Dynamic kinematics of the glenohumeral joint in shoulders with rotator cuff tears

Abstract

BackgroundNo clear trend has emerged from the literature regarding three-dimensional (3D) translations of the humerus relative to the scapula in shoulders with rotator cuff tears (RCTs). The purpose of this study was to evaluate the kinematics of RCT shoulders using 3D-to-two-dimensional (2D) model-to-image registration techniques.MethodsDynamic glenohumeral kinematics during scapular plane abduction and axial rotation were analyzed in 11 RCT patients and 10 healthy control subjects. We measured the 3D kinematic parameters of glenohumeral joints using X-ray images and CT-derived digitally reconstructed radiographs.ResultsFor scapular plane abduction, the humeral head center was positioned significantly more medially in shoulders with RCTs than in controls at 135° of humeral abduction (p = 0.02; RCTs versus controls: − 0.9 ± 1.6 versus 0.3 ± 1.3 mm). There was no significant difference in the superior/inferior translation of the humeral head center (p = 0.99). For axial rotation in adducted position, the humeral head center was positioned significantly more anteriorly in shoulders with RCTs than in controls at − 30° of glenohumeral external rotation (p < 0.0001; RCTs versus controls: 3.0 ± 1.7 versus 0.3 ± 1.5 mm).ConclusionsThis study revealed the kinematics of shoulders with large to massive full-thickness RCTs: the humeral head center showed a medial shift at the late phase of scapular plane full abduction, and an anterior shift at the internal rotation position during full axial rotation. The kinematic data in this study, which describe the patterns of movement of shoulders with large to massive full-thickness RCTs, provide valuable information for future studies investigating glenohumeral translations in other pathological conditions of the shoulder. For clinical relevance, quantitative assessment of the dynamic kinematics of shoulders with RCTs might be a therapeutic indicator for achieving functional restoration.

Investigation of the range of motion of the shoulder joint in subjects with rotator cuff arthropathy while performing daily activities

“…Movements of the shoulder joint during the mentioned tasks were evaluated in this study, and the participants showed weakness of the abductor muscles when performing an abduction task (vertical reaching, task 1); however, for task 2, they demonstrated weakness of the shoulder flexor. The results of this study support previous studies, confirming that those with rotator cuff injuries demonstrate reduced shoulder flexion and abduction [12,16,19].…”

“…The large to massive full thickness of the RCT was confirmed by magnetic resonance imaging prior to study inclusion. Moreover, X-ray imaging was used to classify severity of the disease based on Hameda's classification scheme [12]. According to this classification scheme, all patients exhibited a grade 5 condition (with humeral head collapse).…”

“…Moreover, they have more scapulothoracic lateral flexion relative to that of normal individuals [1]. In research performed by Kozono et al [12], full abduction of the shoulder complex in the scapular plane was investigated, and a medial shift at the late phase of motion of the humeral head center was observed. Moreover, during full axial rotation, the humeral head center experienced a greater anterior shift in the patients with rotator cuff arthropathy relative to in the normal matched group [12].…”

“…In research performed by Kozono et al [12], full abduction of the shoulder complex in the scapular plane was investigated, and a medial shift at the late phase of motion of the humeral head center was observed. Moreover, during full axial rotation, the humeral head center experienced a greater anterior shift in the patients with rotator cuff arthropathy relative to in the normal matched group [12]. In another study, it was reported that the patients with rotator cuff arthropathy demonstrated an altered and predominantly scapular motion pattern [13].…”

Dynamic scapulohumeral rhythm: Comparison between healthy shoulders and those with large or massive rotator cuff tear

“…9 For scapular plane abduction, the SHR was defined as the ratio of the difference between humeral abduction and scapular upward rotation against the scapular upward rotation. 9 The accuracy of measured values was previous evaluated, 21 and the root mean square (RMS) errors for bone were 0.16 mm for in-plane translation, 0.12 mm for out-of-plane translation, and 0.22° for rotations. The RMS error represents the standard deviation of differences between true values and measured values.…”