Quantitative Differences in Fibrocartilage at the Epiphyseal Attachment of Quadriceps Tendon and Semimembranosus Tendon of Man

Abstract

Objective: To determine the width of zone of fibrocartilage at the epiphysial insertion of tendons of quadriceps and semimembranosus muscles to facilitate in the understanding of arthro-mechanics of knee joint.  Study Design: It was cross-sectional comparative study. Place and duration of study: The study was conducted in the Anatomy department at Rawalpindi medical college Rawalpindi from January 2011 to July 2011. Results: All tendons were obtained from autopsy room of DHQ hospital Rawalpindi. The specimens were taken from deceased not beyond 40 years of age. The study was divided into two major groups. Group A included 15 sets of quadriceps tendon. Group B included 15 sets of semimembranosus tendon. The groups were studied for width of zones of fibro cartilage.  There were pronounced quantitative differences between the attachments of these two tendons. There was significantly more fibro cartilage at the attachment of quadriceps tendon than at semimembranosus. Conclusion: The present study suggested that there was striking differences in the width of zone of fibrocartilage at the distal epiphysial attachment sites of quadriceps tendon and semimembranosus tendon. Fibrocartilage is comprised of uncalcified and calcified fibrocartilage. Both are separated by tidemark. Uncalcified fibrocartilage is greater in quadriceps tendon than semimembranosus reflecting the greater range of movement at this site. The amount of calcified fibrocartilage in quadriceps tendon exceed than semimembranosus due to maximum force and greater cross-sectional area.