CT analysis of the anterior nasal airway based on the direction of nasal airflow in patients with nasal obstruction and trauma controls.

PURPOSE: The anterior nose is the nasal segment with the highest resistance to airflow. In a hospital-based case-control study, we compared cross-sectional areas of the nasal cavities anterior to the piriform aperture determined by computed tomography (CT-CSA) in patients with nasal obstruction (cases) and unselected patients with trauma unrelated to the head and face (controls). METHODS: CT-CSA could be reproducibly identified at angles of 0o, 30°, 60°, and 90° to the nasal floor approximately perpendicular to the arcuate direction of nasal airflow using bony landmarks. CT-CSA were manually segmented and compared in cases and controls. In cases, we compared CT-CSA at 30° (CT-CSA30-narrow) with the minimum cross-sectional area determined by acoustic rhinometry (AR-MCA1-narrow), each on the narrower side. RESULTS: CT-CSA ranged from 7 to 250 mm2 with an average of 100 mm2 per nasal side. Side differences of the nasal airways indicating asymmetry of the nasal airways were greater in 40 cases than in 44 controls (p < 0.003). Moreover, bilateral CT-CSA were significantly smaller in cases than in controls (p < 0.001). CT-CSA30-narrow did not significantly correlate with AR-MCA1-narrow (r = 0.33; p = 0.07) and on average was 58% smaller than AR-MCA1-narrow. CONCLUSIONS: Cross-sectional areas of the anterior nose perpendicular to the direction of nasal airflow, which is considered relevant in terms of flow physics, can be reliably measured using CT. Anterior nasal cavities in patients with nasal obstruction were more asymmetric and, as a whole, narrower than in controls, the latter of which is not corrected by routine septoplasty.

Imprecise prediction of implant sizes with preoperative 2D digital templating in total knee arthroplasty.

PURPOSE: To analyze the match between preoperatively determined implant size (2D templating) and intraoperatively used implant size in total knee arthroplasty (TKA). Also examined were the factors that might influence templating accuracy (gender, surgeon experience, obesity, etc.). MATERIALS AND METHODS: The study was retrospective and conducted in a specialized ENDOCERT arthroplasty center. Digital templating was done with the MediCAD software. If the planned and implanted TKA components (both femur and tibia) were the same size, the match was classified "exact." A deviation of ± one size (at the femur or tibia or both) was classified "accurate." A deviation of ± two or more sizes (at the femur or tibia or both) was classified "inaccurate." Obesity, gender, implant type and surgeon experience were investigated for potential influence on templating accuracy. Chi-square tests and Cohen's weighted kappa test were used for statistical analysis. RESULTS: A total of 482 cases [33.6% male, 66.4% female, age 69 ± 11, body mass index (BMI) 30.3 ± 5.8] were included. When the femur and tibia were taken together, exact size match was observed in 34% (95% CI 29.9-38.3%) of cases, accurate size match in 57.5% (95% CI 53-61.8%) and inaccurate size match in 8.5% (95% CI 6.3-11.2%). Inaccurate size match prolonged operative time (p = 0.028). Regarding the factors potentially influencing templating accuracy, only gender had a significant influence, with templating being more accurate in men (p = 0.004). BMI had no influence on accuracy (p = 0.87). No effect on accuracy was observed for implant type and surgeon experience. CONCLUSIONS: The accuracy of 2D size templating in TKA is low, even in a specialized ENDOCERT arthroplasty center. The study findings challenge the usefulness of preoperative 2D size templating and highlight the importance of more reliable templating methods. LEVEL OF EVIDENCE: Level III (retrospective observational study).

Three-dimensional computed tomography reconstruction improves the reliability of tibial pilon fracture classification and preoperative surgical planning.

PURPOSE: In the present study, we aimed to evaluate the impact of two-dimensional multi-planar computed tomography (2D-MP-CT) scans and three-dimensional surface rendering computed tomography reconstruction (3D-SR-CT) on the inter- and intra-observer reliability of four commonly used classification systems for tibial pilon fractures, and on the reliability and validity of surgical treatment planning for fracture fixation. METHODS: Four observers evaluated computed tomography images of 35 cases with pilon fractures according to the classifications of Rüedi and Allgöwer, AO/OTA, Topliss, and Tang, and recommended a surgical treatment plan, including the surgical approach, implant position, and need for bone graft augmentation. Fractures were first evaluated using 2D-MP-CT, followed by 3D-SR-CT. We calculated the Kappa values for the correlation between the fracture classifications, types of surgical approaches, implant positions, and bone graft recommendations by the observers. Furthermore, we assessed the correlation between the treatment plans recommended by the observers and the actual surgical procedure performed. RESULTS: All classifications showed poor inter-observer reliability and moderate intra-observer reliability with 2D-MP-CT scans. The inter-observer reliability of the Rüedi and Allgöwer, AO/OTA, and Tang classifications improved to moderate, whereas the intra-observer reliability of the AO/OTA classification improved to good with additional 3D-SR-CT. The correlation between the suggested and the actually performed surgical approaches was poor with 2D-MP-CT, but improved to moderate with 3D-SR-CT. The suggested plate positions showed a moderate correlation with the actually performed plating; although the correlation improved significantly, it remained moderate with 3D-SR-CT. CONCLUSION: The use of 3D-SR-CT reconstruction can improve the reliability of the Rüedi and Allgöwer, AO/OTA, and Tang classifications. Furthermore, three-dimensional imaging enables a more valid planning of the surgical approach and implant position.

[Trochleoplasty: Surgical technique : Video article]. / Trochleaplastik: Operationstechnik : Videobeitrag.

A 29-year-old physically active patient presented with recurrent right-sided patellar dislocation. Clinical and radiological investigation showed patellar instability with stable cruciate and collateral ligaments, excess internal rotation of the right femur, as well as trochlear dysplasia. Treatment consisted of trochleoplasty in combination with medial patellofemoral ligament reconstruction.

CT comparison of the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction.

BACKGROUND: Nasal airway stenosis may lie anterior and/or posterior to the piriform aperture. We intended to compare the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction. METHODS: Segmented computed tomography cross-sectional areas of the nasal airway anterior (CT-CSAant) and posterior to the piriform aperture (at the level of the head of the inferior turbinate; CT-CSApost) were compared between patients with nasal obstruction (cases) and trauma controls. CT-CSA were approximately perpendicular to the direction of the nasal airflow. Anterior to the piriform aperture, they were tilted about 30o, 60o and 90o to the nasal floor. Posterior to the piriform aperture, they were tilted about 50o, 80o and 100o to the nasal floor. In cases, we examined the Pearson's correlation of active anterior rhinomanometry with CT-CSAant and CT-CSApost. RESULTS: Narrow and bilateral CT-CSApost were similarly large between 56 cases and 56 controls (all p > 0.2). On the contrary, narrow and bilateral CT-CSAant were significantly smaller in cases than in controls (all p < 0.001). The ratio of the size of CT-CSAant-30 to that of CT-CSApost-80 was significantly lower in cases (median: 0.84; lower to upper quartile: 0.55-1.13) than in controls (1.0; 0.88-1.16; Mann-Whitney U test; p = 0.006). Bilateral CT-CSAant correlated significantly with total inspiratory flow (all p < 0.026) in contrast to bilateral CT-CSApost (all p > 0.056). CONCLUSIONS: The nasal airway anterior to the piriform aperture was smaller in patients with nasal obstruction due to skeletal nasal stenosis than that in controls. On the contrary, the nasal airway posterior to the piriform aperture was similarly large between patients with and without nasal obstruction. Furthermore, in patients with nasal obstruction, the anterior nasal airway was narrower compared to that located posterior to it. On the contrary, control patients' anterior nasal airway was as large as the posterior one.

Biomechanical comparison of vertebral augmentation with silicone and PMMA cement and two filling grades.

PURPOSE: Vertebral augmentation with PMMA is a widely applied treatment of vertebral osteoporotic compression fractures. Subsequent fractures are a common complication, possibly due to the relatively high stiffness of PMMA in comparison with bone. Silicone as an augmentation material has biomechanical properties closer to those of bone and might, therefore, be an alternative. The study aimed to investigate the biomechanical differences, especially stiffness, of vertebral bodies with two augmentation materials and two filling grades. METHODS: Forty intact human osteoporotic vertebrae (T10-L5) were studied. Wedge fractures were produced in a standardized manner. For treatment, PMMA and silicone at two filling grades (16 and 35 % vertebral body fill) were assigned to four groups. Each specimen received 5,000 load cycles with a high load range of 20-65 % of fracture force, and stiffness was measured. Additional low-load stiffness measurements (100-500 N) were performed for intact and augmented vertebrae and after cyclic loading. RESULTS: Low-load stiffness testing after cyclic loading normalized to intact vertebrae showed increased stiffness with 35 and 16 % PMMA (115 and 110 %) and reduced stiffness with 35 and 16 % silicone (87 and 82 %). After cyclic loading (high load range), the stiffness normalized to the untreated vertebrae was 361 and 304 % with 35 and 16 % PMMA, and 243 and 222 % with 35 and 16 % silicone augmentation. For both high and low load ranges, the augmentation material had a significant effect on the stiffness of the augmented vertebra, while the filling grade did not significantly affect stiffness. CONCLUSIONS: This study for the first time directly compared the stiffness of silicone-augmented and PMMA-augmented vertebral bodies. Silicone may be a viable option in the treatment of osteoporotic fractures and it has the biomechanical potential to reduce the risk of secondary fractures.

A Tool for Rapid Assessment of Functional Outcomes in Patients with Head and Neck Cancer.

Head and neck cancer (HNC) and its treatment can lead to various functional impairments. We developed and validated an instrument for rapid physician-rated assessment of basic functional outcomes in HNC patients. HNC-relevant functional domains were identified through a literature review and assigned to verbal ratings based on observable criteria. The instrument draft was subjected to systematic expert review to assess its face and content validity. Finally, the empirical validity, reliability, and responsiveness of the expert-adapted Functional Integrity in Head and Neck Cancer (HNC-FIT) scales were assessed in healthy controls and in HNC patients. A matrix of the 6 functional domains of oral food intake, respiration, speech, pain, mood, and neck and shoulder mobility was created, each with 5 verbal rating levels. Face and content validity levels of the HNC-FIT scales were judged to be adequate by 17 experts. In 37 control subjects, 24 patients with HNC before treatment, and in 60 HNC patients after treatment, the HNC-FIT ratings in the 3 groups behaved as expected and functional domains correlated closely with the outcome of corresponding scales of the EORTC-HN35-QoL questionnaire, indicating good construct and criterion validity. Interrater reliability (rICC) was ≥0.9 for all functional domains and retest reliability (rICC) was ≥0.93 for all domains except mood (rICC = 0.71). The treatment effect size (eta-square) as a measure of responsiveness was ≥0.15 (p < 0.01) for fall domains except for breathing and neck and shoulder mobility. The median HNC-FIT scale completion time was 1 min 17 s. The HNC-FIT scale is a rapid tool for physician-rated assessment of functional outcomes in HNC patients with good validity, reliability, and responsiveness.