Humeral Shaft Fracture Healing Rates in Older Patients.

Nonoperative treatment has become the standard of care for the majority of humeral shaft fractures. Published studies have mainly come from trauma centers with a young cohort of patients. The purpose of this study was to determine the nonunion rate of humeral shaft fractures in patients older than 55 years. A retrospective study was performed on a group of orthopedic trauma group treated at a level I trauma center during a 10-year period (2007-2017). Patients 55 years or older and treated for a humeral shaft fracture nonoperatively, with or without manipulation, were identified. Nonunion was defined by no bridging callus radiographically or by gross motion at the fracture at least 12 weeks from injury. There were 31 patients identified with humeral shaft fractures who met the inclusion criteria. The cohort included 21 (67.7%) females and 10 (32.3%) males with a mean age of 72.5 years (range, 55-92 years). Twenty-one fractures went on to union, and there were 10 nonunions, with no significant differences in the demographics or comorbidities. There was no correlation between AO/OTA fracture classification or fracture location and union status. There was a tendency toward higher risk of nonunion in proximal third humeral shaft fractures (45%) compared with middle (26%) and distal third (20%) humeral shaft fractures, although this was not statistically significant. The overall nonunion rate for humeral shaft fractures was 32% for patients older than 55 years. The authors found a significant correlation between age and union rate: as age increased, union rate decreased (R=-0.9, P=.045). The incidence of humeral shaft nonunion in patients older than 55 years was significantly higher than that of younger adults. To the authors' knowledge, this study is the first to report a significant correlation between nonunion and increased age. [Orthopedics. 2020;43(3);168-172.].

Visual evoked potential-based acuity assessment in normal vision, artificially degraded vision, and in patients.

AIMS: To assess visual acuity (VA) objectively using visual evoked potentials (VEPs), avoiding subjective trace evaluation and providing an acuity estimate with associated confidence limits. METHODS: 40 normal subjects and 24 patients (with corneal and retinal diseases, decimal VA range 0.15-1.1 (= 0.8(logMAR) to -0.04(logMAR))) participated in the study. Checkerboard stimuli with six check sizes covering 0.05-0.4 degrees (or 0.09-0.8 degrees for visual acuities below 0.35 (= 0.46(logMAR)) were presented in brief-onset mode (40 ms on, 93 ms off) at 7.5 Hz. In normal subjects, the stimuli were also optically degraded by frosted occluders resulting in a decimal VA range of 0.13-2.8 (= 0.9(logMAR) to -0.45(logMAR)). Altogether, 108 steady-state VEPs were recorded with a Laplacian montage (2xOz-(RO+LO)). Fourier analysis yielded the magnitude (A) at the stimulus frequency, and the average of the two neighboring frequencies as noise estimate (N). A and N determine the significance level p of the response, and from their ratio the non-noise-contaminated response (A*) can be calculated. Tuning curves were obtained by plotting A* vs the dominant spatial frequency of the corresponding checkerboard. A fully automatic algorithm used the significance level (p<5%) and A* to automatically select an appropriate region in the high spatial-frequency range on which a linear regression was performed, yielding a zero-amplitude extrapolated spatial frequency SF0. Subjective VA was obtained with the automated "Freiburg Acuity Test". RESULTS: The brief-onset presentation evoked high VEP amplitudes; however, many tuning curves displayed the well-known "notch" at intermediate check sizes. The fully automated analysis algorithm succeeded in 107 of 108 cases and effectively ignored the notch, if present. The relation between logVA and log(SF0) was a constant factor throughout the range tested: logVA = log(SF0)/17.6 cpd. In more than 95% of all cases, the acuity predicted from SF0 coincided within a factor of two (up and down, or +/-0.3 logMAR) with subjective VA with a coefficient of correlation of 0.90. CONCLUSION: The fully automated analysis avoided subjective problems in peak-trough assessment. The results provide quantitative limits to assess patients with possible malingering.

Electromyographic analysis of relaxed postures.

Six male volunteers assumed either "relaxed" or "unrelaxed" postures, as defined by a Behavioral Relaxation Scale, in seven areas of the body. Electromyographic (EMG) levels in the muscle groups associated with each area were determined for both categories of postures. In all instances, the "relaxed" postures produced significantly lower EMG levels than the "unrelaxed" postures. This indicates that the Behavioral Relaxation Scale is a valid behavioral measure of relaxation. Also, it supports other studies which have shown that direct training in emitting relaxed postures is an effective means of achieving relaxation.