Is residual tendon a predictor of outcome following arthroscopic rotator cuff repair? A preliminary outlook at short-term follow-up.

BACKGROUND: Multiple factors including muscle atrophy, fatty infiltration, smoking, advanced patient age, and increasing tear size have been identified as risk factors for retear after rotator cuff repair. However, little is known about what effect the length of the residual rotator cuff tendon has on the success of repair and patient outcomes. METHODS: This study included 64 patients. Patients were stratified based on a residual tendon length of greater than 15 mm (group 1, residual tendon) or 15 mm or less (group 2, no residual tendon). Rotator cuff tendon integrity was then evaluated using ultrasound imaging at 6 months. Outcome measures included the Single Assessment Numeric Evaluation score, visual analog scale score, EQ5D Index score, Global Rating of Change score, and Penn Shoulder Score. RESULTS: No differences were found between groups regarding demographic data or repair configuration. Assessment of tendon healing demonstrated an increased rate of tendons that had "not healed" in group 2 (19.3% [n = 5] vs. 13.2% [n = 5]), but this difference was not statistically significant (P = .55). Functional outcome scores improved significantly from preoperatively to final follow-up in both groups and displayed no differences at 6-month follow-up. CONCLUSION: A smaller residual tendon length was not a negative predictor of clinical outcomes following arthroscopic rotator cuff repair in patients with short-term follow-up. Although there was a trend toward a decreased rate of healing in patients with smaller residual tendons, this was not significant.

Microwave spectral taxonomy: A semi-automated combination of chirped-pulse and cavity Fourier-transform microwave spectroscopy.

Because of its structural specificity, rotational spectroscopy has great potential as an analytical tool for characterizing the chemical composition of complex gas mixtures. However, disentangling the individual molecular constituents of a rotational spectrum, especially if many of the lines are entirely new or unknown, remains challenging. In this paper, we describe an empirical approach that combines the complementary strengths of two techniques, broadband chirped-pulse Fourier transform microwave spectroscopy and narrowband cavity Fourier transform microwave spectroscopy, to characterize and assign lines. This procedure, called microwave spectral taxonomy, involves acquiring a broadband rotational spectrum of a rich mixture, categorizing individual lines based on their relative intensities under series of assays, and finally, linking rotational transitions of individual chemical compounds within each category using double resonance techniques. The power of this procedure is demonstrated for two test cases: a stable molecule with a rich spectrum, 3,4-difluorobenzaldehyde, and products formed in an electrical discharge through a dilute mixture of C2H2 and CS2, in which spectral taxonomy has enabled the identification of propynethial, HC(S)CCH.