Octenidine-Gel^® proved to be better in terms of ease of care, simplicity application, with gentler and faster detachment of the gel from wound surfaces and consequently far less pain during dressing changes.     

CORR Insights®: What is the Incidence of Suicide in Patients with Bone and Soft Tissue Cancer?

Clinical Orthopaedics and Related Research® -     

Osteonecrosis of the Jaw—a Bone Site-Specific Effect of Bisphosphonates

A known complication that can occur in patients using bisphosphonates (BPs) is osteonecrosis of the jaw (ONJ). ONJ features bone exposure that may be associated with severe pain, swelling, local infection, and pathological fracture of the jaw. Current literature indicates that a complex combination of factors is necessary to induce ONJ. Several hypotheses about the pathophysiology of ONJ were previously reported. Here, we review these hypotheses and introduce new ideas and suggestions on this topic, focusing on bone site-specific cells, and the effect that BPs and other anti-resorptive drugs have on those cells. Gaining more insight into bone site-specific effects may help to better understand the pathogenesis ONJ, and contribute to the development of new bone site-specific anti-resorptive drugs.     

Contasure-needleless® compared with Monarc® for the treatment of stress urinary incontinence

Introduction and hypothesis

For the treatment of stress urinary incontinence (SUI), various retropubic and transobturator techniques have demonstrated high cure rates. Single-incision tapes, such as Contasure-Needleless® (C-NDL), have demonstrated similar cure rates to the inside-out transobturator sling (TVT-O®).The aim of this study was to analyse if C-NDL® is equally as effective as an outside-in transobturator sling (Monarc®) for the treatment of SUI.

Methods

We carried out a prospective, single-centre, randomised trial. The results were analysed for a non-inferiority test with a minimum postoperative follow-up of 12 months. The objective and subjective cure rates were evaluated by a stress test and a postoperative Sandvik Severity Index respectively. Patient satisfaction and operative complications were registered. The cure was defined by a negative stress test and SSI 0.

Results

A total of 187 patients were included, 89 and 98 undergoing C-NDL® and Monarc® respectively. Epidemiological and clinical data did not show and significant differences between both groups except a high prevalence of women who smoke (15.7% C-NDL® vs 6.1% Monarc®, p 0.03). The negative stress test was negative in 72 patients (80.9%) in C-NDL® compared with 85 (88.5%) in Monarc® (p 0.082). The SSI was 0 in 47 (66.2%) for C-NDL® and 61 (70.1%) for the Monarc® group (p 0.01). There were 14 (16.1%) and 8 (8.3%) dissatisfied patients for the C-NDL® and Monarc® groups respectively (p 0.068). The rate of complications was similar in both groups.

Conclusions

According to the non-inferiority test, C-NDL® is not inferior to Monarc® (post-surgical SSI test), but it is inferior in the comparison of a negative stress test and patient satisfaction.

     

Bone Density at the Entry Point Correlates With the Trabecular Bone of the Thoracolumbar Vertebral Bodies – Quantitative Computed Tomography Study

Purpose: To evaluate the relationship between cortical Bone Mineral Density (BMD) at pedicle entry points with trabecular BMD of the vertebral body in a spinal fracture. Methods: Quantitative computed tomography of the thoracolumbar spine was analyzed using dedicated software – QCT Pro (Mindways, Austin, TX). Results:Forty-six patients were evaluated. Among them 36 females were diagnosed with osteoporosis; the remaining 10 randomly selected from the database both males and females served as a control group. Overall measurements for 138 vertebrae were assessed. Cortical BMD of entry points for transpedicular screws was higher than trabecular vertebral BMD in osteoporotic (p < 0.001) and non-osteoporotic patients (p = 0.003). The difference was 3.6 times higher in low BMD cases (osteoporosis), compared to 2.3 times in normal subjects. Spearman's rank correlation coefficient showed the strongest correlation between patient's age and trabecular bone mineral density of L1 vertebral body (r = ?0.94, p < 0.05), while cortical entry points were less correlated (r = ?0.8, p < 0.05 and r = ?0.65, p < 0.05 for left and right entry points, respectively). The strength of the correlations between BMD and age decreased gradually from L1 to L4, from r = ?0.94 to r = ?0.58 for the trabecular vertebral body; from r = ?0.8 to r = ?0.37 for entry points. Significant correlations were not found for BMD and the height or weight of the patients. Conclusions:Cortical BMD at pedicle entry points decreases with osteoporosis. The relative contribution of cortical vs trabecular BMD increases with osteoporosis. Vertebral trabecular BMD is highly correlated with the cortical BMD of the entry points and allows predicting the bone support in fracture cases.