Distal tibia allograft glenoid reconstruction for shoulder instability: outcomes after lesser tuberosity osteotomy.

BACKGROUND: Distal tibia allograft reconstruction of the glenoid in shoulder instability has garnered significant attention over the last decade. Prior studies demonstrate significant improvement in all reported patient outcomes albeit the approach is through a subscapularis split. There have not been prior studies evaluating outcomes after lesser tuberosity osteotomy which provides excellent exposure to the anterior glenoid.We hypothesize there is significant improvement in functional outcomes and no deleterious effects after lesser tuberosity osteotomy for distal tibia allograft reconstruction of the glenoid for shoulder instability. METHODS: A retrospective review was performed from 2016 of 2019 of patients undergoing distal tibia allograft reconstruction of the glenoid through a lesser tuberosity osteotomy. Patients were indicated if they had recurrent anterior shoulder instability with >20% glenoid bone loss and evidence of an off-track lesion. Clinical, imaging, and operative data were evaluated. Objective follow-up data evaluated at minimum 2 years included radiographs, range of motion, DASH, SANE, VAS, SST, ASES, and Constant scores. RESULTS: A total of 12 patients were available with average follow-up 28 months, average age 26 years old, and average glenoid bone loss of 33%. The patients demonstrated significant improvement in their clinical outcomes at final follow-up: DASH 42.9-8.9 (P = .004), SANE 32.2-85 (P = .00005), VAS 4.6-1.1 (P = .003), SST 7-11.4 (P = .01), ASES 50.2-90.5 (P = .001), and Constant 37.6-86.2 (P = .01). Range of motion at final follow-up was forward flexion to 161.4° (135-170°), external rotation 49.5° (40-65°), and internal rotation to T12-L1 (T7-L2) vertebral body. CONCLUSION: The present study demonstrates the effectiveness of a lesser tuberosity osteotomy in exposure of the glenoid for reconstruction with a distal tibia allograft. The functional integrity of the subscapularis is maintained and the patient-reported outcomes are comparable with current literature.

OFFl Models: Novel Schema for Dynamical Modeling of Biological Systems.

Flow diagrams are a common tool used to help build and interpret models of dynamical systems, often in biological contexts such as consumer-resource models and similar compartmental models. Typically, their usage is intuitive and informal. Here, we present a formalized version of flow diagrams as a kind of weighted directed graph which follow a strict grammar, which translate into a system of ordinary differential equations (ODEs) by a single unambiguous rule, and which have an equivalent representation as a relational database. (We abbreviate this schema of "ODEs and formalized flow diagrams" as OFFL.) Drawing a diagram within this strict grammar encourages a mental discipline on the part of the modeler in which all dynamical processes of a system are thought of as interactions between dynamical species that draw parcels from one or more source species and deposit them into target species according to a set of transformation rules. From these rules, the net rate of change for each species can be derived. The modeling schema can therefore be understood as both an epistemic and practical heuristic for modeling, serving both as an organizational framework for the model building process and as a mechanism for deriving ODEs. All steps of the schema beyond the initial scientific (intuitive, creative) abstraction of natural observations into model variables are algorithmic and easily carried out by a computer, thus enabling the future development of a dedicated software implementation. Such tools would empower the modeler to consider significantly more complex models than practical limitations might have otherwise proscribed, since the modeling framework itself manages that complexity on the modeler's behalf. In this report, we describe the chief motivations for OFFL, carefully outline its implementation, and utilize a range of classic examples from ecology and epidemiology to showcase its features.

Gravitational correction to running of gauge couplings.

We calculate the contribution of graviton exchange to the running of gauge couplings at lowest non-trivial order in perturbation theory. Including this contribution in a theory that features coupling constant unification does not upset this unification, but rather shifts the unification scale. When extrapolated formally, the gravitational correction renders all gauge couplings asymptotically free.

Relationship between Hawking radiation and gravitational anomalies.

We show that in order to avoid a breakdown of general covariance at the quantum level the total flux in each outgoing partial wave of a quantum field in a black hole background must be equal to that of a (1+1)-dimensional blackbody at the Hawking temperature.