Objective To evaluate the effect of combining a continuous epitendinous suture with three‐loop pulley (3LP) and locking‐loop (LL) core patterns for flexor tendon repair. Study design Ex vivo biomechanical study. Sample population Seventy‐two cadaveric superficial digital flexor musculotendon (SDFT) units. Methods Tendons were divided into four groups (n = 18/group). After sharp transection, SDFT were repaired with 3LP, LL, 3LP + epitendinous (E), or LL + E suture patterns. After preloading, repaired constructs were tested to failure. Video data acquisition allowed evaluation of failure mode and quantitation of gap formation. Yield, peak, and failure force were measured from force‐displacement data. Significance was set at P < .05. Results Mode of failure did not differ between repairs with or without an epitendinous suture (P = .255). Gap formation was best prevented with 3LP compared with LL when used alone (P = .001). Mean yield force for 3LP, LL, 3LP + E, and LL + E were 91.4 N ± 25.4, 61.3 N ± 18.4, 195.2 N ± 66.0, 165.3 N ± 46.8, respectively. Tenorrhaphies combined with an epitendinous suture achieved higher yield (P < .0001), peak (P < .0001), and failure forces (P < .0001), without gapping between tendon ends. Conclusion Addition of an epitendinous suture eliminated gapping between tendon ends until failure and increased resistance to loads tolerated at the repair site. Clinical significance The addition of an epitendinous suture may increase the strength of tendon repairs and resistance to gap formation over core suture use alone. The influence of epitendinous suture placement on tendinous healing and blood supply warrants in‐vivo testing.

Free cortisol as measured in saliva increases markedly following awakening. It is not clear, however, whether this is truly a stress-neuroendocrine response to awakening or a manifestation of the hypothalamic-pituitary-adrenal (HPA) circadian cycle. We investigated whether the awakening cortisol response can be generated in the middle of nocturnal sleep, when secretory activity in the HPA axis is low. In a within subject design, salivary cortisol response was measured under three different awakening conditions: (1) awakening at the normal morning awakening time; (2) awakening four hours prior to normal awakening time, and (3) awakening the following morning after interrupted sleep. The overall main effect was a linear increase in free cortisol following awakening with no significant interaction with awakening condition. Cortisol levels, as determined by area under the cortisol curve calculated with reference to zero, did differ by awakening condition. The two morning awakening conditions were comparable but values were lower for night awakening. Area under the curve change (calculated with reference to the first awakening cortisol base value), however, did not distinguish the three awakening conditions. We conclude from these data that there is a clear free cortisol response to awakening for both nocturnal and morning awakening although the absolute levels produced are lower for nocturnal awakening when basal cortisol is low. Nocturnal interruption of sleep did not affect the subsequent morning response.

Impact of 6-monthly massive dosings of preschool-age children with oral vitamin A (VAC: 200,000 IU of oil soluble retinyl palmitate with 40 IU vitamin E) was evaluated in Bangladesh. In 100 sites, 11,889 households were visited and eyes of 22,335 children aged 3-71 mo were examined. About half the rural target population and less than 20% urban slum population were being reached. Risk of night blindness was halved for children reportedly given VAC, although 2.5% of the reportedly protected population were still night blind. There was no significant reduction in prevalence of Bitot's spot. Risk of corneal ulcers or keratomalacia (X3A/B) was 2.7 times higher in children not given VAC. Based on reported coverage, efficacy of protection against potentially blinding corneal lesions was 63%. For maximum impact on eye lesions, massive dosing with vitamin A at ideally less than 6-monthly intervals needs to be combined with other nutrition and health interventions.

Background Patients with peripheral artery disease with intermittent claudication (PAD-IC) have altered gait variability from the first step they take, well before the onset of claudication pain. The mechanisms underlying these gait alterations are poorly understood. Aims To determine the effect of reduced blood flow on gait variability by comparing healthy older controls and patients with PAD-IC. We also determined the diagnostic value of gait variability parameters to identify the presence of PAD. Methods A cross-sectional cohort design was used. Thirty healthy older controls and thirty patients with PAD-IC walked on a treadmill at their self-selected speed in pain free walking (normal walking for healthy older controls; prior to claudication onset for PAD) and reduced blood flow (post vascular occlusion with thigh tourniquet for healthy older controls; pain for PAD) conditions. Gait variability was assessed using the largest Lyapunov exponent, approximate entropy, standard deviation, and coefficient of variation of ankle, knee, and hip joints range of motion. Receiver operating characteristics curve analyses of the pain free walking condition were performed to determine the optimal cut-off values for separating individuals with PAD-IC from those without PAD-IC. Results and discussion Patients with PAD-IC have increased amount of variability for knee and hip ranges of motion compared with the healthy older control group. Regarding the main effect of condition, reduced blood flow demonstrated increased amount of variability compared with pain free walking. Significant interactions between group and condition at the ankle show increased values for temporal structure of variability, but a similar amount of variability in the reduced blood flow condition. This demonstrates subtle interactions in the movement patterns remain distinct between PAD-IC versus healthy older controls during the reduced blood flow condition. A combination of gait variability parameters correctly identifies PAD-IC disease 70% of the time or more. Conclusions Gait variability is affected both by PAD and by the mechanical induction of reduced blood flow. Gait variability parameters have potential diagnostic ability, as some measures had 90.0% probability of correctly identifying patients with PAD-IC.

We use second-harmonic generation (SHG) microscopy to quantitatively characterize collagen fiber crimping in the posterior cruciate ligament (PCL). The obtained SHG images are utilized to define three distinct categories of crimp organization in the PCL. Using our previously published spatial-frequency analysis, we develop a simple algorithm to quantitatively distinguish the various crimp patterns. In addition, SHG microscopy reveals both the three-dimensional structural variation in some PCL crimp patterns as well as an underlying helicity in these patterns that have mainly been observed using electron microscopy. Our work highlights how SHG microscopy could potentially be used to link the fibrous structural information in the PCL to its mechanical properties.