The role of a posteriorly positioned fibula in ankle sprain.
BACKGROUND
Specific anatomic variations of the ankle mortise may predispose people to ankle sprains.


OBJECTIVE
There is a correlation between a higher malleolar index (posteriorly positioned fibula) and incidence of ankle sprain.


METHODS
Prospective case control study.


METHODS
We compared the malleolar index (transverse plane of the talus) on computerized axial tomographic images of 61 patients with ankle sprain with that of 101 normal controls. A positive number for the malleolar index meant that the lateral malleolus was posterior to the plane of the medial malleolus. A negative number meant that the lateral malleolus was actually anterior to the plane of the medial malleolus.


RESULTS
The average malleolar index of the patients with ankle sprain was +11.5 degrees with a standard deviation of 7 degrees. Malleolar relationships varied from -6 degrees to +39 degrees, a range of 45 degrees. The average malleolar index in the control group was +5.85 degrees with a standard deviation of 4.9 degrees, which varied from -8 degrees to +16 degrees. However, there was no correlation between recurrence of sprains and malleolar index values.


CONCLUSIONS
Patients with an ankle sprain were more likely to have a posteriorly positioned fibula, possibly predisposing them to ankle sprain.
Eren
Osman Tugrul
OT
First Department of Orthopaedic Surgery, Sisli Etfal Research and Training Hospital, Istanbul, Turkey.
Kucukkaya
Metin
M
Kabukcuoglu
Yavuz
Y
Kuzgun
Unal
U
D000293:Adolescent; D000328:Adult; D000368:Aged; D016512:Ankle Injuries / Q000000981:diagnostic imaging / Q000209:etiology*; D000843:Ankle Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005360:Fibula / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013180:Sprains and Strains / Q000000981:diagnostic imaging / Q000209:etiology*; D014057:Tomography, X-Ray Computed