Variability of landmark acquisition affects tunnel calculation in image-free ACL navigation.
OBJECTIVE
The purpose of this study was to determine the inter- and intraobserver variability of intraarticular landmark identification for tunnel position calculation in image-free anterior cruciate ligament (ACL) navigation.


METHODS
In a test/retest scenario, thirteen experienced ACL surgeons (>50 reconstructions year) experienced in image-free ACL navigation were asked to identify the landmarks required for image-free ACL navigation in the same cadaver knee. Landmark positions were registered using a fluoroscopic ACL navigation system. Positions were determined using validated radiological measurement methods. For variability analysis, mean positions, deviations between the test/retest positions, standard deviations (SD) and range were calculated.


RESULTS
Interobserver analysis showed a mean variability (SD) for the tibial landmark positions of 3.0 mm with deviations of up to 24.3 mm (range). Mean femoral landmark variability was 2.9 mm (SD) with deviations of up to 11.3 mm (range). Intraobserver analysis showed a tibial reproducibility of 2.2 mm (SD 2.0 mm; range 10.9 mm) and a femoral of 1.9 mm (SD 1.9 mm; range 10.4 mm).


CONCLUSIONS
The data of the presented study suggest that a considerable inter- and intraobserver variability in intraarticular landmark identification exists. Reasonable ranges were found that have to be considered as a potential risk for miscalculation of tunnel positions in image-free ACL reconstruction.


CONCLUSIONS
Landmark acquisition affects tunnel calculation in image-free ACL.


METHODS
IV.
Department of Trauma and Orthopaedic Surgery, Cologne Merheim Medical Centre, Witten/Herdecke University, Ostmerheimer Strasse 200, 51109, Cologne, Germany, sven.shafizadeh@me.com.
Sven
S
Shafizadeh
Maurice
M
Balke
Ulrich
U
Hagn
Stefan
S
Grote
Bertil
B
Bouillon
Marc
M
Banerjee
D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D002102:Cadaver; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D005471:Fluoroscopy; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D015588:Observer Variation; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*