Enhancing Post-Surgical Rehabilitation Outcomes in Patients with Chronic Ankle Instability: Impact of Subtalar Joint Axis Balance Exercises Following Arthroscopic Modified Broström Operation.

Background and Objectives: This study aimed to evaluate the effects of subtalar joint axis-based balance exercises on the anterior talofibular ligament (ATFL) thickness, ankle strength, and ankle stability after an arthroscopic modified Broström operation (AMBO) for chronic ankle instability (CAI). Materials and Methods: The study included 47 patients diagnosed with CAI who underwent AMBO and were randomly divided into three groups: control (n = 11), general balance exercise (n = 17), and subtalar joint axis balance exercise (n = 19), regardless of the affected area. Participants in the exercise rehabilitation group performed exercises for 60 min twice a week for six weeks, starting six weeks after AMBO. ATFL thickness, ankle strength, and ankle dynamic stability were measured using musculoskeletal ultrasonography, Biodex, and Y-balance test, respectively, before and after treatment. Results: Compared with the remaining groups, the subtalar joint axis balance exercise group had reduced ATFL thickness (p = 0.000), improved ankle strength for eversion (p = 0.000) and inversion (p = 0.000), and enhanced ankle stability (p = 0.000). Conclusions: The study results suggest that subtalar joint axis-based balance exercises may contribute to the early recovery of the ankle joint after AMBO.

Nanocrystalline Composite Layer Realized by Simple Sintering Without Surface Treatment, Reducing Hydrophilicity and Increasing Thermal Conductivity.

The surface treatment for a polymer-ceramic composite is additionally performed in advanced material industries. To prepare the composite without a surface treatment, the simplest way to manufacture an advanced ceramic-particle is devised. The method is the formation of a nanocrystalline composite layer through the simple liquid-phase sintering. Using magnesia (MgO) which shows hydrophilicity, a nanocrystalline surface layer is realized by liquid-phase sintering. The amorphous matrix of nanocrystalline composite layer makes MgO hydrophobic and ensures miscibility with polymers, and the nanocrystalline MgO ensures high thermal conductivity. In addition, the liquid phase removes the open pores and makes the surface morphology smooth MgO with smooth surface (MgO-SM). Thermal interface materials (TIM) prepared with MgO-SM and epoxy show a high thermal conductivity of ≈7.5 W m-1 K-1 , which is significantly higher than 4.5 W m-1 K-1 of pure MgO TIM. Consequently, the formation process of a nanocrystalline surface layer utilizing simple liquid-phase sintering is proposed as a fabrication method for a next-generation ceramic-filler. In addition, it is fundamentally identified that the thermal conductivity of MgO depends on the Mg deficiency, and therefore a poly-crystal MgO-SM (produced at a low temperature) has a higher thermal conductivity than a single-crystal MgO (produced at a high temperature).

Effect of passive jaw opening on the electromyographic activity of the temporalis, masseter, digastric, and infrahyoid muscles in healthy adults.

OBJECTIVE: To investigate the surface electromyography (EMG) activity of the temporalis, masseter, digastric, and infrahyoid muscles during passive jaw opening in healthy adults. METHODS: The EMG activity of the masseter, temporalis, digastric anterior belly, and infrahyoid muscles on the right side was recorded during the four jaw-opening tasks: active opening to 20 mm (AO20); active opening to 40 mm (AO40); passive opening to 40 mm with a rubber mouth prop on the right posterior teeth (POR40); and passive opening to 40 mm with a mouth prop on the left posterior teeth (POL40). RESULTS: The EMG amplitude of the digastric anterior belly and infrahyoid muscles in either POL40 or POR40 was significantly less than that in AO20 or AO40, respectively. CONCLUSION: Passive jaw opening reduces the EMG activity of the digastric and infrahyoid muscles significantly and could help reduce the load on these muscles during prolonged mouth-opening conditions.

Microstructure and Texture Evolutions During Deep Drawing of Mg-Al-Mn Sheets at Elevated Temperatures.

Texture and microstructure evolution of ingot and twin-roll casted Mg-Al-Mn magnesium sheets were examined during deep drawing at elevated temperatures. The twin-roll casted sheets possessed smaller grain sizes and weaker basal intensity levels than the ingot-casted sheets. The strength and elongation at room temperature for the twin-roll casted sheets were greater than those of the ingot-casted sheets. At elevated temperatures, the ingot-casted sheets showed better elongation than the twin-roll casted sheets. Different size and density of precipitates were examined using transmission electron microscopy (TEM) for both ingot-casted and twin-roll-casted sheets. The deep drawing process was also carried out at various working temperatures and deformation rates, 225 °C to 350 °C and 30 mm/min to 50 mm/min, respectively. The middle wall part of cups were mainly tensile deformation, and the lower bent regions of drawn cups were most thinned region. Overall, the ingot-casted sheets revealed better deep drawability than the twin-roll casted sheets. Microstructure and texture evolution of the top, middle and lower parts of drawn cups were investigated using electron backscatter diffraction. Increased deformation rate is important to activate tensile twins both near the bent and flange areas. Ingot casted sheets revealed more tensile twins than twin-roll casted sheets. Increased working temperature is important to activate non-basal slips and produce the DRXed grain structure in the flange. Dynamic recrystallization were frequently found in the top flanges of the cups. Both tensile twins and non-basal slips contributed to occurrence of the dynamic recrystallization in the flange.

Dural Tears in Percutaneous Biportal Endoscopic Spine Surgery: Anatomical Location and Management.

OBJECTIVE: To determine the rate and anatomical location of dural tears associated with spinal surgery using a percutaneous biportal endoscopic surgery (PBES) technique. We investigated the relationship between dural tears and the type of procedure and type of instrument used. METHODS: We retrospectively analyzed 643 PBES cases by reviewing the medical records, operative records, and operative videos. Incidental durotomy was identified in 29 cases. We analyzed the size and anatomical location of the dural tears, the surgical instrument that caused the tear, and the technique used to seal the tear. RESULTS: The dural tear incidence was 4.5% (29 of 643 cases). Tears in the exiting nerve area (2 cases; 6.9%) had mainly been caused by curettage, tears in the thecal sac area (18 cases; 62.1%) were associated with electric drill and forceps use; and tears in the traversing nerve area were associated with the use of a Kerrison punch (9 cases; 31%). Of the 29 cases of dural tear, 12 were treated with in-hospital monitoring and bed rest, 14 were treated with a fibrin sealant, 2 were treated with a nonpenetrating titanium clip, and 1 was converted to microscopic surgery. One case of postoperative meningocele after conservative treatment required endoscopic revision surgery to close the dural tear. CONCLUSIONS: Most cases of incidental dural tear during PBES were treated with an endoscopic procedure. The incidence of dural tear was no greater than that associated with microscopic surgery. Our management strategy for incidental dural tears during PBES has been shown to be safe and effective.

Pooled analysis of unsuccessful percutaneous biportal endoscopic surgery outcomes from a multi-institutional retrospective cohort of 797 cases.

BACKGROUND: Spinal percutaneous biportal endoscopic surgery (PBES) is a minimally invasive surgery; however, it is associated with several poor outcomes. This study aimed to analyze unsuccessful PBES outcomes and verify their relationships with patient satisfaction. METHODS: From May 2015 to June 2018, PBES was performed at several institutions. Unsuccessful outcomes (reoperation and prolonged hospital stay) due to various reasons (hematoma, lesion recurrence, incomplete decompression, dural tear, instability, ascites, and infection) were analyzed. To verify the relationships between surgical experience and unsuccessful outcomes, the first 50 cases and the later cases were compared. Logistic regression was used to assess the relationships between unsuccessful outcomes and patient dissatisfaction. RESULTS: Among 866 patients, 797 cases with 1-year follow-up and complete data were analyzed. In total, 82 patients with unsuccessful outcomes were identified (10.29%). The incidences of hematoma (p < 0.04), incomplete operation (p < 0.01), and dural tear (p < 0.01) were significantly higher in the first 50 cases than in the later cases. Analyses of the relationship between unsuccessful outcomes and patient dissatisfaction showed that incomplete decompression (odds ratio (OR) 4.06), postoperative instability (OR 3.64), hematoma (OR 3.25), ascite (OR 3.25), dural tear (OR 3.02), and local recurrence (OR 2.45, 95%) contributed significantly. CONCLUSIONS: Unsuccessful PBES outcomes were mostly associated with hematomas, incomplete decompression, and dural tears; instability, ascites, and infection contributed to a lesser extent. Incomplete decompression, instability, hematoma, ascite, dural tear, and local recurrence were significantly related to patient dissatisfaction. The potential for poor outcomes should be described to the patient and considered prior to surgery.

In situ Observation of Phase Transformation in MnAl(C) Magnetic Materials.

The phase transformation in two modes, including both displacive and massive growth of τ-phase from ε-MnAl(C), was observed by in situ transmission electron microscopy. The exact temperature range for different phase transformation modes was determined by magnetic measurements. The displacive growth of ε→τ in Mn54Al46 (or Mn54Al46C2.44) occurs at temperatures below 650 K (or 766 K), above which both modes coexist. One-third or less of the ε-phase can be transformed into τ-phase via displacive mode while the remaining two-thirds or more via massive mode. In bulk τ-phase, most τ-nanocrystals formed via displacive mode are distributed in the matrix of large τ-grains that formed via massive mode. The typical massive growth rate of the τ-phase is 8-60 nm/s, while the displacive growth rate is low. A more complete understanding of the ε→τ phase transformations in the MnAl-based magnets was provided in this work, based on which the annealing process for ε→τ was optimized and thus high purity τ-phase with high saturation magnetization was obtained.

Repeatability of measurements of surface electromyographic variables during maximum voluntary contraction of temporalis and masseter muscles in normal adults.

This study evaluated the intraexaminer repeatability of measurements of surface electromyography (EMG) variables and functional indices of the myoelectric signals from the masseter and temporalis muscles bilaterally in 15 healthy men. The test was repeated on two different days without templates. The resting muscle activity was recorded once, and two kinds of maximum voluntary contraction (MVC) tasks were performed and recorded three times. The two MVC tasks involved clenching the teeth and biting down on two cotton rolls bilaterally with the posterior teeth. The intraclass correlation coefficient (ICC) of amplitude was >88% and that of frequency was >95% during the two MVC tasks but not under resting conditions. The ICC of the asymmetry and activity indices during the two MVC tasks was >76%. A Bland-Altman analysis revealed no significant difference in amplitude or frequency or in the two indices between the two days during the MVC tasks. In conclusion, the measurements of surface EMG variables and the indices obtained according to the study protocol were highly repeatable in healthy men. Additional studies using templates and intraexaminer measurement errors are warranted in both men and women for complete validation of these findings.

Microstructure characterization of ZK60 magnesium alloys using TEM and HR-EBSD.

ZK60 (Mg-Zn-Zr) alloys exhibited a variation in precipitates with aging, and their mechanical properties also changed. Microindentation tests were carried out on two types of ZK60 alloys of solid solution (T4) and peak aging (T6). Microstructure and texture evolution during indentation was investigated using electron backscatter diffraction. Twinning occurred near the indentation marks in most grains. It was found that tensile twinning was dominant, and two twin variants were usually observed. Texture and microstructure evolution by twinning and slip activation was further examined by uniaxial compression test with strain. The initial random orientation gradually changed into basal fibers with strain. Some grains with nonbasal orientations aligned with the loading direction easily underwent twinning followed by slip deformation. Other grains near basal orientations revealed only slip deformation.

Gastrocsoleus fascial release for correction of equinus deformity in residual or relapsed clubfoot.

BACKGROUND: Regardless of the mode of treatment, clubfoot has a strong tendency to relapse, especially hindfoot equinus. Because contraction or shortening of the Achilles tendon causes an equinus deformity of the ankle, release of this tendon is required to correct equinus deformity in patients with residual or relapsed clubfoot. This study assessed the effectiveness of the Vulpius technique in correcting equinus deformity in patients with residual or relapsed clubfoot. METHODS: Of the 80 idiopathic clubfeet treated conservatively using the Ponseti protocol, between March 2000 and July 2008, 32 were found to have residual or relapsed equinus deformity, with 22 feet in 17 patients undergoing Vulpius-type Achilles tendon lengthening. Mean age at the time of surgery was 29 (range, 6 to 52) months, and mean follow-up was 48 (range, 24 to 78) months. Clinical evaluation included the dorsiflexion angle of the ankle and radiographic evaluation included the talocalcaneal and tibiocalcaneal angles on dorsiflexion lateral views. RESULTS: All 22 feet showed satisfactory results at last follow-up, with significant improvements in mean ankle dorsiflexion angle, mean tibiocalcaneal angle, and mean lateral talocalcaneal angle (p < .05 each). CONCLUSION: The Vulpius procedure is an effective surgical procedure for correcting equinus deformity in residual and relapsed clubfeet.