Quantitative assessment of classic anteroinferior bony Bankart lesions by radiography and computed tomography.
BACKGROUND
An anteroinferior osseous defect of the glenoid rim is sometimes encountered in patients with recurrent anterior dislocations of the shoulder. A defect of more than 21% of the glenoid length is reported to cause instability after Bankart repair.


OBJECTIVE
We can estimate the critical size of glenoid defects by using radiography or computed tomography.


METHODS
A controlled laboratory study.


METHODS
Osseous defects of 0%, 9%, 21%, 34%, and 46% of the glenoid length were created stepwise in 12 cadaveric scapulae, and plain radiographs simulating the axillary and West Point views and computed tomographic images were obtained. The maximum width of the remnant glenoid was measured under each condition and expressed as a percentage of the width of the intact glenoid.


RESULTS
A 21% defect appeared to be 18.6% of the intact glenoid on the West Point view. With computed tomography, a 21% defect resulted in loss of 50% of the width on a single slice across the lower one-fourth of the glenoid.


CONCLUSIONS
We can estimate the size of a glenoid defect by using the West Point radiographic view or computed tomogram.


CONCLUSIONS
These images gave decisive information as to whether an osseous glenoid defect required bone grafting to achieve stability after Bankart repair.
Itoi
Eiji
E
Biomechanics Laboratory, Division of Orthopedic Research, Rochester, Minnesota, USA.
Lee
Seok-Beom
SB
Amrami
Kimberly K
KK
Wenger
Doris E
DE
An
Kai-Nan
KN
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D012783:Shoulder Dislocation / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D012785:Shoulder Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D014057:Tomography, X-Ray Computed