title: The relationship of the anterior drawer sign to the shape of the tibial plafond in chronic lateral instability of the ankle.
abstract: To determine what factors correlate with values for tested anterior drawer (AD) sign, we investigated stress radiographs in 71 patients with severe chronic lateral instability of the ankle as well as 320 normal controls. We found no correlation between AD and talar tilt (TT), but measurement of the anterior tip ratio (ATR) (ATR=tanA x 100) demonstrated a link of ATR with AD (r=0.74, p<0.001). The posterior tip ratio (PTR) (PTR=tanP x 100) was not correlated with AD (r=0.34, p=0.16). The ankle mortise angle (AMA) (the anterior opening of the lateral ankle mortise) was also not correlated with AD (r=0.27, p=0.23). Investigation of 320 normal ankles revealed a mean ATR of 9.1%+/-1.4%. The ATR in patients was 7.6%+/-1.7%, significantly lower than in the control patients. The values in female patients with chronic lateral instabilities were significantly less than the values in the females in the control group. But values for male patients were not different from the control group. Thus the anterior tip of the lateral tibial plafond, as it affects the ATR, may influence instability in anterior drawer function, especially in female patients with chronic lateral ligamentous instability of the ankle.
authors.affiliation: Department of Orthopaedic Surgery, Gunma University School of Medicine, Japan. kqk9@psu.edu
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Kanbe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009985:Orthopedics / Q000379:methods; D011859:Radiography; D016059:Range of Motion, Articular; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D013628:Talus / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013977:Tibia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016474:Weight-Bearing