Can we separately measure glenoid vs. humeral lateralization and distalization in reverse shoulder arthroplasty?

BACKGROUND: Lateralization and distalization in reverse shoulder arthroplasty (RSA) can be measured on anteroposterior (AP) radiographs using 2 previously described angles: lateralization shoulder angle (LSA) and distalization shoulder angle (DSA). However, these 2 angles measure global lateralization and distalization but do not allow to differentiate how much lateralization or distalization are attributable to the glenoid and the humerus. We hypothesized that new angles could allow us to separately measure glenoid vs. humeral lateralization and distalization. A more precise understanding of independent glenoid and humeral contributions to lateralization and distalization may be beneficial in subsequent clinical research. METHOD: Retrospective analysis of postoperative AP radiographs of 100 patients who underwent primary RSA for cuff-tear arthropathy, massive cuff tear, or glenohumeral osteoarthritis were analyzed. The new angles that we proposed use well-known bony landmarks (the acromion, glenoid, and humerus) and the most lateral point of the glenosphere, which we termed the "glenoid pivot point" (GPP). For lateralization, we used the GPP to split LSA into 2 new angles: glenoid lateralization angle (GLA) and humeral lateralization angle (HLA). For distalization, we introduced the modified distalization shoulder angle (mDSA) that can also be split into 2 new angles: glenoid distalization angle (GDA) and humeral distalization angle (HDA). Three orthopedic surgeons measured the new angles, using the online tool Tyche. Mean values with overall and individual standard deviations as well as intraclass correlation coefficients (ICCs) were calculated. RESULTS: Because the angles form a triangle, the following equations can be made: LSA = GLA + HLA, and mDSA = GDA + HDA. All angles showed excellent inter- and intraobserver reliability (ICC = 0.92-0.97) with low means of individual standard deviations that indicate a precision of 2° for each angle. CONCLUSION: Use of the most lateral part of the glenosphere (termed glenoid pivot point) allows us to separately measure glenoid vs. humeral lateralization and distalization. The 4 new angles (HLA, GLA, GDA, HDA) described in the present study can be used on true AP radiographs, routinely obtained after shoulder replacement, and the measured angles may be used with all types of reverse prostheses available.

Transferencias tendinosas en hombro. Técnica quirúrgica y revisión de la literatura / Tendon transfers in shoulder. Surgical technique and literature review

En lesiones con criterios de irreparabilidad del manguito rotador en pacientes jóvenes y activos se considera realizar transferencia tendinosa como una opción de tratamiento; transferencia del trapecio inferior en lesiones irreparables posterosuperiores del manguito rotador; transferencia del dorsal ancho vía anterior en lesiones irreparables de supraespinoso y transferencia de dorsal ancho en lesiones irreparables del subescapular. En este trabajo realizamos una revisión narrativa de la técnica quirúrgica. Además, se puede observar el video de la experiencia anatómica de cada técnica descripta

In rotator cuff injuries with irreparable criteria in active and young patients, tendon transfer is considered as a treatment option. We describe our experience in performing lower trapezius transfer in irreparable posterosuperior rotator cuff injuries, anterior latissimus dorsi transfer in supraspinatus injuries, and latissimus dorsi transfer in subscapularis injuries. We carry out a narrative review of the surgical technique with the subsequent video of the anatomical experience of each technique described

Transferencias tendinosas en escápula. Experiencia en cadáveres / Scapular tendon transfers. Experience in cadavers

Las transferencias tendinosas son consideradas para mejorar la función de la escápula y restablecer la biomecánica de la cintura escapular en aquellos pacientes con escápula alada que tienen alteración en la funcionalidad y que no han progresado con tratamiento conservador. Existen diferentes técnicas de transferencias tendinosas como parte del tratamiento. En este artículo realizamos una revisión narrativa, además, ilustramos con videos las siguientes técnicas: la triple transferencia tendinosa en parálisis del trapecio y la transferencia del pectoral mayor hacia la escápula en disfunción del serrato anterior

Tendon transfers are used in management of winged scapula refractory to conservative treatment to improve scapula function and reestablish adequate shoulder biomechanics. There are different techniques described for these tendon transfers. In this article we reviewed these techniques, in addition, we illustrate with videos on cadavers the following techniques: triple tendon transfer for trapezius paralysis and pectoralis mayor tendon transfer to scapula for serratus anterior disfunction