Dial Test: Unrecognized Predictor of Anterior Cruciate Ligament Deficiency.
OBJECTIVE
To evaluate the effect of isolated anterior cruciate ligament (ACL) injury on tibial external rotation as measured by the dial test.


METHODS
Twenty-seven consecutive patients scheduled to undergo a primary ACL reconstruction were prospectively evaluated. Physical examination and magnetic resonance imaging findings were analyzed to exclude multiligamentous injury. The dial test was performed with the patient under anesthesia with a goniometer on both the affected and unaffected knees at 30° and 90°. Intraoperatively, the arthroscopic posterolateral corner gaps before reconstruction and after reconstruction were documented. Postoperatively, the dial test was again performed on both knees at 30° and 90°.


RESULTS
At 30°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.0°, P < .0001) and compared with the unaffected knee (27.6° vs 20.5°, P < .0001), but this difference was eliminated after reconstruction (21.0° vs 20.5°, P = .5089). At 90°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.1°, P < .0001) and compared with the unaffected knee (27.6° vs 20.9°, P < .0001), with this difference was eliminated after reconstruction (21.1° vs 20.9°, P = .7831).


CONCLUSIONS
Incompetence of the ACL accounts for nearly 7° of tibial external rotation found by the dial test. During examination of an injured knee, if the dial test is positive, an isolated ACL injury should not be excluded. Findings of the dial test should thus be interpreted with caution in the setting of ACL injury.


METHODS
Level II, prospective comparative study.
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.. Electronic address: forsythe.research@rushortho.com.
Brian
B
Forsythe
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Bryan M
BM
Saltzman
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Gregory L
GL
Cvetanovich
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Michael J
MJ
Collins
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Thomas A
TA
Arns
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Nikhil N
NN
Verma
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Brian J
BJ
Cole
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Bernard R
BR
Bach
D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000175:diagnosis* / Q000601:surgery; D053587:Arthrometry, Articular; D050376:Bone-Patellar Tendon-Bone Grafting; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010808:Physical Examination / Q000379:methods*; D011446:Prospective Studies; D012399:Rotation