Press-fit fixation using autologous bone in the tibial canal causes less enlargement of bone tunnel diameter in ACL reconstruction--a CT scan analysis three months postoperatively.
BACKGROUND
Bone tunnel enlargement is a phenomenon present in all anterior cruciate ligament (ACL)- reconstruction techniques. It was hypothesized that press-fit fixation using a free autograft bone plug reduces the overall tunnel size in the tibial tunnel.


METHODS
In a prospective cohort study twelve patients who underwent primary ACL reconstruction using an autologous quadriceps tendon graft and adding a free bone block for press-fit fixation (PF) in the tibial tunnel were matched to twelve patients who underwent ACL reconstruction with a hamstring graft and interference screw fixation (IF). The diameters of the bone tunnels were analysed by a multiplanar reconstruction technique (MPR) in a CT scan three months postoperatively. Manual and instrumental laxity (Lachman test, Pivot-shift test, Rolimeter) and functional outcome scores (International Knee Documentation Committee sore, Tegner activity level) were measured after one year follow up.


RESULTS
In the PF group the mean bone tunnel diameter at the level of the joint entrance was not significantly enlarged. One and two centimeter distal to the bone tunnel diameter was reduced by 15% (p = .001). In the IF group the bone tunnel at the level of the joint entrance was enlarged by 14% (p = .001). One and two centimeter distal to the joint line the IF group showed a widening of the bone tunnel by 21% (p < .001) One and two centimeter below the joint line the bone tunnel was smaller in the PF group when compared to the IF group (p < .001). No significant difference for laxity test and functional outcome scores could be shown.


CONCLUSIONS
This study demonstrates that press-fit fixation with free autologous bone plugs in the tibial tunnel results in significantly smaller diameter of the tibial tunnel compared to interference screw fixation.
Department of Trauma and Reconstructive Surgery, Asklepios Clinic St. Georg, Hamburg, Germany. rakoto@me.com.|Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. rakoto@me.com.
Ralph
R
Akoto
Clinic for diagnostic Radiology and Nuclear medicine, Cologne-Triangle, Cologne, Germany. jmh@praxis-im-koelntriangle.de.
Jonas
J
Müller-Hübenthal
Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. maurice.balke@gmail.com.
Maurice
M
Balke
Clinic for Sports Traumatology at Cologne Merheim Medical Center, Cologne, Germany. maltealbers@hotmail.com.
Malte
M
Albers
Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. bouillonb@kliniken-koeln.de.
Bertil
B
Bouillon
Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. helmp@kliniken-koeln.de.
Philip
P
Helm
Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. banerjeema@kliniken-koeln.de.
Marc
M
Banerjee
Clinic for Sports Traumatology at Cologne Merheim Medical Center, Cologne, Germany. jhoeher@t-online.de.
Jürgen
J
Höher
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods* / Q000639:trends; D016025:Bone Transplantation / Q000379:methods* / Q000639:trends; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016268:Internal Fixators / Q000639:trends; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods* / Q000639:trends; D011446:Prospective Studies; D013977:Tibia / Q000637:transplantation*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000639:trends; D014182:Transplantation, Autologous / Q000379:methods / Q000639:trends; D055815:Young Adult