Relationship between Mucoid Degeneration of the Anterior Cruciate Ligament and Posterior Tibial Slope in Patients with Total Knee Arthroplasty

Youm, Yoon Seok; Cho, Sung Do; Cho, Hye Yong; Jung, Seung Hyun

Abstract

PURPOSE
The purpose was to analyze the relationship between posterior tibial slope (PTS) and mucoid degeneration of the anterior cruciate ligament (ACL) in patients with total knee arthroplasty.
MATERIALS AND METHODS
Four hundred and twenty-four patients (24 males and 400 females; 636 knees) who received total knee arthroplasty for osteoarthritis were included. Their mean age was 68.9 years (range, 48 to 88 years). The patients were classified into three groups according to the status of ACL; normal ACL group (group I), mucoid degeneration of ACL group (group II) and ruptured or absent ACL group (group III). Plain lateral radiographs were used to measure the PTS and the values were compared among groups.
RESULTS
There were no significant differences with regard to gender, age and left-to-right side ratio among groups (p>0.05). The mean PTS was 9.9degrees (range, 0.6degrees to 20.1degrees) in group I (161 knees), 10.8degrees (range, 0.2degrees to 21.8degrees) in group II (342 knees) and 12.3degrees (range, 2degrees to 22.2degrees) in group III (133 knees), which showed significant differences (p<0.001).
CONCLUSIONS
The patients with mucoid degeneration of the ACL and those with ruptured or absent ACL had greater PTS than those with normal ACL. These findings suggest that an increased PTS may be one of the causative factors for mucoid degeneration of the ACL.