Stress radiography for clinical evaluation of anterior shoulder instability.
BACKGROUND
The purpose of this study was to examine the validity of stress radiography using the Telos GA-IIE as a clinical methodology to evaluate shoulder instability.


METHODS
On 36 anterior shoulder dislocators and 23 uninjured volunteers, 4 types of stress radiographs were captured while applying 15 daN of force anteriorly (AER0 and AER60) and posteriorly (PER0 and PER60) at 2 different positions: (1) 90° of abduction combined with 0° external rotation and (2) 90° of abduction combined with 60° external rotation. The results of the anterior drawer test and of the same test under anesthesia were correlated.


RESULTS
AER0 and AER60 from the affected shoulder revealed significantly larger displacement than on the normal side (P < .05), and all 4 radiographs from the affected joints demonstrated significantly larger displacement (P < .05) than in the volunteers. Among the 4 types of radiographs, AER0 and AER60 showed significantly higher displacement in the patients (P < .001), whereas there were no differences in the volunteers (P = .167). The results of the anterior drawer test positively correlated to AER60 (Pearson correlation coefficient [PCC] = 0.453; P = .005) and AER0 (PCC = 0.529; P = .001), and those of examination under anesthesia weakly correlated to AER60 (PCC = 0.287; P = .264) but highly correlated to AER0 (PCC = 0.695; P = .002).


CONCLUSIONS
Stress radiographs on the affected shoulder frequently correlated with physical examinations, and the displacement of >3 mm on AER0 suggests anterior instability.
Global Center for Shoulder, Elbow & Sports, NEON Orthopaedic Clinic, Konkuk University Medical Center, College of Medicine, Konkuk University, Seoul, Republic of Korea.
Jin-Young
JY
Park
Orthopedic Surgery, Haeundae Paik Hospital, College of Medicine, Inje University, Busan, Republic of Korea. Electronic address: neomed95@gmail.com.
Youngbok
Y
Kim
Orthopedic Surgery, Konkuk University Medical Center, College of Medicine, Konkuk University, Seoul, Republic of Korea.
Kyung-Soo
KS
Oh
Institute of Statistics, Korea University, Seoul, Republic of Korea.
Hwa-Kyung
HK
Lim
Orthopedic Surgery, Busan Paik Hospital, College of Medicine, Inje University, Busan, Republic of Korea.
Joo-Yong
JY
Kim
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning / Q000295:instrumentation*; D012189:Retrospective Studies; D012399:Rotation; D012785:Shoulder Joint / Q000000981:diagnostic imaging*; D013314:Stress, Mechanical; D055815:Young Adult
Shoulder; Telos GA-IIE; instability; shoulder positioning device; stress radiography; validity