Summary
The study utilised a combined anatomical and imaging approach, incorporating dissections of arterial-injected knee specimens and post-injection CT and MRI scans, further analysed using 3D rendering software, to provide a comprehensive visualisation of the vascular supply to the anterior cruciate ligament (ACL) and its surgical relevance.
Abstract
Study Objectives
The study aimed to expand existing knowledge of ACL vascular supply by integrating anatomical dissections with advanced imaging techniques, building upon prior research, including Scapinelli’s (1968). The objective was to enhance the surgical relevance of ACL vascular anatomy for reconstruction. A secondary aim was to assess its influence on surgical decision-making, identifying high-risk zones during arthroscopy and tunnel drilling, optimising graft integration conditions, and refining post-surgical rehabilitation strategies.
Materials And Methods
An interdisciplinary approach was adopted, combining anatomical dissections with advanced imaging to provide a detailed, surgically relevant analysis of ACL vascularisation. The research team included an orthopaedic surgeon, musculoskeletal radiologist, anatomist, researcher, and 3D engineer to ensure comprehensive assessment.
Sixty fresh-frozen cadaveric knee specimens (24 female, 36 male) aged 21–87 years (mean: 60.58) were examined, with BMI ranging from 15.7 to 43.2 (mean: 25.98). Eighteen specimens underwent arterial injection with a gelatine-based contrast mixture to enhance vascular visualisation. Post-injection, CT and MRI scans were obtained and analysed using 3D rendering software. Cadaveric dissections were systematically performed in accordance with ethical and legal standards.
Findings from imaging and dissection were compared with surgical observations and an extensive literature review to ensure data validation and accuracy of resulting hypotheses.
Results
ACL blood supply varies with knee movement, with arterial tension increasing in flexion and minimising when extended or flexed up to 30°. The mid-substance is supplied by a branch of the medial genicular artery running between the ACL and PCL. The proximal ACL receives blood from the superior lateral genicular artery, while the distal portion is primarily vascularised by the inferior medial genicular artery, with additional supply from Hoffa’s vascular plexus.
Discussion
The mid-substance is a danger zone during arthroscopy due to the variable positioning of its vascular supply with knee flexion. The proximal portion, supplied by a posterior vessel close to the bone, shifts less during movement, reducing iatrogenic injury risk. In contrast, the more mobile mid-substance and distal portions are prone to vascular shifts and reported as areas of worse graft endurance. Knee flexion may shift vessels into the instrument path, increasing damage risk and affecting recovery.
Studies have demonstrated that knee positioning significantly influences femoral blood flow. Knee extension improves circulation by reducing vessel tension, whereas flexion increases tension, causing capillary tortuosity and potential vessel kinking, which may obstruct blood flow (McDaniel et al., 2011; Nagita et al., 2024). These findings highlight the importance of carefully considering vascular shifts during reconstruction and implementing gradual post-operative range-of-motion protocols to minimize blood flow obstruction, thereby supporting optimal healing conditions.
Conclusions
This study provides crucial insights into the vascular supply of the ACL, directly informing surgical steps during arthroscopy and tunnel placement. Recognising vascular distribution is essential for minimising disruption, optimising graft integration, and ensuring surgical success. Moreover, these findings are critical for monitoring graft maturation and refining rehabilitation protocols. Adjusting knee bracing and range-of-motion progression based on vascular considerations can enhance healing while reducing graft failure and re-injury risk, ultimately improving patient outcomes following ACL reconstruction.