**1. Introduction**

In 1970, Neer established a new classification system for proximal humeral fractures that is still widely used in clinical practice today [1]. This classification system is based on the four main fracture fragments (humeral shaft, calotte, and greater and lesser tuberosity), firstly described by Codman in 1934 [2]. Neer assumed that traction of the rotator cuff is responsible for the characteristic fragment displacement, especially of the greater tuberosity. The supraspinatus and infraspinatus tendons are known to be responsible for the dorsocranial displacement of this key fragment [1]. In elderly patients with humeral head fractures, concomitant chronic degenerative rotator cuff pathologies are common [3,4]. Milgrom et al., for example, found rotator cuff lesions in 80% of asymptomatic patients 80 years of age and older [5].

Corresponding to the coexistent pattern of rotator cuff degeneration and humeral head fractures, it would be desirable to identify reciprocal influences between these pathologies [6]. The hypothesis was that patients with chronic degenerative changes of the posterosuperior rotator cuff do not show the typical dorsocranial displacement of the greater tuberosity, as described by Neer [1]. The aim of the present study was to evaluate whether the integrity of the posterosuperior rotator cuff influences the displacement characteristics of the greater tuberosity in proximal humeral fractures [7].

**Citation:** Klute, L.; Pfeifer, C.; Weiss, I.; Mayr, A.; Alt, V.; Kerschbaum, M. Displacement of the Greater Tuberosity in Humeral Head Fractures Does Not only Depend on Rotator Cuff Status. *J. Clin. Med.* **2021**, *10*, 4136. https://doi.org/10.3390/ jcm10184136

Academic Editor: Gianluca Testa

Received: 27 July 2021 Accepted: 10 September 2021 Published: 14 September 2021

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