The cementless taper wedge vs. fit-and-fill stem in primary total hip arthroplasty: risk of stem-related complication differs across Dorr types.

INTRODUCTION: The choice between a cementless taper wedge stem and a fit-and-fill stem in total Hip arthroplasty (THA) for various proximal femoral morphological types has not been thoroughly evaluated. This study aimed to compare the risk of stem-related complications between these two stem types in Dorr type A, B, and C femurs. MATERIALS AND METHODS: From January 2015 through April 2021, we retrospectively reviewed 1995 cementless THA procedures. We stratified all procedures into three groups: Dorr type A (N = 360, 18.0%), B (N = 1489, 74.7%) and C (N = 146, 7.3%). The primary outcome domain was stem-related complications, including stem subsidence ≥ 3 mm, intraoperative fracture, periprosthetic fracture and aseptic stem loosening. We performed multivariate regression analysis to compare the risk of stem-related complication between the two stem types. Other factors included age, sex, body mass index, diagnosis, age-adjusted Charlson comorbidity index, stem alignment and canal fill ratio. RESULTS: The incidence of stem-related complications in the taper wedge and fit-and-fill stem groups was 4.4% (N = 15) and 6.5% (N = 107), respectively. Fit-and-fill stems showed an increased risk of stem-related complications (aOR: 9.903, 95% CI: 1.567-62.597) only in Dorr type C femurs. No significant difference in risk was observed in Dorr type A and B femurs. Furthermore, the canal fill ratio at the lesser trochanter, 2 cm and 7 cm below the lesser trochanter, did not exhibit an association with stem-related complications in any Dorr type. CONCLUSIONS: Concerning the risk of stem-related complications, the taper wedge stem was a better choice in Dorr type C femurs. However, there was no difference in risk between the taper wedge stem and fit-and-fill stem in Dorr type A and B femurs.

Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 µV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

Traumatic indirect carotid cavernous fistulas: angioarchitectures and results of transarterial embolization by liquid adhesives in 11 patients.

BACKGROUND: The angioarchitectures of traumatic indirect CCFs and the effectiveness and safety of transarterial liquid adhesive embolization for these fistulas remain to be evaluated. METHODS: A total of 276 consecutive patients with traumatic craniofacial arteriovenous fistula were referred for embolization in the past 15 years. Eleven had traumatic indirect CCFs and were managed with transarterial liquid adhesive embolization. This group was composed of 8 men and 3 women ranging from 15 to 46 years of age. The most frequently observed symptoms were neuro-ophthalmic, followed by bruit and headache. All lesions were single fistula and fed exclusively by meningeal artery. The accessory meningeal artery was involved most often (n = 7), followed by the middle meningeal artery (n = 4). Venous drains were the ophthalmic vein (n = 11) and/or inferior petrous sinus (n = 8). No cortical vein drainage was observed. Liquid adhesives (60%) were used to obliterate all fistulas; 2 patients were also treated with detachable coils. RESULTS: All fistulas were totally occluded with resolutive fistula-related symptoms. Asymptomatic migration of liquid adhesives into the nearby arterial branch was observed in 1 patient. One patient had partial ocular choroidal infarction. No recurrent or residual fistula was found upon clinical follow-up. CONCLUSIONS: Angioarchitecture and treatment of traumatic indirect CCFs differed from the spontaneous type of fistulas. By transarterial liquid adhesive embolization, treatment of all fistulas was safe, with effective occlusion and associated low peri-procedural risk. This procedure may be considered as the primary treatment for these traumatic fistulas.

Periodontal status in post-menopausal osteoporosis: a preliminary clinical study in Taiwanese women.

BACKGROUND: Osteoporosis and periodontitis are common diseases affecting post-menopausal women; however, the exact relationship between the diseases is still uncertain. The purposes of this study were to examine the periodontal status in a group of type I post-menopausal women with and without osteoporosis and to elucidate the possible role of the osteoporosis in the pathogenesis of periodontal disease. METHODS: Thirty-four patients (18 in the osteoporotic and 16 in the non-osteoporotic group) were selected from 329 post-menopausal Taiwanese women who had completed radiographic measurements of spinal bone mineral density and received full-mouth periodontal examination. Periodontal measurements, including O'Leary plaque index, probing depths, clinical attachment level, and gingival recession, on 6 sites of each tooth of full mouth were examined and recorded by 1 examiner. RESULTS: Significantly greater probing depth was noted at the interproximal, but not at the facio-lingual, osteoporotic sites if compared to those non-osteoporotic sites. The depth was also significantly influenced by the examining factors of plaque accumulation, tooth location, and jaws. By individual jaw, increased attachment loss accompanied by greater probing depth and gingival recession was found at the osteoporotic sites on mandible if compared to non-osteoporotic sites. On maxilla, however, less gingival recession and attachment loss were observed at the osteoporotic sites. CONCLUSIONS: In the present study, increased attachment loss accompanied by greater probing depth and gingival recession was found at the osteoporotic sites on mandible. However, the parameters were also influenced by the examining factors of plaque accumulation, tooth location, and jaws. Therefore, we suggest that post-menopausal osteoporosis may play a role in the pathogenesis of periodontal disease, especially on the mandible, although the etiology of periodontal disease is still multi-factorial.