Informasjon om prosjekttittel 'Anatomy and vascularity of the quadriceps tendon in a young population'
Anatomy and vascularity of the quadriceps tendon in a young population
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|Robert LaPrade, Lars Engebretsen, Gilbert Moatshe
Background: The qualitative anatomy of the quadriceps tendon is well-known. However, the tendon insertion on the patella is not well defined regarding quantitative descriptions. A comprehensive qualitative and quantitative description of the anatomy, and especially the vascularity, of the quadriceps tendon relative to pertinent bony and soft tissue in young specimens is needed.
A thorough understanding of the anatomy and vascularity of the quadriceps tendon is clinically relevant and is essential during graft harvesting to avoid iatrogenic injuries and as a foundation for improving surgical techniques and biological healing. There is increasing interest in utilizing the quadriceps tendon in knee ligament reconstruction because of its biomechanical properties, the potential lower donor site morbidity versus a BTB autograft, and the reported greater risk of ACL reconstruction graft failure when the using hamstring tendon. A study will be performed:
1) To quantitatively and qualitatively describe the quadriceps tendon anatomy with reference to surgically-relevant landmarks, and 2) to determine the vascularity of the quadriceps tendon relative to the different layers of the quadriceps tendon and to the distance from the proximal pole of the patella.
Materials and methods for anatomy:
Specimen preparation: Ten non-paired, fresh frozen human cadaveric knees less than 40 years of age with no history of injury, previous surgery, or degenerative changes of the quadriceps tendon will be utilized for this study (n=5 male, n=5 female). After dissection of the skin and subcutaneous tissue, the muscle tendons forming the quadriceps tendon, the insertion on the patella, and the medial and lateral structures will be identified. Using both inside-out and outside-in dissection, the different layers of the quadriceps tendon and the surrounding tissue will be identified.
A portable coordinate measuring device (7315 Romer Absolute Arm, Hexagon Metrology, North Kingstown, RI) will be used to quantify the location of pertinent bony landmarks, tendon and ligament attachment areas. This method has been validated and utilized in previous studies. The qualitative and quantitative anatomy will be reported.
Materials and methods for vascularity:
Specimen preparation: Ten non-paired, fresh frozen human cadaveric knees less than 40 years of age with no history of injury, previous surgery, or degenerative changes will be utilized for this study. The vessels branching from the popliteal artery will be clamped 10 cm distal to the knee joint, and 60 ml of Higgins Black Magic India Ink (Chartpak Inc., Leeds, MA) will be injected into the femoral artery under manual pressure. The knee will then be placed into full extension and frozen to -10° C.
A band saw will be used to section the frozen knee specimens into 5 mm thick sections. Sections will be obtained in the sagittal plane for half the specimens and axial plane for the other half. Next, specimens will be scrubbed clean under cold running water and then fixed with 10% neutral-buffered formalin for three days. Fixed specimens will be photographed using a high-resolution digital single lens reflex camera (Nikon, USA) and transferred to 10% nitric acid for decalcification. Specimens will then be dehydrated with three changes of ethanol (70%, 95%, and 100%) for two days each and defatted in chloroform for two more days. Specimens will then be cleared through a 24-hour incubation in Spalteholz solution (3:5 benzyl benzoate: methyl salicylate), visualized, and photographed under illumination with an X-Ray film light box. Measurements will be taken utilizing image processing software (Image J; US National Institutes of Health). This method is validated to define tissue vascularity and has been previously utilized in similar studies in other body parts.
Statistics: Statistical analysis will be performed with the use of Predictive Analytics SoftWare (PASW) Statistics Version 18 (IBM Corporation, Armonk, New York), comparing data for each group in the anatomy part using a one-way analysis of variance (ANOVA).
Results for anatomy: The surgically relevant quantitative and qualitative anatomy of the quadriceps tendon will be described relative to bony and soft tissue landmarks. This information will determine the length and thickness of the quadriceps tendon, and the relationship to the proximo-superior patellar pole and other pertinent bony and soft tissue landmarks. This will guide surgeons during graft harvesting for ACL reconstruction, quadriceps tendon repair and medial patellofemoral ligament reconstruction using a quadriceps tendon graft.
Results for vascularity: The vascularity of the quadriceps will be described relative to the different layers of the quadriceps tendon and to the distance from the proximal pole of the patella. This information will map areas of hyper- and hypo-vascularity of the quadriceps tendon and potentially provide information for areas of reduced potential for biological healing when used as an ACL graft.