Tarallo Nicola, Morgano Maria C, Curti Marco, Spanò Emanuela, Castagna Alessandro, Genovese Eugenio A
The Circolo Hospital and Macchi Foundation, University of Insubria, Varese, Italy.
Orthopedics of the Shoulder and Elbow Unit, Rozzano Hospital, Milan, Italy.
Pol J Radiol. 2021 Feb 28;86:e93-e101. doi: 10.5114/pjr.2021.104206. eCollection 2021.
Anatomical variants of the long head of the biceps (LHB) and diseases of the rotator interval structures may contribute to shoulder instability. The rotator interval and the LHB tendon are closely associated anatomic structures that confer stability to the shoulder. Anatomical variants around the origins of the long head of the biceps (LHB) are reported to occur with a frequency of 1.9-7.4%. In the past years, many authors have proposed different approaches for the identification and characterization of LHB and rotators interval. Magnetic resonance (MR) arthrography is considered the reference standard in imaging to diagnose superior shoulder diseases. However, few authors have analysed the anatomical variants and the relation between those and shoulder instability. This study aimed to identify the frequency of variants observed during arthroscopic shoulder surgeries, and to classify them based on the Dierickx classification system.
In 326 MR arthrograms we investigated the incidence of LHB anatomical variations and their association with shoulder diseases.
We found 252/326 (77.3%) cases of LHB free, 40/326(12.26%) cases of LHB adherent, 31/326(9.50%) cases of mesotenon, and 3/326(0.9%) cases of split biceps. The prevalence of rotator interval synovitis in the mesotenon group was greater than in the LHB-free group. Moreover, in the LHB-adherent group we observed increased incidence of sublabral recess and SLAP lesions compared with the LHB-free group.
MR-arthrography is useful in the evaluation of superior shoulder structures. A relationship exists between LHB anomalies and superior shoulder instability.
肱二头肌长头（LHB）的解剖变异以及旋转间隙结构疾病可能导致肩关节不稳定。旋转间隙和LHB肌腱是密切相关的解剖结构，对肩关节起稳定作用。据报道，肱二头肌长头（LHB）起点周围的解剖变异发生率为1.9 - 7.4%。在过去几年中，许多作者提出了不同的方法来识别和描述LHB及旋转间隙。磁共振（MR）关节造影被认为是诊断肩关节上部疾病的影像学参考标准。然而，很少有作者分析解剖变异及其与肩关节不稳定之间的关系。本研究旨在确定在肩关节镜手术中观察到的变异频率，并根据迪里克克斯分类系统对其进行分类。
在326例MR关节造影中，我们研究了LHB解剖变异的发生率及其与肩部疾病的关联。
我们发现252/326（77.3%）例LHB游离，40/326（12.26%）例LHB附着，31/326（9.50%）例有腱系膜，3/326（0.9%）例肱二头肌分裂。腱系膜组旋转间隙滑膜炎的患病率高于LHB游离组。此外，与LHB游离组相比，在LHB附着组中我们观察到盂唇下隐窝和SLAP损伤的发生率增加。
MR关节造影有助于评估肩关节上部结构。LHB异常与肩关节上部不稳定之间存在关联。
