Coracoid transfer as described by Latarjet can effectively restore anterior glenohumeral shoulder stability if previous operation(s) have failed to do so. If recurrence is associated with chronic pain, the pain is likely to persist and compromise the subjective outcome.

In this article, we explore the extraction of recursive nested structure in the processing of binary sequences. Our aim was to determine whether humans learn the higher‐order regularities of a highly simplified input where only sequential‐order information marks the hierarchical structure. To this end, we implemented a sequence generated by the Fibonacci grammar in a serial reaction time task. This deterministic grammar generates aperiodic but self‐similar sequences. The combination of these two properties allowed us to evaluate hierarchical learning while controlling for the use of low‐level strategies like detecting recurring patterns. The deterministic aspect of the grammar allowed us to predict precisely which points in the sequence should be subject to anticipation. Results showed that participants’ pattern of anticipation could not be accounted for by “flat” statistical learning processes and was consistent with them anticipating upcoming points based on hierarchical assumptions. We also found that participants were sensitive to the structure constituency, suggesting that they organized the signal into embedded constituents. We hypothesized that the participants built this structure by merging recursively deterministic transitions.

Background The Cobb angle measurement is well established for the measurement of coronal deformity aspect of scoliotic curves. The effect of positional differences in relation to the apex side of the scoliosis is not yet fully quantified. While theoretically plausible that positioning error with rotation toward the apex of the scoliosis would decrease the Cobb angle, the relations are not investigated yet and were object of this study. Materials and methods Multiple measurements of the Cobb angle were performed, while turning a spine-pelvic cadaveric specimen with a right-sided thoracic scoliosis of 47°(in neutral position) from 45°to -45°in steps of 5°u sing biplanar radiography. Statistical methods were applied to find the critical position, in which measurement errors potentially become clinically relevant (Cobb angle deviation [5°). Results Turning the specimen to the right (toward the apex of the scoliosis) produced during the first -15°of rotation, a Cobb angle ranging from 47°to 45°. At -20°, the Cobb angle was 42°, at -25°rotation 37°and at -30°r otation 36°. Above -30°rotation, the measured Cobb angle decreased to 36°(77 % of the original Cobb angle). No relevant differences were found by rotating the specimen to the left (away from the apex) (47°at neutral rotation and 44°at maximal error rotation of ?45°). Conclusion The influence of rotational misplacement of the patient at the time of image acquisition on Cobb angle measurements is negligible for a rotational misplacement of ±20°of rotation for a idiopathic right-sided thoracic scoliosis of 47°. Over 20°of rotational misplacement of the patient toward the apex of the scoliosis falsely decreases the Cobb angle.

Overall, the variances of spinopelvic parameters in different AIS curve types do not seem statistically large enough for a potential clinical relevance. However, the sacrum is more verticalized in AIS curves with major curves located in the lumbar/thoracolumbar region. It remains to be investigated whether such a verticalized sacrum might be a compensatory mechanism to keep the whole spine balanced and if it reverses with correction of the scoliosis.

Administration and discontinuation of anticoagulant and platelet-inhibiting medications in the perioperative setting of spinal surgery differ vastly between different units and surgeons. Recommendations from the spine surgeon societies may be helpful to develop nationwide guidelines.

Non-parallel pedicle screws in the sagittal plane have at least equal initial fixation strength compared to parallel pedicle screws in the setting of the here performed cadaveric calf spine experiments.

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A minimal surgical intervention, namely decompression, improves walking ability, decreases pain and has marginal potential for complications in patients with DLSS who are over 80 years old.