Intraarticular hydraulic distension (IHD) has been utilized to treat painful stiff shoulders by distending and then rupturing the joint capsules. However, no attempts have been made to optimize the capsule distension, which might give a better clinical outcome. To set up a prerequisite technique for a maximal distension without rupturing the capsule, real-time pressure monitoring of IHD procedures was performed in 16 patients, which revealed triphasic pressure-volume profiles in 10 patients and biphasic in 6 patients. The IHD procedures were terminated without rupturing the capsule by observing the real-time pressure-volume curves (N ¼ 10) or by pain (N ¼ 3). The pressure profiles of the 13 patients who had the infusion stopped without rupture demonstrated stress-relaxation curves of the capsules. The biphasic group showed a steeper slope of the second phase of linearly increasing pressure (p ¼ 0.017) and higher pressure (p ¼ 0.005) with slightly larger volume (p ¼ 0.095) at the termination of fluid infusion than did the triphasic group. The stiffness of the glenohumeral joint capsule had a close correlation with the limitation in range of motion. Real-time pressure monitoring would be helpful to develop a novel IHD technique that could distend the glenohumeral joint as much as possible without rupturing it. The biomechanical parameters derived from the pressure-volume profiles would also be useful to characterize the properties of the joints of painful stiff shoulder patients.

We design and fabricate efficient, narrow-band, transmission color filters whose operating principle resides in a narrow-band guided-mode resonance associated with a surface-plasmon resonance. The fundamental device consists of an aluminum grating over a 200-nm-thick aluminum oxide film on a glass substrate. Numerical simulations show a sharp resonance-derived spectral profile that is additionally shaped by a neighboring Rayleigh anomaly. Besides the Rayleigh effect, we show numerically that the narrow bandwidth is predominantly due to the low refractive-index contrast between the waveguide film and the substrate. Red, green, and blue filters are fabricated using ultraviolet holographic lithography followed by a lift-off process. The experimental spectral efficiency in transmission exceeds 80% with full-width-at-half-maximum linewidths near 20 nm. We provide color images of the zero-order transmitted spectra, and illustrate the pure colors associated with the modal resonance extracted as side-coupled output light.

The effect of intraarticular hydraulic distension (IHD) for a painful stiff shoulder (or adhesive capsulitis) has been affirmed, but whether rupturing the joint capsule during this process is beneficial remains controversial. By monitoring real-time pressure-volume (PV) profiles during IHD, we could infuse the largest possible volume without rupturing the capsule. Using the novel technique, we compared the short-term effects of IHD when the capsule was preserved versus when it was ruptured. Fifty-four patients with a painful stiff shoulder underwent IHDs intended to preserve or rupture the capsule and then classified into capsule-ruptured (n ¼ 26) and capsule-preserved (n ¼ 20) groups, based on the obtained PV profiles. Their profiles were triphasic or biphasic; eight with flat profiles were excluded from the comparison. Clinical outcomes were evaluated at 3-day and 1-month follow-ups, in terms of pain and range of motion (ROM). Although both groups showed significant increase in ROM and decrease in pain after IHD, the improvements were greater in the capsule-preserved group than in the ruptured group at both follow-up times, and in triphasic and biphasic cases. In conclusion, the therapeutic effects of IHD in short-term follow-ups were enhanced by preserving the capsule. Keywords: painful stiff shoulder; hydraulic distension; joint capsule; rupture; frozen shoulder Intraarticular hydraulic distension (IHD) is an established treatment for painful stiff shoulders (PSS, also known as adhesive capsulitis or frozen shoulder). [1][2][3][4][5][6][7][8][9] However, whether the capsule should be ruptured or not during IHD to gain appropriate clinical improvements remains controversial. Many physicians have favored rupture without clear evidence.The capsule of the glenohumeral joint (GHJ) is contracted in PSS. 10-15 IHD aims to stretch and enlarge the capsule by applying excessive hydraulic pressure. The effect of stretching can be optimized by applying force strong enough to achieve plastic deformation of the tissue for a prolonged period. 16 Infusing fluid till rupturing the capsule applies the strongest force, but the deforming stress would disappear immediately after rupture. Also, most ruptures occur at the subscapularis recess or long biceps sheath, 3-4,7,13,17 not at the thickened capsule. Therefore, the belief of favoring ruptures should be questioned.The belief presumably stemmed from a practical obstacle of the conventional IHD technique; when IHD is intended to avoid rupture, it can hardly infuse a sufficient volume of fluid. A novel IHD technique, devised in our previous studies, 18,19 provided a measure to circumvent this obstacle. The technique monitors intraarticular pressure and volume (PV) in real-time and characterizes the PV curves into three phases: initial filling, elastic deformation, and plastic deformation. Based on the PV profiles, the fluid infusion can be advanced into plastic deformation and be terminated prior to rupture.By applying the technique, we aimed to address the short-term ...

The steeply rising, high IA pressure can be considered as a predominant characteristic of the PSS compared with other conditions that showed flat, low-pressure profiles, suggesting the P-V profiles might be used in evaluation of the capsular tightness of various shoulder problems. The triphasic curve appears to be a preruptural sign; however, there are several practical limitations to terminating hydraulic distension before rupture occurs.

Capsular stiffness of the glenohumeral joint significantly correlated with limitation in shoulder ROM, especially in the abduction and external rotation directions, whereas there were no meaningful relationships with shoulder pain during motion or rest. This is the first study to reveal the relationships between in vivo quantified capsular stiffness and shoulder ROM limitations.

Resonant nanogratings and periodic metasurfaces express diverse spectral and polarization properties on broadside illumination by incident light. Cooperative resonance interactions may yield shaped spectra for particular applications, in contrast to a multilayer dielectric mirror. Here, we provide guided-mode resonance filters with flat-top spectra suitable for wavelength division multiplexing systems. Applying a single one-dimensional grating layer sandwiched by two waveguides, we theoretically achieve high-efficiency flat-top spectra in the near-infrared region. This result is obtained by inducing simultaneous nearly degenerate resonant modes. The resonance separation under this condition controls the width of the flat-top spectrum. This means we can implement spectral widths ranging from a sub-nanometer to several nanometers applying fundamentally the same device architecture.

Engaging both theory and experiment, we investigate resonant photonic lattices in which the duty cycle tends to zero. Corresponding dielectric nanowire grids are mostly empty space if operated as membranes in vacuum or air. These grids are shown to be effective wideband reflectors with impressive polarizing properties. We provide computed results predicting nearly complete reflection and attendant polarization extinction in multiple spectral regions. Experimental results with Si nanowire arrays with 10% duty cycle show ~200-nm-wide band of high reflection for one polarization state and free transmission for the orthogonal state. These results agree quantitatively with theoretical predictions. It is fundamentally extremely significant that the wideband spectral expressions presented can be generated in these minimal systems.

We report surface-plasmon mediated total absorption of light into a silicon substrate. For an Au grating on Si, we experimentally show that a surface-plasmon polariton (SPP) excited on the air/Au interface leads to total absorption with a rate nearly 10 times larger than the ohmic damping rate of collectively oscillating free electrons in the Au film. Rigorous numerical simulations show that the SPP resonantly enhances forward diffraction of light to multiple orders of lossy waves in the Si substrate with reflection and ohmic absorption in the Au film being negligible. The measured reflection and phase spectra reveal a quantitative relation between the peak absorbance and the associated reflection phase change, implying a resonant interference contribution to this effect. An analytic model of a dissipative quasi-bound resonator provides a general formula for the resonant absorbance-phase relation in excellent agreement with the experimental results.