The remaining teres minor and subscapularis may contribute to preventing superior migration of the humeral head and progression of osteoarthritic change in rotator cuff tears

Background: Superior migration of the humeral head is common in large and massive rotator cuff tears (RCTs). Humeral heads migrate superiorly according to an increase in the RCT size; however, the relevance of the remaining cuff has not been elucidated. This study investigated the relation between superior migration of the humeral head and the remaining rotator cuff, especially the teres minor (TM) and subscapularis (SSC), in RCTs involving tears and atrophy of the infraspinatus (ISP). Methods: Plain anteroposterior radiographic and magnetic resonance imaging examinations were performed on 1345 patients between January 2013 and March 2018. A total of 188 shoulders with tears of the supraspinatus and ISP with atrophic ISP were evaluated. Gradings of superior migration of the humeral head and osteoarthritic change were evaluated using the acromiohumeral interval, Oizumi classification, and Hamada classification on plain anteroposterior radiographs. The cross-sectional area of the remaining rotator cuff muscles was evaluated using oblique sagittal magnetic resonance imaging. The TM was classified as hypertrophic (H) and normal and atrophic (NA). The SSC was classified as nonatrophic (N) and atrophic (A). All shoulders were classified as groups A (H-N), B (NA-N), C (H-A), and D (NA-A). Age- and sex-matched patients with no cuff tears were also enrolled (control). Results: The acromiohumeral intervals of the control group and groups A-D were 11.4 ± 2.4, 9.5 ± 3.8, 7.8 ± 4.1, 7.2 ± 4.0, and 5.4 ± 3.5 mm (84, 74, 64, 21, and 29 shoulders, respectively), with significant differences between groups A and D (P < .001) and groups B and D (P = .016). Grade 3 of the Oizumi classification and grades 3, 4, and 5 of the Hamada classification were significantly higher in group D than in others (P < .001). Conclusion: The group showing hypertrophic TM and nonatrophic SSC prevented significantly migration of the humeral head and cuff tear osteoarthritis compared to the group showing atrophic TM and SSC in posterosuperior RCTs. The findings indicate that the remaining TM and SSC may prevent superior migration of the humeral head and progression of osteoarthritic change in RCTs. In treating patients with large and massive posterosuperior RCTs, the status of the remaining TM and SSC muscles should be assessed

Variable phenotype expression with a frameshift mutation of the cardiac sodium channel gene SCN5A

Loss-of-function mutations in the cardiac sodium channel α-subunit gene SCN5A result in multiple inherited arrhythmic syndromes. This case report describes 2 unrelated probands carrying an identical SCN5A frameshift mutation, V1764fsX1786, who exhibited distinct clinical manifestations: progressive cardiac conduction defect (PCCD)/Brugada syndrome (patient #1) and idiopathic ventricular fibrillation (IVF) (patient #2). Using a whole-cell patch clamp technique, cells expressing V1764fsX1786 showed no observable Na+ current. Therefore, a significant phenotypic overlap was found between IVF and PCCD/Brugada syndrome in the 2 probands with the V1764fsX1786, loss-of-function frameshift mutation of the cardiac sodium channel gene SCN5A