The medial coracoclavicular ligament: anatomy, biomechanics,and clinical relevance—a research study

Abstract

BackgroundThe medial coracoclavicular ligament (MCCL), is a structure that shows defined morphologic and histologic features. However, little attention has been paid to the MCCL to date. This study was conducted to (1) determine whether the MCCL is a constant structure, (2) analyze its mechanical properties, and (3) determine its possible role in acromioclavicular (AC) stability.MethodsAC joints, lateral coracoclavicular ligaments (LCCLs; conoid and trapezoid), and MCCLs were dissected in 30 fresh frozen upper limbs. In 6 of these specimens, we performed a sequential sectioning following the aforementioned order. A 20-N cephalad force was applied to the lateral clavicle at each step, recording the AC distance and coracoclavicular space and their variation. In 6 other specimens, we evaluated the anteroposterior motion of the clavicle following the MCCL section. Biomechanical testing was performed in 8 specimens, comparing the resistance of the MCCL to the LCCLs.ResultsThe MCCL in all of the specimens featured a sharp-edge bundle stretching from the coracoid process to the clavicle and subclavius sheath. It showed ligament-like mechanical properties although less tensile resistance than the LCCLs. Once the AC and LCCLs were sectioned, transection of the MCCL determined a significant increase in both cephalad and posterior displacement.ConclusionThe MCCL is a constant structure with the mechanical behavior of a ligament. It may act as the last container of the coracoclavicular space both in cephalad and posterior directions, precluding additional displacement in the absence of the LCCLs.

Avaliação dos ligamentos acromioclavicular, coracoclaviculares e coracoclavicular medial na luxação acromioclavicular

“…Ao iniciarmos os nossos estudos do LCCM verificamos existir pouquíssima literatura atual e que Poitevin et al, 10 Moyá et al 15 Procuramos utilizar metodologia semelhante pois assim poderíamos confrontar nossos resultados, discutir, concordar e ou discordar de suas conclusões. Em nossas descrições os valores absolutos encontrados para aferição do comprimento ligamentar foi semelhante ao encontrado por outros autores em suas dissecções.…”

“…A dissecção da articulação AC e a transecção de seus ligamentos intrínsecos foram realizadas pela primeira vez; depois, uma secção sequencial dos ligamentos trapezoide e conoide seguidos pelo LCCM. A cada passo, foi aplicada uma força 15 Foi realizada análise descritiva dos dados, apresentadas através de média e desvio padrão. As diferenças das variâncias foram verificadas por meio da Análise da Variância (ANOVA) com medidas repetidas.…”

A retrospective comparative study of arthroscopic fixation for acute acromioclavicular joint dislocation: coracoid sling technique versus single-tunnel technique

“…The CC distance (vertical distance between the inferior border of the clavicle and superior border of the CP), and the AC distance (vertical distance between the superior edge of the acromion to the superior edge of the distal clavicle) in both groups were determined via radiographic analysis in millimeters (mm) and compared preoperatively and at 2 year postoperatively [12]. With respect to the contralateral side, an increase in CC distance by 50-100% and increase in CC distance higher than 100% were considered to be subluxation and redislocation, respectively [13].…”

Imaging of the Acromioclavicular Joint: Anatomy, Function, Pathologic Features, and Treatment

“…An additional thin cordlike structure extending from the coracoid to the medial clavicle and subclavius sheath has been described recently. This structure, named the medial CC ligament, may have a role in supplementing stabilization (33). Others consider this structure to be a thickening of the CC fascia rather than a true ligament (34).…”