The anatomy and variation of the coracoid attachment of the subclavius muscle in humans.

The functions of the subclavius muscle (SM) are described as stabilization of the sternoclavicular joint (SCJ) and resisting elevation of the lateral end of the clavicle. During systematic cadaveric dissections, we observed additional fibrous structures, previously described as variants of the anatomy, extending from the SM and inserting into the coracoid process (CP). Due to the high incidence of these structures in our dissections, we hypothesized that the attachment at the CP is more common than appreciated and that, as a corollary, the function of the SM was (or has been) more complex than simply depressing the clavicle and generating stability at the SCJ. For our investigation, fifty-two upper extremities of 26 human cadavers were dissected. The SM was demonstrated from costal to clavicular attachment. We documented additional fibrous structures apparently derived from the SM inserting into the CP. Measurements of the length of the SM, the length of its attachment, and the length of the clavicle were taken in situ, with the specimens supine and the upper extremity in the anatomical position. Variations in the anatomy of the SM and its coracoidal attachment were recorded, and potential correlations were investigated. For documentation purposes photographs and video sequences of passive motion of the shoulder girdle of the specimens were taken. In 49 of the 52 specimens we found additional fibrous structures passing from the SM to the CP. We differentiated three types: (1) a strong cord-like structure; (2) a small or thin cord-like structure or structures; and (3) a planar twisted sheet-like structure. The SM and its extension to the CP appears to contribute to a 'functional scapular suspension system' together with the other muscles enveloped by the clavipectoral fascia (pectoralis minor, coracobrachialis and the short head of the biceps brachii). This system assists in the control of the position of the scapula in relation to the thorax, particularly in elevated positions of the upper extremity. We speculate that the differentiation of the fibrous structure depends on the functional demands of the individual. Level of Evidence: Basic science study.

Does cement augmentation of the screws in angular stable plating for proximal humerus fractures influence the radiological outcome: a retrospective assessment.

BACKGROUND: Screw-tip augmentation in angular stable plating offers new possibilities for the treatment of complex proximal humerus fractures. This retrospective analysis was performed to evaluate the radiological outcome of proximal humerus fractures treated with angular stable plates and additional screw-tip cement augmentation in patients over the age of 60. MATERIALS AND METHODS: A retrospective single centre analysis was conducted from June 2013 to December 2016. The minimum follow-up time was set to 6 months after surgery. Anatomical reduction and fixation were evaluated in respect to reattached tuberosities to the head fragment and the adequate restoration of the calcar area not showing any valgus or varus malalignment. Complete fracture healing was determined 3 months after surgery. Any failures such as secondary displacement, primary screw perforation, intraarticular cement leakage and avascular necrosis of the humeral head with concomitant screw cut-out were assessed. RESULTS: In total, 24 patients (21 females; 3 males) at a median age of 77.5 (62-96) years were included. Five 2-part, twelve 3-part and seven 4-part fractures were detected. The measured median BMD value of 23 patients was 78.4 mg/cm3 (38.8-136.9 mg/cm3). Anatomical reduction was achieved in 50% of the patients. In most cases, the A level screws and the B1 screw were augmented with bone cement by a median of 7 (5-9) head screws used. Postoperative varus displacement was not detected in any of the patients. One patient (4.2%) sustained an early secondary displacement. Intraarticular cement leakage was detected in 3 patients (2 head-split fractures). Avascular necrosis of the humeral head was observed in 4 patients (16.7%). Revision surgery was necessary in four cases, using hemiarthroplasty twice and reverse shoulder arthroplasty the other two times. CONCLUSION: Screw-tip augmentation in angular stable plating for proximal humerus fracture treatment showed a low secondary displacement rate of 4.2% in patients suffering from poor bone quality. Nevertheless, the occurrence of avascular necrosis of the humeral head with mainly severe fracture patterns observed in this study was higher compared to previously reported results in the literature. Cement augmentation in head-split fractures is not recommended, considering the high risk of an intraarticular cement leakage.

Retrospective Analysis of Nosocomial SARS-CoV-2 Infections in Orthopedic and Traumatological Inpatients.

SARS-CoV-2 has had a measurable impact on the field of orthopedic and traumatological surgery. To date, scarce data on intramural SARS-CoV-2 infections in orthopedic and traumatological patients have been reported. Therefore, the aim of our study was to investigate the effect of nosocomial SARS-CoV-2 infections in orthopedic and traumatological inpatients regarding symptoms of infection, mortality, duration of hospitalization, and other relevant patient-dependent factors. Patients admitted to hospital for an orthopedic or traumatological indication were screened retrospectively for nosocomial SARS-CoV-2 infections and included in this study. An age-, sex-, and ICD 10-matched control group was assigned and demographic data, clinical symptoms of a SARS-CoV-2 infection as well as mortality, length of hospital stays, time to surgery, pre-existing conditions, LKF-points representing the financial effort, and the Charlson Comorbidity Index were collected. A significantly higher length of stay was observed in the SARS-CoV-2 group (25 days; 4-60; SD 12.5) when compared to the control group (11 days; 2-36; SD 7; p < 0.05). LKF points were significantly higher in the SARS-CoV-2 group (13,939 points vs. 8542 points). No significant difference in mortality could be observed. An infection with SARS-CoV-2 in inpatients significantly increases length of hospital stay and cost of treatment. Although no significant difference in mortality was found, care should be taken to avoid intramural SARS-CoV-2 infections, resulting in prolonged hospitalization, higher costs, and potentially further individual risks.