The effect of concomitant glenohumeral joint capsule release during rotator cuff repair--a comparative study.

BACKGROUND: There is debate as to whether to operate or to defer surgery on patients with concomitant rotator cuff tear and shoulder stiffness. The purpose of this study was therefore to compare the outcomes in those patients who had both their rotator cuff tear and shoulder stiffness treated with the outcomes of patients who had a rotator cuff repair but no stiffness. METHODS: Twenty-five patients formed the stiffness group (receiving a concomitant rotator cuff repair and manipulation under anesthesia ± arthroscopic capsular release for preoperative ipsilateral stiffness), and a chronologically matched group of 170 rotator cuff repair-only patients formed the nonstiffness group. Patients ranked their pain and function scores preoperatively and at 1 week, 6 weeks, 12 weeks, 6 months, and 2 years postoperatively; examiners recorded range of motion, strength, and presence of impingement signs. Repair integrity was determined using ultrasound. RESULTS: Patients from both groups had significantly improved clinical outcomes at the 2-year follow-up compared with preoperative values. Range of motion was similar between groups at 2 years for forward flexion, abduction, and external rotation, whereas the nonstiffness group had a superior range of internal rotation (P = .014). Stiffness patients had 0 of 25 (0%) retears at 2 years compared with 34 of 170 (20%) in the nonstiffness group (P = .009). CONCLUSIONS: The good outcomes of rotator cuff repair with glenohumeral capsular release disproved our hypothesis and suggest that there is no advantage in delaying repair of a rotator cuff tear to allow stiffness to resolve and that stiffness confers an advantage in terms of repair integrity. LEVEL OF EVIDENCE: Level III; Retrospective Cohort Design; Treatment Study.

Light-emitting diodes as a light source for intraoperative photodynamic therapy.

The development of more cost-effective light sources for photodynamic therapy of brain tumors would be of benefit for both research and clinical applications. In this study, the use of light-emitting diode arrays for photodynamic therapy of brain tumors with Photofrin porfimer sodium was investigated. An inflatable balloon device with a light-emitting diode (LED) tip was constructed. These LEDs are based on the new semiconductor aluminum gallium arsenide. They can emit broad-spectrum red light at high power levels with a peak wavelength of 677 nm and a bandwidth of 25 nm. The balloon was inflated with 0.1% intralipid, which served as a light-scattering medium. Measurements of light flux at several points showed a high degree of light dispersion. The spectral emission of this probe was then compared with the absorption spectrum of Photofrin. This analysis showed that the light absorbed by Photofrin with the use of the LED source was 27.5% of that absorbed with the use of the monochromatic 630-nm light. Thus, to achieve an energy light dose equivalent to that of a laser light source, the LED light output must be increased by a factor of 3.63. This need for additional energy is the difference between a 630- and 677-nm absorption of Photofrin. Using the LED probe and the laser balloon adapter, a comparison of brain stem toxicity in canines was conducted. LED and laser light showed the same signs of toxicity at equivalent light energy and Photofrin doses. The maximal tolerated dose of Photofrin was 1.6 mg/kg, using 100 J/cm2 of light energy administered by laser or LED. This study concludes that LEDs are a suitable light source for photodynamic therapy of brain tumors with Photofrin. In addition, LEDs have the potential to be highly efficient light sources for second-generation photosensitizers with absorption wavelengths closer to the LED peak emission.

Light-emitting diodes as a radiation source for plants.

Development of a more effective radiation source for use in plant-growing facilities would be of significant benefit for both research and commercial crop production applications. An array of light-emitting diodes (LEDs) that produce red radiation, supplemented with a photosynthetic photon flux (PPF) of 30 micromoles s-1 m-2 in the 400- to 500-nm spectral range from blue fluorescent lamps, was used effectively as a radiation source for growing plants. Growth of lettuce (Lactuca sativa L. Grand Rapids') plants maintained under the LED irradiation system at a total PPF of 325 micromoles s-1 m-2 for 21 days was equivalent to that reported in the literature for plants grown for the same time under cool-white fluorescent and incandescent radiation sources. Characteristics of the plants, such as leaf shape, color, and texture, were not different from those found with plants grown under cool-white fluorescent lamps. Estimations of the electrical energy conversion efficiency of a LED system for plant irradiation suggest that it may be as much as twice that published for fluorescent systems.