Estudio comparativo de la distancia coracohumeral en pacientes con patología degenerativa del subescapular y una población voluntaria asintomática / Comparative analysis of the coracohumeral distance between patients with degenerative subscapularis tendon pathology and a normal age-matched population

INTRODUCCIÓN: El pinzamiento subcoracoideo secundario a una distancia coracohumeral (DCH) disminuida, ha sido descrito como una posible etiología de las lesiones degenerativas del tendón del Subescapular (SSC), sin embargo, esa teoría aún es controversial. OBJETIVO: Evaluar si existe una diferencia significativa entre la DCH promedio de pacientes con patología degenerativa del SSC y un grupo control. MATERIALES Y MÉTODOS: Se diseñó un estudio de casos-controles y se estableció un tamaño muestral mínimo de 36 casos por grupo. De nuestra base de datos, y dentro de un periodo de 6 meses, se rescataron 46 Resonancias Magnéticas (RM) de hombro con patología degenerativa avanzada y/o roturas del SSC (grupo SSC). El grupo control fue conformado por 36 RM realizadas a voluntarios asintomáticos sin patología del mango rotador. Se incluyeron en ambos grupos solo pacientes entre 40 y 60 años. Se utilizó prueba de t para determinar las diferencias entre 2 grupos con un nivel de confianza del 95%. RESULTADOS: La edad promedio del grupo SSC fue 50,1 6,1 años y del grupo control 51,7 6,8 años, no existiendo diferencia estadísticamente significativa entre ambos (p » 0.43). La DCH promedio en el grupo SSC fue 8,58 mm [IC: 7,95­9,21 mm], y en el grupo control fue 11,04 mm [IC: 10,05­12,04 mm]. Al comparar la DCH, se encontró una diferencia estadísticamente significativa entre grupos (p » 0,00048). CONCLUSIÓN: Nuestros resultados respaldan la existencia de una asociación estadísticamente significativa entre una DCH disminuida y la presencia de patología degenerativa del SSC. NIVEL DE EVIDENCIA: III (Estudio de casos y controles).

BACKGROUND: The incidence of subscapularis tears is increasing as diagnostic imaging and arthroscopic technology improves. Decreased coracohumeral distance (CHD) with associated Subcoracoid Impingement is thought to be one, potential etiology for these lesions. OBJECTIVE: The purpose of this study was to identify the association between reduced CHD and degenerative pathology of the subscapularis tendon. METHODS: A comparative case-control study was performed. The sample size required to determine significance was calculated to be 36 cases. In total, 46 patients with severe degenerative SSC tendinopathy or subscapularis tears on magnetic resonance imaging (MR) were collected consecutively from our database (SSC group). The control group consisted of 36 asymptomatic volunteers undergoing shoulder MR. Only patients between 40 and 60 years of age were included. An independent t-test was used to determine the statistical significance between the two groups (with a 95% level of confidence). RESULTS: No statistically relevant difference was found between the average age of the two groups (50.1 6.1 and 51.7 6.8; p » 0.43). In the control group, the mean CHD was found to be 11.04 mm [CI:10.05­12.04 mm] and was 8.58 mm [CI: 7.95­9.21 mm] in the subscapularis group. The statistical analysis, comparing the CHD showed a significant difference between groups (p » 0.00048). CONCLUSION: This study supports the conclusion that degenerative subscapularis pathology is associated with narrowed coracohumeral distance, when compared with an asymptomatic age-matched group. LEVEL OF EVIDENCE: III (case-control study).

Arthroscopic Evaluation of Subluxation of the Long Head of the Biceps Tendon and Its Relationship with Subscapularis Tears

BACKGROUND: The purpose of this study was to evaluate the angle between the long head of the biceps tendon (LHBT) and the glenoid during arthroscopic surgery and its correlation with biceps subluxation on magnetic resonance imaging (MRI). Furthermore, we evaluated the relationship of this angle with subscapularis tears and biceps pathologies. METHODS: MRI and arthroscopic images of 270 consecutive patients who had undergone arthroscopic surgery were retrospectively evaluated. On MRI, 60 shoulders with biceps subluxation and 210 shoulders without subluxation were identified. On the arthroscopic view from the posterior portal, the angle between the LHBT and the glenoid (biceps-glenoid angle) was measured. The biceps-glenoid angle, tears of the LHBT, degenerative superior labrum anterior to posterior (SLAP) lesions, and presence of a subscapularis tear were compared according to the presence of biceps subluxation on MRI. RESULTS: In the subluxation group, 51 (85%) had a subscapularis tendon tear and all shoulders showed biceps tendon pathologies. In the non-subluxation group, 116 (55.2%) had a subscapularis tendon tear, 125 (60%) had tears in the biceps tendon, and 191 (91%) had degenerative SLAP lesions. The incidences of subscapularis tears (p < 0.001) and biceps pathologies (p < 0.001) showed significant differences. The mean biceps-glenoid angle was 87.0° (standard deviation [SD], 11.4°) in the subluxation group and 90.0° (SD, 9.6°) in the non-subluxation group, showing a statistically significant difference (p = 0.037). CONCLUSIONS: Shoulders with subluxation of the biceps tendon on the preoperative MRI revealed more pathologies in the subscapularis tendon and biceps tendon during arthroscopy. However, the arthroscopically measured biceps-glenoid angle did not have clinical relevance to the determination of subluxation of the LHBT from the bicipital groove.